盐渍化灌区秸秆深埋控盐条件下水肥药耦合调控机制研究

In the process of agricultural production,Soil pollution environment system has seriously affect the agricultural products quality、ecological environment security and other issues, beyond the scope of environmental capacity . Be aimed at the problem of soil salinizationhe in Inner Mongolia hetao irrigation area、farmland as the core of the agricultural non-point source pollution and the policy to cut of the Yellow River water.This research use straw embedded technology dividing farmland vadose zone into the ground-straw barrier-three interface phreatic aquifer system,to conduct resistance of salt-water-control medicine joint control test,reasonable adjustment of water, salt, fertilizer, medicine distribution in time and space,reveal that increase crop straw interlayer water use of multi-factor multi-channel coordinated regulatory mechanism,analysis the migration of salt and nitrogen at the interface of farmland system, reveal the regularity of the straw interlayer on the release of base ions, exchange, cushioning effect and nitrogen absorption, transport, balance ,to explore the pesticide residues in soil, dispelling effect and on the interface of farmland transfer, exchange, circulation pattern. Building water, salt, fertilizer, medicine coupling model based on the condition of straw buried deep.Revealling the plant physiological, morphological indexes and soil ecological environment factors on the response mechanism of straw buried.Put forward a resistance salt-water-accused of medicine mode that is suitable for salinization straw buried deep shallow buried area ,it has important practical significance to maintain the ecological health of farmland .

在农业生产过程中，土壤环境系统污染已经严重影响农产品质量、生态环境安全等问题，超出了环境容量所承受的范围。针对内蒙古河套灌区土壤盐渍化、以农田为核心的农业面源污染及引黄水量的政策性削减等问题，本研究利用秸秆深埋技术将农田非饱和带分隔成地面-秸秆隔层-潜水层三界面系统，进行阻盐-调水肥-控药联合调控试验，合理调节水、盐、肥、药在时空上的分布，揭示秸秆隔层对提高作物水分利用的多因素多途径协同调控机制；分析盐分、氮素等在农田界面系统的迁移转化，揭示秸秆隔层对农田盐基离子的释放、交换、缓冲效应及氮素吸收、转运、平衡规律；探究农药在土壤中的残留、消解效应及在农田界面上的迁移、交换、循环规律；构建基于秸秆深埋条件下的水、盐、肥、药耦合模型，揭示植物生理、形态指标及土壤生态环境因子对秸杆深埋的响应机理；提出适合盐渍化浅埋区的秸秆深埋阻盐-调水肥-控药模式，对于维持农田生态健康具有重要的现实意义。

内蒙古河套灌区引黄水锐减导致土壤盐渍化、农业面源污染等问题突出，影响着农业生态环境安全。本研究以优化秸秆深埋下水肥调控为切入点，进行抑盐-调水肥-降药的联合调控试验。以内蒙河套灌区永济灌区双河镇农业示范区为研究区，开展田间试验与数值模拟相结合，优化了秸秆深埋的水肥耕作制度，并基于深度学习理论及技术，建立了秸秆深埋下水盐运移模型。研究论证了秸秆深埋与深翻耕作措施能够提高大于40 cm土层的根长密度，形成“深窄”型根系，利于夏玉米吸收水分养分，提高水分利用效率，显著提高夏玉米产量及产量相关的其他指标；秸秆深埋配施适量水肥（单次灌水量85~102mm，施氮量180 kg/hm2）能够改善水、肥时空分布，秸秆隔层能够有效拦截氮素迁移，减少氮素往深层土壤淋失，降低地下水质氮素污染；同时能够有效促进土壤莠去津的消解，显著缩短莠去津降解半衰期，减少莠去津在土壤中的累积，减少莠去津的分布；秸秆隔层在适量灌水量下，改善水盐时空分布，有效抑制深层土壤返盐，缓解土壤水分蒸发，淡化夏玉米根系环境，改良土壤盐渍化。研究取得的成果旨在丰富秸秆深埋技术与理论体系，为河套灌区盐渍土改良和秸秆资源化利用提供科学依据，同时为深度学习理论及技术在农业水土工程模型的建立与应用等方面奠定基础。