控释尿素对旱作马铃薯产量及水分利用效率的影响

[目的]探究控释尿素对覆膜马铃薯氮素诊断指标、产量、经济效益及水分利用效率的影响.[方法]通过田间试验,研究了不施肥(CK)、普通尿素(CF,N施量200 kg/hm2)和控释尿素(CRU1(N施量180 kg/hm2)、CRU2(N施量160 kg/hm2)和CRU3(N施量140 kg/hm2))对马铃薯叶片叶绿素...

The Effects of Controlled-release of Urea on Yield and Water Use Efficiency of Rain-fed Potato

【Background】Drought and low nitrogen use efficiency are double whammy of developing sustainable agriculture in many countries in semi-arid areas that face increased land degradation and climate change.【Objective】This paper is to investigate the effects of controlled-release of urea onnitrogen form in soil,as well as yield,economic benefit,nitrogen partial productivity and water use efficiency of rain-fed potato,in attempts to provide guidance for improving fertilization management in loess hilly-gully region.【Method】The experiment was conducted in a field,and it compared the impact of common urea application(CF)and the controlled-release of urea(CRU)on yield,chlorophyll(Chl),flavonols(Flav),nitrogen balance index(NBI),nitrogen partial productivity and water use efficiency of the potato.The amount of urea used in the conventional application was 200 kg N/hm²(CF),and those used in the controlled-release were 10%(CRU1),20%(CRU2)30%(CRU3)of that used in CF,respectively.The control was non-fertilization(CK).【Result】With nitrogen application increasing,the Chl and NBI content in the leaves increased whereas the Flav decreased.Growth stage and the amount of nitrogen application both affected the Chl,NBI and Flav at significant level(P<0.01).However,the interactive effects of fertilization and growth stage were not significant(P>0.05).Both NBI and Flav were highly correlated with the yield during the tuber expansion stage.Reducing nitrogen application led to a decrease in tuber yield and economic benefit,and the reduction in economic benefit was ranked in the order of CF>CRU1>CRU2>CRU3>CK.The yields of potato in CRU2 and CRU3 were 88.90%and 85.33%of that in CF,respectively.Compared to CRU1,CF increased the tuber yield and economic benefit by 5.18%and 24.26%respectively,but it reduced the marketable potato rate and nitrogen partial productivity by 6.50%and 5.33%respectively.Reducing nitrogen application resulted in a decrease in water consumption and water use efficiency.CF increased water consumption and improved water use efficiency significantly(P<0.05)compared to CRU2 and CRU3,but insignificantly compared to CRU1(P>0.05).【Conclusion】Our results showed that compared to CRU1,CRU2,CRU3 and CF increased water consumption by 2.79%~5.02%,and water use efficiency by 2.33%~11.58%respectively.They are thus optimal urea applications to improve both potato yield and water use efficiency,while in the meantime increased the economic benefit in the loess hilly-gully region we studied.