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Farming and Herding in Eastern Africa: Archaeological and Historical Perspectives
Summary and Keywords
The inception of agriculture in eastern Africa is a major topic of discussion among Africanist archaeologists, although very sparse evidence exists. Questions range from whether domestication was a local invention or whether it was introduced from the Near East, Asia, or elsewhere outside of Africa. These questions have remained unanswered because wild progenitors and models of the spread of African domesticates are yet to be established using undisputable data. The paucity of direct data has therefore necessitated the use of objects of material culture such as pottery, beads, burial cairns, architectural structures, and so on as indicators of pastoralism and cereal farming. In addition to the origins of African domesticates, research in eastern Africa has concerned itself with questions of farming technologies from later archaeological and historical times to the present. The remains of elaborate farming systems with extensive irrigation networks have drawn considerable attention. Though not unchanged, some of these farming systems remain in contemporary use in Kenya, Tanzania, and Ethiopia.
Keywords: domestication, pastoralism, crops, Pastoral Neolithic, Iron Age, intensive agriculture
Just like anywhere else in the world, the inception of farming in eastern Africa was more than a technological and economic event—it was a social event that transformed relations, ideologies, and modes of life.
To some extent, the origins of food production in Africa are less well known than those regions from which the most popular syntheses are often drawn (the Near East, China, Mesoamerica etc.), but research from the last couple of decades has now significantly clarified our understanding of early food production in the region.1 Nevertheless, data on the domestication of plants in eastern Africa have remained scarce, largely because archaeologists have struggled to recover plant remains due to the logistical challenges of undertaking floatation and other recovery methods in remote areas with poor access to water or electricity, and in some cases due to problems of preservation.2 In addition, archaeologists in eastern Africa have been more preoccupied with questions of human origins and development of early tool kits. To this end, the region has produced some of the most diverse and complete range of hominins, as well as the oldest stone tools in the world. Given this focus Africa was generally excluded from discussions relating to the origins of agriculture until the 1970s.3 As a result, only more recently has evidence emerged for initial cultivation and shifts toward morphological domestication in most regions and for most of crops of African origin.4 Where evidence has been obtained, plant domestication in Africa occurred quite late when compared to the other parts of the world: slightly before circa 1800 bce in southwestern and south central Sahara and later in other parts of the continent, a difference of at least 1,500 years with Americas, 5,000 years with China, and 6,000 years with Near East.5 Several suggestions have been put forward for this delay. Some of these relate to harvesting techniques that are not sufficiently different from natural seeding and thus did not produce the selection pressures that result in the morphological changes by which domestication is inferred.6 Due to this paucity of direct botanic evidence, many archaeological researchers have used "material signatures" such as pottery and grindstones to infer the presence of farming.7
In contrast to the paucity of direct evidence for crops, rock paintings and bones of domestic animals have been recovered from a range of sites in eastern Africa, and have helped in discerning both the antiquity and types of domestic fauna. Marshall and Hildebrand note that in Africa, domestication of animals happened before crops.8 During the last circa 10,000 years, the Sahara was wet and contained good vegetation, which was conducive to the domestication of cattle. As conditions started to dry out from around the 7th to 6th millennium, these Saharan herders started to move southward toward the Sahel and later farther south, reaching the Turkana region of northern Kenya, where a number of sites with clear domestic cattle remains (such as Jarigole) have been dated to around 4,500–5,000 years ago.9 The mammalian remains and presence of pottery associated with hunter-gatherers (Kansyore and Elementaitan), from some sites in eastern Africa (e.g., Wadh Lan'go in Western Kenya), have suggested that while the occupants were foragers they also began to consume domesticated animals due to their contacts with herders perhaps as early as mid- to late 3rd millennium bce. Models of the spread of domestic animals in Africa have ranged from those envisioning large-scale movements of intrusive herding populations to the hypothesis of independent domestication of local but yet undiscovered wild cattle. The latter hypothesis remains speculative in sub-Saharan Africa but quite probable in the Sahara.10 The appearance of large-scale cattle-based economies seems to have been delayed by as much as a thousand years after the appearance of small stock in both eastern and southern Africa. This may have been due to the new diseases (i.e., trypanosomiasis and wildebeest catarrhal fever) encountered by pastoral colonists entering new biogeographical zones south of the Sahara.11
Initially, these earliest herding communities in eastern Africa were lumped together by the term "Neolithic." The cultural terms "Stone Age," "Neolithic," and "Iron Age" have been borrowed from Europe and Southwest Asia based on the assumption that the whole world went through the same phases of cultural evolution and that these cultural changes were adopted as a package universally.12 In Southwest Asia pastoralism occurred after the domestication of crops, and the development of settled village life. The term "Neolithic" was therefore used in European prehistory to designate assemblages with pottery, polished axes, domesticated cereals, and domesticated animals.13 Emergence of pastoralism before farming is so contrary to this Southwest Asian orthodoxy that it has taken some time for scholars working in other regions to accept the implications of the evidence as it stands.14 As already noted, it is, however, now becoming clear that Africa did not take the same trajectory to food production as other parts of the world with domestic animals preceding the domestication of crops by several millennia.15 To suit this eastern African situation, "the Neolithic" was further modified to "Pastoral Neolithic," which Nelson and Bowerdefined as those cultures that relied substantially on domesticated stock for their livelihoods, used pottery, and employed typical later Stone Age technology for the manufacture of edged tools16. This term too has attracted controversy because it masks the considerable diversity regarding relative importance of livestock in subsistence strategies, preferred ceramics styles, and range of formal tools.17 Where metallurgy appears in eastern African pastoral sites, circa 1250 years ago, archaeologists introduced the term Pastoral Iron Age (PIA) for this period, but this term too is equally problematic given that stone-tool usage and manufacture continued for up to circa 500 years following the first use of iron.18
First Food Producers (circa 5,000–2,500 Years Ago)
A great deal of information is published from Pastoral Neolithic and Iron Age sites in Kenya and northern Tanzania, but due to the unevenness of previous research, much less data are available from Ethiopia, southern Tanzania, and Uganda.19 Before the coming of herders, there existed fishing communities that exploited lake and river resources. These communities have been referred to as the "Aquatic civilization," although the term "complex hunter-fishers" may be a much more appropriate descriptive label.20 These communities are characterized by bone harpoons, fish-bone middens, and wavy-line pottery, named after its distinctive decorative pattern, which was often executed with a catfish spine or a mollusc shell. To the north, Philipson has suggested that these populations of hunter-fishers paved the way for herders. According to him, it was through these communities that herding spread out of the Sahara with cattle, goat, and sheep first appearing by the 6th millennium BCE BP south of the Sahara in the central Nile region of Sudan at sites like Kadero. Origins of African cattle have been controversial, with some archaeologist suggesting independent domestication, others suggesting introduction from Southwest Asia through the Nile Valley, or via the Horn of Africa.21 Some have further suggested that the widespread humped cattle breeds of Africa are a cross-breed of South Asian introductions and zebu, which were introduced by the British into Sudan and other parts of eastern Africa in the 19th century.22 It is also argued that humped indigenous cattle breeds may have derived from an earlier admixture during the Islamic Indian Ocean trade.23 Genetic evidence has however provided more solid data, although the history of Zebu cattle is more complex, due to repeated admixture with wild aurochsen, male and female, over time.24 A distinctive mtDNA haplogroup, T1, in modern African breeds, with high frequencies in Africa and low ones in Asia, led geneticists to suggest independent domestication from the wild North African aurochs, though due to new evidence, this view has been modified, but evidence exists for male African aurochsen genetic material in African cattle.25 The only early site with a substantial sample of domestic animals securely dated in eastern Africa is Dongodian in Turkana, Kenya, with cattle and small stock at circa 4,000 years ago. However, large quantities of fauna remains from domestic cattle and sheep/goat dating between circa 5,000 and 4,000 years ago have been found at Jarigole pillar site, Lothagam, Dongodien, Kalokol, IIlokeridede, and Ileret, among other sites in Turkana, Kenya, in association with Nderit and Ileret ceramic style wares and fired clay figurines.26 Nderit pottery is also found in central western and southern Kenya, and northern Tanzania. In sites like Ngamuriak and Maasai Gorge, the pastoral remains are dated to between circa 3,000 and 2,000 years ago. Regardless of whether early dates are confirmed by future research, it is apparent that during this initial phase of the expansion of food production there was a continued reliance on wild species as part of daily subsistence by herding communities.27 In eastern Africa, archaeologists have had to grapple with the identification of purely pastoral sites from those of Holocene hunter-gatherers because in many cases, they have similar assamblages. For example, reduced stone tools, ceramics, and domestic and wild animal bones are found in association at most sites.28 Sites such as Enkapune ya Muto have produced evidence of mode 5 stone tools, which are generally associated with hunter-gatherer communities.29 However, evidence of domestication was also found, indicating that this site was occupied by hunting and gathering peoples who may have acquired animals from neigboring pastoralists. Moreover, on the basis of higher ratios of domestic to wild fauna and of slaughtering patterns, Marean has proposed an indigenous transition to pastoralism due to the presence of unchanged tool kit from the preceding levels where wild fauna dominated the assemblage.30 Overall it has been demonstrated that the introduction of domestic animals in eastern Africa was not a single revolutionary event. Studies show that cattle did not come in one wave replacing the hunter-gatherers; rather, multiple local indigenous pathways blending different economic practices seem to have been the norm.31 Theoretically the separation of foragers from food producers on the basis of patterns that discern domestic from wild resources has proven a quagmire.32 Blending of economic practices likely acted as a buffer strategy for pastoralists, enabling them to recover from occasional loss of animals through the support that they received from their hunting neighbors. The relationships may have ranged from exchange to intermarriages to blood-brother relationships.33 These relationships therefore may account for the occurrence of mixed cultural and faunal materials in pastoral and hunter-gatherer sites.
Evidence of Plant Domestication
The first evidence of domesticated plants in eastern Africa appears in Ethiopia, from Lalibela circa 500 bce consisting of introduced crops only (including wheat and barley?). Pastoralists known as C group from the Sahara to Nubia likely started to move southward shortly after mid-3rd millennium bce bringing with them goat, sheep, and long-horned cattle, but they may have been embryonic cultivators, as evidenced by their extensive use of pottery and the presence of grindstones.34 The general picture is that the 3rd through 1st millennia bce may be estimated as the period during which the majority of African crops were brought under cultivation in both the Sudanic lowlands and Ethiopian highlands. However, full morphological domestication seems to have been a long drawn-out process with clearly domesticated cereals only present from the latter part of this period. Excessive annual and short-term variability in rainfall, associated with pronounced temporal and spatial unpredictability of water and food resources, is considered one of the key factors stimulating the initiation of domestication. The onset of desertification of the Sahara may have especially motivated populations to move southward until they reached ecological limits for cultivation of sorghum and millet.35
Theories concerning the stimulus to domestication focus on population growth, environmental deterioration, and social economic gains.36 However, in addition to these, ethnographic examples show that domestications have occurred due to the need for predictable access to certain foods especially if the individuals who have an exceptional need for the plant live in locations where the desired plant is relatively scarce.37 These reasons may have led to the domestication of sorghum for example in Egypt circa 8000 bce, Sudan circa 7000–3000 bce, and Nubia circa 500 bce, although direct botanic evidence remains elusive.38 To date, the earliest direct botanic evidence for African sorghum comes from Yemen and India.39 Among Africa's many indigenous crops, direct archaeobotanical evidence from within Africa is only available for pearl millet and teff. Teff has its earliest evidence in northern Ethiopia and Eritrea around 500 bce, while pearl millet and sorghum only appear around 400 ce in Eastern Africa long after pastoralism was established.40
Millet and sorghum have however been replaced in many parts of eastern Africa by bananas and maize. Although bananas constitute an important diet for east Africans, the evidence for their date of introduction has been elusive. Cultivated bananas are seedless, with rare exceptions, and in Africa propagation has been by vegetative means.41 Their presence in an archaeological site can only be detected through recovery of phytoliths. Bananas were first domesticated in East Asia during the 5th millennium bce and may have been introduced to eastern Africa from Madagascar, which was colonized by East Asians in the 1st millennium ce, or from India, where 3rd-millennium bce phytoliths of domesticated bananas have been found.42 These assumptions have recently been thrown into doubt based on linguistic, botanic, and geographic data.43 Further evidence of banana cultivation has been found from the Munsa site in Uganda dating to the 5th millennium bce, pushing back the earlier suggested dates by circa 4,000 years.44 This discovery introduces new debates and calls for more research not only in Uganda and the east African coast but also in the rest of the east African interior, where banana is an important crop.
