【摘要】 优化垄沟配置方式、种植密度和施肥方式可显著提高降水利用效率、作物产量和水分利用效率。以西北半干旱区全膜覆盖垄上微沟种植马铃薯,设置49,500株hm–2(低密度)和64,500株hm–2(高密度) 2个播种密度,传统施肥(PM)、减量追施(PMN)、有机肥替代(PMO) 3个施肥模式,随机区组设计。研究施肥和密度对马铃薯不同生育期土壤温度、阶段耗水量、产量及水分利用效率的影响。结果表明,增密对土壤温度、叶绿素相对含量(SPAD)和产量无显著影响,但降低了花前耗水量、单株地上生物量和水分利用效率,提高了叶面积指数(LAI)和花后耗水量。在块茎膨大期,高密度处理的LAI较低密度增加了3.64%～15.01%;花后耗水量在2015—2016年较低密度增加了6.50%～48.52%。与PM处理相比, PMN和PMO均能提高花前土壤温度、现蕾期-块茎膨大期的马铃薯叶片SPAD值和LAI,其中LAI在花期增加了10.42%～44.26%。PMN和PMO降低了花前耗水量,增加花后耗水量和地上生物量,在块茎膨大期地上生物量较PM增加了6.95%～49.85%。PMN能提高低密度马铃薯的块茎产量和水分利用效率(WUE),2015—2017年产量较PM和PMO分别提高了9.96%～20.87%和13.64%～17.61%,水分利用效率提高了5.46%～20.81%和13.25%～45.24%。因此,增加密度对产量和水分利用效率无显著影响,但化肥减量追施或有机肥替代均可显著促进马铃薯花后耗水和提高LAI,使马铃薯块茎产量和WUE显著增加,是西北黄土高原半干旱区增产增效的养分管理模式。更多还原

【Abstract】 The optimization of ridge-furrow construction,plant density and fertilizer application are three promising ways to increase rainwater use efficiency,crop yield and water use efficiency.A long-term field experiment was carried out in semi-arid area of northwestern China from 2015 to 2017,using potatoes planted in mini-ditch on ridges with plastic mulching,to explore the effects of fertilizer application and plant density on soil temperature,water consumption at different growth stages,yield and water use efficiency.Two plant densities(low density of 49,500 plants ha–1,and high density of 64,500 plants ha–1) and three fertilization methods(traditional fertilizer application,PM;reduced chemical fertilizer dressing,PMN;and organic fertilizer substitution,PMO) were set up as treatments,using randomized block design with three replications.The high density did not affect soil temperature,SPAD values and yield significantly,but lowered water consumption in pre-flowering stage,above-ground biomass per plant,and water use efficiency.However,LAI and water consumption were improved in post-flowering stage.Compared with low density treatments,LAI in high density increased by 3.64%–15.01%,and water consumption in tuber bulking period increased by 6.50%–48.52%.Both PMN and PMO increased soil temperature in pre-flowering stage,potato foliar SPAD and LAI from squaring to tuber bulking stage,compared with PM.For example,LAI increased by 10.42%–44.26% at flowering stage.PMN and PMO decreased water consumption during pre-flowering period,but increased it during post–flowering period,resulting in a 6.95%–49.85% increment in aboveground biomass at bulking stage.On average,PMN increased potato tuber yield and WUE under low density by 9.96%–20.87% and 13.64%–17.61%,5.46%–20.81% and 13.25%–45.24%,respectively,compared with PM and PMO.Consequently,the increment of plant density did not affect potato tuber yield and WUE.However,PMN and PMO promoted potato water utilization in post-flowering period and increased LAI,resulting in significant increment of potato tuber yield and WUE,showing an efficient way for fertilization management of potato in semiarid loess plateau of northwestern China.更多还原