Effect Of Subsoiling Tillage On Soil Physicochemical Characteristics And Root Spatial Distribution Of Maize

For the study of subsoiling tillage effect on soil hydrothermal property, root spatial distribution andyield of maize, the experements were conducted at Huang-Huai-Hai region. No tillage, shallow rotatetillage and subsoiling tillage were setting with three planting density (low, middle and high plantingdensity). The soil and root were sampled simultaneously using the root soil sampler basing on thesampling method of “3D monolith”. The change and spatial distribution of soil moisture and rootwere analyzed under different management. Confirm the regulation and control mechanism of thespatial distribution coordination of soil water and root to maize yield. The main results were as follows:Subsoiling tillage could disrupt the soil plough pan which was in20-30cm soil layer. It decreased soilbulk density0.05-0.16g/cm3in0-30cm soil layer significantly. While shallow rotate tillage onlydecreased soil bulk density0.05-0.09g/cm3in0-20cm soil layer significantly. After analyzing soilmoisture content of different soil layer, it concluded that subsoiling tillage mainly increased soilmoisture content of deep soil layer under soil plough pan. Subsoiling tillage management increased it by7.14%in20-50cm soil layer compared with no tillage, and20.18%in0-50cm soil layer compared withshallow rotate tillage. For the spatial distribution of soil moisture, it showed a significant low value atthe center of plant and a significant high value at the around of plant. The region of plant root growthcenter or the region with high root length density was the soil moisture depletion region. The soilmoisture depletion region was significant decreased under subsoiling tillage management. Inadditionally, the increment effect of subsoil tillage on soil moisture content was increasing with thesubsoil tillage date bring forward.Root length of maize was significant higher under subsoiling tillage management than under shallowtillage and no tillage management. Subsoiling tillage could promote root growth into deep soil layer.After analyzing root length density of different soil layer, it increased by10.6%-12.6%at20-50cm soildepth under subsoiling tillage management. The horizontal distribution of root was very concentrationunder subsoiling tillage management. The decrement of root length density with the increment distancefrom plant root centre was significant larger in0-20cm soil layer while there were no significantchanges in20-50cm soil layer. Under high planting density management, individual root lengthdecreased significant, while the population root length density showed on significant change. But for thespatial distribution of population root, the change was very significant. With the plant density increased,root length density increased between two plants while it decreased significantly at the centre of plant.Subsoiling tillage management increased the root length density of deep soil layer to decrease rootcrowd of up soil layer.Subsoiling tillage promoted the root and shoot dry matter accumulation significantly. The incrementwas larger in shoot dry matter accumulation than in root dry matter accumulation. This leaded to a highshoot/root ratio. With planting density increased, the shoot/root ratio showed an increment tendency. Comparing with shallow rotate tillage and no tillage, subsoiling tillage increased the maize yield by6.9%-12.5%. High planting density management could increase the maize yield by7.82-10.72%.According to the analyses of yield components, subsoiling tillage could increase kernels per ear andthousand kernel weight, and high planting density could increase maize ears per area. The subsoilingtillage with high planting density management is an effect way to improve maize yield throughoptimizing root spatial distribution and shoot structure.