Maize, having been introduced by missionaries, merchants, and slave traders after the 15th century and promoted by the European colonialists, now accounts for 30 percent of all calories in east Africa with Kenya and Tanzania being sixth and fifteenth on the world list of percentage consumption, and Ethiopia, being one of the world's centers of genetic diversity in crop germplasm, now produces more of this New World food than any other crop.45 The overall impact of maize may be greatest in Africa where its growth as a major food source has parallel the continent's economic and nutritional crises.46
Settled Farmers (circa 2,500–1,000 Years Ago)
Food production in its various forms laid the foundation for social transformations that shaped the development of complex societies in different parts of the world. Similarly to the eastern African Pastoral Neolithic, there is very sparse direct botanic information on agriculture from later sites in eastern Africa, although stronger evidence appears later with more settled farmers and associated material signatures. The Derolaine site dated to around 1,185 years ago in the Kenyan Rift Valley is one of the few Iron Age sites where direct botanic evidence in the form of finger millet was found.47 To identify the origins and cultural attributes of early farmers in eastern and southern Africa, historical linguists have proposed lists of borrowed words of a technical nature for crops and cultural practices related to the usage of animal secondary products.48 As much as these propositions have added value to the archaeological debates on the identities of the early farmers, they have in the past been used by archaeologists to suggest farming communities in the archaeological record regardless of independent archaeological data—often involving circular arguments wherein the archaeologists cited the linguists in support of unclear data and vice versa.
The paucity of relevant botanical evidence is partially because archaeological research in the so-called Iron Age has largely focused on "Bantu origins" and its material signatures, especially ceramics and iron working, rather than analysis of subsistence economies.49 Since at least the 1960s, models of transition to food production in east Africa tended to be driven by various hypothesis concerning the spread of various language families across the continent through the process of population migration.50 Consequently, cereal cultivation and iron smelting were assigned to proto-Bantu languages (often referred to as the Early Iron Age EIA), while domestic livestock was associated with proto-Cushitic or southern Nilotic languages (as in the PN, see above). 51 After finding domesticated pearl millet dated between circa 400 and 200 bce in southern Cameroon, Kahlheber and others have put forward the hypothesis that an agricultural system with pearl millet was brought into the rainforest during the 1st millennium bce and that it spread across central Africa coinciding with the dispersal of certain Bantu subgroups.52 This runs counter to the evidence of historical linguistics, which implies that historical linguistic evidence suggests that terms for livestock, grain crops, other subsistence terminologies, and certain terms of material culture used by Bantu speakers were derived from Nilotic and Cushitic loanwords.53
Based on linguistic evidence, Bantu speakers originated from the Cameroon/Niger border about 4,000 years ago54 and their "movement" are commonly thought to have proceeded from north of central Africa and resulted in the progressive colonization of vast areas farther south but with multiple interactions and admixture with autochthons.55 Historical linguists further propose that that the Bantu speakers introduced iron working and root crops such as yam from their central African home to east and southern Africa. In tandem with this, archaeologists have looked specifically for Bantu speakers' sites using what was known as their "material signature"—dimple-based pots (Urewe ware), sedentism, and metal working. Phillipson named this material signature "the Chifumbaze complex."56 Early Iron Age sites with Chifumbaze complex characteristics have been identified across a wide area from eastern to southern Africa. Variations in the ceramics of the Chifumbaze complex include Kwale and Channelled wares thought to represent different Bantu subgroups as well as an elaboration and diversification of the Early Iron Age signature as it spread geographically. Based on this rather limited evidence, several archaeologists have warned that it is premature to develop broader models of early Bantu ideology given not just the paucity of data from putative proto Bantu sites but also the accumulating evidence for quite varied pathways to the transition of food production.57
Environmental impacts associated with the period circa 2500 and later have also been attributed to these "Bantu" farming communities. It has been argued that due to the use of iron, these early Bantu speakers modified landscapes by clearing forests from large tracts of land for cultivation, and felling trees to produce charcoal used in smelting iron ore. Studies on such environmental degradation have been conducted around the Lake Victoria by MacLean and in Tanzania by Schmidt and in Uganda by Taylor and Marchant.58 According to Schmidt, specific species of wood such as syzygium are presently preferred for charcoal. Therefore, Taylor and Marchant have attributed the decline of this species during the Iron Age to farming and Iron smelting in the Rukinga highland. Same observation has been made by MacLean in Rakai, Uganda, where she points out that people settled in areas with not only good soils for cultivation but also abundant forests with syzygium, which they felled for charcoal production.
Intensive Farming (circa 1000–1900 ce)
During and after the first centuries of the Common Era, many presumed Bantu settlements and sites that display intensive iron-working activities have been reported along the Kenyan and Tanzanian coasts and in the respective highlands. These include areas with Tana ware or Triangular incised ware (TIW) on the coast and sites with Gatung'ang'a pottery in the Pare Mountains and Mount Kilimanjaro in Tanzania and around the Mount Kenya region.59 These later Iron Age sites presumed to be those of Bantu speakers are dated to between 1st millennium ce along the Tanzanian coast, and circa 11th to 14th century ce in the highlands. Tana and Kwale wares are mostly found in town ruins of Manda, Ungwana, and Shanga in the Lamu archipelago; Kenya; and Kilwa, Ugunja Ukuu, and Songo Mnara, among other sites in the Tanzanian coast. They are also recorded in Comoros, and Madagascar.60 Tana ware in particular appears in association with imported goods, a fact that prompted early archaeologists and historians of European descent to attribute the origins and development of these coastal towns to external forces.61 Several written historical sources by early travelers of 10th century ce , however, attest to farming that took place in these areas before the inception of intensive trade. For example, Wagboldus cites Abu Zaid Hasan and al-Masudi in the Arabic writings as referring to the plants and foods of the east African coast as "black" consisting of Dhura (Sorghum or "people's food") as the staple as well as sugarcane and the produce of certain "trees."62 This information of coastal urban origins is corroborated by the presence of Tana ware in these sites and mud houses that underlie the stone walls.63 In Ungwana for example, excavations of a large mound just outside the town wall produced in the lowest levels quantities of bones of domestic animals, mostly cattle but also a few goat/sheep and camel.64 Equally important is the layout and planning of these early settlements, which Horton in particular has argued suggest that cattle kraals were an essential and central feature of sites from the circa 7th century ce.
Besides the coastal towns in east Africa, other states developed in the highlands including the Ethiopian Highlands where there are good soils, seasonal rainfall, and extensive pasturage, which provided the natural setting for the earliest state formation in the Horn of Africa. As the Sahara desiccated, Axum profited from marked agricultural fertility that was the result of annual Nile flooding as well as from the long-distance trade with the Mediterranean and northeastern worlds. These factors allowed for rapid population growth, settled life, and the production of agricultural surpluses leading to development of urban centers.65
In sum, agriculture underpinned the development of complex polities in these regions. For example, Kerma culture, which was centered in Sudan, flourished in Nubia, Upper Egypt, and northern Sudan between circa 2500 and 1500 bce.66 Other kingdoms including Bigo, Baganda, Bunyoro, Karagwe, and Rwanda later sprung up and developed in the interacustrine region.67
Case Studies of Extinct Intensive and Extensive Farming in Eastern Africa
Despite the more urban developments listed above, much African farming has in the recent past been described as extensive and employing shift-and-burn methods, and systems of intensive agriculture are usually seen as an exceptional development in special environments.68 It has been argued that while it is not always inappropriate to describe African farming as extensive, this description has been used glibly and derogatorily to imply crude or technically underdeveloped systems of cultivation.69 This description has, however, been proven untrue since there are several examples of extinct and extant complex (and often intensive) farming systems in eastern Africa. An example of elaborate extinct intensive farming is Engaruka in Tanzania. At Engaruka, an extensive field system of some 2,000 hectares remains largely visible and is laid out to receive water channeled through irrigation channels taken off one permanent and several seasonal rivers descending the Rift Escarpment.70 Although the origins of this irrigation system probably date to at least the 15th century ce, there is little agreement on the original impetus for the construction of the channels.71 The eventual fall of Engaruka took place during the circa 17th or possibly 18th century ce with again the reasons unclear—possibly due to a tectonic shift in hydrology or perhaps Maasai raiding.72 Although Engaruka may be the most extreme example of such farming systems, other similar settlements seem to have arisen very widely throughout the Rift Valley region over the last 500 years, persisting to historic times. An example of an extinct extensive agropastoral system is the Sirikwa tradition, which is found across Kenya's western highlands between Mount Elgon and southeastward as far as Nakuru and dating from the circa 12th to circa 15th century ce. This tradition is evidenced by hollows (about 15 meters in diameter) that occur on the hillsides in groups numbering anything between five and fifteen sometimes even a hundred. These hollows were known to represent cattle pens of the old "Sirikwa people" according to the Kalenjin elders, and archaeological research has corroborated this interpretation.73 The hollows acted as livestock pens designed to protect herds and herders.74 Suttonsuggests that before the insurgence of the Maasai, they were used for protecting the cattle from petty thieves.75 Reinterpretation of an early central site at Hyrax Hill in central Kenya suggests that at times the Sirikwa economy was much more pastoral in nature, with domestic animals kept in quantities and proportions to the modern specialized pastoral communities, and with more ephemeral surrounding settlements.76 While cattle and also goats and sheep were already in the region two thousand years before the Sirikwa, Sutton argues that they perfected a specialized form of dairy pastoralism combining milk, cattle, flocks of goats, and sheep for the regular meat feasting.77 In addition to a pastoral economy, the presence of permanent houses as well as finds of cooking pots and grinding stones at sites within the wetter districts of Nandi and Kericho suggests that residents partly depended on grains.78
Farming in the 20th Century
