有机肥对蔬菜无机氮利用率及氮去向的影响

为了明确蔬菜农田大量施用有机肥对无机氮肥利用率的影响，本研究采用微区15N示踪法，连续2季研究了增施有机肥对蔬菜无机氮肥利用率及其有机肥后效对土壤残留化学N肥（15N标记尿素）利用的影响。结果表明：单施化学氮肥（CF）和增施有机肥（CF+M）2个处理第1季蔬菜体内分别有25%~26%和14%~18%的N来自化学N肥，化学氮肥利用率（UEN）分别为25.61%和18.16%；有机肥后效也显著影响第2季蔬菜体内来自土壤残留15N标记尿素的百分数（NDF）和第2季蔬菜对第1季残留15N标记尿素的利用率；CF和CF+M 2季累积对第1季所施15N标记尿素的利用率分别为28.76%、19.60%。与CF比较，CF+M对每季收获后0~200 cm土壤剖面15N标记尿素的回收率影响不显著，但增施有机肥促进剖面硝态氮的累积与下移；CF+M也显著提高了每季收获后15N标记尿素的损失率，第2季收获后CF和CF+M的15N标记尿素损失率分别为53.7%、61.2%。

Responses of Manure Application to Inorganic Nitrogen Use Efficiency and Its Fate in a Vegetable Field Soil

In order to continued and safly apply organic manure and nitrogen fertilizer and clear the effect law about fertilizing large amount of manure to inorganic nitrogen use efficiency during vegetable cultivation,the 15N tracer method was used in the study,which was used to show the response of increase the application of manure to inorganic nitrogen utilization efficiency and the manure aftereffect to the use of soil residual 15N-urea.The results showed:1st season vegetables insided 25%-26% N from 15N-urea in ...