育秧箱全量施肥对水稻产量和氮素流失的影响

采用育秧箱全量施肥技术,通过2年田间小区试验,研究中量控释氮肥(80 kg N·hm-2)、高量控释氮肥(120kgN·hm-2)和常规施肥(300 kg N·hm-2)处理对水稻产量和氮素流失的影响.结果表明:与常规施肥相比,高量控释氮肥处理的水稻产量未显著降低.常规施肥处理2年平均氮素利用率为33.2％,中量和高量控释氮肥处理的平均氮素利用率分别比常规施肥处理提高26.2％和20.7％.常规施肥处理田面水的总氮含量在施肥后1～3d达最大值,中量和高量控释氮肥处理的高峰期为施肥后7～9d,全生育期内,中量和高量控释氮肥处理田面水的总氮含量均显著低于常规施肥处理.常规施肥处理的氮素渗漏流失主要在分蘖期,中量和高量控释氮肥处理的氮素渗漏流失后移至分蘖-开花期.各处理硝态氮流失量占总氮流失量的59.7％～64.2％,高量控释氮肥处理的总氮净流失量比常规施肥处理减少51.8％.

Effects of seeding-box total fertilization on rice yield and nitrogen loss

By using seeding-box total fertilization technology,a two-year field plot experiment was conducted to study the effects of applying medium rate of controlled-release urea fertilizer(MN,80 kg N·hm-2),high rate of controlled-release urea fertilizer(HN,120 kg N·hm-2),and conventional urea fertilizer(FP,300 kg N·hm-2) on rice yield and nitrogen loss.As compared with FP,HN did not decrease rice yield significantly,and MN and HN increased the two-year average nitrogen use efficiency(NUE) by 26.2% and 20.7%,respectively(the NUE in treatment FP was 33.2%).In treatment FP,the total N concentration in surface water peaked after 1-3 days of urea application;while in treatments MN and HN,the total N concentration in surfate water peaked after 7-9 days of urea application,and was significantly lower than that in treatment FP throughout the rice growth period.The nitrogen leaching loss in treatment FP mainly occurred at tillering stage,while that in treatments MN and HN delayed to tillering-flowering stage.In all treatments,the NO3--N loss accounted for 59.7%-64.2% of the total N loss.HN decreased the total N leaching loss by 51.8%,as compared with FP.