不同植物篱对石灰性紫色土坡耕地土壤微生物学特性影响研究

以资阳市长期定位试验(10年)小区土壤为材料,研究了种植香根草植物篱、紫穗槐植物篱处理对紫色土坡耕地土壤微生物数量、微生物生物量碳(SMBC)和微生物生物量氮(SMBN)、土壤氨化强度、亚硝化作用和硝化作用强度、土壤脲酶和碱性磷酸酶活性的影响。结果表明,种植香根草和紫穗槐植物篱处理土壤细菌、放线菌、真菌数量分别比对照土壤增加了63.43%和36.63%,47.87%和71.89%,74.60%和43.65%;SMBC和SMBN分别增加了90.02%和83.32%,24.97%和45.04%;土壤脲酶活性和碱性磷酸酶活性分别增加了45.20%和61.86%,26.68%和38.95%;土壤氨化作用强度分别增加了73.28%和75.65%,而土壤硝化和亚硝化强度则分别降低了26.97%和52.96%,6.46%和22.19%。植物篱处理能够较好地改善土壤微生态环境,增加土壤中微生物数量、SMBC和SMBN,提高土壤氮素和磷素的利用效率。

Microbial features of sloping farmland soil in calcareous purple area affected by different hedgerows treatments in Sichuan Basin

A fixed field experiment has been established for 10 years in Ziyang, Sichuan Province, and different hedgerows such as Vetiveria zizaniodes hedgerow (VH) and Amorpha fruticosa hedgerow (AH) were used to control the soil and water loss. In this study, we determined soil microbial features affected by the above treatments, the results showed that, compared with the CK, the amount of soil bacteria, actinomycetes and fungi of the VH and AH treatments increased by 63.43% and 36.63%, 47.87% and 71.89%, 74.60% and 43.65% respectively; soil microbial biomass carbon (SMBC) increased by 90.02% and 24.97%; soil microbial biomass nitrogen (SMBN) increased by 83.32% and 45.04%; ammonification activity increased by 73.28% and 75.65%; urase activity and alkaline phosphatase activity increased by 45.20% and 61.86%, 26.68 % and 38.95%; however, nitrosification and nitrification activity decreased by 26.97% and 52.96%, 6.46% and 22.19%, respectively. Thus, hedgerows treatments could improve soil physical and biochemical properties, and increase the microbial quantity, SMBC and SMBN, and reduce the soil nitrogen loss and enhance the utilization efficiency of soil nitrogen and phosphate.