连续施用养殖场鸡、鸽粪对土壤养分和重金属含量的影响

按照养殖场鸡粪和鸽粪含氮量计算其用量，进行连续6茬施用鸡粪和鸽粪（N 0～450 kg·hm^-2）菜心田间试验，研究对土壤养分和重金属含量的影响.结果表明，连续施用3茬鸡粪和鸽粪后，土壤铵态氮、硝态氮、有效磷及速效钾含量均明显提高，4种养分累积量随鸡、鸽粪用量增加而提高.由于后3茬遭遇较长时间强降雨，施用6茬后土壤硝态氮和速效钾含量不但比第3茬后有明显下降，甚至低于土壤原始含量，但铵态氮和有效磷含量仍比原始含量提高，而且含量增量随鸡、鸽粪用量增加而提高.鸡粪和鸽粪Pb、Cd、Cr含量及鸽粪As含量很低，连续施用6茬对土壤总Pb、总Cd、总Cr及总As含量影响不大，但2种粪肥Zn含量较高（分别为172.0、299.8 　mg·kg^-1），施用6茬后土壤总Zn含量提高0.7～17.1 　mg·kg^-1.同时，鸡粪Cu（117.7 　mg·kg^-1）、As（39.6 　mg·kg^-1）含量相对较高，施用6茬后土壤总Cu、总As含量也有累积趋势.

Effect of Continuous Application of Chicken and Pigeon Manure from Poultry Farms on Concentrations of Soil Nutrients and Heavy Metals

Animal manures of intensive livestock farms are composed of complex materials. Effect of continuous application of chicken manure (CM) and pigeon manure (PM) for six cropping on soil nutrients and heavy metals was investigated in a vegetable soil in Guangzhou south China. Application rates (N 0~450 kg.ha-1) of CM and PM were calculated considering their N contents. The results indicate that concentrations of soil ammonium N, nitrate N and phosphorous extracted with sodium bicarbonate (P-NaHCO3), potassium extracted with ammonium acetate (K-C2H3O2NH4) increase considerably after continuous application of CM and PM for three cropping. Moreover, their concentration increments go up with the rates of CM and PM. Concentrations of soil nitrate N and K-C2H3O2NH4 after the sixth cropping reduce compared to those after the third cropping, and also decrease compared to their original ones due to the heavy rainfall during the three latter cropping. However, concentrations of soil ammonium N and P-NaHCO3 are still higher than their original ones, and their concentration increments increase with the rates of CM and PM, respectively. Two manures contain low Pb, Cd, Cr and pigeon manure contains low As, there is no great influence on soil Pb, Cd, Cr and As by continuous application. Two manures contain higher Zn (172.0 and 299.8 mg.kg-1, respectively), leading to soil Zn concentration increments from 0.7 to 17.1 mg.kg-1 after the sixth cropping. Meanwhile, CM has relatively high Cu (117.7 mg.kg-1) and As (39.6 mg.kg-1), indicating the trend to accumulate Cu and Zn in soil after the sixth cropping.