喷灌条件下土壤中的氮素分布研究

用地中渗透仪实验证实 ,喷灌 50 mm的水将土壤表层硝态氮和表施的尿素淋洗到 5～ 2 0 cm作物根系密集层 ,利于作物吸收 ,不产生深层渗漏损失。表施碳铵喷灌 ,铵态氮主要分布在 0～ 5cm土层 ,不利于氮肥保蓄

The Nitrogen Distribution in Soil after Surface Application of Nitrogenous Fertilizer under Sprinkling Irrigation Condition

An amount of 50 mm of water was irrigated on the soil in Lysimeters by means of sprinkler at a time just after nitrogenous fertilizers was applied on the soil surface. In 48 hours after the irrigation, soil samples were taken for chemical analysis. The results indicate that sprinkler irrigation make urea and nitrate nitrogen in the upper layer to be leached into 5～20cm of soil layer with dense roots where nitrogen is assimilated effectively by crops and the seepage loss of nitrogen may not occur. Sprinkler irrigation was implemented just after NH 4HCO 3 was spreaded on soil surface, which made the most of NH + 4 N store up in the 0～5cm soil layer and the surface application of NH 4HCO 3 is unfavorable for the maintenance of NH + 4 N.