不同牧草对农牧交错带土壤呼吸作用的效应研究

Effect of Different Herbages on Soil Respiration in Agropastoral Region

通过对林西县内不同牧草地的土壤进行土壤原位呼吸及土壤微生物指标的测定和分析,研究了不同牧草对农牧交错带土壤呼吸作用的效应。结果表明,含水量较高的牧草地,土壤原位呼吸速率与温度间呈正相关关系;在土壤水分含量较低的牧草地,土壤温度持续上涨,土壤微生物的呼吸作用受到抑制,土壤原位呼吸速率降低,所以土壤原位呼吸速率随地温的升高而变小。在不同牧草地,冰草和无芒雀麦草地土壤表现出较高的微生物生物量和较低的呼吸商。与其他牧草地相比,冰草和无芒雀麦草地表现出更好的土壤微生物指标。混播草种以后的盐荒地土壤有良好的微生物指标;退耕以后的苜蓿草地与荞麦农田相比,土壤微生物指标有所好转。

The soil respiration rate and soil microbial index at sites with different forages growing were measured and analyzed in situ in Linxi county. There was a positive relation between the soil respiration rate and temperature in the grassland with high content of soil water, while, under the condition of lack of soil water, soil microbial respiration would he restrained and soil respiration rate would he reduced if the soil temperature rose continually. Among the sites that grew different forages, the microbial biomass of soil at the two sites that grown Agropyron cristatum and Bromus inermis was bigger with lower respiration quotient. Compared with the other forages, Agropyron cristatum and Bromus inermis could improve the soil microbial indexes. After sowing mix-genus herbages, the microbial index in salt-wild soil improved greatly. The cancelled farming land with Medicago sativa growing showed a little better in soil microbial index than Fagopyrum esculentum farmland.