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长期放牧对内蒙古荒漠草原土壤不同组分有机磷含量的影响

花匠小妙招
2024-12-21 04:31

摘要： 探究长期放牧对荒漠草原土壤不同组分有机磷含量的影响，对干旱半干旱草地生态系统的合理利用和地力提升具有重要意义。本研究依托于乌兰察布市四子王旗内蒙古农牧业科学院研究基地的长期放牧平台，设置4个不同放牧强度：轻度(Light grazing，LG)、中度(Moderate grazing，MG)、重度(Heavy grazing，HG)和对照(Control，CK)，通过测定土壤理化性质、微生物群落特性，并利用Bowman-Cole磷分级体系测定不同组分有机磷含量，揭示不同组分有机磷对放牧强度的响应机制。结果表明：荒漠草原土壤有机磷组分占比情况为：中活性有机磷＞活性有机磷＞稳性有机磷。其中，活性有机磷含量随放牧强度增加显著增加，中活性有机磷含量随放牧强度增加显著降低，而稳性有机磷含量的差异未达显著水平。放牧通过改变土壤微生物和间接影响土壤有机质来调控活性有机磷含量；放牧通过改变土壤磷养分间接调控中活性有机磷含量。综上，长期放牧对荒漠草原不同组分有机磷含量的影响存在差异，可通过提高微生物代谢底物养分缓解放牧导致的磷资源短缺，这将有助于提高土壤养分有效性从而维持草地生态功能的可持续利用。

关键词: 荒漠草原, 放牧强度, 有机磷组分, 微生物生物量磷, 土壤碱性磷酸酶

Abstract: Exploring the effects of long-term grazing on the different components of soil organic phosphorus content in desert grassland ecosystems is critical for the rational utilization and land enhancement of arid and semi-arid ecosystem. This study relied on a long-term grazing platform at the research base of the Inner Mongolia Academy of Agricultural and Animal Husbandry Sciences (IMAHS) in Siziwang Banner,Ulaanchab City,and set up four different grazing intensities:light (LG),medium (MG),heavy (HG) and control (CK),so as to reveal the response mechanism of the different components of organic phosphorus to the intensities of grazing,through the determination of the soil physical and chemical properties,the characteristics of microbial community,and the determination of the different components of organic phosphorus content using Bowman-Cole phosphorus grading system. The results showed that the proportion of soil organic phosphorus in desert grassland was as follows:moderately labile organic phosphorus> labile organic phosphorus> non-labile organic phosphorus. Among them,the labile organic phosphorus content increased significantly with the increase of grazing intensity,the moderately labile organic phosphorus content decreased significantly with the increase of grazing intensity,while the difference of non-labile organic phosphorus content did not reach a significant level. Grazing regulated labile organic phosphorus content by changing soil microorganisms and indirectly affecting soil organic matter;grazing indirectly regulated moderately labile organic phosphorus content by changing soil phosphorus nutrients. In summary,the effects of long-term grazing on the different components of organic phosphorus content in desert grassland varied,and the shortage of phosphorus resources caused by grazing could be alleviated by improving microbial metabolism of substrate nutrients,which would help to improve soil nutrient effectiveness and thus maintain the sustainable use of grassland ecological functions.

Key words: Desert grassland, Grazing intensity, Organic phosphorus fraction, Microbial biomass phosphorus, Soil alkaline phosphatase

中图分类号:

S812.2