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以浙江嘉兴地区水稻(明珠2号,晚稻)为研究对象,在稻田原状土柱渗漏池条件下研究施氮量与水稻产量及氨挥发损失关系,进一步构建基于环境和粮食安全的氮肥投入阈值。结果表明,水稻籽粒产量随施氮量变化符合二元一次方程,从粮食安全和经济效益考虑,最佳施氮量为252.80 kg hm-2,稻田体系氮肥利用率随施氮量增加线性递减,氮损失随施氮量增加递增,不同处理下氮素损失比例达15.31%~66.32%;稻田氨挥发主要集中在施肥后的7天内,施肥后1~2 d便迅速达到峰值,随后迅速降低,低温降雨会延迟氨挥发峰值的出现,基肥期氨挥发量远高于穗肥期,氨挥发总量随施氮量的增加呈指数增长,施氮量217.73 kg hm-2为氨挥发量拐点;基于粮食安全、经济效益和以氨挥发为指标的环境安全的多重考虑,在仅施用尿素配施有机肥条件下,浙江嘉兴地区氮肥投入阈值推荐量为217.73~252.80 kg hm-2。
Taking rice (Pearl No.2 and late rice) in Jiaxing of Zhejiang Province as the research object, the relationship between nitrogen application rate and rice yield and ammonia volatilization loss was studied under the condition of the original soil column leachate in paddy field, and the threshold of nitrogen fertilizer input based on environment and food security . The results showed that the grain yield of rice was in accordance with the bivariate equation according to the change of nitrogen application rate. Considering the food security and economic benefits, the optimum nitrogen application rate was 252.80 kg hm-2. The nitrogen use efficiency of paddy field decreased linearly with the increase of nitrogen application rate, The nitrogen loss increased with the increase of nitrogen application rate, and the nitrogen loss rate reached 15.31% ~ 66.32% under different treatments. The ammonia volatilization of paddy field mainly concentrated within 7 days after fertilization, and peaked rapidly from 1 to 2 d after fertilization, then decreased rapidly, Low temperature rainfall delayed the appearance of ammonia volatilization. The ammonia volatilization rate in base fertilizer stage was much higher than that in panicle stage. The total amount of ammonia volatilization increased exponentially with the increase of nitrogen application rate. The amount of nitrogen application was 217.73 kg hm-2, Based on multiple considerations of food security, economic benefits and environmental safety with ammonia volatilization as an indicator, the recommended threshold for nitrogenous fertilizers input in Jiaxing, Zhejiang Province was 217.73 ~ 252.80 kg hm-2 under application of urea alone.