生石灰和钙镁磷肥对晚稻生长及稻米镉含量的影响

为研究不同培肥措施对镉污染稻田的修复效果,采用小区试验的方法,研究了生石灰和钙镁磷肥及与化肥、有机肥配施对土壤镉有效性、水稻生长和稻米镉含量的影响。结果表明:施用生石灰、钙镁磷肥可以显著提高土壤pH值,其增幅为10.5%～16.1%,其中耦合石灰、钙镁磷肥和化肥(NPKML)处理增幅最大,达到16.1%,施用生石灰次之、钙镁磷肥增幅最小。有机肥与生石灰、有机肥与化肥和生石灰配施可使土壤有效镉含量降低7.9%～23.5%、使糙米的镉含量降低35.1%～47.5%,其中NPKML对两者的降低效果最佳。施用生石灰、钙镁磷肥等对水稻生长和稻谷品质没有显著影响。研究表明,有机肥、化肥、钙镁磷肥和石灰合理配施,对镉污染稻田修复具有较好的效果。

Effects of quicklime and calcium magnesium phosphate application on late-season rice growth and grain cadmium uptake

The aim of the present study is to evaluate the remediation effect of different fertilization measures on cadmium(Cd) -contaminated paddy fields. The effects of quicklime, calcium magnesium phosphate fertilizer, or their combined application with chemical and organic fertilizers on soil Cd availability, rice growth, and grain Cd content were determined in a field plot experiment. The addition of quicklime and calcium magnesium phosphate fertilizer significantly increased the soil pH by 10.5%~16.1%. In comparison, the combined application of quicklime, calcium magnesium phosphate fertilizer, and chemical fertilizer(NPKML) resulted in a maximum increase of 16.1% in soil pH, followed by quicklime and calcium magnesium phosphate fertilizer. The combined application of organic fertilizer and quicklime along with NPKML significantly decreased the contents of soil available Cd by 7.9%~23.5% and the grain Cd content by 35.1%~47.5%. NPKML showed optimal efficiency in decreasing the soil available Cd and grain Cd content. No significant effect on rice growth and quality was observed after application with quicklime and calcium magnesium phosphate fertilizer. In conclusion, the combined application of organic fertilizer, chemical fertilizer, calcium magnesium phosphate fertilizer, and quicklime is a better immobilizer of Cd in paddy soils.