Effects Of Different Tillage Practices And Water Retention Measures On Soil Physicochemical Properties And Maize Yield

In view of the fragile ecological environment in semi-arid areas,low rainfall,uneven seasonal distribution and strong evaporation of soil moisture as well as the long-term adoption of traditional tillage methods,resulting in changes in soil structure,massive loss of nutrients and water from the soil and significant reduction in soil fertility,efficient tillage and water conservation technology measures are taken to achieve land fertilization.In order to improve the physical and chemical properties of the soil,strengthen the soil’s ability to store water and retain moisture,reduce soil erosion and improve the yield of crops.Screening of suitable cropping technology patterns in the mountainous areas of Ningnan.In this paper,by setting up two tillage patterns in the main treatment:tillage and deep loosening,and three measures of no mulching,mulching and mulching+water retention agent(full film duopoly furrow sowing)in each main zone cleft area,we did correlation analysis and research on soil physical and chemical properties,soil enzyme activity and crop yield.The following conclusions were drawn:Deep pine without mulching has more advantages to improve soil organic matter compared with tillage without mulching,which indicates that deep pine is more favorable to soil organic matter accumulation than tillage.The combination of deep loosening with water retention and deep loosening with mulching was significantly higher than the rest of the treatments,which showed that the combination of deep loosening and water retention could further improve the soil organic matter content.Soil total nitrogen content was highest in deep pine mulch with water retention and lowest in tillage without mulch,and decreased with the increase of soil depth,indicating that deep pine reduced the loss of soil total nitrogen compared with tillage.Under the same tillage method,the soil fast-acting phosphorus content increased significantly in all growth periods of corn under mulch+water retention and mulch treatment,indicating that different water retention measures under deep loosening and tillage modes could promote the uptake of fast-acting phosphorus by the crop.Under the mulching condition,the soil fast-acting potassium content increased significantly in the deep-pine treatment,76.3%for 0-20 cm and 32.0%for 20-40 cm,indicating that deep-pine significantly increased the soil fast-acting potassium content compared with tillage,while different water retention measures had no significant effect on the soil fastacting potassium.Deep loosening reduced the soil capacity of 0-20 cm by 3.96%and that of 20-40 cm by 4.05%compared with tillage.This indicates that deep loosening can loosen the soil and reduce the compactness of the soil,which in turn reduces the soil capacity.All treatments increased the water content of the soil at different depths compared to tillage without mulching.Among them,deep loosening and mulching+water retention agent had the best effect on the 0-60 cm soil layer.In the deep loosening and tillage modes,the content of soil aggregates with particle size>0.25 mm was significantly increased in the mulch,mulch plus water retention agent treatments compared to the no mulch treatment.Under the same water retention measures,the deep pine treatment had a better effect on the content of large-size agglomerates than tillage.Under the deep loosening pattern,soil β-glucosidase activity increased by 14.9%and 9.1%for the mulch plus water retention and mulch treatments,respectively;and soil n-acetylglucosaminidase activit increased by 10.5%and 2.5%,respectively.The mulching plus water retention agent treatment increased cellulose disaccharide hydrolase activity by 20.6%compared to the no-mulching treatment,and there was no significant difference between the mulching and no-mulching treatments.In the tillage mode,the mulching and mulching plus water retention agent treatments increased yields by 76.2%and 125.4%,respectively,compared with the no-mulching treatment,and 78.6%and 91.7%,respectively,in the deep loosening mode.Under the no-mulch,mulch and mulch plus water retention conditions,deep loosening increased yields by 42.1%,44.0%and 20.8%,respectively,compared with tillage.In conclusion,deep loosening can effectively improve soil nutrient content,optimize soil structure,improve soil enzyme activity and increase crop yield.Under the deep loosening mode,mulching+water retention agent could increase soil moisture retention,reduce nutrient loss,and improve land productivity.Therefore,deep loosening and mulching+water retainer is a suitable local tillage and water retention method.