醋渣生物炭对土壤铬修复及苋菜萌发的影响

Effects of Vinegar Residue Biochar on Chromium Contaminated Soil Remediation and Amaranth Germination

为了缓解重金属铬(Cr)给农田和作物带来的负面影响,将2%醋渣生物炭、2%市售土壤调理剂、基肥(由硫酸钾、磷酸二氢铵和尿素构成,施用量分别为0.05%、0.08%和0.08%)、2%醋渣生物炭+基肥施用于Cr污染的土壤中,对比各处理组对土壤修复及苋菜萌发的作用.结果表明:与对照组(5.12%)相比,醋渣生物炭可降低土壤弱酸可提取态Cr的相对含量(4.19%),但其他处理组会不同程度提升土壤中弱酸可提取态Cr的含量,土壤中弱酸可提取态Cr含量与pH(r=0.74)、脲酶活性(r=0.81)呈正相关,与过氧化氢酶活性呈负相关(r=-0.55).醋渣生物炭可减轻弱酸可提取态Cr对苋菜幼苗的胁迫作用,使苋菜幼苗长势最佳(其干质量是对照组的3.5倍),作用效果优于市售土壤调理剂.该结果为耕地重金属钝化和作物生长研究提供了技术支持.

To alleviate the negative impact of chromium(Cr)on farmland and crops,2%modified vinegar residue biochar,2%commercial modifier,base fertilizer(It is composed of potassium sulfate,ammonium dihydrogen phosphate and urea,with application rates of 0.05%,0.08%and 0.08%respectively.)and 2%vinegar residue biochar+base fertilizer(the same as above)were applied to Cr contaminated soil,and the effects of each treatment group on soil remediation and amaranth germination were compared.The results showed that compared with the control group(5.12%),vinegar residue biochar could reduce the relative content of weak acid extractable Cr in the soil(4.19%),but other treatment groups could increase the content of weak acid extractable Cr.Morcover,the content of weak acid extractable Cr was positively correlated with soil pH(r=0.74),significantly positively correlated with urease activity(r=0.81),and negatively correlated with catalase activity(r=-0.55).The results of amaranth germination experiment showed that vinegar residue biochar could reduce the stress of weak acid extractable Cr on seedlings and lead to the best amaranth,which was better than commercial modifier,and its dry weight was 3.5 times than that of the control group.The results provide technical support for the study of heavy metal passivation and crop growth in cultivated land.