摘要
【目的】研究不同耕作条件下水稻田土壤收缩变化,为防治土壤收缩产生裂隙以及水稻安全生长提供理论依据及指导。【方法】以水稻田为研究对象,在轮作与非轮作条件下,利用van-Genuchten修改方程得到的土壤收缩曲线模型对不同土壤含水量条件下的水稻田原状土壤进行土壤线性伸展系数变化和土壤收缩曲线拟合的研究。【结果】土壤收缩特征曲线拟合值和原状土壤样品实测值拟合度高(R^2>0.97);在轮作条件下,土壤黏粒含量大于非轮作,而土壤孔隙度却与之相反;轮作与非轮作条件下,土壤线性伸展系数都随土层深度的增加而减小,0~8 cm土层和18~26 cm土层土壤收缩曲线呈现"S"型,在40~46 cm土层非轮作区土壤收缩曲线呈现线性关系;不同含水量条件下,土壤收缩能力不同,土壤含水量越大土壤收缩越明显,两者呈正相关关系。【结论】相较于非轮作条件下,轮作可以有效的改善土壤理化性质,调节土壤结构,增强土壤收缩能力。
【Objective】To provide theoretical basis for soil shrinkage cracks and theoretical guidance for the safe growth of rice,the soil shrinkage changes in paddy fields under different tillage conditions were studied.【Method】The paddy fields were studied under the conditions of rotation and non-rotation. Under the different soil moisture contents,the soil shrinkage curve model modified by van-Genuchten equation was used to study the variation of soil linear extension coefficient and the fitting of soil shrinkage curve in paddy fields.【Result】The SSS software could fit the measured data well（ R^2 0. 97）; under the rotation condition,the soil clay content was greater than non-rotation,but soil porosity was opposite; The linear extension coefficient of soil decreased with the increase of soil depth,the soil shrinkage curves in the 0-8 cm soil layer and 18-26 cm soil layer showed‘S＇type in the rotation area,however,it showed a linear relationship in the 40-46 cm soil layer under the non-rotation condition; Under the different soil moisture content,the soil shrinkage ability was different,and the greater the soil moisture content was,the more obvious the soil shrinkage was,and the positive correlation between them.【Conclusion】Compared with the non-rotation,the rotation could effectively improve soil physical and chemical properties,regulate soil structure,and enhance soil shrinkage.
出处
《西南农业学报》
CSCD
北大核心
2018年第2期270-275,共6页
Southwest China Journal of Agricultural Sciences
基金
国家自然科学基金项目(41301289)
广西自然科学基金项目(2014GXNSFBA118098
2016GXNSFAA380197
2017G XNSFBA198102)
广西中青年教师基础能力提升项目(2017KY0270)
桂林理工大学科研启动基金项目(GUTQDJJ2017001)
关键词
轮作与非轮作
土壤收缩
线性伸展
收缩曲线
Rotation and non-rotation
Soil shrinkage
Linear extension
Shrinkage curve
