放牧对冷蒿根际微生物区系及土壤酶活性的影响

发布时间：2018-08-27 09:10

【摘要】：为了揭示放牧对退化草原冷蒿Artemisia frigida群落阻击草场进一步退化的机制,以小区控制放牧试验(不放牧、轻度放牧、重度放牧)冷蒿根际与非根际土壤为对象,研究了不同程度放牧干扰对冷蒿根际土壤微生物数量、类群和酶活性的影响及其相互关系。结果表明:各放牧区土壤微生物数量均表现为细菌放线菌真菌;各处理之间冷蒿根际土壤微生物细菌、放线菌、真菌数量均显著高于非冷蒿根际土壤(P0.05)。冷蒿根际土壤氨化细菌和好氧纤维素分解菌数量高于非冷蒿根际土壤;轻度放牧区冷蒿根际土壤氨化细菌和好氧纤维素分解菌数量显著增加(P0.05)。冷蒿根际土壤轻度放牧后碱性磷酸酶、脱氢酶、淀粉酶、转化酶、脲酶、硝酸还原酶活性明显高于对照和重度放牧;各放牧区冷蒿根际土壤7种酶活性显著高于非冷蒿根际土壤(P0.05)。相关分析表明,氨化细菌与碱性磷酸酶、脱氢酶、淀粉酶、转化酶、硝酸还原酶活性存在极显著正相关关系(P0.01),好氧纤维素分解菌与酶活性存在正相关(P0.05)。重度放牧后土壤中微生物数量减少,酶活性降低,轻度放牧使冷蒿根际土壤微生物数量和酶活性显著增加,改善土壤微生态环境。合理放牧有助于冷蒿阻击草原进一步退化。
[Abstract]:In order to reveal the mechanism of grazing preventing the further degradation of Artemisia frigida community in degraded steppe, Artemisia frigida Rhizosphere and non-rhizosphere soil were studied in plot controlled grazing experiment (non-grazing, light grazing and heavy grazing). The effects of grazing disturbance on the number, group and enzyme activity of microorganism in rhizosphere of Artemisia frigida were studied. The results showed that the number of soil microbes in each grazing area was bacteria actinomycetes, and the number of microbes, actinomycetes and fungi in soil of Artemisia frigida rhizosphere was significantly higher than that of non-cold artemisia rhizosphere soil (P0.05). The number of ammoniated bacteria and aerobic cellulose decomposing bacteria in Artemisia annua rhizosphere soil was higher than that in non-Artemisia annua rhizosphere soil, and the number of ammoniated bacteria and aerobic cellulose decomposition bacteria in Artemisia frigida rhizosphere soil was significantly increased (P0.05). The activities of alkaline phosphatase, dehydrogenase, amylase, invertase, urease, nitrate reductase in Artemisia annua rhizosphere soil after light grazing were significantly higher than those in control and heavy grazing. The activities of seven enzymes in rhizosphere soil of Artemisia frigida were significantly higher than those in non-Artemisia annua rhizosphere soil (P0.05). Correlation analysis showed that there was a significant positive correlation between ammoniated bacteria and alkaline phosphatase, dehydrogenase, amylase, invertase, nitrate reductase activity (P0.01), and there was a positive correlation between aerobic cellulose decomposing bacteria and enzyme activity (P0.05). After heavy grazing, the amount of microorganism and enzyme activity in soil decreased, and light grazing significantly increased the number of microorganism and enzyme activity in rhizosphere of Artemisia frigida, which improved the soil microecological environment. Reasonable grazing is helpful for Artemisia annua to prevent further degradation of grassland.
【作者单位】：浙江农林大学省部共建亚热带森林培育国家重点实验室;内蒙古大学生命科学学院;
【基金】：国家自然科学基金资助项目(31270756,31470704) “十二五”国家科技支撑计划项目(2011BAC07B01) 国家重点基础研究发展计划(“973”计划)项目(2014CB138805)
【分类号】：S812.2

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