氮肥形态对污泥农用土壤中重金属活性及玉米对其吸收的影响

Effects of forms of nitrogen fertilizer on the bioavailability of heavy metals i n the soils amended with biosolids and their uptake by corn plant

采用根箱试验,研究了不同形态氮肥对污泥处理的根-土界面氮素转化、pH、重金属活性以及植物吸收重金属的影响.结果表明,铵态氮肥能降低根际土壤的pH,提高根际土壤中的重金属活性,促进玉米对重金属的吸收;而硝态氮的作用刚好相反.因此,氮肥形态的选择供应可作为控制作物对重金属吸收的一种措施.

Rhizobox experiments were carried out to study the effects of the application of different forms of nitrogen fertilizer on nitrogen transformation, soil pH and heavy metals bioavailability in the rhizosphere soil amended with biosolids, as well as the uptake of heavy metals by plant. The results obtained from experiments showed that application of NH4^＋-N decreased pH of rhizosphere soil, increased bioavailability of heavy metals and resulted in a more active uptake of heavy metals by corn plant, whereas the effect of NO3 - -N was just opposite to that of NH4^＋-N. Therefore, selection of the forms of nitrogen applied may be considered as an effective measure of controlling uptake of heavy metals by crops.