耕作模式对黄土高原地区新增耕地土壤紧实度、养分含量及玉米产量的影响

Effects of Tillage Patterns on Soil Compaction,Nutrient Content and Yield of Newly Cultivated Land in Loess Plateau

[目的]探明不同耕作模式对以生土为构建材料的新增耕地的改良效应,为该类土地的高产高效利用提供科学依据。[方法]于2017年6-9月分别在免耕、深松、翻耕3种耕作处理模式下的玉米地开展定位监测试验,分析耕作模式对土壤紧实度、养分含量以及作物产量的影响。[结果]0-20 cm土层紧实度在免耕模式下最低,分别较深松和翻耕低约37.49和38.48 kPa/cm 2,且各模式下0-20 cm土层均呈分层紧实的状态。玉米出苗期土壤紧实度最小,喇叭口期紧实度最高。0-40 cm土层有机质、全氮和有效磷含量在深松模式下均最高,分别为免耕的1.20,1.22,1.36倍,是翻耕的1.18,1.08,1.34倍。深松和翻耕模式下的速效钾含量相近,均为免耕的1.09倍。从出苗期到灌浆期,有机质和全氮含量增加,有效磷和速效钾含量减小。深松耕作模式下玉米产量最高,是免耕和翻耕条件下的1.30,1.19倍。[结论]深松耕作模式土壤紧实度适中,能有效增加土壤养分含量,提高作物产量,是新增耕地最理想的耕作改良方式。

[Objective]The improvement effect of different tillage modes on the newcultivated land with raw soil as construction material was explored in order to provide scientific basis for high-yield and efficient utilization of this kind of land.[Methods]During the period from June to September in 2017,a location monitoring experiment was conducted in maize fields under three tillage modes of no-tillage,subsoiling and plowing,respectively.And the effects of tillage modes on soil compactness,nutrient content and crop yield were analyzed.[Results]The compactness of 0-20 cm soil layer was the lowest under the no-tillage mode,which was 37.49 and 38.48 kPa/cm 2 lower than that of subsoiling and plowing,respectively.And the compactness of 0-20 cm soil layer in each mode presented a stratified state.The soil compactness was the lowest at maize seedling stage and the highest at bell stage.The contents of organic matter,total nitrogen and available phosphorus in the 0-40 cm soil layer were the highest in the subsoiling mode,which were 1.20,1.22,1.36 times of no-tillage mode,and 1.18,1.08,1.34 times of plowing mode,respectively.The content of available potassium in subsoiling and plowing was similar,which was 1.09 times of that in no-tillage.From the seedling stage to the filling stage,the content of organic matter and total nitrogen increased,while the content of available phosphorus and available potassium decreased.The maize yield under subsoiling mode was the highest,which were 1.30 and 1.19 times of that under no-tillage and plowing,respectively.[Conclusion]The soil compactness of subsoiling mode is moderate,which can effectively increase the soil nutrient content and crop yield.It is the most ideal tillage and improvement method for the new cultivated land.