重庆市食用菌菌渣养分与重金属含量分析

Nutrient and heavy metal contents in edible fungus residues in Chongqing

【目的】分析不同食用菌品类菌渣的养分和重金属含量状况,为菌渣资源的安全高效利用提供依据。【方法】对重庆9个区县的84户食用菌种植户进行调研和菌渣取样,分析了食用菌菌渣有机碳(C)、氮(N)、磷(P)、钾(K)、钙(Ca)、镁(Mg)和重金属砷(As)、镉(Cd)、铬(Cr)、铜(Cu)、汞(Hg)、铅(Pb)、锌(Zn)含量。【结果】1)食用菌菌渣中C、N、P、K、Ca、Mg的平均含量分别为354、13.9、3.48、8.93、35.0、7.07 g/kg,且C/N值均较高,平均为22.9~42.2;菌渣中K/Mg和Ca/Mg值分别为1.36和5.70,K/Mg值显著高于0.6(黑木耳和香菇菌渣除外),Ca/Mg值均低于7.0。2)食用菌菌渣中As、Cd、Cr、Cu、Hg、Pb、Zn的平均含量分别为0.69、0.30、1.54、12.5、0.07、4.36、55.8 mg/kg,变异系数为46.9%~179%,含量差异较大;依据我国NY 525—2021有机肥中重金属限量标准,84个菌渣样品中Cd的超标率为1.19%,而其他重金属含量均处于标准限值内。【结论】重庆食用菌菌渣的重金属A s、C d、C r、H g、Pb平均含量分别为N Y 525—2021中有机肥相应重金属限值的1.03%~10.0%,生态安全性高。重庆食用菌菌渣总养分含量(N+P_(2)O_(5)+K_(2)O)不高,但有机质含量(61.0%)丰富,适宜作为畜禽粪便堆肥辅料。

【Objectives】The nutrient and heavy metal concentrations in the residual substrate of edible fungus production were investigated for their safety and efficient recycling as organic material resources.【Methods】The residual substrate samples were collected from 84 producers across nine districts of Chongqing City for the determination of the concentrations of organic carbon(C),total N,P,K,Ca,Mg,and heavy metals(As,Cd,Cr,Cu,Hg,Pb,and Zn).【Results】1)The concentrations of C,N,P,K,Ca,and Mg in the residual substrates were 354,13.9,3.48,8.93,35.0,and 7.07 g/kg,respectively.The C/N ratios of the residue substrates were generally high(22.9-42.2),and the K/Mg and Ca/Mg ratios were 1.36 and 5.70,respectively.The K/Mg ratio was markedly greater than 0.6(except for black fungus and mushroom residues),whereas the Ca/Mg ratio was less than 7.0.2)The average concentrations of As,Cd,Cr,Cu,Hg,Pb,and Zn in the residual substrates were 0.69,0.30,1.54,12.5,0.07,4.36,and 55.8 mg/kg,respectively,with high variations(CV 46.9%-179%).According to the NY 525—2021 standard for heavy metals limits in organic fertilizers in China,all the heavy metal concentrations were within the permissible limits.【Conclusions】In the residual substrate of edible fungus produced in Chongqing,the average content of heavy metals As,Cd,Cr,Hg and Pb were only 1.03%-10.0%of the threshold value in the national standard for organic fertilizer,which indicated a high ecological security.Although not rich in N,P_(2)O_(5),K_(2)O,edible fungus residue has high organic matter content(61.0%)which makes it suitable as an auxiliary material for livestock manure co-composting.