秸秆深还对黑土耕层根区养分空间分布的影响

Effects of Corn Stover Deep Incorporation on Spatial Distribution of Nutrients in Root Zone of Black Soil

针对秸秆深还对黑土养分空间变异影响机理不清的问题,在吉林省榆树市恩育乡黑土耕地进行了秸秆深还试验,设对照(ck)、秸秆深还(CS) 2种处理。建立根区土壤立体模型和坐标系,采用三维立体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:垂直方向上,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(10～25 cm)具有明显的增加作用,且增加幅度随着深度的增加而增加;水平方向上,距离玉米主根越近,秸秆深还对养分的增加作用越明显。这说明用三维立体取样来研究根区土壤养分的分布是可行的,研究结果可为秸秆深还养分运移机理和空间分布及秸秆深还实践提供理论依据。

In view of the unclear mechanism of the effects of corn stover deep incorporation（ CSDI）on spatial variation of black soil nutrients,CSDI tests were carried out on the black soil cultivated land in Enyu town,Yushu city of Jilin province,and two treatments,ck（ control） and CS（ CSDI）,were designed. The spatial distribution of available N,P and K nutrients in the root zone of black soil in vertical direction and horizontal direction was studied by using three-dimensional sampling method. The results show that in the vertical direction,CSDI had little effect on the content of available N,P and K in the surface soil,but a significant effect on deep soil（ 10-25 cm）,and the increase rate increased with depth. In the horizontal direction,the closer was CSDI to the main root of corn,the more obvious was the effect of CSDI on the increase of nutrients,indicating that it is feasible to study soil nutrient distribution in root zone by using three-dimensional sampling method.The results not only provide a theoretical basis for the mechanism of nutrient transport and spatialdistribution of CSDI,but also support for the practice of CSDI.