浙江省安全利用类稻田土壤硅含量调查及施硅对水稻的增产降镉效果分析

Investigation of soil silicon content in safe utilization paddy fields in Zhejiang Province and effect of silicon application on increasing rice yield and decreasing cadmium

调查表明,浙江省安全利用类稻田土壤有效硅含量在28~166 mg·kg^(-1),多数稻田属于土壤硅含量中等和缺乏2个等级,缺硅问题较为突出。土壤有效硅平均含量由高至低依次为滨海平原>水网平原>河谷平原,随土壤pH值和黏粒含量的增加而增加。9个硅肥试验的结果表明,基施硅肥对水稻具有明显的增产降镉作用,水稻产量增加4.75%~13.71%,稻谷镉含量降低6.92%~32.73%;叶面喷施硅肥对水稻增产作用不明显,但可使稻谷镉含量降低5.19%~18.18%;基施硅肥的增产降镉作用随土壤本身有效硅降低而增加。研究结果表明,在浙江省土壤有效硅较低的污染稻田中,基施硅肥是一种很好的水稻增产和稻谷降镉措施。

The investigation showed that content of soil available silicon in the safe utilization type of polluted paddy fields in Zhejiang Province was between 28-166 mg·kg~(-1).Most of the paddy fields had medium or low available silicon,and the problem of soil silicon deficiency in the province was more prominent.Average content of soil available silicon decreased in the order of coastal plain>water network plain>valley plain,which increased with the increase of soil pH value and clay content.The results of nine silicon fertilizer experiments showed that application of basal silicon fertilizer had an obvious effect on increasing rice grain yield by 4.75%-13.71%,and reducing cadmium in brown rice by 6.92%-32.73%.Foliar spraying of silicon fertilizer had no obvious effect on rice yield,but could reduce the content of cadmium in brown rice by 5.19%-18.18%.The effect of silicon fertilizer on increasing rice yield and reducing cadmium in brown rice increased with the decrease of soil available silicon.The results showed that basic silicon fertilizer was a good measure to increase rice yield and reduce cadmium in brown rice on polluted paddy fields with low soil available silicon in Zhejiang Province.