秸秆深还对土壤理化性质以及根区土壤养分空间分布的影响

发布时间：2018-04-17 18:07

本文选题：秸秆深还 + 土壤物理性质　；参考：《吉林农业大学》2017年硕士论文

【摘要】：秸秆深还对改善土壤结构,提升土壤有机质,增加根区养分储量,促进作物根系发育和增加作物产量具有重要意义。探究秸秆深还对土壤理化性质和根系养分空间变异的影响机制,旨在了解秸秆深还养分运移机理和空间分布规律,为合理利用秸秆资源实践提供理论支撑。本文通过小区试验和大田试验,设CK(对照)、CS1(秸秆浅施)、CS2(秸秆深还CSDI)、TF(传统耕作)、SNT(留茬免耕)、CS(秸秆深还)6种处理。建立根区土壤立体模型和坐标系,采用三维空间取样的方法研究了在垂直方向和水平方向上黑土耕层根区速效N、P、K养分的空间分布。结果表明:(1)秸秆还田后土壤紧实度和容重降低,土壤含水量、持水量和孔隙度增加;秸秆深还较秸秆浅施、传统耕作和留茬免耕相比对土壤物理性质改善作用更明显。(2)秸秆还田后土壤和腐殖质各组分有机碳含量、HA的ΔlgK值增加,秸秆深还较秸秆浅施相比增加效果更显著。(3)垂直分布上,秸秆深还对表层土壤速效N、P、K的含量影响不大,对深层土壤(10~25cm)具有明显的增加作用,且增加幅度随着深度的增加而增加。水平分布上,距离玉米主根越近,秸秆深还对养分的增加作用越明显。(4)垂直分布上,秸秆深还对表层土壤含水率影响不大,对深层土壤(10~25cm)具有明显的增加作用,且增加幅度随着深度的增加而增加;水平分布上,距离玉米主根越近,秸秆深还对含水量的增加作用越明显。(5)垂直方向上,根区土壤有机碳含量随剖面深度(0~25cm)增加而减小,随与主根距离减小而减少,秸秆深还处理的变化幅度较对照处理更明显;在水平分布上,随距离主根越近,有机碳含量越低,秸秆深还处理降低的幅度加大。垂直方向上,秸秆深还对表层土壤有机碳含量影响不大,对深层土壤(10~25cm)具有明显的增加作用。水平方向上,距离玉米主根越近,秸秆深还对有机碳的减少作用越明显。(6)在垂直分布上,根区根系的生长随剖面深度增加而增加,秸秆深还对表层根系的生长影响不大,在15~20cm土层达到最大;在水平分布上,随距离主根距离的减小而增加。距离玉米主根越近,秸秆深还对作物根系生长的改善作用越明显。(7)用三维立体取样研究根区土壤养分分布是可行的,研究结果为秸秆深还养分运移机理和空间分布提供理论依据,也为进行秸秆深还实践提供支撑。
[Abstract]:Straw depth also plays an important role in improving soil structure, enhancing soil organic matter, increasing nutrient storage in root region, promoting crop root development and increasing crop yield.The purpose of this study was to understand the mechanism and spatial distribution of straws' nutrient transfer, and to provide theoretical support for the practice of rational utilization of straw resources.In this paper, through plot experiment and field experiment, six kinds of treatments were set up, namely CK (control) CS1 (control straw application) CS2 (straw depth and CSDIN) TF( traditional tillage) SNTs (stubble no-tillage) CSS (straw depth was also added to CS2).Three dimensional spatial sampling method was used to study the spatial distribution of available N ~ (2 +) P ~ (1 +) K nutrients in the root zone of black soil in vertical and horizontal directions.The results showed that the soil compactness and bulk density decreased, the soil moisture content, water holding capacity and porosity increased, and the straw depth was applied to the surface of the straw.The effect of traditional tillage and stubble no-tillage on the improvement of soil physical properties was more obvious. (2) the 螖 lgK value of soil and humus organic carbon content and HA in soil and humus components were increased after straw was returned to the field, and the effect of straw depth was more significant than that of straw shallow application.The straw depth also had little effect on the content of available N ~ (2 +) P ~ (+) K in the surface soil, but obviously increased the content of 10 ~ 10 ~ (25 cm) N ~ (2 +) in the deep soil, and the increasing range increased with the increase of the depth.In the horizontal distribution, the closer to the main root of maize, the more obvious the effect of straw depth on the increase of nutrient.) the vertical distribution of straw depth also had little effect on the surface soil moisture content, but had obvious increasing effect on the deep soil layer of 1010 ~ 25 cm).In horizontal distribution, the more close to the main root of maize, the more obvious the effect of straw depth on water content increased in vertical direction, and the soil organic carbon content in root zone decreased with the increase of profile depth (0 ~ 25 cm).With the decrease of the distance to the main root, the range of the change of the straw depth was more obvious than that of the control treatment; in the horizontal distribution, the lower the organic carbon content was, the lower the organic carbon content was, and the greater the decrease of the straw depth was in the horizontal distribution.In the vertical direction, the straw depth had little effect on the organic carbon content in the topsoil, but it could obviously increase the organic carbon content in the deep soil (10 ~ 25 cm).In the horizontal direction, the closer to the main roots of maize, the more obvious the effect of straw depth on the reduction of organic carbon.) in the vertical distribution, the root growth of root zone increased with the depth of the profile, and the growth of the surface root system was not affected by the straw depth.In the 15~20cm soil layer, the maximum is reached, and the horizontal distribution increases with the decrease of the distance from the main root.The closer it is to the main roots of maize, the better the effect of straw depth on the growth of crop roots is.) it is feasible to study the distribution of soil nutrients in root zone by three-dimensional sampling.The results provide a theoretical basis for the mechanism and spatial distribution of nutrient transport in straw depth, and also provide support for the practice of straw depth.
【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S158;S153

【参考文献】