Though not unchanged or static, some intensive farming systems have persisted from precolonial times to the present.79 Intensity of farming was/is closely related to precipitation patterns and topography. Certain areas with dense population of grain farmers exhibit the most clearcut examples of intensive and sustainable farming practices with histories of flood re-accessioning cropping, residual moisture cropping, rising flood cropping, rainwater harvesting, terracing, manuring, and mulching.80 Examples of river–flood-plain irrigation in eastern Africa include delta of the Tana River Kenya, Omo Valley in Ethiopia, Rufiji in Tanzania; furrow irrigation systems include Konso in Ethiopia, Marakwet and Pokot in Kenya, the Sonjo of Tanzania, and on the Mountains of Northern Kilimanjaro.81 In many of these areas, neighboring farming and pastoral communities, while radically different in terms of economy and settlement patterns, nevertheless have similar social structures and concepts of governance that allow for linkages across ethnic and ecological boundaries and resulting in extensive regional exchange networks.82 Gourou (1961) argues that intensive agriculture in Africa developed as a result of duress due to stress on resources following political unrest between herders and farmers—a theory that is termed "siege hypotheses."83 Kejkshus, however, has argued against this theory and instead embraced Boserup's 1965 thesis that population growth is the key variable that determines agricultural innovation under subsistence conditions.84 According to Boserup, an increasing population causes food shortages and forces humans to intensify their efforts through technological advances and longer hours of work.85 The siege hypothesis finds some support in Stump's argument that some of the agricultural intensification may have developed in eastern Africa due to the need to support families forced to retreat from raids by Maasai pastoralism, or to avoid the danger of attacks by animals or hostile neighbors while collecting domestic water. In addition, the need to produce surplus that could be traded for cattle, or efforts by chiefs to increase production of finger millet for beer, have also been suggested.86 Furthermore, Davies reviews previous models and proposes a new model based on economic specialization.87 Whatever the motivation, several agricultural intensification methods have been used whether motivated by a desire for surplus or for the need to feed a growing population. The aim of all these methods is to water and drain the soils in a controlled manner in order to increase production. Therefore, intensification can be more broadly understood as an effect of pressure on production.88
Marakwet in Kenya and Konso in southern Ethiopia represent some of the best-studied traditional intensive farming communities in eastern Africa. Intensification in Konso derives from a long historical process related to the formation of complex sociopolitical and socioeconomic systems whose important political institutions can be traced by genealogies dating back to 16th century according to the oral traditions. The agricultural methods here include permanent cultivation on terraced fields, soil conservation, and fertilizing measures, combined with cattle raising.89 In Konso areas of terraced fields are often served by short irrigation canals led off streams whose discharge therefore supplements rainfall and allows those fields to be used for special crops or as a failsafe for the economy.90
In Kenya, Marakwet furrows have been in existence for about 300–200 years with reorganization, expansion, and abandonment over time.91 The furrows are taken from the parent stream via the construction of wood, brush, and stone dams of various sizes and led precipitously from the parent gorge. They are normally partially incised into the natural slope of the hillside, but terraces and embankments often lined with flat upright stones and constructed of stone and earth act to reinforce the down-slope side of the furrow and raise the course to maintain a steady gradient—thus avoiding erosion and allowing water channels to be contoured up to 14 km in distance.92
In sum, although a variety of studies have been carried out on the inception and development of cattle herding and agriculture in eastern Africa, a considerable amount of research remains to be done. Using modern scientific techniques, new studies can now provide secure dates for domestication, revisit earlier theories regarding the variety of African domesticates and their spread, and also conduct research on unexplored early farming systems that are currently widespread in eastern African landscapes and yet poorly known among global audiences. New interdisciplinary historical, archaeological, and anthropological analyses that address the temporal dynamisms of these farming technologies in relation to social, cultural, and economic developments can shed more light on understandings of farming trajectories in eastern Africa both past and present.93
Discussion of the Literature
Farming in antiquity has preoccupied research queries in eastern Africa since the 1970s. The questions that researchers sought to answer partially pertained to the origins of domestication of both animals and plants and when it happened in eastern Africa.94 Research into origins and inception of domestication have raised questions concerning which species might have been domesticated locally and which were brought into Africa. Moreover, further questions on the models of spread in the case of foreign introduction have widely been discussed in the literature.95 In the absence of direct botanic evidence for farming various cultural materials associated with farming populations have been used as signatures of these communities. These included burial cairns, particular pottery types, figurines, architectural types, beads, and so on.96 As questions on the impetus of agriculture and its spread continued to be debated, attention turned to the cultural identities of the farmers who facilitated the spread of animals and crops into eastern Africa during these periods. The debates featured predominantly among historical linguists and archaeologists as they discussed the origins and movement of Bantu speakers.97 Identities of the early farming communities were not linked to any ethnoliguistic groups as opposed to the later farmers. As such, the question of identity was more about economies, pastoral versus hunting and gathering. This question became central to the archaeologists as material culture that was thought to belong to pastoral groups and vice versa were found in association.98 In some cases, however, sites with purely pastoral materials were identified. Contrary to this, identification of farmers in the later periods became problematic as scholars started to associate the spread of different crops to movement of various ethnolinguistic groups such as Cushitic, Nilotic, or Bantu speakers. Therefore, a large body of literature exists regarding later farmers of the Iron Age period in eastern Africa. Several sites believed to be of Bantu speakers have been recorded, which by extension means spaces of Iron Age farmers.99 However, until recently, little attention had been paid to historical farming systems as the African traditional farming technologies were thought to be backward and unchanging; hence it was imagined that there was little to learn from it. Research on these technologies has now been carried out, and it has revealed that the African farming technology is more complex than previously thought.100 Many sites in eastern Africa that had been excavated earlier in the century continue to be investigated with new questions on farming and farming technologies being raised. Such sites include Engaruka in Tanzania, Konso in Ethiopia, and Marakwet in Kenya. New questions include social and political structures governing these irrigation systems, and the technologies involved (e.g., current work by Matthew Davies in Marakwet and by Daryl Stump in Engaruka and Sonjo). Many such farming technologies exist in eastern Africa, although the current focus is on the above-mentioned three locations.
Primary Sources
In eastern Africa, archaeological sites are part of each respective country's heritage, and as such all the collections from these sites are deposited in the national repositories such as national museums and state universities. For example, fauna and cultural materials from all the Kenyan sites listed in the text can be found in the archaeology department of the National museums of Kenya. Here too, primary documents such as original catalogues, site documentation (maps and survey forms), photographs, and regional topographic maps can be found. Original research documents can also be found in the museum library and at the British Institute in Eastern Africa's library, where several PhD and master's theses have been deposited by Africanist archaeologists. The journal of the British Institute in eastern Africa, the Azania, contains reports and synthesized data emanating from various sites in eastern Africa this journal has been in circulation since 1965 and can now be found in hard copy and online. At the BIEA website, one can gain access to the British Institute archaeological site maps and other grey literature. For site locations, detailed maps can also be purchased from various government departments dealing with land survey.
Links to Digital Materials
Oxford Research Encyclopedia of African History.
Africa Farming: Farming systems across Africa.
Ceramics and Society web: Early Tana tradition and the Swahili coast.
Resilience in east African landscapes web: Historical perspectives on human-environments interactions.
Photomap Kenya web: Air photos.
AFSIS web: African soil information services.
African Pollen Database (APD) web: Pollen data base.
Further Reading
Blench, M. Roger, and C. Kevin MacDonald. The Origins and Development of African Livestock, Archaeology, Genetics, Linguistics and Ethnography. London: University College London, 2000.Find this resource:
Clark, J. Desmond, and Steven A. Brandt. From Hunters to Farmers: The Causes and Consequences of Food Production in Africa. Berkeley: University of California Press, 1984.Find this resource:
Davies, Matthew J. I. "The Archaeology of Clan and Lineage Based Societies in Africa." In The Oxford Handbook of African Archaeology. Edited by Mitchell, Peter and Lane, Paul, 723–736. Oxford: Oxford University Press, 2013.Find this resource:
Paul, Lane J. "Early Agriculture in Sub-Saharan Africa to ca. AD 500." In Cambridge World History Volume II: A World with Agriculture. Edited by G. Barker and C. Goucher, 736–773. Cambridge, U.K.: Cambridge University Press, 2015.Find this resource:
Lane, Paul J. "Entangled Banks and the Domestication of East African Pastoralist Landscapes." In Archaeology of Entanglement. Edited by F. Fernandini and L. Der, 127–150. Walnut Creek, CA: Left Coast Press, 2016.Find this resource:
Lane Paul, J. "Places and Paths of Memory: Archaeologies of East African Pastoralist Landscapes." In Cultural Heritage Landscapes in Sub-Saharan Africa. Edited by J. Beardsley. Dumbarton Oaks Texts in Garden and Landscape Studies, 193–234. Harvard, MA: Harvard University Press, 2016.Find this resource:
Kjekshus, Helge. Ecology Control and Economic development in East African History the Case of Tanganyika 1850–1950. London: James Currey, 1985.Find this resource:
Mitchell, Peter, and Lane Paul. The Oxford handbook of African Archaeology: Oxford: Oxford University Press, 2013.Find this resource:
Philipson, W. David. The Later Prehistory of Eastern and Southern Africa. Nairobi: Heinmann, 1977.Find this resource:
Philipson, W. David. African Archaeology. London: Cambridge University Press, 2005.Find this resource:
Shaw, Thurstan, Paul Sinclair, Bassey Andah, and Alex Okpoko. The Archaeology of Africa, Food, Metals and Towns. London: Routledge, 1993.Find this resource:
Stahl, Ann Brower. African Archaeology: A Critical Introduction. Oxford: Blackwell, 2005.Find this resource:
Sutton, E. John. A Thousand Years of East Africa. Nairobi: British institute in East Africa, 1990.Find this resource:
Sutton, E. G. John. Engaruka: An Irrigation Agricultural Community in Northern Tanzania before the Maasai. British Institute in Eastern Africa, 2000.Find this resource:
Van Der Veen, Marijke. The Exploitation of Plant Resources in Ancient Africa. New York: Kluwer Academic/Plenum, 1999.Find this resource:
(1.) Fiona Marshall and Elizabeth Hildebrand, "Cattle Before Crops: The Beginnings of Food Production in Africa," Journal of World Prehistory 16.2 (2002): 100.
(2.) Ruth Young and Gill E. Thompson, "Missing Plant Foods? Where Is the Archaeobotanical Evidence for Sorghum and Finger Millet in East Africa?," in The Exploitation of Plant Resources in Ancient Africa, ed. Marijke, Van der Veen (New York: Kluwer Academic/Plenum, 1999), 63–72; and Dorian Fuller and Elisabeth Hildebrand, "Domesticating Plants in Africa," in The Oxford Handbook of African Archaeology, eds. Peter Mitchell and Paul Lane (Oxford: Oxford University Press, 2013), 507–525.
(3.) Katharina Neumann "The Romance of Farming: Plant Cultivation and Domestication in Africa," in African Archaeology: A Critical Introduction, ed. Ann Brower Stahl (Oxford: Blackwell, 2005), 250.
(4.) Fuller and Hildebrand, "Domesticating Plants in Africa," 507.
(5.) Neumann, "The Romance of Farming," 264.
(6.) Randi Haaland, "The Puzzle of the Late Emergence of Domesticated Sorghum in the Nile Valley," in One World Archaeology 32 (1999): 404.
(7.) John E. Sutton, A Thousand Years of East Africa (Nairobi: British institute in East Africa, 1990).
(8.) Marshall and Hildebrand, "Cattle Before Crops."
(9.) Katherine M. Grillo and Elizabeth A. Hildebrand, "The Context of Early Megalithic Architecture in Eastern Africa: the Turkana Basin C. 5000–4000 BP," Azania: Archaeological Research in Africa 48.2 (2013): 198.
