传统和优化水氮管理对蔬菜地土壤氮素损失与利用效率的影响

Comparison of nitrogen loss and use efficiency of vegetable in vegetable field under traditional and improved water and N-fertilizer management

通过3年田间定位试验利用氮素平衡方程模拟了传统水氮管理和优化水氮管理下连作蔬菜地土壤无机态氮含量的变化,分析了两种水氮管理对土壤氮素损失量及氮素利用效率的影响。结果表明:优化水氮管理下花椰菜、苋菜和菠菜生长期内土壤平均(2年或3年)氮素损失量(氨挥发、反硝化和硝态氮淋洗的总和)只有传统水氮管理下花椰菜、苋菜和菠菜生长期内土壤平均氮素损失量的9%、8%和18%;氮素利用效率是传统水氮管理下各蔬菜氮素利用效率的2.3倍、3.2倍、1.7倍,而两处理间蔬菜平均产量并无显著差异。

A vegetable sequence system（Cauliflower-Amaranth-Spinach） used by farmer was set up. Changes of soil mineral nitrogen in vegetable field were simulated by using nitrogen balance model. The loss of soil mineral nitrogen and Nitrogen Use Efficiency（NUE） were analyzed under traditional and improved water and N-fertilizer managements. The results showed that the average soil mineral nitrogen losses （the total of ammonia volatilization and denitrification and nitrate leaching） of vegetable field during Cauliflower and Amaranth and Spinach growth under improved conditions were about 9% and 8% and 18% of those of traditional water and nitrogen management. But NUE of Cauliflower and Amaranth and Spinach were 2.3 times and 3.2 times and 1.7 times as much as those of traditional water and N-fertilizer management. Yield of vegetable was not significantly different under improved and traditional water and N-fertilizer management practices.