{'fraction_non_alphanumeric': 0.045064377682403435, 'fraction_numerical': 0.02074391988555079, 'mean_word_length': 4.3396946564885495, 'pattern_counts': {'":': 0, '<': 1, '<?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}}
A laboratory method to simulate field losses of applied nitrogen fertiliser by volatilisation.

Recent work in the South African sugar industry has indicated how losses of nitrogen may be limited by using a simple soil test to determine the probability of losing urea-N via volatilisation. Where a danger of loss is indicated, alternative N carriers such as limestone ammonium nitrate (LAN; 28% N) or ammonium sulphate (AS; 21% N) are recommended, albeit at a higher cost per unit N. To further investigate the potential losses of N applied to sugarcane soils, incubations (at 25°C) were carried out using 3 kg of moist topsoil (12% clay; 1% OM: pH 5.7) in 5 L containers. Nitrogen fertiliser materials (urea, LAN and AS) were applied at rates equivalent to 160 kg N/ha, directly to the bare soil surface or onto a layer of sugarcane crop residue (simulating 10 t/ha). On bare soil 15.8 kg N/ha (or 10%) of the urea-N was lost by volatilisation; by comparison, the losses of LAN-N and AS-N were negligible. Loss of urea N applied to sugarcane trash was 46.8 kg N/ha (29%), whilst the losses of LAN-N and AS-N were minimal (<1%). The method has confirmed the substantial losses of N that are likely to occur when urea is applied to some sugarcane soils, particularly where there are crop residues on the soil surface. Under such conditions, it is advisable for growers to use alternative N carriers.