半干旱区耕作模式对砂质土壤结构及玉米生长的影响OA

[Objective]This study aims to investigate the effects of different tillage practices on soil structure and rainfed maize growth in sandy soil in semi-arid regions,and to clarify how different tillage practices affect crop yield by altering soil structure,soil water-holding capacity,and root growth characteristics.[Methods]Taking sandy loess in Dingbian County,Shaanxi Province as the research object,three tillage practices were set up:ploughing(depth 30 cm),rotary tillage(depth 15 cm),and no-tillage+straw mulching,to investigate their effects on soil physical properties and maize growth.[Results]1)Different tillage practices significantly changed the vertical profile of soil penetration resistance.The soil penetration resistance under ploughing was generally low,with no obvious plow pan,while pronounced subsurface compaction was observed under both rotary tillage and no-tillage.2)Soil bulk density in the 0-20 cm soil layer was lower under ploughing and rotary tillage than under no-tillage.In the 20-40 cm layer,rotary tillage and no-tillage had higher bulk density than ploughing.In the 40-60 cm layer,no-tillage showed lower bulk density than ploughing.3)Soil water-holding capacity in the 0-20 cm layer followed the order:no-tillage>rotary tillage>ploughing.In the 20-40 cm layer,ploughing had the highest water-holding capacity.During the maize growing season,soil water storage in the 0-40 cm layer was highest under no-tillage.4)Ploughing reduced penetration resistance in the ploughing layer,improved soil aeration,and promoted maize root growth.Aboveground biomass and ear dry weight were 1.33 and 2.10 times greater than those under rotary tillage,and 1.94 and 3.39 times greater than those under no-tillage,respectively.[Conclusion]Ploughing improves maize yield by optimizing the soil structure of the ploughing layer and root growth environment,while no-tillage has advantages in water conservation in deep soil but suffers from high surface soil compaction in the short term.