(10.) Stanley H. Ambrose, "The Introduction of Pastoral Adaptations to the Highlands of East Africa," in From hunters to Farmers: The Causes and Consequences of Food Production in Africa, eds. John Desmond Clark and Steven A. Brandt (Berkeley: University of California Press, 1984), 212–239; and John Bower, "The Pastoral Neolithic of East Africa," Journal of World Prehistory 5 (1991): 49–82.
(11.) Diane Gifford-Gonzalez, "Animal Disease Challenge the Emergence of Pastoralism in SubSaharan Africa," African Archaeological Review 17.3 (2000): 95–139.
(12.) Ofer Bar-Yosef and Belfer A. Cohen, "From Foraging to Farming in Mediterranean Levant," Prehistory Press Monographs in World Archaeology 59.4 (1992): 21–48; and Ann Brower Stahl, "Introduction: Changing Perspectives on Africa's Pasts," in African Archaeology: A Critical Introduction, ed. Ann Brower Stahl (Oxford: Blackwell, 2005), 7.
(13.) Diane Gifford-Gonzalez, "Pastoralism and Its Consequences," in African Archaeology: A Critical Introduction, ed. Ann Brower Stahl (Oxford: Blackwell, 2005), 189.
(14.) Gifford-Gonzalez, "Pastoralism and Its Consequences," 188.
(15.) Fuller and Hildebrand, "Domesticating Plants," 512.
(16.) Nelson and Bower (1978, 562).
(17.) Paul J. Lane, "The Archaeology of Pastoralism and Stock Keeping in East Africa," in The Oxford Handbook of African Archaeology, eds. Peter Mitchell and Lane Paul (Oxford: Oxford University Press, 2013), 585–601.
(18.) Lane, "The Archaeology of Pastoralism," 586.
(19.) Fiona Marshall, "The Origins and Spread of Domestic Animals in Africa," in The Origins and Development of African Livestock, Archaeology, Genetics, Linguistics and Ethnography, eds. Roger M. Blench and Kevin C. Mac Donald (London: University College London, 2000), 210.
(20.) John E. Sutton, "The Aquatic Civilization of Middle Africa," Journal of African History 15 (1974): 527–556; and John E. Sutton, "Sonjo and Engaruka: Further Signs of Continuity," Azania: Journal of the British Institute in Eastern Africa 25.1 (1990): 91–93.
(21.) Frauke Stock and Diane Gifford-Gonzalez, "Genetics and African Cattle Domestication," The African Archaeological Review 30.1 (2013): 51–72.
(22.) Gifford-Gonzales, "Pastoralism and Its Consequences."
(23.) Gifford-Gonzales, "Pastoralism and Its Consequences."
(24.) Stock and Gifford-Gonzales, "Genetics and African Cattle."
(25.) Stock and Gifford-Gonzales, "Genetics and African Cattle."
(26.) Gifford-Gonzales, "Pastoralism and Its Consequences." Grillo and Hildebrand, "The context of Early Megalithic."
(27.) Paul Lane, "The Moving Frontier and the Transition to Food Production," Azania Archaeological Research in Africa 39.1 (2004): 247.
(28.) Kennedy K. Mutundu, "An Ethnoarchaeological Framework for the Identification and Distinction of Late Holocene Archaeological Sites in East Africa," Azania: Archaeological Research in Africa 45.1 (2010): 6–23.
(29.) Ambrose, "The Introduction of Pastoral Adaptations."
(30.) Curtis W. Marean, "Hunter to Herder: Large Mammal Remains from the Hunter-Gatherer Occupation at Enkapune Ya Muto Rock-Shelter, Central Rift, Kenya," The African Archaeological Review 10 (1992): 65–127.
(31.) Gifford-Gonzalez, "Pastoralism and Its Consequences," 192.
(32.) Chapurukha M. Kusimba and Sibel B. Kusimba, "Mosaics and Interactions: East Africa, 2000 B.P. to the Present," in African Archaeology: A Critical Introduction, ed. Ann Brower Stahl (Oxford: Blackwell, 2005), 392.
(33.) Kusimba and Kusimba, "Mosaics and Interactions," 392.
(34.) Philipson, "The Later Prehistory."
(35.) Katharina Neumann, "The Romance of Farming." Randi Haaland and Gunnar Haaland, "Early Farming Societies along the Nile," in The Oxford Handbook of African Archaeology, eds. Peter Mitchell and Lane Paul (Oxford: Oxford University Press, 2013), 541–553.
(36.) Marshall and Hildebrand, "Cattle Before Crops," 101.
(37.) Marshal and Hildebrand, "Cattle Before Crops," 103.
(38.) Fuller and Hildebrand, "Domesticating Plants," 512.
(39.) Haaland, "The Puzzle of the Late Emergence," 546.
(40.) Fuller and Hildebrand, "Domesticating Plants," 512.
(41.) Christopher Wrigley, "Bananas in Buganda," Azania: Journal of the British Institute in Eastern Africa 24 (1989): 64–70.
(42.) Christopher Wrigley, "Bananas in Buganda," 68.
(43.) Philippe Beaujard, "The First Migrants to Madagascar and Their Introduction of Plants: Linguistic and Ethnological Evidence"; and Peter Robertshaw, "The Earliest Bananas," Archaeology 59.5 (2006): 25–29.
(44.) Peter Robertshaw, "The Earliest," 28.
(45.) James McCann, "Maize and Grace: History, Corn, and Africa's New Landscapes, 1500–1999," Comparative Studies in Society and History 43.1 (2001): 246–272.
(46.) McCann, "Maize and Grace." Fiona D. MacKenzie, "Betterment and the Gendered Politics of Maize Production Murang'a District Central Province, Kenya, 1880–1952," Canadian Journal of African Studies 33.1 (1999): 64–97.
(47.) Stanley Ambrose, "Excavations at Deloraine, Rongai, 1978," Azania: The Journal of the British Institute in Eastern Africa 19 (1984): 82; and David P. Collet and Peter T. Robertshaw, "The Pottery Traditions of Early Pastoral Communities in Kenya," Azania 18 (1983): 107–125.
(48.) Christopher Ehret, Ethiopians and East Africans the Problem of Contacts (Nairobi: East African Publishing House, 1974).
(49.) Marshall, "The Origins and Spread."
(50.) Lane, "Moving Frontier," 243.
(51.) Pierre de Maret, "Archaeologies of the Bantu Expansion," in Handbook of African Archaeology, eds. Peter Mitchell and Paul Lane (Oxford: Oxford University Press, 2013), 627–643.
(52.) Stefanie Kahlheber, Koen Bostoen, and Katharina Neumann, "Early Plant Cultivation in the Central African Rain Forest: First Millennium BC Pearl Millet from South Cameroon," Journal of African Archaeology 7.2 (2009): 253–272.
(53.) Christopher Ehret, An African Classical Age: Eastern and Southern Africa in World History, 1000 B.C. to A.D. 400 (Charlottesville: University Press of Virginia, 1998); and Jan Vansina, "A Slow Revolution: Farming in Subequatorial Africa," Azania: Journal of the British Institute in Eastern Africa 29–30 (1994/1995): 15–26.
(54.) Ehret, Ethiopians and East Africans.
(55.) Peter Mitchell, "Early Farming Communities of Southern Africa and South-Central Africa," in The Oxford Handbook of African Archaeology (Oxford: Oxford University Press, 2013), 657; and Jan Vansina, "New Linguistic Evidence and the 'Bantu Expansion,'" African History 36.2 (1995): 173–195.
(56.) David W. Philipson, African Archaeology (London: Cambridge University Press, 2003), 187.
(57.) Lane, "Moving Frontiers," 259.
(58.) Rachel M. MacLean, "The Social Impact of the Beginnings of Iron Technology in the Western Lake Victoria Basin: A District Case Study" (unpublished PhD diss., Archaeology London Cambridge, 1996); Peter L. Schmidt, A New Look at Interpretations of the Early Iron Age in East Africa (London: Mayfield, 1975); and David Taylor and Robert Marchant, "Human Impact in the Interlacustrine Region: Long-Term Pollen Records from the Rukiga Highlands," Azania: Journal of the British Institute in Eastern Africa 29–30 (1994/1995): 283–295.
(59.) Ari Siriainen, "The Iron Age Sites at Gatug'ang'a, Central Kenya: Contributions to the Gumba Problem," Azania 6 (1971): 199–232; and Knut Odner, "Usangi Hospital and Other Archaeological Sites in the North Pare Mountains North-Eastern Tanzania," Azania 6 (1971): 91–130.
(60.) H. O. George, "Communities on the River Tana, Kenya: An Archaeological Study of Relations between the Delta and River Basin 700–1800 AD" (unpublished PhD diss., University of Cambridge, 1989).
(61.) James Kirkman, "The Culture of the Kenyan Coast in Later Middle Ages: Some Conclusions from Excavations 1948–1956," The South African Archaeological Bulletin 11.44 (1956): 89–99; and Neville Chittick, Kilwa: An Islamic Trading City on the East African Coast, BIEA Memoir 5 (Nairobi: The British Institute in Eastern Africa, 1974).
(62.) J. S. Wigboldus, "The Spread of Crops into Sub-equatorial Africa during the Early Iron Age: A 'Minimalist' View Based on Documentary Evidence from the Indian Ocean Side," Azania: The Journal of the British Institute in Eastern Africa 29–30 (1994/1995): 121–291.
(63.) Mark C. Horton, Shanga: The Archaeology of a Muslim Trading Community on the Coast of East Africa (London: British Institute in Eastern Africa, 1996); and George H. O. Abungu, Communities on the River Tana.
(64.) George H. O. Abungu, "Agriculture and Settlement Formation along the East African Coast," Azania 29–30 (1994/1995): 248–256; and W. M. Adams, "Definition and Development of African Indigenous Irrigation," Azania 24 (1989): 21–27.
(65.) Cameroon, J. Monroe, "The Archaeology of the Precolonial States in Africa," in The Oxford Handbook of African Archaeology, eds. Peter Mitchell and Paul Lane (Oxford: Oxford University Press, 2013), 708.
(66.) Henriette Hafsaas-Tsakos, "The Kingdom of Kush: An African Centre on the Periphery of the Bronze Age World System," Norwegian Archaeological Review 42.1 (2009): 50–70; and Derek Welsby, "Kerma and Kush and Their Neighbours," in The Oxford Handbook of African Archaeology, eds. Peter Mitchell and Paul Lane (Oxford: Oxford University Press, 2013), 751–763.
(67.) Andrew Reid, "The Emergence of States in Great Lakes Africa," in The Oxford Handbook of African Archaeology, eds. Peter Mitchell and Paul Lane (Oxford: Oxford University Press, 2013), 887–899.
(68.) Thomas Hakansson, "Social Political Aspects of Intensive Agriculture in E. Africa: Some Models from Cultural Anthropology," Azania 24 (1989): 12.
(69.) Sutton, "Towards History," 99.
(70.) Sutton, "Towards History," 103.
(71.) John E. G. Sutton, Engaruka: An Irrigation Agricultural Community in Northern Tanzania before the Maasai (Nairobi: British Institute in Eastern Africa, 2000), 25; and Daryl Stump, "The Archaeology of Agricultural Intensification in Africa," in The Oxford Handbook of African Archaeology, eds. Peter Mitchell and Paul Lane (Oxford: Oxford University Press, 2013), 671–688.
