补播模式对喀斯特地区草地土壤养分和酶化学计量特征的影响OA

To investigate the effects of reseeding patterns on soil nutrients and enzyme stoichiometry of degraded grasslands,a study was conducted in the Dushan of Guizhou,China,using a degraded grassland(CK)as the control.Two reseeding treatments were established:oat(Avena sativa L.)+ryegrass(Lolium perenne L.)(AL)and oat+ryegrass+clover(Trifolium L.)(ALT).The results showed that both AL and ALT sig-nificantly increased the contents of organic carbon,total nitrogen,and available phosphorus in the 0～10 cm soil layer,with increasing by 42.66%and 57.29%,75.54%and 116.30%,and 90.78%and 155.59%,respec-tively.Under the ALT treatment,the C/N ratio in the 0-10 cm soil layer significantly decreased,while the N/P ratio increased,alleviating soil nitrogen deficiency.The activities of β-1,4-glucosidase and β-1,4-N-acetyl-glucosaminidase significantly increased by 182.21%and 186.85%,respectively,with a higher increase than that in the AL treatment.ALT significantly increased the enzyme vector length in the 0～10 cm soil layer,intensifying microbial carbon limitation.Correlation analysis indicated that extracellular enzyme activities were mainly regulated by the combined effects of total nitrogen and organic carbon.In conclusion,the ALT reseed-ing pattern could effectively improve soil organic carbon and available nutrients,alleviate nitrogen deficiency,and enhance soil enzyme activities related to carbon and nitrogen cycling in degraded grasslands in this region.However,it also strengthened the carbon limitation of surface soil microorganisms.