垦殖与自然恢复黑土土壤微生物量碳和土壤酶活性的季节性变化

对比研究中国科学院海伦农业生态实验站长期定位试验区中黑土自然恢复（NR）及垦殖中不施肥（NoF）、施化肥（CF）和化肥配施有机肥（CF＋M）处理下的土壤微生物量碳和土壤酶活性季节性变化情况。结果表明：黑土土壤微生物量碳季节性变化明显,所有处理土壤微生物量碳的峰值均出现在早春,自然恢复较垦殖处理提高了黑土土壤微生物量碳含量。对土壤酶活性研究发现,除垦殖处理的转化酶活性季节性变化较小外,其他处理酶活性季节性变化显著。NR处理促进了土壤过氧化氢酶、转化酶和磷酸酶活性的提高,而对土壤脲酶活性影响不大。垦殖处理下施肥较不施肥处理土壤酶活性高,但单施化肥对土壤过氧化氢酶活性有一定的抑制作用。

Seasonal Changes of Black Soil Microbial Biomass C and Enzyme Activities as Influenced by Cultivation and Natural Restoration Treatments

Based on the soil samples obtained from a long-term experiment at Hailun Agricultural Ecology Experimental Station of Chinese Academy of Sciences,the seasonal changes of soil microbial biomass C（MBC） and enzyme activities as influenced by natural restoration（NR） and cultivation treatments of no fertilizer（NoF）,chemical fertilizers（CF） and chemical fertilizer plus manure（CF＋M） were investigated in this study.Results showed that the soil MBC content in black soil significantly changed with seasons.The highest value of soil MBC for all treatments was observed at early spring,and the content of soil MBC in NR treatment was higher than that in cultivation treatments.Results of soil enzyme activities indicated that they were also significantly changed with seasons,exception of invertase in cultivation treatments changed a little.Compare with cultivation treatments,NR increased the soil enzyme activities of phosphatase,catalase and invertase,but had little effect on urease.Among the cultivation treatments,CF and CF＋M treatments increased soil enzyme activity compared with NoF treatment,however,for soil catalase,CF inhibited its activity.