The Effects Of Different Fertilization On Cadmium Accumulation And Transference In Soil

Cadmium is a highly toxic element.Excessive cadmium in soil will not only affect agricultural safety,but also pose a great threat to people's health.Fertilization is an important means to increase soil nutrients and produce.But imprope fertilization will worsen soil quality because fertilizers contain cadmium inevitably.In order to study the effect of different fertilization on cadmium accumulation,speciation,transport in soil and be absorbed by corn,six long-term location fertilization soils were selected to determined the cadmium content in different soil layers and corn,analyzed cadmium speciation,and calculated Bioconcentration factor and Transport factor of cadmium.The results show that:1.Fertilizers increased cadmium accumulation in soil significantly;manure had little effect on cadmium accumulation in soil;manure combined with fertilizers reduced cadmium accumulation in 20-40 cm soil layer,but increased in 0-20 cm and 40-60 cm soil layer.2.The resid-cadmium in a main position in soil.Fertilizers increased the FDC of ex-cadmium and resid-cadmium in soil;manure increased the FDC of Fe-MnO-cadmium and OM-cadmium in soil;manure combined with fertilizers had little effect on speciation.The speciation was influenced by pH,CEC,and organic matter content in soil.3.Manure had little effect on cadmium vertical transference;fertilizers conducived to the cadmium vertical transference,and manure combined with fertilizers obstructed cadmium transference.4.Fertilizers increased cadmium concent in corn significantly;manure in low-lever had little effect on cadmium concent in corn,but manure in high-lever had the risk of increase cadmium concent in corn.5.Fertilizers enhanced the absorption of cadmium by corn roots,stems,and leaves.Manure reduced the absorption of cadmium by corn stems,leaves,and grains.Long-term different fertilization weakened the ability of cadmium transport,and the effect of fertilizers was more obvious.There is a significant positive correlation between the transport of cadmium and CEC of the top soil layer.