{'fraction_non_alphanumeric': 0.031037827352085354, 'fraction_numerical': 0.026188166828322017, 'mean_word_length': 4.083743842364532, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Decréscimo da retenção de fósforo no solo pelo aumento do pH

This study aimed to quantify the effect of the soil pH on P sorption retention curves. It was conducted in laboratory, during 1986 and 1987, in Lages, State of Santa Catarina, Brazil. Samples from 20 Brazilian soils were used, each with three pH levels. The retention curves were obtained by using 12 P rates, from 0 to 5,120 mg P kg -1 , and the amount of P retained was calculated subtracting the P in the liquid extracts (measured after 20 hours of shaking) from the P added initially. In the majority of soils, P retention decreased as pH increased, but with highest magnitude up to the first pH value (approximately 5.8). In five soils, the pH had no effect on P retention. Raising the pH to near 5.8 decreased by half the amount of P necessary to maintain 0.2 mg of P L -1 in the equilibrium solution. The Freundlich equation was more efficient than the Langmuir equation to describe the relationship between solution P (P li ) and P retained by the soil (P si ).