氮密互作对玉米辽单575产量和氮素积累的影响

Effect of Nitrogen and Density Interaction on Yield and Nitrogen Accumulation of Liaodan575

以国审玉米新品种辽单575为供试材料,采用随机试验设计,设3个种植密度:6.0万株/hm^(2)(D_(6.00))、6.75万株/hm^(2)(D_(6.75))和7.5万株/hm^(2)(D_(7.50)),3个施氮量:135(N_(135))、180(N_(180))和225 kg/hm^(2)(N_(225)),研究氮密互作对辽西地区春玉米地上部干物质积累、氮素积累及子粒产量的影响。结果表明,与D_(6.00)处理相比,D_(6.75)、D_(7.50)处理下玉米群体干物质积累量显著升高,2017年提高14.9%、17.6%,2018年提高0.4%、11.3%。与N_(135)处理相比,N_(180)、N_(225)处理的氮素积累量较高,分别提高0.2%、0.9%(2017年)和9.3%、8.1%(2018年)。两年间玉米子粒最高产量均在D_(6.75)和N_(225)处理下获得。2017年D_(6.75)N_(225)处理和2018年D_(6.75)N_(180)、D_(6.75)N_(225)处理的玉米产量显著高于其他处理,密度和氮肥的互作效应对玉米产量的影响显著,说明适量增密减氮是协同提高玉米产量的重要途径。两年间收获指数、氮收获指数和氮肥偏生产力最高值均在D_(6.75)处理下获得。辽单575适宜的种植密度从常规的密度增加到6.75万株/hm^(2),施氮量第一年为225 kg/hm^(2),第二年减少为180 kg/hm^(2),可实现减氮增密增产的目标。

A new maize hybrids released in China,Liaodan575,was used as experimental materials.Three plant densities(60 thousand,67.5 thousand and 75 thousand plants per hectare)and three nitrogen rates(135,180 and 225 kg/ha)were designed by random experiment in 2017 and 2018.The results showed that compared with D_(6.00),D_(6.75) and D_(7.50) dry matter accumulation of maize significantly increased by 14.9% and 17.6% in 2017,0.4% and 11.3%in 2018.Compared with N_(135),N_(180) and N_(225) nitrogen accumulation were higher,increased by 0.2%and 0.9%(in 2017),9.3%and 8.1%(in 2018),respectively.During the 2017 and 2018,the highest maize yield was obtained under the treatment of D_(6.75) and N_(225).The maize yield of D_(6.75)N_(225) in 2017 as well as D_(6.75)N_(180) and D_(6.75)N_(225) in 2018 was significantly higher than that of other treatments,and the interaction effect of planting density and nitrogen applica⁃tion amount significantly affected maize yield,indicated that increased plant density with reduced N rate properly was an important way to synergistic improve maize yield.The highest harvest index,nitrogen harvest index and nitro⁃gen partial productivity were obtained under D_(6.75) treatment in 2017 and 2018.Therefore,it is recommended for Liao⁃dan575 that suitable planting density should be increased from the conventional density to 67.5 thousand plants per hectare,and the amount of nitrogen application should be 225 kg/ha in the first year,and then to 180 kg/ha in the next year.It can achieve the goals of reducing nitrogen,increasing density and increasing maize yield.