麦秸覆盖还田对大豆耕层物理性状及产量形成的影响

Effects of wheat straw mulching on physical properties of topsoil and yield formation in soybean

黄淮海是我国优质高蛋白大豆主产区,但前茬小麦秸秆严重制约着该地区的大豆生产。本试验通过研究秸秆免耕覆盖还田下大豆耕层温度、含水量、容重、团粒结构等耕层物理性状以及大豆产量构成因素,试图解析免耕配合秸秆覆盖还田对耕层结构及大豆产量的调控机制,为黄淮海地区大豆高产耕作模式的选择提供理论依据。采用裂区试验设计,主区为肥料处理,设施肥(F:225 kg hm-2)与不施肥(NF);副区为秸秆处理,设免耕秸秆不还田(SR)、免耕秸秆覆盖还田(SM)和免耕秸秆粉碎还田(SC)。结果表明:(1)免耕配合秸秆覆盖还田对耕层的影响主要集中在0~10cm内。(2)SM与SC较SR耕层温度分别下降0.21℃和0.17℃,土壤含水量分别增加13.18%和9.07%;SM较SR与SC土壤容重分别下降2.61%和2.87%,耕层固相占比分别降低2.60%和3.01%,>2mm土壤团聚体分别增加6.84%和3.14%。(3)SM与SC较SR单株荚数分别增加22.41%和9.49%,单株粒数分别增加18.20%和7.51%,百粒重分别增加1.18%和2.40%,单株产量分别增加39.16%和18.07%,单位面积产量分别增加11.56%和5.43%;SM较SC增产效果显著,施肥对秸秆还田的增产效果具有促进作用。综上所述,麦茬夏大豆免耕覆秸精量播种技术在大豆耕层环境优化与促进产量形成方面具有显著优势。

Huang-Huai-Hai Rivers region is the main producing area of soybean with high protein content in China.However,the previous wheat straw seriously restricts the production of summer soybean in this area.The traditional farming system with high input and low output cannot meet the demand for high-quality soybean.In this experiment,the soil temperature,soil moisture content,soil apparent density,and soil aggregate structure of the topsoil,yield and yield composition of soybean under different crop system were investigated.The aim of this study is to analyze the regulation mechanism of no-tillage combined with straw mulching on surface soil structure and soybean yield,and to provide theoretical reference for the selection of the best crop system for soybean in the Huang-Huai-Hai Rivers region.A split-plot experimental design was adopted in the experiment.The main plot was fertilizer treatment[fertilization(F:225 kg hm-2)and no fertilization(NF)].The subplot was straw treatment[no-tillage without straw returning(SR),no-tillage with straw mulching(SM),and no-tillage with straw crushing returning(SC)].The results showed that:(1)The effect of no-tillage combined with straw returning on the surface layer was mainly concentrated in soil depth of 0–10 cm.(2)Compared with SR,the soil temperature of SM and SC decreased by 0.21℃and 0.17℃,respectively.The soil water content increased by 13.18%and 9.07%,respectively.Compared with SR and SC,the soil apparent density of SM decreased by 2.61%and 2.87%,respectively,the solid phase proportion of the plough layer decreased by 2.60%and 3.01%,respectively,and the soil aggregate>2 mm increased by 6.84%and 3.14%,respectively.(3)Compared with SR,the number of pods per plant in SM and SC treatments increased by 22.41%and 9.49%,the 100-seed weight of soybean under SM and SC increased by 1.18%and 2.40%,while the number of grains per plant under SM and SC increased by18.20%and 7.51%,respectively.In addition,compared with SR,the yield and yield per plant were increased by 11.56%and 39.16%in SM and 5.43%and 18.07%in SC,respectively.In this study,the fertilization can promote yield increase effects on straw returning,and SM has a more significant yield increase effect than SC.In conclusion,no-tillage plus straw mulching and precise sowing cultivation technology for summer soybean after winter wheat has significant advantages in optimizing soybean root layer environment and promoting yield formation.