【作者】 张瑜；

【导师】 冯绍元； 王娟；

【作者基本信息】 扬州大学 ， 农业水土工程， 2019， 硕士

【摘要】 随着城市化和工业化进程的加速,我国耕地面积表现为净减少的趋势。在中国正式提出实施生态文明建设和耕地面积基本稳定的背景下,土地复垦便成为增加可利用耕地面积的重要措施之一。但是,新复垦的耕地往往存在耕层浅薄,结构性差,保水保肥能力低等问题,导致其生产能力较低。基于此,本研究依托扬州大学农水与水文水生态试验基地进行田间试验,设置了传统耕作(CK)、地膜覆盖(FM)、秸秆深埋(BS)、秸秆深埋结合地膜覆盖(F+S)4种试验处理,研究了不同覆盖耕作方式对土壤水分、温度、养分及春玉米生长的影响,探讨了秸秆深埋及其覆膜栽培技术改土培肥、提高玉米产量的效果,以期为新复垦区土地资源的合理开发与高效利用提供理论依据。得到的主要结论如下:(1)试验条件下,不同覆盖耕作处理农田土壤水分分布具有明显的分层现象,春玉米生育期内各处理土壤含水量总体表现为随土层深度的增加而升高。0-40cm 土层土壤含水量变化幅度较大,60-100cm 土层土壤含水量变化幅度相对较小。地膜覆盖能够减少土壤水分蒸发,提高作物根层土壤含水量;秸秆深埋能够有效拦截、蓄存降雨,提高秸秆层及其附近土层含水量;秸秆深埋结合地膜覆盖可综合发挥地膜覆盖抑蒸保墒和秸秆深埋对水分的有效截留作用,有效调控、优化土壤水分分布,具有良好的蓄水、保墒效果,可为玉米生长提供充足的水分保障。不同处理土壤蓄水量的变化主要集中在0-40cm 土层,尤其是0-20cm表土层土壤蓄水量的变化最为明显。2017年和2018年各处理春玉米收获前后0-100cm 土层土壤蓄水量的变化值由高到低分别为:CK>BS>F+S>FM、CK>FM>F+S>BS。(2)试验条件下,与CK、BS处理相比,FM、F+S处理均有显著的增温效果,且苗期-抽雄初期的增温幅度高于抽雄初期-收获期。春玉米全生育期秸秆深埋与覆膜在提升土壤温度方面存在一定的累积效应。秸秆深埋对地膜覆盖的热量传递强度存在一定的影响。(3)试验条件下,土壤剖面有机质、碱解氮分布具有明显的分层现象,040cm土层有机质、碱解氮含量较高,40-100cm 土层有机质、碱解氮含量较低,并且受覆盖耕作方式的影响表现出较为明显的差异。秸秆深埋结合地膜覆盖与秸秆深埋能够提高0-40cm 土层土壤有机质、碱解氮含量,有效改善作物生长的土壤养分环境。(4)试验条件下,各覆盖耕作均能促进玉米生长与产量提高。各处理春玉米全生育期株高和叶面积指数变化规律一致,均表现为F+S>FM>BS>CK。F+S处理的增产效果最好,2017年F+S、BS和FM处理的产量分别比CK增加了15.9%、10.5%、5.6%;2018年F+S、BS和FM处理的产量分别比CK增加了 17.0%、6.6%、13.5%。综上所述,秸秆深埋与地膜覆盖相结合方式在改善土壤环境、增加土壤有机质含量及促进作物生长和提高产量方面效果较好,是研究区较为适宜的覆盖耕作方式。更多还原

【Abstract】 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.更多还原