为了解不同降镉措施对镉轻度污染农田土壤的治理及降低水稻糙米镉含量的效果,为污染农田安全利用提供技术支撑,在浙江省桐庐县江南镇和瑶琳镇各选择镉轻度污染农田开展了不同用量石灰调控pH降低水稻镉积累、施用腐殖质型土壤调理剂+钙镁磷肥降低水稻镉积累、施用等量不同土壤改良剂降低水稻镉积累、石灰与叶面阻控剂配合施用降低水稻镉积累和不同土壤改良剂+叶面阻控剂组合降低水稻镉积累等5个比较试验。结果表明,糙米Cd含量随石灰用量的增加而下降,以中量为宜（300 kg/667 m²）;施用钙镁磷肥的降镉效果优于腐殖质型土壤调理剂;降酸—腐殖质型土壤调理剂和降酸—黏土矿物型土壤调理剂对降低糙米Cd含量均有明显的效果,但其效果略低于石灰或钙镁磷肥;仅喷施叶面阻控剂可降低糙米Cd含量,但糙米Cd含量仍超过食品卫生标准;叶面阻控剂与腐殖质型土壤调理剂、粘土型土壤改良剂、钙镁磷肥与石灰配合施用能有效降低糙米Cd含量,达到安全生产的目的。

In order to understand the effects of different Cd reducing measures on Cd content in brown rice and improving efects on slightly polluted farmland soil by Cd, and provide technical support for safe utilization of the polluted farmlands, selected farmlands with slight Cd pollution in Jiangnan town and Yaolin town of Tonglu county, Zhejiang province, and carried out five comparative experiments in 2020. The experiments included the different lime amounts for reducing Cd in brown rice, the effects of humus soil conditioner + calcium magnesium phosphate fertilizer on Cd in brown rice, different soil amendments on Cd in brown rice, the combination of lime and foliar fertilizer on Cd in brown rice, and the combination of different soil amendments + foliar fertilizer on Cd in brown rice. The results showed that the content of Cd in brown rice decreased with the increase of lime dosage, and the appropriate lime amount was 300 kg/667 m². The effect of applying calcium magnesium phosphate fertilizer on reduction of Cd in brown rice was better than that of humus soil conditioner. Both acid-reducing humus soil conditioner and acid-reducing clay mineral soil conditioner had obvious effect on reducing Cd content in brown rice, but the effect was slightly lower than that of lime or calcium magnesium phosphate fertilizer. Spraying foliar fertilizer could reduce the content of Cd in brown rice, but Cd content in brown rice still exceeded the food hygiene standard. Combined application of foliar fertilizer with humus soil conditioner, clay soil conditioner, calcium magnesium phosphate fertilizer or lime could effectively reduce the Cd content of brown rice and achieve the purpose of food safe production.