Physiological Mechanism Of Spring Maize Soil-root-canopy System Response To Subsoiling And Irrigation

Due to long-term unreasonable tillage measures,the soil tillage layer becomes shallow,which affects crop yields,and subsoiling is widely used as a protective tillage measure.However,how to combine the subseasonal season with the subseasonal depth to maximize the yield increase is worth studying..Under drought conditions,it is of great significance to clarify the response mechanism of the deep pine period and deep pine depth to the drought tolerance of maize,so as to improve the drought tolerance of corn.In order to further promote the high-yield and stable yield of corn in Inner Mongolia,this study passed the three-year and three-region deep pine positioning experiment,setting different deep pine periods(spring deep pine,autumn deep pine)and deep pine depth(30cm,40cm,50cm)to explore Which subsoil mode is more suitable.The main findings are as follows:(1)After deep soil loosening,it can effectively improve the physical structure of the soil,increase the number of soil microorganisms is conducive to fertility fertility,reduce soil bulk density and soil compactness to increase soil porosity,permeability and water infiltration capacity.Reasonable subsoiling measures can form an effective reservoir inside the soil to increase soil water retention.The reasonable deep pine period and deep pine depth have a significant effect on corn grain water use efficiency.(2)When the corn is subjected to drought stress,the growth conditions are blocked,which causes the conversion of nutrients between the above and below the ground,resulting in a decrease in the accumulation of dry matter above the ground.The growth of the ground is accelerated,and the yield of corn is reduced.Superoxide dismutase(SOD)and peroxidase(POD)are reliable biochemical indicators for drought tolerance analysis after drought stress.After drought stress,the activities of these protective enzymes increased significantly and the content of malondialdehyde(MDA)increased.(3)Reasonably deep pine can increase the activity of SOD and POD to a certain extent,thereby alleviating the damage of corn from active oxygen and improving its resistance to stress;the level of malondialdehyde(MDA)directly reflects the severity of the stress of the crop,and Reasonable deep pine reduces the content of MDA and alleviates the impact of drought stress on crops.(4)Deep pine has a positive effect on root growth and development.Because deep pine breaks the bottom of the plow,increases the range of soil tillage,and loosens the soil,it directly promotes the rooting of corn roots and enhances the ability of corn roots to absorb deep nutrients and water.The morphological characteristics of maize root system are further improved with the increase of deep pine depth.(5)Subsoiling has a positive effect on improving the dry matter quality and grain yield of corn at the mature stage.Deep pine also has a positive effect on the improvement of water use efficiency.Compared with traditional farming methods,deep pine can promote high and stable corn yield.