环境条件对麻纤维地膜降解及其土壤微生物量和酶活性的影响

通过设置不同土壤pH、施氮量、季节和作物种植的土壤环境条件,采用盆栽埋袋试验方法研究麻纤维地膜的降解规律变化,并分析其与土壤微生物生物量及酶活性的关系。结果表明:麻纤维地膜的降解过程均服从Olson衰减模型(R~2=0.689～0.996,P0.05)。施氮量和使用季节对麻纤维地膜的降解产生显著影响,在秋冬季节施氮量增加和种植小白菜呈抑制地膜降解的趋势,夏季地膜降解速率显著高于秋冬季,但土壤pH(5.80～8.34)对地膜的降解速率影响较弱。不同土壤环境条件下,试验末期麻纤维地膜的降解率与土壤微生物生物量碳、氮(MBC、MBN)、纤维素酶及过氧化氢酶活性呈显著正相关关系(P0.05)。因此,土壤环境条件改变导致的土壤微生物生物量及酶活性变化可能是其影响麻纤维地膜降解速率的重要原因。

Effects of Environmental Conditions on the Degradation of Bast Fiber Mulch Film, Soil Microbial Biomass and Enzymes Activities

The pot buried experiments were conducted to study the effects of soil pH, nitrogen application, seasons and pakchoi planting on the degradation of bast fiber mulch film(BFMF) and the changes in soil microbial biomass and enzymes activities. The results showed that the degradation process of BFMF obeyed the Olson attenuation model (R²=0.689~0.996, P<0.05). The application of nitrogen and planting of pakchoi during the autum-winter season significantly inhibited the degradation of BFMF (P<0.05). Further, the degradation rate of BFMF was significantly higher during summer than autumn-winter season (P<0.05). While, limited effect of soil pH (5.80~8.34) on the degradation of BFMF was observed (P>0.05). Moreover, there were significantly positive relationships between the degradation rates of BFMF and the soil microbial biomass carbon, nitrogen (MBC, MBN), cellulose and catalase activities at the end of the experiments periods (P<0.05).These results indicated that the different degradation characters of BFMF might be due to the changes in soil microbial biomass and enzymes activities under different soil environment conditions.