碱性肥料对稻田土壤和稻米镉含量的影响

以碱性复合肥为材料,在湖南郴州松柏村进行大田小区试验,研究了碱性复合肥及其与微生物菌剂配合施用对稻田土壤和稻米镉含量的影响.结果表明: 水稻分蘖期、灌浆期和收获期碱性肥料处理的土壤有效镉含量较常规肥料处理分别降低8.3%、6.7%和16.4%.收获期碱性肥料处理土壤有效镉含量较插秧前降低了7.2%,而常规肥料处理却增加了11.0%.配施微生物菌剂使土壤有效镉增加了1.2%～23.3%.与常规肥料处理相比,碱性肥料处理根系、茎鞘、叶片、籽粒、稻米镉含量显著降低,分别降低了54.9%、56.6%、41.8%、62.7%、67.6%.与微生物菌剂配施时,碱性肥料处理稻米镉含量却增加63.2%.表明施用碱性肥料可显著降低土壤中镉的有效性及水稻各器官和稻米镉含量,而碱性肥料与微生物菌剂配施则削弱了其对稻米镉含量的降低效果.

Effects of alkaline fertilizer on cadmium content in rice and paddy soil

A field plot trial was conducted at Songbai Village, Chenzhou, Hunan Province to exa-mine the effects of alkaline fertilizer with and without combination application of bacterial regent on cadmium accumulation in rice and paddy soil. Compared with the conventional fertilizer, the alkaline fertilizer reduced the available cadmium content in soil at the tillering, filling and the harvest stages by 8.3%, 6.7% and 16.4% respectively. Compared with the Cd content in soil before transplanting, it was reduced by 7.2% at harvest time in alkaline fertilizer treatment, while increased by 11.0% in the conventional fertilizer treatment. The available cadmium content in soil was increased by 1.2% to 23.3% by bacterial regent. Compared with the conventional fertilizer, the cadmium content of root, stem sheath, leaf, grain and brown rice of the alkaline fertilizer treatment reduced by 54.9%, 56.6%, 41.8%, 62.7% and 67.6% respectively. The alkaline fertilizer treatment combined with bacterial regent increased the cadmium content of brown rice by 63.2%. It was concluded that the alkaline fertilizer could significantly reduce the available cadmium content in both soil and the different organs of the rice, however, when it was combined with bacterial regent together, the effect of alkaline fertilizer to reduce Cd content of brown rice would be declined.