采用盆栽实验研究了水稻秸秆和玉米秸秆两种生物炭在1%、3%、5%的3种用量下对露天煤矿排土场土壤紫花苜蓿干重、土壤微生物数量和土壤酶活性的影响规律.结果表明,紫花苜蓿的出苗率和干重随着生物炭用量的增加而提高,其中5%用量的水稻秸秆生物炭和玉米秸秆生物炭分别将紫花苜蓿干重显著提高了42.54%和27.63%.3%和5%用量的生物炭显著增加了土壤细菌、真菌、放线菌数量,土壤真菌与细菌数量比值,土壤过氧化氢酶、淀粉酶、蛋白酶、脱氢酶活性,显著降低了土壤磷酸酶活性,显著提高了表征土壤肥力质量的土壤肥力生物指数(BIF)和酶活性指数(EAN),其中5%用量的水稻秸秆生物炭和玉米秸秆生物炭将BIF分别提高了125.94%和84.67%,将EAN分别提高了109.71%和66.93%.两种秸秆生物炭之间比较,在各用量下水稻秸秆生物炭处理的紫花苜蓿出苗率、干重,土壤微生物数量和土壤酶活性均高于玉米秸秆生物炭处理,其中5%用量下,水稻秸秆生物炭处理的出苗率,细菌、真菌、放线菌数量,蛋白酶、脱氢酶活性,BIF、EAN比玉米秸秆生物炭处理显著提高了26.11%、24.71%、30.23%、30.38%、27.37%、24.44%、22.35%、25.63%.综上所述,生物炭能够提高排土场土壤的生态质量,进而增加了紫花苜蓿产量,其中5%用量的水稻秸秆生物炭效果最好.
Effects of rice and corn straw biochar with 1%,3%,5% rate of soil weight on Medicago sativa dry weight,soil microbe number and enzyme activities in opencast coal mine dump were investigated by indoor culture experiments. The results showed that emergence rate and dry weight of Medicago sativa were enhanced with increasing amount of biochar,and application of 5% rice straw biochar and corn straw biochar enhanced the Medicago sativa dry weight by 42. 54% and 27. 63%respectively. Application of 3% and 5% biochar significantly increased the number of soil bacteria,fungi,acitnomycete,ratio of fungi and bacteria number,activities of catalase,amylase,protease,dehydrogenase,decreased phosphatase activity,enhanced biological index of fertility( BIF) and enzyme activities number( EAN) which represented soil fertility quality. Application of 5% rice straw biochar and corn straw biochar enhanced BIF by 125. 94% and 84. 67%,EAN by 109. 71% and66.93% respectively. Emergence rate,dry weight of Medicago sativa,number of soil microbes,activities of soil enzyme under rice straw biochar treatment were all higher than that under corn straw biochar treatment at three rates. Emergence rate of Medicago sativa,number of bacteria,fungi,actinomycete,activities of protease,dehydrogenase,BIF and EAN under rice straw biochar with 5%amount were significantly enhanced by 26. 11%,24. 71%,30. 23%,30. 38%,27. 37%,24. 44%,22.35%,25. 63% compared with that under corn straw biochar. All the analysis showed biochar could ameliorate soil ecological quality of dump and increase Medicago sativa yield. Soil ecological quality of 5% rate of rice straw biochar treatment was the highest.