Effect Of Different Mulching Tillage Methods On Soil Environment And Growth Of Spring Maize

With the rapid development of urbanization and industrialization,the area of cultivated land has been threatened and showed net decrease tendency.Under the background of the implementation of ecological civilization construction and the basic stability of cultivated land was formally put forward by the Chinese government,land reclamation has become one of the important measures to ensure the available cultivated land area.However,the new reclaimed land has much problems as shallow topsoil,poor structure as well as low in water and fertilizer conservation capacity,which leads to unsatisfied productivity.Based on this,field experiments were carried out at the agricultural water and hydrology experimental site of Yangzhou University with four treatments as traditional tillage(CK),plastic film mulching(FM),straw burying(BS),straw burying covered with plastic mulching(F+S).The effects of different mulching tillage methods on soil moisture,temperature,nutrients as well as spring maize growth were studied,and the effect of straw burying and mulching technology on improving soil fertility and spring maize yield were discussed,thereby supplying theoretical basis for land productivity improvement and sustainable development of agriculture in new reclaimed farmland.T he main conclusions obtained are as follows:(1)Under the experimental conditions,the soil water distribution under different treatments showed obvious stratification,and the soil water content of each treatment increased with the increase of soil depth during the growth of spring maize.The variation of soil water content was larger at 0-40 cm depth than that at 60-100 cm depth.The plastic film mulching can reduce the evaporation of soil moisture and improve the soil water content at crop root layer;the straw burying can effectively intercept and store rainfall to increase soil water content in straw layer and its surrounding soil.The straw burying covered with plastic film mulching played a comprehensively role as steaming suppression,moisture conservation and water retention,thereby effectively regulating and optimizing the soil moisture distribution,and providing sufficient moisture protection for the growth of maize.The varations of soil water storage were mainly showed at 0-40 cm depth,especially at topsoil(0-20 cm).The variation of soil water storage in 0-100 cm depth before and after spring maize harvest was in the order of CK>BS>F+S>FM in 2017,CK>FM>F+S>BS in 2018,respectively.(2)Under the experimental conditions,Compared to CK and BS treatment,FM and F+S treatment had significant warming effects,and the temperature variation was obvious at seedling-early male-setting stage than that at male-setting stage-harvest stage.There was a cumulative effect of straw burying and plastic film mulching on soil temperature during the whole growth stage of spring maize.Straw burying will affect the heat transfer intensity under plastic film mulching.(3)Under the experimental conditions,the distribution of soil organic matter and available nitrogen in the soil profile showed obvious stratification.The content of organic matter and available nitrogen in the 0-40cm soil was relatively high,while that in the 40-100cm soil was relatively low.Moreover,there was a significant difference under the influence mulching tillage.Straw burying covered with plastic film mulching and straw burying increased the organic matter and available nitrogen at the depth of 0-40 cm,thereby providing better nutrient conditions for crop growth.(4)Under the experimental conditions,the yield of maize was enhanced under all mulching and tillage treatments.The changes of plant height and leaf area index of Spring Maize under all treatments showed a similar tendency of F+S>FM>BS>CK.Compared to CK,the yield of F+S,BS and FM treatment increased by 15.9%,10.5%,5.6%in 2017,and 17.0%,6.6%,13.5%in 2018,respectively.Comprehensively,straw burying covered with plastic film mulching has a satisfying effect in improving soil hydrothermal environment,increasing soil organic matter content as well as promoting crop growh and yield,therefore,can be considered as an appropriate mulching tillage method in the study area.