| 摘要: |
| 为了解放牧干扰下草原土壤微生物量变化特征，以内蒙古锡林郭勒典型草原放牧控制试验样地为研究平台，采用双因素方差分析对2014—2017年不同放牧强度下土壤微生物量碳(Microbial biomass carbon，MBC)、微生物量氮(Microbial biomass nitrogen，MBN)、微生物量磷(Microbial biomass phosphorus，MBP)含量进行了调查。结果表明:1)连续4 年不同放牧强度下MBC、MBN含量年际变化不显著(P>0.05)，全年平均值分别为306.00和55.98 μg/g，MBP含量年际变化显著(P<0.001)，放牧第一年土壤MBP含量平均为40.99 μg/g，第二年以后土壤MBP含量大幅度降低，降低了50.38%~79.97%；2)不同放牧强度下，土壤MBC、MBN、MBP含量均在G8处理下达到最大值，且均高于不放牧处理(G0)；3)土壤微生物量碳氮含量的比值一直保持相对稳定，微生物量碳磷含量比值在中度放牧强度(G8)下与对照保持一致。因此，放牧对土壤微生物量的影响，尤其是对微生物磷含量的影响不仅与放牧强度有关，还与放牧时间有关。4 年连续放牧尚未对该地区土壤微生物量碳、氮含量造成显著影响，对土壤微生物量磷含量的影响明显。中度放牧强度(G8)可能最适宜微生物生存，可提高土壤微生物量，维持合理的微生物量碳氮磷含量比值，有利于维持草原群落的稳定，提高草原群落的生产力。 |
| 关键词: 内蒙古 典型草原 放牧 土壤微生物量 |
| DOI：10.11841/j.issn.1007-4333.2020.09.13 |
| 投稿时间：2020-01-08 |
| 基金项目:国家重点基础研究发展计划(973)计划(2014CB138801) |
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| Differences of soil microbial biomass C, N and P contents in typical grasslands of Inner Mongolia under different grazing intensities |
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ZHU Xiaoya,LI Zihao,ZHAO Xiaorong,LIN Qimei,LI Guitong
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| (College of Land Science and Technology, China Agricultural University, Beijing 100193, China) |
| Abstract: |
| In order to understand the change characteristics of soil microbial biomass under the disturbance of grazing, this study took the grazing control test plot of Xilin Gol in Inner Mongolia as the research platform, and the content soil microbial biomass carbon(MBC), microbial biomass nitrogen(MBN)and microbial biomass phosphorus(MBP)were investigated under different grazing intensities between 2014 and 2017. The results showed that: 1)There were no significant annual changes in MBC and MBN content under different grazing intensities for four consecutive years(P>0. 05). The annual average values were 306. 00 and 55. 98 μg/g, respectively. The annual change of MBP content was significant(P<0. 001). The soil MBP content in the first year of grazing was 40. 99 μg/g on average. After the second year, the soil MBP content decreased by 50. 38%-79. 97%. 2)Under different grazing intensities, the contents of soil MBC, MBN and MBP reached the maximum under G8 treatment, and were higher than those under non-grazing treatment(G0); 3)Soil MBC∶N ratio remained relatively stable, and MBC∶P ratio was consistent with the control under moderate grazing intensity(G8). Therefore, the effect of grazing on soil microbial biomass, especially MBP content, is not only related to grazing intensity, but also related to grazing times. However, continuous grazing for 4 years displayed no significantly impact on the content of soil MBC and MBN in this area, but its impact on MBP content was obviouse. The moderate grazing intensity(G8)was the most suitable for microbial survival, which improved soil microbial biomass, maintained a reasonable ratio of microbial biomass carbon to nitrogen and phosphorus, and was conductive to maintain soil microbial biomass and the stability of grassland community and improve the productivity of grassland community. |
| Key words: Inner Mongolia typical grassland grazing soil microbial biomass |
