摘要
【目的】探讨尿素施用量、基施比例和方法对水稻产量、吸氮量和氮肥利用率的影响,以及肥料氮的去向,为制定科学合理的施氮措施提供理论依据。【方法】水稻季田间试验于2019年和2020年在江苏太湖地区开展。供试脲酶抑制剂为N-丁基硫代磷酰三胺(NBPT),硝化抑制剂为对羟基苯丙酸甲酯(MHPP),二者用量均为施氮量的1%。试验共设6个处理:1)不施氮肥对照(CK);2)表施尿素N 300 kg/hm^(2)(当地常规施肥,CN);3)表施尿素N 225 kg/hm^(2)(RNB);4)尿素N 225 kg/hm^(2),50%表施,50%深施(RND);5)表施尿素N 225 kg/hm^(2)+NBPT+MHPP(RNB+DI);6)尿素N 225 kg/hm^(2)+NBPT+MHPP,50%表施,50%深施(RND+DI)。表施氮肥处理基肥∶分蘖肥∶孕穗肥为4∶3∶3;深施氮肥处理基肥∶孕穗肥为7∶3。2020年在处理小区内设置了^(15)N示踪微区试验。调查了水稻产量、吸氮量、氮肥利用率以及^(15)N肥料植株利用、土壤残留和总损失量。【结果】与CN相比,除RNB处理2020年的秸秆生物量外,其余三个处理的籽粒与秸秆生物量均无显著差异;两年4个处理的氮肥表观利用率、农学利用率和偏生产力利用率均显著提高;15N示踪试验结果表明,4个处理均显著减少了^(15)N吸收量,RND、RNB+DI和RND+DI还显著降低了氮肥总损失量。与RNB相比,RND处理的水稻产量增加3.3%—4.0%,氮肥表观利用率显著增加20.4%—27.3%,^(15)N吸收量和利用率显著增加28.2%,总损失率显著降低34.6%;RNB+DI处理的水稻产量和氮肥表观利用率没有显著增加,15N吸收量和利用率显著增加11.6%,总损失率显著降低13.1%;RND+DI处理的水稻产量增加2.6%—4.3%,氮肥表观利用率显著增加23.4%,^(15)N吸收量和利用率显著增加36.9%,损失率显著降低45.0%。与RND相比,RND+DI处理的水稻产量、氮肥利用率和^(15)N植株吸收量均无显著差异,但降低了总损失率。【结论】在太湖地区水稻生产中,将氮肥用量由N 300 kg/hm^(2)减至225 kg/hm^(2),基施比例由40%提高到70%,同时将基肥中的50%深施,不会降低水稻产量,还显著提高了氮肥利用率,降低了氮肥总损失率,将此技术与添加氮肥抑制剂技术集成,可进一步降低氮素的损失率。从生产成本和应用效果考虑,减少氮肥总量的前提下,加大氮肥基施比例并配合基肥深施加少量撒施,是提高水稻产量和效益的适宜措施。
【Objectives】We studied the effects of urea fertilization methods on rice yield,nitrogen utilization efficiency,and the fate of nitrogen fertilizer in soil to propose economically and environmentally friendly N management measures.【Methods】A paddy field experiment was conducted in the Taihu Lake region in 2019 and 2020,and a 15N-urea micro-plot experiment was installed in the same field plot in 2020.Urease inhibitor N-(nbutyl)thiophosphoric triamide(NBPT)and nitrification inhibitor methyl 3-(4-hydroxyphenyl)propionate(MHPP)were added at 1%of urea-N.We included six fertilizer treatments:no N application(CK);broadcasted urea N at 300 kg/hm^(2)(conventional fertilization,CN);broadcasted urea N at 225 kg/hm^(2)(RNB);50%in deep and 50%in broadcasting of urea N at 225 kg/hm^(2)(RND);broadcasted urea N at 225 kg/hm^(2)+NBPT+MHPP(RNB+DI);50%in deep and 50%in broadcasting of urea N at 225 kg/hm^(2)+NBPT+MHPP(RND+DI).Broadcasted urea N was applied in three splits(4:3:3)as basal,at tillering and panicle initiation stages.Deep-placed nitrogen was applied in two splits(7:3)as basal,and at panicle initiation stage.Rice yield,N uptake,N utilization,absorptive capacity,soil residual and total 15N loss were quantified.【Results】Compared with CN,RNB,RND,RNB+DI and RND+DI treatments recorded similar grain yield and straw biomass,except the lower straw biomass in RNB in 2020;However,all the four treatments achieved higher N use efficiency,agronomic efficiency and partial factor productivity of nitrogen fertilizer,and 15N tracing result also proved the significant reduction in 15N uptake and total N loss under the four treatments.Compared with RNB,RND enhanced apparent N recovery efficiency(NRE)and 15N use efficiency by 20.4%-27.3%and 28.2%,and reduced 15N loss by 34.6%(P<0.05).RNB+DI had no impact on NRE,but(P<0.05)increased 15N use efficiency by 11.6%and reduced 15N loss rate by 13.1%.RND+DI increased rice yield by 2.6%-4.3%,NRE by 23.4%,15N use efficiency by 36.9%,and reduced 15N loss by 45.0%.Compared with RND,RNB+DI had no impact on rice yield and NRE but reduced the 15N loss rate.【Conclusions】In the rice production of Taihu lake area,the measurement of reducing urea-N rate from 300 kg/hm2 to 225 kg/hm^(2),but increasing the basal fertilizer ratio from 40%to 70%,and changing total broadcasting to 50%by deep placement,will not decrease rice yield,but significantly increase nitrogen fertilizer use efficiency,decrease total N loss.Adding NBPT and MHPP in urea will further decrease the total N loss.We recommend that a higher proportion of urea should be allocated to the deep basal placement and a lower proportion to broadcasting,rather than adding N inhibitors,to increase rice yield and N use efficiency.
作者
曾科
朱文彬
田玉华
尹斌
ZENG Ke;ZHU Wen-bin;TIAN Yu-hua;YIN Bin(State Key Laboratory of Soil and Sustainable Agriculture/Institute of Soil Science,Chinese Academy of Sciences,Nanjing Jiangsu 210008,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2023年第3期427-436,共10页
Journal of Plant Nutrition and Fertilizers
基金
国家重点研发计划项目(2017YFD0200104,2016YFC0207906)。
