黑土稻田节水灌溉减施氮肥的土壤氮素分布及氮肥利用

Effect of Reducing Nitrogen Fertilizer Application on Soil Nitrogen Distribution and Nitrogen Use Efficiency in Black Soil Paddy Field under Water-Saving Irrigation

为揭示黑土稻田节水灌溉减施氮肥的土壤氮素分布及氮肥利用情况,研究节水灌溉减施氮肥下各土层中铵态硝态氮、可溶性有机氮、微生物量氮分布情况,以及对产量和氮肥利用的影响。结果表明:浅湿干灌溉使0~20cm土层铵态氮和硝态氮含量增加,而20~60cm土层铵态氮和硝态氮含量降低,浅湿干灌溉适当减施氮肥增加了0~20cm土层铵态氮的含量;浅湿干灌溉下各层土壤可溶性有机氮含量均随着施氮量减少而降低,浅湿干灌溉适当减施氮肥增加了0~20cm土层土壤可溶性有机氮的含量;浅湿干灌溉下各层土壤微生物量氮含量均随着施氮量减少而降低,节水灌溉适当减施氮肥增加了0~20cm土层土壤微生物量氮的含量。节水灌溉适当减施氮肥大幅度提高了水稻产量、氮肥农学利用率(NAE)和氮肥吸收利用率(NUE),综合考虑黑土供氮能力和土壤氮库稳定及氮肥利用节水灌溉减施10%氮肥处理最优。

In order to reveal the soil nitrogen distribution and nitrogen utilization of water-saving irrigation and reduced nitrogen fertilizer in black soil paddy field,the distribution of ammonium nitrate nitrogen,soluble organic nitrogen and microbial biomass nitrogen in each soil layer under water-saving irrigation and reduced nitrogen fertilizer were studied,as well as their effects on Yield and nitrogen utilization.The results showed that shallow wet dry irrigation increased the content of ammonium nitrogen and nitrate nitrogen in 0~20cm soil layer,while the content of ammonium nitrogen and nitrate nitrogen in 20~60cm soil layer decreased.The appropriate reduction of nitrogen fertilizer in shallow wet dry irrigation increased the content of ammonium nitrogen in 0~20cm soil layer.Under shallow wet dry irrigation,the content of soluble organic nitrogen in each layer of soil decreased with the reduction of nitrogen application,and the appropriate reduction of nitrogen application in shallow wet dry irrigation increased the content of soluble organic nitrogen in 0~20cm soil layer.Under shallow wet and dry irrigation,the soil microbial biomass nitrogen content in each layer decreased with the reduction of nitrogen application.The appropriate reduction of nitrogen application in water-saving irrigation increased the soil microbial biomass nitrogen content in 0~20cm soil layer.Proper reduction of nitrogen fertilizer application in water-saving irrigation increased rice yield,Nitrogen Agronomic utilization efficiency and nitrogen absorption and utilization efficiency.Considering the nitrogen supply capacity of black soil,the stability of soil nitrogen pool and nitrogen utilization,water-saving irrigation with a reduction of 10%nitrogen fertilizer treatment was the best.