(72.) Sutton, "Towards History," 107.
(73.) Sutton, A Thousand Years; and David M. Kyule, "The Sirikwa Economy: Further Work at Site II on Hyrax Hill," Azania 32 (1997): 21–30.
(74.) Sutton, A Thousand Years.
(75.) Sutton, A Thousand Years; and Matthew J. I. Davies, "The Archaeology of Clan and Lineage Based Societies in Africa," in The Oxford Handbook of African Archaeology, eds. Peter Mitchell and Paul Lane (Oxford: Oxford University Press, 2013), 723–736.
(76.) Matthew J. I. Davies, "The Archaeology of Clan and Lineage," 728.
(77.) Sutton, A Thousand Years, 49.
(78.) Sutton, A Thousand Years, 49.
(79.) Matthew I. J. Davies, "Economic Specialisation, Resource Variability, and the Origins of Intensive Agriculture in Eastern Africa," Rural Landscapes: Society, Environment, History 2.1 (2015): 2.
(80.) Adams, "Definition and Development," 23.
(81.) Mats Widgren and John E. G. Sutton, In Islands of Intensive Agriculture in Eastern Africa (Oxford: James Currey, 2004); and Davies, "Economic Specialization."
(82.) Davies, "The Archaeology of Clan," 723–736.
(83.) Pierre Gourou, The Tropical World: Its Social and Economic Conditions and its Future Status (London: Longmans, 1961).
(84.) Helge Kjekshus, Ecology Control and Economic Development in East African History: The Case of Tanganyika 1850–1950 (London: James Currey, 1985).
(85.) Kjekshus, Ecology Control and Economic, 27.
(86.) Stump, "The Archaeology of Agricultural," 675; and Thomas Hakansson, "Social Political Aspects."
(87.) Davies, "Economic Specialisation."
(88.) Davies, "Economic Specialisation," 6.
(89.) Hermann Amborn, "Agricultural Intensification in Burji-Konso Cluster of South-Western Ethiopia," Azania 24 (1989): 71.
(90.) John, E. Sutton, "Towards History of Cultivating the Fields," Azania 24 (1989): 103.
(91.) Davies, "Economic Specialization," 3.
(92.) Matthew I. J. Davies, Timothy K. Kipkeu, and Henirietta L. Moore, "Revisiting the Irrigated Agricultural Landscape of the Marakwet Kenya Tracing Local Technology and Knowledge Over Recent Past," Azania: Archaeological research in Africa 49.4 (2014): 499.
(93.) Davis, Kipkeu, and Moore, "Revisiting the Irrigated," 486–523.
(94.) Marshall and Hildebrand, "Cattle Before Crops." Neumann, "The Romance of Farming." Fuller and Hildebrand, "Domesticating Plants in Africa."
(95.) Marshall, "The Origins and Spread." Philipson, Later Prehistory. Diane Gifford-Gonzalez, "Animal Disease Challenge the Emergence of Pastoralism in SubSaharan Africa," African Archaeological Review 17.3 (2000): 95–139; Diane Gifford-Gonzalez and Olivier Hanotte, "Domesticating Animals in Africa," in The Oxford Handbook of African Archaeology, eds. Peter Mitchell and Paul Lane (Oxford: Oxford University Press, 2013), 491–505; Hassan, "Desert Environment"; Haaland, "The Puzzle of the Late Emergence"; Harlan, "The Tropical African"; Philipson, "Later Prehistory"; and Julliet Clutton-Brock, "The Spread of Domestic Animals in Africa," in The Archaeology of Africa Food, Metals and Towns, eds. Thurstan Shaw, Paul Sinclair, Bassey Andah, and Alex Okpoko (London: Routledge, 1993), 60–70.
(96.) Stanley Ambrose, "Chronology of the Later Stone Age and Food Production in East Africa," Journal of Archaeological Science 25 (1998): 377–392; Peter Robertshaw, "Elmenteitan: An Early Food Producing Culture in East Africa," World Archaeology 20.1 (1988): 57–69; Sutton, A Thousand Years; Grillo and Hildebrand, "The Context of Early"; Prendegarst, "Diversity of East Africa"; Dale and Ashely, "Holocene Hunter-Fisher"; and Lane, Ashley, and Oteyo, "New Dates for Kansyore."
(97.) Ehret, Ethiopians and East Africans; Christopher Ehret, "On the Antiquity of Agriculture in Ethiopia," The Journal of African History 20.2 (1979): 161–177; Christopher Ehret, "Bantu expansions: Re-visioning a Central Problem of Early African History," International Journal of African Historical Studies 34.1 (2001): 5–41; Vansina, "New Linguistic"; Brandely, Robbertson, et al., "A New Paradigm: The African Early Iron without Bantu Migration," History in Africa 27 (2000): 287–323; Ronald Oliver, "The Problem of the Bantu Expansion," Journal of African History 7.3 (1966): 361–376; Stanley Ambrose, "Archaeology and Linguistic Reconstructions of History in East Africa," in Linguistic Evidence the Archaeological and Linguistic Reconstruction of African History, eds. Christopher Ehret and Merrick Posnansky (Berkeley: University of California Press, 1982), 104–157; and Philipson, "Later Prehistory."
(98.) Mutundu, "An Ethnoarchaeological Framework"; Kusimba and Kusimba, "Mosaics and Interactions"; and Ambrose, "Chronology of the Later Stone Age."
(99.) Robbert C. Soper, "Kwale: An Early Iron Age Site in South-Eastern Kenya"; Siiriainen, "The Iron Age Site"; and Odner, "Usangi Hospital."
(100.) Davies, "The Irrigation System"; Davies, Kipkeu, and Moore, "Revisiting the Irrigated Agricultural Landscape"; Daryl Stump, "The Development and Expansion of the Field and Irrigation Systems at Engaruka Tanzania," Azania: Journal of the British Institute in Eastern Africa 41.1 (2006): 1–26; Stump, "The Archaeology of Agriculture"; Adams, "Definition and Development"; Wilhelm Ostberg, "The Expansion of Marakwet Hill-Furrow Irrigation in the Kerio Valley of Kenya," in Islands of Intensive Agriculture in Eastern Africa, eds. Mats Widgren and John E. G. Sutton (Oxford: James Currey, 2004), 19–48; and Elizabeth Watson, "Agricultural Intensification and Social Stratification: Konso in Ethiopia Contrasted with Marakwet," in Islands of Intensive Agriculture in Eastern Africa, eds. Mats Widgren and John E. G. Sutton (Oxford: James Currey, 2004), 49–67.


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For Your Reading Pleasure
Transcripts from the Dover trial
There are separate sessions for morning and afternoons of each day. Unfortunately, Day 2 AM, Day 3 AM, and Day 4 AM files came to us unusable. We're working on getting new copies.
If Charles Darwin could have attended a meeting in Dover on Thursday, he would have been shocked by the disrespect shown his theory, according to his great-great-grandson Matthew Chapman.
Chapman was among about 150 people, including about 20 members of the media, who came to Dover Fire Station (6) for a presentation involving a video of "More Reasons Why Evolution is Stupid."
LOS ANGELES-State Superintendent of Public Instruction Jack O'Connell today defended California's science standards from efforts to inject the theory of intelligent design into natural science curriculum.
"The introduction of intelligent design theory in natural science courses would be a blow to the integrity of education in California," O'Connell said. "Our state has been recognized across the country and around the world for the quality and rigor of our academic standards. Just like I will fight tooth and nail to protect California's high academic standards, I will fight to ensure that good science is protected in California classrooms."
LOS ANGELES - A group representing California religious schools has filed a lawsuit accusing the University of California system of discriminating against high schools that teach creationism and other conservative Christian viewpoints.
The Association of Christian Schools International, which represents more than 800 schools, filed a federal lawsuit Thursday claiming UC admissions officials have refused to certify high school science courses that use textbooks challenging Darwin's theory of evolution.

subset: commoncrawl


text:
Child Psychology and Development For Dummies
Child Psychology and Development For Dummies
ISBN: 978-1-118-03221-3 February 2011 384 Pages
In the U.S., more than 10% of children are diagnosed with psychiatric disorders, while countless others remain undiagnosed. Defining what is "normal" and what is not is of great concern to anyone who works with, guides, nurtures, teaches, or parents children.
With new discoveries in mental disorders that affect children, Child Psychology & Development For Dummies provides an informational guide to cognitive development at every stage of a child's life, as well as how to diagnose, treat, and overcome the cognitive barriers that impede learning and development.
- How to identify and treat mental disorders
- Covers behavior disorders, autism, attention deficit disorder, reading disabilities, bipolar disorder, and more
- Guidance on helping a child control impulses, develop self esteem, and have good relationships
An essential guide for parents, teachers, and caregivers, Child Psychology & Development For Dummies provides a detailed overview of an average child's cognitive development, how to detect abnormalities, and what to do next.
Table of contents
Part I: Understanding Children: The Big Picture.
Chapter 1: Exploring Child Psychology.
Chapter 2: What Makes Kids Tick?
Chapter 3: Goals of Growing Up.
Part II: Watching Kids Grow.
Chapter 4: Pregnancy, Delivery, and the First Year.
Chapter 5: Tackling the Toddler Years (Ages 1–4).
Chapter 6: The Middle Childhood Years (Ages 5 – 12).
Chapter 7: Traversing the Teen Years (Ages 13–18).
Part III: Growing Great Kids.
Chapter 8: Creating Functional Families.
Chapter 9: Optimizing Education.
Chapter 10: Building the Right Village for Kids.
Part IV: Spotting Troubled Development.
Chapter 11: Facing Physical Problems.
Chapter 12: Understanding Problems That Interfere with Learning.
Chapter 13: Addressing Autism Spectrum Disorders.
Chapter 14: Emotional Disorders.
Chapter 15: Exploring Behavior Disorders.
Chapter 16: Looking at Trauma and Abuse.
Part V: Getting the Right Therapies.
Chapter 17: Types of Therapy That Work.
Chapter 18: Enhancing Educators' Efforts.
Chapter 19: Knowing What Parents Can Do.
Part VI: The Part of Tens.
Chapter 20: Ten Ways to Calm Kids Down.
Chapter 21: Ten Signs of Gifted Kids.
Chapter 22: Ten Signs That a Kid Needs Help.
Appendix: Developmental Milestones.


text:
Traveling essential! This comfy track suit features a hooded zipper jacket, ribbed trim, side pockets, and soft velour like material. Matching bottoms feature upper ribbed trim, drawstring style, side and back pockets, and finished hem. Cotton/Polyester/Spandex.
You're reviewing: ROYAL BLUE HOODED JACKET AND BOTTOM VELOUR SET TRACK SUIT
© 2017 Lollicouture.com. All Rights Reserved.


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Our Mission:
To expand the world of possibilities for aging.
We are LeadingAge:
Our national partner, LeadingAge, is an association of 6,000 not-for-profit organizations dedicated to expanding the world of possibilities for aging. Together, we advance policies, promote practices and conduct research that supports, enables and empowers people to live fully as they age.


text:
UK Wine Tax Calculator app, showing pre-budget duty levels
Today's budget adds a further 11p to the tax burden carried by an average bottle of wine. Many - most? - retail prices will rise to accommodate the tax, but there will still doubtless be bottles on offer at 3-for£12 in which the wine content will be minimal.
