氮肥深施对作物产量和氮肥利用率的影响

应用盆栽试验和15N示踪技术，研究了辽宁省两种主要耕作土壤氮肥施用方法对玉米、水稻产量和肥料利用率影响。结果表明，氮肥深施能显著提高作物产量和肥料利用率。玉米以硫铵深施10或15m，尿素深施10cm时增产效果明显；水稻施硫铵和尿素均以深施15m增产效果最好。两种氮肥表施和施5cm效果不好。旱田流铵和尿素均以深施10或15cm利用率最高，平均达到52.62％；水田施硫铵以深施10或15cm利用率最高，平均达到57．48％，尿素则以深施10cm；。利用率较高。氮肥深施能增加土壤肥料氮残留率，减少氮素损失。

Effect of Deep Placement of N Fertilizers on Crop Yields and Use Efficiency of Nitrogen

This paper dealt with the effects'of nitrogcn deep placement On crop yields and use efficicncyof nitrogen fertilizer in Liaoning two main cultivated soileResults from pot experiment and 15N tracertechnique in brown earth and meadow soil showed that nitrogen fergilizer deep placement could raise cropyields and nitrogen use elliciency. When ammonium sulphate was applied tO 10 or 15 cm layer ofsoil andurea was applied to 10 cm layer of soil, increasing yield of' corm was applied to 10 cm. la}yer or soil,increasing yield of corn was remarkable when ammonium sulphate and urea werel added to 15 cm layer ofsoil, the rice was significantly incrased. The nitrogen use efliciency of corn was highest at 10 or 15 cmdeep placement, averagely 52.62%; The average use efficiency of rice was 57.48% when (NH4)2=SO4 wasapplied to 10 or 15cm layer of soil. Otherwise, the use efficiency of urea was highest when it was added tO10 cm layer of soil.