连续施用鸡粪对菜心产量和重金属含量的影响

由于养殖业普遍使用微量元素添加剂,导致禽畜粪中重金属残留过高现象广泛存在.根据养殖场鸡粪含氮量计算其用量（N 0～450 kg·hm^-2）,进行连续4茬菜心施用鸡粪田间实验,探讨对菜心产量及重金属含量的影响.结果表明,第1、3茬所有施用鸡粪处理菜心产量比单施无机肥处理降低,第2茬则提高,第4茬鸡粪与无机肥配施处理提高了菜心产量.不同茬别菜心产量差别较大,第2茬显著高于其它茬别.从不同处理4茬菜心重金属平均含量来看,施用鸡粪可提高As、Zn含量,降低Cr、Cd含量,对Pb含量无明显影响,配施鸡粪提高Cu含量.除第2茬因产量稀释作用影响外,不同茬别所有处理菜心As、Pb、Cr、Cu、Zn平均含量随施用茬数增加而提高,Cd平均含量则下降.建议在无公害或绿色食品生产中避免一次性大量施用或连续施用养殖场禽畜粪.

Yield and Heavy Metal Content of Brassica parachinensis Influenced by Successive Application of Chicken Manure

High heavy metal content in animal manures commonly occurs in the world since microelement additives are widely used in intensive animal production. Successive field trials in Brassica parachinensis (BP) were conducted to investigate the influence of successive application of chicken manure (at the rate of) on the yield and heavy metal content of BP. The application rate of chicken manure was calculated by its N content and ranged from N 0-450 kg x hm(-2). The results indicate that compared to single application of inorganic fertilizers, chicken manure decreases the yield of BP in the first and the third crop, increases that in the second crop. Combinations of chicken manure and inorganic fertilizers increase the yield in the fourth yield. Mean yields of all treatments in various crops are greatly different. The second crop is significantly higher than all other crops. In terms of mean heavy metal contents of BP of four crops in various treatment, As and Zn contents increase with applying chicken manure, Cr and Cd contents decrease, Pb contents don't change considerably, and Cu contents increase with applying chicken manure and inorganic fertilizers together. Generally, except for the second crop, mean As, Pb, Cr, Cu and Zn contents of BP in various crops increase with the increasing application times of chicken manure, mean Cd contents decrease. Hence, mass application for one crop or repeated application of chicken manure should be avoided in crop production.