Unfortunately, few consumers have any idea how little of their £5 actually goes towards the liquid in the bottle - and how much more wine they get for every extra pound they spend.
So here's a modest proposal for independents and maybe even a few larger retailers) to consider.
Why not print the tax contribution on shelf talkers beneath each bottle? Calculating the figure is simple, using the UK Wine Tax Calculator iPhone app which I believe is being updated to adjust to the new rates.
Obviously, it wouldn't turn back the tax tide or reduce the likelihood of further hikes, but maybe, just maybe, we might persuade a few British consumers of the logic behind buying a slightly pricier bottle.
If you find these posts interesting, why not subscribe here


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Journal of soil science and plant nutrition
On-line version ISSN 0718-9516
J. Soil Sci. Plant Nutr. vol.12 no.1 Temuco 2012
Journal of Soil Science and Plant Nutrition, 2012, 12 (1), 1-14
Effect of cerium on growth, dry matter production, biochemical constituents and enzymatic activities of cowpea plants [Vigna unguiculata (L.) Walp.]
1R. Shyam and 1N.C. Aery*
1Laboratory of Geobotany and Biogeochemistry, Department of Botany, University College of Science, Mohanlal Sukhadia University, Udaipur-313001 (Rajasthan) India Corresponding author: firstname.lastname@example.com
A pot culture experiment was conducted to study the effect of various concentrations of cerium provided as cerium nitrate (0.713, 3.568, 17.841, 89.206 and 446.030 μM) on the growth performance, dry matter production, biochemical constituents and enzymatic activity of cowpea plants [Vigna unguiculata (L.) Walp.]. Low concentrations of cerium were observed to be beneficial for the test plants. A positive correlation was observed between a lower level of cerium (0.713-17.841 μM) and foliar chlorophyll content, relative yield (dry matter) and nitrate reductase activity. Higher levels of cerium (89.206-446.030 μM) significantly increased the proline content and polyphenol oxidase activity of the test plants. Root growth was more adversely affected than shoot growth.
Keywords: Cerium; enzymatic activity; foliar chlorophyll content; free proline content; Vigna unguiculata (L.) Walp.
Abbreviations: NR, Nitrate reductase; NiR, Nitrite reductase; PPO, Polyphenol oxidase; REEs, Rare earth elements; ROS, Reactive oxygen species.
1. Introduction
Of the 92 elements present in the earth's crust, only 17 elements are known to be essential to all plants, and 12 elements have been proven to be potentially beneficial in trace amounts. These include Silver (Ag), Cerium (Ce), Chromium (Cr), Fluoride (F), Iodine (I), Lanthanum (La), Rubidium (Rb), Tin (Sn), Strontium (Sr), Titanium (Ti), Vanadium (V) and Tungsten (W) (Pilon-Smits et al., 2009).
Lanthanum and cerium belong to the group of light rare earth elements (REEs) because their atomic mass is lower than 153 amu. These elements are fairly abundant in nature and beneficial for plant growth (Yin et al., 2009). Chloride and the nitrate forms of lanthanum and cerium are the main constituents of commercial REEs micro-fertilisers, and they have been widely used in China since the 1970s as REEs micro-fertilisers to improve crop plant growth and yield (Hu et al., 2004).
There are conflicting results regarding the effects of REEs on plant growth and development, most likely due to the effects of factors such as soil pH, soil chelates and the available level of fertilisers. He and Loh (2000) reported that cerium provided as cerium nitrate (0.5-10 μmol L-1) in a culture medium significantly enhanced the primary root growth of Arabidopsis thaliana. However, REEs as (REE)xOy decreased root length in rice plants (Hu and Ye, 1996). REEs enhanced the speed of seed germination and growth (shoot-root length) of agricultural crops such as rice, wheat, barley and vegetable crops (Guo et al., 1988; Ni, 1995; Shyam and Aery, 2011). A general requirement by crop plants for lanthanum and cerium has not yet been established.
With these facts in mind, cerium as cerium nitrate was applied to cowpea plants [Vigna unguiculata (L.) Walp.], an important leguminous agricultural crop grown in silty sand, to evaluate the effect of cerium on plant growth, dry matter production, biochemical constituents and enzymatic activities.
2. Material and methods
Cerium as cerium nitrate [Ce(NO3)3.6H2O] was applied at doses of 0.713, 3.568, 17.841, 89.206 and 446.030 μM. The different concentrations of cerium were prepared separately by taking corresponding amounts (calculated based on molecular weight) of the chemical/kg of air-dried soil. Pots without added cerium constituted the control. Three kilograms of soil were filled into earthen pots of 30 cm height and 25 cm diameter. The soil used was silty sand. The experiments were set up during the month of July under natural conditions. The maximum and minimum temperatures during the study period were 31.1° C and 24.5° C, respectively, and the photoperiod was 12 hrs. Fifteen certified seeds of Vigna unguiculata (L.) Walp. Var. Sephali Sikha-313 were sown equidistantly at a 2-cm depth in each replicate. Watering was performed on alternate days, with 200 ml of water added to each pot. After establishment, the seedlings were thinned to 10 in each replicate. The sets were prepared in triplicate to record observations during the life stage.
2.1. Statistical analysis
The standard procedures suggested by Fisher (1950) were employed by applying the analysis of variance ratio (F) technique for "Complete Randomised Block Design" to test the significance of the experimental results (Table 1 and 2). In most cases, the F values were found to be highly significant. Critical differences (CD) for the treatment means were calculated at a 5% and 1% level of significance. Table 1 and 2 summarises the effects, along with the LSD ± and CD and their analysis of variance (ANOVA), and the correlation coefficient (r) and regression equations (y) were calculated as described by Panse and Sukhatme (1995).
2.2. Measurement of growth and dry weight
After flowering, the cowpea plants were harvested and washed with double distilled water, and the shoot-root length was measured. The plant samples were dried at 80° C for 48 hours in an oven and weighed to obtain the dry weight of the shoot and roots.
2.3. Estimation of Foliar Chl.'a', Chl. 'b ' and total chlorophyll
The foliar Chl.'a', Chl. 'b' and total chlorophyll were determined using the Arnon method (1949).
2.4. Determination of free proline contents
The free proline contents of the cowpea leaves were determined according to Bates et al. (1973) using the ninhydrin method. The fresh cowpea leaves (0.5 g) were hand-homogenised in 10 ml of 3% (w/v) sulfo-salicylic acid. The homogenate was filtered through Whatman No. 2 filter paper. In another test tube, 2 ml of acid ninhydrin and 2 ml of glacial acetic acid were added to 2 ml of the filtrated extract. The resulting mixture was incubated at 100° C in a hot water bath. The reaction was then stopped using an ice bath, and the contents were extracted with 4 ml of toluene and mixed vigorously using a test tube stirrer for 15-20 seconds. The chromophore containing toluene was aspirated from the aqueous phase and thawed to room temperature, and the absorbance of the solution was measured at 520 nm using a UV-visible spectrophotometer (PHARMASPEC UV 1700, SHIMADZU). A mixture without the leaf sample was used as the blank. The proline concentration was determined from a standard curve prepared with L-proline. The results are expressed (free proline content) as umoles of proline g-1 of fresh weight.
2.5. Estimation of polyphenol oxidase (PPO) activity
The polyphenol oxidase activity was measured according to the method described in Mahadevan and Sridhar (1982).
Enzyme assay
Fresh leaf samples (0.05 g) were homogenised in 0.1 M phosphate buffer (10 ml), pH 6.0, and the homo-genate was centrifuged for 30 minutes at 2000 g at 4° C. The supernatant was used as the enzyme source. The enzyme activity in each extract was assayed in triplicate. Three ml of catechol (0.1 M) were placed in a clean, dry cuvette that was transferred to a UV-visible spectrophotometer (PHARMASPEC UV 1700, SHIMADZU). To start the reaction, 0.1 ml of supernatant was added to the cuvette. The initial ab-sorbance and the subsequent changes in absorbance after each 30-second interval for 3 minutes at 495 nm were noted. A blank without supernatant was run simultaneously. The PPO activity was expressed as the change in absorbance/min/g fresh weight of leaf.
2.6. Estimation of Nitrate reductase (NR) activity The NR activity was assayed according to Malik and Singh (1980).
Enzyme assay
Fresh cowpea leaves (0.2 g) were cut into slices. The chopped plant leaves were suspended in 5 ml of assay mixture. The assay mixture contained 4 ml of 0.1 M phosphate buffer (pH 7.0), 0.5 ml of 0.1 M KNO3 and 0.5 ml of 5% n-propanol. After capping, the test tube containing the assay mixture and plant tissue was incubated in the dark at 30° C for one hour in a cooling incubator (REMI-CI-10S). A blank without the leaf sample was also run simultaneously. After incubation, a 0.4-ml aliquot of the reaction mixture was removed and transferred into another test tube containing 1 ml of 1% sulphanilamide (prepared in 1 N HCl) followed by 1 ml of 0.02% NEDH (2-Napthylene diamine hydrochloride). After 20 minutes, 4 ml of distilled water was added to each test tube. After 10 minutes, the asorbance was measured at 540 nm using a UV-visible spectrophotometer (PHARMASPEC UV 1700, SHI- MADZU).
3. Results and Discussion
Cerium showed a positive effect on the shoot-root growth and relative yield (dry matter) and affected the biochemical constituents and enzymatic activity of the cowpeas [Vigna unguiculata (L.) Walp.].
The maximum enhancement in the foliar chlorophyll (Chl. 'a', Chl. 'b', Total Chl.) contents was observed at the 17.841 μM concentration of cerium (Table 1 and Figure 1). The increase in chlorophyll 'a' (Chl. 'a'), chlorophyll 'b', (Chl. 'b') and total chlorophyll over the controls were 188.68%, 212.59% and 145.57%, respectively.
In soybean seedlings, cerium provided as cerium chloride (20 mg/L) enhanced the rate of photosynthesis and the chlorophyll content in aquaculture experiments (Li et al., 2007). An increase in the chlorophyll a and b contents were observed in wheat leaves after the plants were treated with individual rare earth elements and a mixture of light rare earths (Jie et al., 1985).
An increase in the absorption of nitrogen and phosphorus, an induction in the synthesis of a pre-compound of chlorophyll formation and an enhancement in the chlorophyll contents of spinach have been observed (Liao et al., 1994). Perhaps REEs play an indirect role in chlorophyll formation because some REEs are catalysts or because Ce3+ could enter into the chloroplast and bind easily to chlorophyll, replacing Mg2+ and form Ce- chlorophyll (Hong et al., 2002). In Mg2+-deficient Hoagland media, cerium chloride increased the synthesis of organic nitrogen, protein and chlorophyll in spinach plants. An 84.31% increase in the chlorophyll content over the control was observed at a 15 μM Ce3+ level (Yin et al., 2009) in spinach plants.
Higher concentrations of Ce (89.206 and 446.030 μM) resulted in a decrease in the chlorophyll (Chl. 'a', Chl. 'b', Total Chl.) contents over the control. Wang et al. (2007) have also observed that La and Ce reduce chlorophyll content in Hydrilla verticillata. The reduction in chlorophyll content (Table 1 and Figure 1) may be due to the formation of chlorophyllase, which is responsible for chlorophyll degradation (Mali and Aery, 2009), damage to the photosynthetic apparatus and disturbance of chlorophyll biosynthesis or its degradation caused by lipid peroxidation (Somashekaraiah, 1992).
