大豆重迎茬减产的原因及农艺对策研究Ⅴ.重迎茬大豆的水分问题

通过连续8年在全省5个生态区9个9区固定轮作场圃综合试验,试验区专项研究,框区、盆栽试验,实验室分析,以及大量的大面积生产调查,发现大豆重迎茬种植,土壤水分有一些不利的变化,但其程度低于重茬玉米、重茬小麦,某些时期重茬大豆耕层土壤的水分含量还会高于正茬轮作.这说明土壤水分没有明显恶化,不是造成大豆重迎茬减产的一个重要原因.

STUDY ON THE REASON REDUCING PRODUCTION OF SOYBEAN PLANTED CONTINUOUSLY AND THE WAY TO GET MORE OUTPUT Ⅴ.Water of Soil Planted Soybeans Continuously and Alternately

Aseries of experiments had been carried out by 8 years in 9 rotation nurses with 9 plots in 5 ecological regions of Heilongjiang Province since 1993. In the same time, the investigation was made in soybean fields. The results showed that,when soybean was planted continuously, the soil water would become adverse somewhere. But it was not severity too much, and the degree was some lower than that of corn and wheat planted continuously. The amount of soil water in continuous cropping soybeans was higher than that in normal rotation also. All of this showed that when soybeans were planted continuously, the soil water didn't become poor distinctively. It would not effect on growing and developing of soybeans significatively, and was not one of the important reasons to reduce output of soybeans planted continuously and alternately.