不同施氮量对单季稻养分吸收及氨挥发损失的影响

 以杂交晚粳浙优12为材料，研究了不同氮素用量对单季晚稻养分吸收和氨挥发损失的影响。结果表明，施氮量在0~330  kg/hm2范围内水稻植株氮积累量、磷积累量及钾积累量均表现为随施氮量的增加而增加，施氮水平超过270  kg/hm2后增施氮肥反而降低水稻对氮磷钾的吸收。施氮量在150  kg/hm2时增施有机肥有助于杂交粳稻浙优12对土壤中氮素、磷素以及钾素的吸收利用。水稻拔节期至抽穗期为吸氮量最大时期，施氮量在0~270  kg/hm2范围内杂交粳稻浙优12各生育期植株氮积累量随着施氮量增加而增加。相关分析表明，水稻产量与水稻植株全生育期氮积累量、磷积累量和钾积累量极显著正相关，其中，与水稻吸氮总量的相关系数最大。氨挥发速率、累计氨挥发量随施氮量的增加而增加，以施用基肥阶段氨挥发速率最快，累计氨挥发量最高。在基肥氮肥和分蘖肥氮肥施入后，高施肥水平(270  kg/hm2、330  kg/hm2)下氨挥发速率均远高于其他处理，其中，施氮量330  kg/hm2处理施基肥后测得的累计氨挥发量占基肥施氮量的23.9%。

Effects of Different Nitrogen Application Levels on Rice Nutrient Uptake and Ammonium Volatilization

The effects of different nitrogen application levels on nutrient uptake and ammonium volatilization were studied in a field experiment with rice variety Zheyou 12 as material.The results showed that the accumulative amounts of nitrogen,phosphorus and potassium showed an increasing tendency with the increasing nitrogen application level from 0 to 330 kg/hm2.The accumulative amounts of nitrogen,phosphorus and potassium decreased when the nitrogen application level was above 270 kg/hm2.The accumulative amounts of nitrogen,phosphorus and potassium increased with organic manure addition at 150 kg/hm2 nitrogen application level.The nitrogen uptake peaked from jointing stage to heading stage,and also increased with the increasing nitrogen application level from 0 to 270 kg/hm2.The rice grain yields were positively correlated with the accumulative amounts of nitrogen,phosphorus and potassium.Among those,the accumulative nitrogen amount was most closely correlated with rice yield.Velocity and accumulative amounts of ammonium volatilization increased with the increasing nitrogen application level.Compared with other stages,faster ammonium volatilization velocity and higher ammonium accumulative amount were observed several days after the basal fertilizer was applied.Ammonium volatilization velocity at nitrogen application rate of 270 kg/hm2 and 330 kg/hm2 were far higher than those in other treatments.The ammonium nitrogen volatilization loss accounted for 23.9% of the total applied nitrogen at the nitrogen application level of 330 kg/hm2.