不同膜上遮挡措施对旱地玉米土壤理化性状及产量的影响

Effects of different cooling methods on maize soil physical and chemical properties and yield in dryland

针对西北雨养旱作地区玉米长期地膜覆盖下出现的植株早衰现象,从不改变地膜保水功能的角度出发,采取地膜玉米膜上遮挡降温覆盖措施,研究不同膜上遮挡措施下土壤温度变化及对玉米产量形成的影响,分析不同膜上遮挡措施下玉米耕层土壤物理化学性状变化,为解析普通地膜玉米生育后期早衰提供理论参考。试验以陕单609为材料,基于2年田间试验,对比分析普通地膜覆盖+膜上覆黑色遮阳网(A)、普通地膜覆盖+膜上覆盖秸秆(B)与普通地膜覆盖(C)3种模式对农田土壤温度、土壤养分及玉米干物质量积累、产量和水肥利用效率的影响。结果表明:(1)在普通地膜覆盖的基础上添加遮挡物(黑色遮阳网、秸秆)可以有效降低土壤温度和紧实度,其中玉米生育前期降温效果最为明显。(2)与对照处理C相比,膜上遮挡降温处理A和处理B玉米生长后期土壤的有机质和全氮、全钾含量均增加,玉米肥料偏生产力分别提高7.24%和6.97%。(3)降温处理能够延缓玉米生长后期绿叶面积的衰减速率,提高植株干物质量的积累,增加玉米粒重。与处理C相比,降温处理A和处理B的2年平均玉米产量分别较普通地膜覆盖处理提高6.39%和5.93%,平均水分利用效率分别提高8.17%和7.67%。在西北雨养旱作区,适当降低普通地膜玉米的膜下温度有助于改善土壤理化性状,促进玉米籽粒干物质积累和产量形成,提高肥水利用效率。

Aiming at the phenomenon of premature senescence of plants under long-term maize plastic film mulching in rainfed and arid regions in Northwest China,adding cooling measures on mulched maize were taken to study the effects of soil temperature change on maize yield formation and analysis the changes of soil physical and chemical properties in topsoil of maize from the perspective of never changing the water conserving function of plastic film,which would provide the theoretical reference for the analysis of the early senescence in the later growth stage of ordinary plastic film maize.This experiment design using Shaandan 609(SD 609)as tested materials,based on a 2-year field experiment,compared with the effects of three modes,ordinary plastic film mulch+black sunshade net(A),ordinary plastic film mulch+straw(B)and ordinary plastic film mulch(C)on soil temperature,soil nutrients,dry matter mass accumulation yield and water and fertilizer use efficiency in yield.The results were as follows:(1)Adding coverings on plastic film mulching(black sunshade net,straw)can effectively decrease the soil temperature and compactness,especially early stage of maize growth.(2)Compared with the control treatment C,cooling treatment A and treatment B significantly increased the content of organic matter,total nitrogen and total potassium in the later stage of maize growth,and the average partial fertilizer productivity increased by 7.24%and 6.97%,respectively.(3)Cooling treatments can delay the attenuation of green leaf area in the later stage of maize growth,improve the accumulation rate of dry matter and increase the kernel weight of maize.Compared with treatment C,the 2-year average maize yields of cooling treatment A and treat ment B were increased by 6.39%and 5.93%and the average water use efficiency by 8.17%and 7.67%,respectively.In rainfed and arid regions in Northwest China,properly reducing the temperature under the film of mulched maize are helpful to improve soil physical and chemical properties,promote the accumulation of dry matter and the formation of yield and improve the high utilization efficiency of fertilizer and water.