沼液施用对花生小麦轮作土壤养分和重金属含量的影响

Effects of Biogas Slurry Application on Nutrient and Heavy Metal Content in Soil under Peanut-wheat Rotation

为研究沼液施用对花生远杂6号和小麦中洛08-2轮作作物产量及土壤养分和重金属含量的影响,试验共设置6个沼液处理(22.5(B1)、45.0(B2)、67.5(B3)、90.0(B4)、112.5(B5)t/hm2和不施沼液(B6,对照)),研究不同处理对作物产量、籽粒中重金属含量、土壤养分及其中重金属含量的影响。结果表明,施沼液处理的花生产量比对照均增产,增幅为3.15%~11.27%,施沼液处理的小麦产量比对照均增产,增幅为2.68%~11.53%,其中,B4、B5处理的花生和小麦产量与对照相比均差异极显著;与对照相比,施沼液处理增加了土壤养分含量,土壤有机质、全氮、有效磷、速效钾含量的变幅分别为43.27~55.57 g/kg、0.19%~0.32%、73.60~107.63 mg/kg和200.67~321.33 mg/kg。花生籽仁中均未检测出Hg、Pb、Cr和As;小麦籽粒中均未检测出Hg和As,且Pb、Cd和Cr含量分别为0.023~0.029、0.025~0.042、0.025~0.047 mg/kg,均低于国家标准;不同沼液处理的土壤中Hg、Pb、Cd、Cr和As含量变幅分别为0.045~0.076、22.90~27.60、0.110~0.230、71.80~90.30、11.60~15.20 mg/kg,远低于国家标准。综上,B5(112.5 t/hm2)处理是花生和小麦高产的适宜施沼液量,施用沼液可提高土壤肥力,同时不会造成籽粒(仁)中重金属和土壤重金属含量超标。

In order to reveal the effects of biogas slurry application on yield of crops and nutrient and heavy metal content in soil under peanut Yuanza 6-wheat Zhongluo 08-2 rotation,in this study,field experiments were carried out including six biogas slurry treatments,they were 22.5(B1),45.0(B2),67.5(B3),90.0(B4),112.5(B5)t/ha,and no biogas slurry treatment(CK,B6).The grain yield of crops,the heavy metal content in grains,the soil nutrient and heavy metal content were determined respectively.The results showed that the yield of peanut in the treatments using biogas slurry increased by 3.15%-11.27%compared with that in the control,the yield of wheat in the treatments using biogas slurry increased by 2.68%-11.53%compared with that in the control,the yield of peanut and wheat treated with B4 and B5 had significant difference from that of the control.The addition of biogas slurry increased the soil nutrient content,the contents of soil organic matter,total nitrogen,available phosphorus,and available potassium ranged from 43.27-55.57 g/kg,0.19%-0.32%,73.60-107.63 mg/kg,and 200.67-321.33 mg/kg,respectively.Hg,Pb,Cr,and As were not detected in peanut grains.Hg and As were not detected in wheat grains.The contents of Pb,Cd,and Cr ranged from 0.023-0.029,0.025-0.042,0.025-0.047 mg/kg,respectively,which were lower than The National Food Safety Standard Maximum Levels of Contaminants in foods(GB 2762-2017).The contents of Hg,Pb,Cd,Cr,As in soil treated by different biogas slurry ranged from 0.045-0.076,22.90-27.60,0.110-0.230,71.80-90.30,11.60-15.20 mg/kg,respectively,which were much lower than The Soil Environmental Quality Agricultural Land Soil Pollution Risk Control Standard(Trial)(GB 15618-2018).In conclusion,treatment B5 was the appropriate amount of biogas slurry for high yield of peanut and wheat.Application of biogas slurry could improve the soil fertility,would not cause heavy metal content in both grains and soil to exceed the national standard.