Proline (Pyrrolidin-2-carboxylic acid) is a five-carbon amino acid that is known to accumulate in plant tissues in response to salt, water and heavy-metal stress. The accumulation of proline by plants is an adaptive mechanism. Proline accumulation helps plants tolerate stress as the proline accumulates in the cytoplasm (Ketchum et al., 1991) where it functions as an osmotic buffer and an ROS-scavenger in addition to its function as osmo-protectant and membrane stabiliser. Lehoczky et al. (2000) proposed that proline also acts as a source of carbon and nitrogen for rapid recovery from the stress.
The maximum proline contents were observed at the 446.030 μM level of cerium and were 25.37% higher than the control (Table 1 and Figure 2). The minimum proline content was observed at the 2.5 μg g-1 concentration of cerium and was 26.83% lower than the control. An increased proline content at the higher cerium concentrations (89.206-446.030 μM) might contribute to the involvement of proline in scavenging reactive oxygen species (ROS). This increase was significant at the 5% and the 1% level of significance. Li Guotai (2010) studied the effect of cerium on the chilling resistance of cucumber seedlings and showed that under chilling stress conditions, cerium increased the chlorophyll content and proline level in cucumbers. Toxic levels of La and Ce (30-100 μM) increased the free proline level of Hydrilla verticillata (Wang et al., 2007). REEs are also supposed to be involved in increasing the water use efficiency of plants by increasing their proline content. Proline has a strong ability for hydration. This indicates that an increased amount of proline may help plants to conserve water during drought periods ( El-Ramady, 2008).
NR is the key enzyme in nitrate metabolism and is important in providing the organic nitrogen that is essential for plant growth. The maximum increase (38.46%) in the activity of NR over the control was observed at the 17.841 μM concentration of cerium, and this increase was significant at the 5% and 1% level of significance. The minimum NR activity was observed at the 446.030 μM level of cerium, which was 23.07% lower than the control (Table 1 and Figure 3). NR catalyses the reduction of nitrate to nitrite during the assimilation of nitrate by the plant cell. Nitrogenase converts nitrogen gas to ammonia in a nitrogen-fixing microorganism. The reduction of nitrate to ammonium proceeds by the sequential action of the NR and NiR (Guerrero et al., 1984). NR, a molybdoflavo-protein, has Mo as a cofactor required for the transfer of electrons from NADH2 to nitrate. The source of the reductant is either the mitochondrial electron transport in the dark or the photosynthetically produced reductant in the light (Beevers and Hageman, 1969). Nitrate reductase is very sensitive to heavy metals because they have an affinity for sulfhydryl groups. The inhibition of NR activity at higher concentrations (89.206-446.030 μM) of Ce3+ might be due to interference with the NR structure, either due to the replacement of Mo or by weak binding with the -SH groups, which often determine the secondary and tertiary structure of proteins (Awasthi, 2005).
PPO is essentially a Cu-dependent enzyme (Del Rio, 1983) and is involved in the oxidation of phenolic compounds as well as in the biosynthesis of lignins. The oxidation of phenolic compounds led to the production of quinones. Quinones are responsible for the reduction of toxic oxygen species and are considered to be more toxic than the phenols from which they are derived (Pillinger et al., 1994).
In the present study, the PPO-activity was found to be at a minimum at the 17.841 μM concentration of cerium and was 52.61% lower than the control, and the maximum increase (44.32% higher than the control) in PPO activity was observed at the 446.030 μM level of cerium (Table 1 and Figure 4). An enhancement in the enzymatic activity was also observed at the 89.206 μM level of cerium, which was 21.80% higher than the control. It is possible that the mechanism for increasing PPO activity occurs in a 'latent form' in plants. The increased activity of PPO in the plant tissue after metal stress could have resulted from the activation of 'latent phenolase' or from 'solubilising' phenolase from the cellular structure as reported by Robby et al. (1964) for diseased plants under pathogen stress or due to de novo synthesis of polyphenol oxidase under metal stress (Michalak, 2006).
In a solution culture study, cerium as cerium nitrate (0.5 μg g-1) significantly increased the shoot-root growth (14.99% and 47.44%) and relative yield (153.75% and 266%) of wheat seedlings (Shyam and Aery, 2011). The results of the present study indicate that certain low concentrations (0.713-17.841 μM) enhanced the growth (shoot-root length) and relative yield of cowpeas (Table 2 and Figure 5&6). The maximum enhancement in shoot-root length and relative yield was observed at the 17.841 μM concentration of cerium, which was 23.91%, 67.53% for shoot and root length and 178.08%, 207.14% for shoot and root relative yield, respectively, over the control. Beyond this concentration, a gradual decrease in the shoot-root length and relative yield was observed. Retardation in growth was observed at higher concentrations of cerium (89.206 and 446.030 μM). The maximum decrease in shoot-root length and relative yield (26.08%, 49.31% for shoot and root length; 44.94%,53.57% for shoot and root relative yield, respectively, over the control) was observed at the 446.030 μM dose of cerium. At the 446.030 μM cerium level, the root growth was drastically affected, and this concentration was proved to be highly toxic for cowpea plants. Diatloff et al. (1999) also found that 0.03-0.7 mg/l La or Ce reduced growth and the uptake rate of all nutrients for mungbeans and that 0.7 mg/l La or Ce had little effect on growth but reduced the uptake of Ca for corn.
Growth inhibition caused by cerium can be attributed to the loss of cellular turgor (Gabbrielli et al., 1990) or to a reduced extensibility of the cell wall (Pandolfini et al., 1992; Aery and Jagetiya 1997; Mali and Aery, 2009), or it might be due to a decreasing efficiency of certain enzymes involved in food and energy utilisation. d' Aquino et al. (2009) has attributed the reduction in root growth after the treatment of REEs to a decrease in cell division.
4. Conclusion
Cerium is not essential for crop plants, but the present study indicates that low levels of cerium enhance the shoot-root growth and relative yield (dry matter production), and cerium is beneficial for cowpea plants. Higher levels of cerium decrease plant growth and relative yield. Applied cerium concentrations showed a significant positive correlation with the proline content and polyphenol oxidase activity and a negative correlation with the foliar chlorophyll content, nitrate reductase activity, shoot-root length and relative yield. The probable role of cerium as a substitute for Mg2+ in chlorophyll synthesis is indicated.
The authors are thankful to UGC, New Delhi, for providing financial assistance in the form of a meritorious fellowship to Radhe Shyam.
Aery, N. C., Jagetiya, B. L. 1997. Relative toxicity of cadmium, lead and zinc on barley. Commun. Soil Sci. Plant Anal. 28 12), 949-960. [ Links ]
Arnon, D. I. 1949. Copper enzyme in isolated chlo-roplast: Polyphenol oxidase in Beta vulgaris L. Plant Physiol. 24, 1-15. [ Links ]
Awasthi, M. 2005. Nitrate reductase activity: A solution to nitrate problems tested in free and immobilized algal cells in presence of heavy metals. Int. J. Environ. Sci. Tech. 2(3), 201-206. [ Links ]
Bates, L. S., Waldren, R. P., Teare, I. D. 1973. Rapid determination of free proline for water stress studies. Plant and Soil 39, 205-207. [ Links ]
Beevers, L., Hageman, R. H. 1969. Nitrate reduction in higher plants. Annu. Rev. Plant Physiol. 20, 495-522. [ Links ]
d'Aquino, L., de Pinto, M. C., Nardi, L., Morgana, M., Tommasi, F. 2009. Effect of some light rare earth elements on seed germination, seedling growth and antioxidant metabolism in Triticum durum. Chemosphere 75, 900-905. [ Links ]
Del Rio, L. A. 1983. Metalloenzyme as biological markers for the appraisal of micronutrient imbalances in higher plants. Life Chemistry Reports 1, 1-33. [ Links ]
Diatloff, E., Asher, C. J., Smith, F. W. 1999. The effects of rare earth elements on the growth and nutrition of plants. Rare earths' 98, Materials Science Forum 315(3), 354-360. [ Links ]
El. Ramady,Hassan Ragab Hassan. 2008. A contribution on the bio-actions of rare earth elements in the soil/ plant environment. Ph.D. Thesis, TU-Braunschweig, 173 p. [ Links ]
Fisher, R.A. 1950. Statistical methods for research workers. Oliver and Boyd. Edinburg, London, 354p. [ Links ]
Gabbrielli, R., Pandolfini, T., Vergnano, O., Palandri, M. R. 1990. Comparison of two serpentine species with different nickel tolerance strategies. Plant and Soil 122(2), 271-277. [ Links ]
Guerrero, MG., Vega J., Losada M. 1981. The assimilatory nitrate- reducing system and its regulation. Annu. Rev. Plant Physiol. 32, 169-204. [ Links ]
Guo, B. S, Zhu, W. M., Xiong, P. K., Ji, Y. J., Liu, Z., Wu, Z. M. 1988. Rare earths elements in agriculture. Agricultural Scientific Technological Press, Beijing: 23-208 (In Chinese). [ Links ]
He, Y. W., Loh, C. S. 2000. Cerium and lanthanum promote floral initiation and reproductive growth of Arabidopsis thaliana. Plant Sci.159, 117-124. [ Links ]
Hong, F. S., Wie, Z.G., Zhao, G. W. 2002. Mechanism of lanthanum effect on the chlorophyll of spinach. J. Science in China, Series C, 45 (2), 166-176. [ Links ]
Hu, Q. H., Ye, Z. J. 1996. Physiological effects of rare earth elements on plants. Chin. Plant Physiol. Commun. 32(4), 296-300. [ Links ]
Jie, H. G., Yu, Z. H. 1985. Effects of REEs on increasing yield and physiology of wheat. J. Heilongjiang Agric. Sci. 1, 25-29. [ Links ]
Ketchum, R. E. B., Warren, R. C., Klima, L. J., Lopez -Gutierrez, F., Nabors, M. W. 1991. The mechanism and regulation of proline accumulation in suspension cultures of the halophytic grass Distichlis spicata L. J. Plant Physiol. 137, 368-374. [ Links ]
Lehoczky, E., Marth, P., Szabados, I., Szomolanyi, A. 2000. The cadmium uptake by lettuce on contaminated soils as influenced by liming. Commun. Soil Sci. Plant Anal. 31, 2433-2438. [ Links ]
Li Guo-tai. 2010. Effect of cerium on chilling resistance of cucumber seedlings. Northern Horticulture 16, 47-48. [ Links ]
Li, J. M., Liang, C. J, Zhou, Q. 2007. Effect of cerium on photosynthesis in young soybean plants. Chinese J. Oil Crop Sci. 29(1), 90-92. (In Chinese) [ Links ]
Liao, T. J., Huang, Y., Su, L. B. 1994. Study of rare earths on yields, qualities and physiological effect of Spinach. Rare Earths 15, 26-29 (In Chinese). [ Links ]
Mahadevan, A., Sridhar, R. 1982. Methods in physiological plant pathology. Siva Kami Publication, Madras, 316 p. [ Links ]
Mali, M., Aery, N. C. 2009. Effect of silicon on growth, biochemical constituents and mineral nutrition of cowpea (Vigna unguiculata (L.) Walp.). Commun. Soil Sci. Plant Anal. 40, 1041-1052. [ Links ]
Malik C. P., Singh, M. B. 1980. Plant enzymology and histoenzymology. Kalyani Publishers, New Delhi, India, 433 p. [ Links ]
Michalak, A. 2006. Phenolic compounds and their antioxidant activity in plants growing under heavy metal stress. Polish J. of Environ. Stud. 15(4), 523-530. [ Links ]
Ni, J. Z. 1995. The use of rare earth elements in agriculture and medicine. In: Bioinorganic Chemistry of Rare Earth Elements. Science Press, Beijing, China, pp: 13-55. [ Links ]
Pandolfini, T., Gabbrielli, R., Comparini, C. 1992. Nickel toxicity and peroxidase activity in seedlings of Triticum aestivum L. Plant Cell Environ. 15, 719-725. [ Links ]
Panse, V.G. and Sukhatme, P.V. 1995. Statistical methods for agricultural works. Indian Council of Agricultural Research, New Delhi, 330p. [ Links ]
Pillinger, J. M., Cooper, J. A., Ridge, I. 1994. Role of phenolic compounds in the antialgal activity of barley straw. J. Chem. Ecol. 20(7), 1557-1569. [ Links ]
Pilon-Smits, EAH, Quinn, CF, Tapken, W., Malagoli, M., Schiavon, M. 2009. Physiological functions of beneficial elements. Current Opinion in Plant Biology 12, 267-274. [ Links ]
Robby, D. A., Mapson, L. W., Swain, T. 1964. Activation of the latent tyrosinase of broad bean. Nature 201, 503-504. [ Links ]
Shyam, R., Aery, N. C. 2011. Effect of cerium on seed germination and early seedling growth of wheat. NBU J Plant Sc. 5, 51-55. [ Links ]
Somashekaraiah, B. V., Padmaja, K., Prasad, A. R. K. 1992. Phytotoxicity of cadmium ions on germinating seedlings of mung bean (Phaseolus vulgaris): involvement of lipid peroxides in chlorophyll degradation. Physiologia Plantarum 85(1), 85-89. [ Links ]
Wang, X., Shi, G. X., Xu, Q. S., Xu, B. J, Zhao, J. 2007. Lanthanum and cerium induced oxidative stress in submerged Hydrilla verticillata plants. Russ. J. Plant Physiol. 54, 693-697. [ Links ]
Yin, S., Ze, Y., Liu, C., Li, N., Zhou, M., Duan, Y., Hong, F. 2009. Cerium relieves the inhibition of nitrogen metabolism of spinach caused by magnesium deficiency. Biol. Trace Elem. Res. 132, 247-258. [ Links ]


text:
Things to do with kids in Asheboro, US, North Carolina and nearby
In the surrounding of 100 km
Show me things to do with kids near city:
28 indoor/outdoor places to go with kids in and near Asheboro, US, North Carolina:
In the area of 100 kms
|North Carolina Zoo
|Asheboro; US, North Carolina
|Visit the North Carolina Zoo for fun with family and friends, for face-to-face animal encounters, to enchant and educate children or perhaps to enjoy the glorious gardens.
