猪粪发酵沼液沼渣在豇豆种植中的应用及重金属积累研究

Effects of Biogas Residues on Yield and Quality of Cowpea and Heavy Metal Accumulation in Soil

针对种养一体规模化循环农业园区，以豇豆为材料，研究了猪粪、沼渣为底肥和不同浓度沼液灌溉对豇豆品质、豇豆可食部分和土壤重金属积累的影响。结果表明：与清水灌溉对照相比，各处理豇豆可溶性糖和可溶性蛋白含量比对照显著增加；粗纤维含量比对照显著降低；硝酸盐含量增加，但未超标。当沼液浓度较大时，豇豆可食用部分重金属含量比对照略有增加，但低于国家标准（GB2762-2012）规定的含量；收获后土壤中Cu、As含量比种植前有所增加，增幅分别为1．5％～8．3％和2．2％～15．4％；Zn、Pb、Hg、Cd、Cr含量较种植前有所下降，其中Hg含量降幅最大，为11．1％～25．0％，其次为Cd含量，降幅为0～17．6％。收获后各处理土壤重金属含量都在国家标准（GB15618-2008）规定的土壤一级重金属含量阈值范围内。

A field experiment was carried out to study the effects of the biogas residues on the yield and quality of cowpea and heavy metal accumulation in soil. The results showed the yield of each treatment was higher than that of control（CK）. After harvest, the soluble sugar and soluble protein content of different treatments increased signifi cantly than that of CK, and the crude fiber content reduced significantly, and the nitrate content of different treat- ments was higher than that of CK, but within the range of the National Standards. The heavy metal in the edible cow- pea was a little higher than that of CK, but was lower than the value of the National Standards. The content of Cu and As in the soil after harvest increased 1.5% -8.3% and 2.2% -15.4%, respectively,compared with that of before planting. While the content of Zn, Pb, Hg, Cd and Cr decreased, and the content of Hg decreased 11.1% - 25.0% compared with that of before planting, and the content of Cd decreased 0 - 17.6%. But the content of all the heavy metal were within the range of the National Standards of the soil. In production, some research should be carried outaceording to the different types of soil, different crops and the safe threshold value of heavy metal in soil under the recycling agriculture.