土壤调理剂对砂姜黑土农田土壤理化性状和夏玉米生长的影响

Efficacy of Soil Conditioners in Improving Properties of Lime Concretion Black Soil and Their Consequence for Summer Maize Yield

砂姜黑土农田由于土壤黏板僵闭,耕层浅薄以及肥力低下等问题,往往导致玉米根系下扎困难,倒伏严重,产量下降。【目的】利用土壤调理剂改善土壤理化性状,以提高砂姜黑土农田生产力,促进玉米生长,增加玉米产量。【方法】在砂姜黑土农田上以冬小麦播前旋耕(RT)为对照,设置深耕(DP)、旋耕+松土促根剂(RT+RP)、旋耕+土壤修复剂(RT+RA)和旋耕+土壤改良剂(RT+SI)等处理,研究了土壤调理剂对土壤理化性状、土壤肥力和酶活性以及夏玉米抗倒伏性能和玉米产量的影响,并与深耕(DP)的作用效果进行了比较。【结果】RT+RP、RT+RA和RT+SI处理均可提高砂姜黑土农田的土壤含水率,并降低土壤体积质量;显著提高土壤脲酶、蔗糖酶和中性磷酸酶活性;显著提高土壤中有效磷、铵态氮和硝态氮量;显著增加了夏玉米株高和茎粗,提高了夏玉米茎秆抗弯曲力和地上部第三茎节横折强度,增强抗倒伏性能;RT+RP、RT+RA和RT+SI处理下产量分别较RT处理增加15.73%、9.02%和8.82%,经济效益分别增加12.05%、5.40%和3.37%。3种土壤调理剂的产量普遍优于深耕和旋耕处理,其中松土促根剂处理下的夏玉米产量最高,经济效益最好。【结论】施用土壤调理剂可以显著改善砂姜黑土农田的土壤环境,增加土壤含水率,提高土壤养分和土壤酶活性,增强夏玉米抗倒伏能力并实现增产。

【Background】Lime concretion black soil is widely distributed in central China including Henan and Anhui provinces.Apart from its low fertility,it is also hard and less porous for roots to penetrate.These combine to hinder crop growth and comprise crop yield.Traditional remediation methods including deep tillage to loosen the soil are effective but are tedious and laborious.As an alternative,soil conditioners have been increasingly used over the past years to improve the properties of the black soil to sustain its productivity.【Objective】The objective of this paper is to compare the effectiveness of different soil conditioners in improving soil properties and the consequence for crop growth and yield.【Method】We took summer maize as an example and the soil was plowed using conventional tillage after maize harvest but before winter wheat was drilled.There were three treatments:rotary tillage+application of root promoter(RT+RP),rotary tillage+application of soil remediating agent(RT+RA),rotary tillage+soil improvement agent(RT+SI).Traditional deep tillage was taken as the control(CK).In each treatment,we measured the changes in soil properties and fertility,enzyme activity,as we as the resistance of the maize against lodging and the eventual yield.【Result】Compared to CK,all treatments increased soil water content and reduced soil bulk density although the change varied with treatments;they also boosted the activity of soil enzymes including urease,sucrase and neutral phosphatase,and improved the contents of available P,ammonium N and nitrate N in the soils,as well as plant height and stem diameter.All improvements and increases were at significant level(p<0.05).These together improved the cross breaking strength of the third shoot node,thereby enhancing the resistance of the maize against bending loading.Compared with CK,RT+RP,RT+RA and RT+SI increased crop yield by 15.73%,9.02%and 8.82%,respectively,and the economic benefit by 12.05%,5.40%and 3.37%,respectively.【Conclusion】Amending the lime concretion black soil with soil conditioners is more effective than deep ploughs in improving soil properties and crop yield.Of the three treatments we studied,rotary tillage combined with root-promoting agent was most effective in improving soil water contents,enzymatic activity and summer maize yield.