|Wet n Wild Emerald Point
|water park
|Greensboro; US, North Carolina
|When you think summer, think Wet'n Wild. The largest water park in both the Carolinas is the place to cool off, get sun and have fun.
|Piedmont Environmental Center
|High Point; US, North Carolina
|At Piedmont Environmental Center (an environmental preserve named for Rebecca Rhodes Smothers), we make environmental education fun for children and adults of all ages.
|Putt-Putt Fun Center High Point
|High Point; North Carolina
|To provide families with a safe clean, wholesome entertainment venue where they can have an enjoyable experience for a reasonable cost in their own community
|Greensboro Childrens Museum
|Greensboro; US, North Carolina
|Today, more than 400 children's museums throughout the United States break the rules of traditional institutions by encouraging visitors to touch, talk, have fun and learn. In a children's museum, the audience is most important, not the objects.
|Putt-Putt Fun Center Burlington
|Burlington; North Carolina
|To provide families with a safe clean, wholesome entertainment venue where they can have an enjoyable experience for a reasonable cost in their own community
|Winston-Salem; US, North Carolina
|SciWorks' 25000 square feet of exhibit space, 119-seat Planetarium and 15-acre outdoor Environmental Park are able to serve several hundred group visitors at a time.
|Morehead Planetarium and Science Center
|Chapel Hill; US, North Carolina
|Morehead Planetarium and Science Center is one of the largest planetariums in the United States
|Kannapolis Recreation Park
|water park
|Kannapolis; US, North Carolina
|Kannapolis Recreation Park is located just minutes from your home in Cabarrus or Rowan county.
|Eno River State Park
|Durham; US, North Carolina
|Minutes from Durham, Hillsborough, and Chapel Hill the Eno River State Park offers secluded wilderness trails with the serenity of a clear river drifting and cascading over a rocky stream bed.
|Hanging Rock State Park
|Danbury; US, North Carolina
|Not far from the cities of the Triad area, off the four-lane highways there's another North Carolina to be discovered—sheer cliffs and peaks of bare rock, quiet forests and cascading waterfalls, views of the piedmont plateau that stretch for miles.
|The Lazy 5 Ranch
|Mooresville; US, North Carolina
|The Lazy 5 Ranch is a privately owned exotic animal drive thru park that offers a 3.5 mile safari through the gently sloping pasturelands of Piedmont, North Carolina.
|Museum of Life and Science
|Durham; US, North Carolina
|Our mission is to create a place of lifelong learning where people, from young child to senior citizen, embrace science as a way of knowing.
|Danville Science Center
|Danville; US, Virginia
|Located at the historic Crossing at the Dan, the Danville Science Center delights all ages with its hands-on exhibits and special programs that make science fun for everyone.
|The Pit Indoor Kart Racing
|Mooresville; US, North Carolina
|The Pit Indoor Kart Racing is one of North Carolina's premier entertaiment destinations. Located just 30 minutes north of donwtown Charlotte, The Pit offers over 140,000sq-ft of floor space providing excitement for any age group.
|Virginia Museum of Natural History
|Martinsville; US, Virginia
|The Virginia Museum of Natural History in Martinsville, Virginia is a place where scientific research about the Commonwealth of Virginia's natural history and public understanding merge.
|Putt-Putt Fun Center Hope Mills Fayetteville
|Fayetteville; North Carolina
|To provide families with a safe clean, wholesome entertainment venue where they can have an enjoyable experience for a reasonable cost in their own community
|AAF Tank Museum
|Danville; US, Virginia
|Prepare yourself for an awesome adventure for both young and old alike!
|Fantasy Lake
|water park
|Hope Mills; US, North Carolina
|Fantasy Lake Water Park is the Carolinas best spot for summer fun!
|Discovery Place
|Charlotte; US, North Carolina
|Spend a day at Discovery Place and we'll introduce you to a world of wonder, where science amazes, educates and entertains. There's something for everyone in the family to enjoy, from little ones just starting to explore to adults who have seen the world.
|Rays Splash Planet
|water park
|Charlotte; US, North Carolina
|Ray's Splash Planet is unlike anything in the Carolinas!!
|North Carolina Museum of Natural Sciences
|Raleigh; US, North Carolina
|The North Carolina Museum of Natural Sciences is the largest museum of its kind in the Southeast. Through our exhibits, programs and field experiences, we provide visitors with opportunities to get up close and personal with science and nature.
|Carolina Raptor Center
|Huntersville; US, North Carolina
|Carolina Raptor Center is dedicated to environmental stewardship and the conservation of birds of prey through education, research, and the rehabilitation of injured and orphaned raptors.
|theme park
|Charlotte; US, North Carolina
|We've got the most hair-raising rides, the wettest water park, the most sizzling stage shows, and tons of other cool stuff everyone can enjoy.
|Falls Lake State Recreation Area
|Wake Forest; US, North Carolina
|Hours of relaxation await you at Falls Lake State Recreation Area. Just moments away from the hustle and bustle of the city, Falls Lake is a great way to escape urban life.
|ClayEscape Paint Your Own Pottery
|Fort Mill; US, South Carolina
|With more than 700 different bisque items and no hourly fees, ClayEscape offers lower prices & a larger inventory than other local contemporary studios.
|Lumber River State Park
|Orrum; US, North Carolina
|The Lumber River flows through the south-central portion of our state. The river's headwaters are in Montgomery, Moore, Richmond and Scotland counties where the waterway is known as Drowning Creek.
|Settlemyre Planetarium
|Rock Hill; US, South Carolina
|The Settlemyre Planetarium, located at the Museum of York County, uses a sophisticated star projector and a domed ceiling to recreate the night sky at any time of the year
If you are searching for things to do with kids in some of USA country you can use links bellow:
Alabama -- Alaska -- Arizona -- Arkansas -- California -- Colorado -- Connecticut -- Delaware -- Florida -- Georgia
Hawaii -- Idaho -- Illinois -- Indiana -- Kansas -- Kentucky -- Louisiana -- Iowa -- Maine -- Maryland -- Massachusetts
To have fun with kids select some of the pages
Michigan -- Minnesota -- Mississippi -- Missouri -- Montana -- Nebraska -- Nevada -- New Hampshire -- New Jersey
New Mexico -- New York -- North Carolina -- North Dakota -- Ohio -- Oklahoma -- Wisconsin -- Wyoming -- Oregon
For family fun days out navigate to
Pennyslavia -- Rhode Island -- South Carolina -- South Dakota -- Tennessee -- Texas -- Utah -- Vermont -- Virginia
Washington -- West Virginia
On the following link you can find things to do with kids in UK.
As shortcut for things to do and where to go with the kids in the USA cities use following links:
Newark -- Phoenix -- Denver -- Reston -- Stockton -- Boston -- Washington -- Los Angeles -- Irvine
San Francisco -- Miami -- New York -- Chicago -- San Antonio -- San Diego -- San Diego -- Indianapolis
Albuquerque -- Anchorage -- Salt Lake City
As shortcut for family days out and day trips in the UK you can also use following links:
London -- South East - Milton Keynes -- North West - Manchester -- Scotland - Glasgow -- Ireland - Belfast
South West - Plymouth -- South East - Southampton -- Wales - Cardiff -- West Midlands - Birmingham
Scotland - Edinburgh


text: The Southington High School Class of 2003 will be holding its 10-Year Reunion on Nov. 30 at Testa's Banquet Facility from 7:30 to 11:30 p.m. Tickets must be purchased by Nov. 15 at www.ezevent.com/shs10year. Tickets will not be sold at the door. Ticket price is $62 and includes buffet dinner, DJ, and open bar. For more information, email email@example.com


text:
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The Federal Communications Commission (FCC) has rules requiring telecommunications service providers like Bloomingdale Communications to make their services and products accessible to people with disabilities, if such access is readily achievable. These rules implement Section 255 of the Federal Communications Act. Section 255 requires telecommunications service providers to make their services and devices compatible with peripheral devices and specialized customer premises equipment that are commonly used by people with disabilities, if such compatibility is readily achievable. Please contact us at (269) 521-7300 for further information or to discuss your accessibility needs and the options we may have to assist you in using our services.
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text:
"What makes a car right for the times shouldn't make it wrong for Saturday night"—We imagine this is precisely what the brains behind the Cavalier based Oldsmobile Firenza were thinking when they designed it.
Although this classic advertisement—originally intended for the Canadian market—doesn't come out and explain this
statement, we think we get what they were trying to say.
If you wanted a compact capable of 52mpg on the highway and still "stylish" enough to show up at a country music jam session the Firenza was obviously the car for you