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分别在半湿易旱地区的澄城、杨陵二地，以冬小麦为供试作物安排了田间和１５Ｎ试验，研究了表施、深施和混施氮肥对其肥效的影响。由于土壤肥力、水分状况及氮肥用量不同，两地的结果有异。分析各种施氮方法在两地满足作物养分需要和土壤氮挥发的特点，可以看出，无论在何种情况下，表施的氮肥肥效或较深施和混施逊色，或则近似，但均未比后两种施肥效果优越。在土壤供氮能力差，水分条件欠佳的情况下，氮肥用量较低时，混施有利于根系发育，效果显著优于深施；而用量较高时，深施和混施肥效不相上下。在土壤供氮能力较高时，水分条件又较好的情况下，作物幼苗对肥料氮依赖性较少，深施既减少了氮挥发，又有着较大的移动性，肥效明显高于其它两种施肥方法。
Field experiments and 15N experiments were conducted on winter wheat in Chengcheng and Yangling, respectively, in semi-humid and drought-prone areas. The effects of top dressing, deep application and mixed application of nitrogen fertilizer on their efficiency were studied. Due to different soil fertility, water status and nitrogen fertilizer use, the results of the two places are different. Analysis of various nitrogen application methods to meet the nutrient requirements of crops and soil nitrogen volatilization in the two places shows that no matter under what circumstances, the application of nitrogen fertilizer on the surface is less effective or less effective, No better than the latter two kinds of fertilization. Under the conditions of poor soil nitrogen supply and poor water condition, the mixed application was beneficial to the root development when the nitrogen fertilizer was low, and the effect was better than that of the deep application. . Under the conditions of higher soil nitrogen supply and better water conditions, crop seedlings have less dependence on fertilizer nitrogen. Deep application not only reduces nitrogen volatilization but also has greater mobility and fertilizer efficiency is significantly higher than the other two Fertilization methods.