To study the effects of grass hedgerows and mulching measures on soil enzyme activity and limitation of microbial nutrients in red soil sloping croplands, an experiment was taken which was based on a long-term field soil and water conservation measures experimental plots conducted in 2009 with four treatments: conventional tillage (CK), hedgerows (GH), rice straw mulching (RM) and hedgerows+mulching (HM). The changes in soil physicochemical properties, extracellular enzyme activities and ecological stoichiometry were measured. The results showed that compared with CK, soil organic carbon (SOC), total phosphorus (TP), available phosphorus (AP), alkali-hydrolyzable nitrogen (AN) and available potassium (AK) were increased by 16.0%-24.0%, 1.7%-26.1%, 3.4%-27.0%, 3.2%-17.0% and 2.6%-24.6%, respectively, and with the effect of HM being more significant. Compared with CK, GH, RM and HM significantly increased the activities of β-1,4-glucosidase (BG) and had different effects on the activities of β-1,4-N-acetylglucosamine glucosidase (NAG), cellobiohydrolase (CBH) and acid phosphatase (ACP). GH significantly increased the values of C/N_EEA(ln(βG+CBH)/ln(NAG)) and C/P_EEA(ln(βG+CBH)/lnACP), while RM significantly decreased the values of C/N_EEA, HM significantly increased the values of C/P_EEA and N/P_EEA(ln(NAG)/ lnACP). The red soil sloping upland was generally co-limited by phosphorus (nutrient) and energy (carbon). RM weakened the carbon limitation of microorganisms, while GH increased the carbon limitation. Vector angles significantly decreased by 5.7% and 9.9% in RM and HM, respectively. Redundancy analysis (RDA) showed that DOC, N/P, AN, AK, NO- 3-N and TN were all the main factors affecting enzyme activities and their ratios. Random forest analysis illustrated that N/P, DOC and NO- 3-N were the main explanatory variants for microbial carbon limitation, while AK and TN contents contributed more to soil microbial phosphorus limitation. These results indicate that straw mulching and hedgerows can enhance carbon sequestration and nutrient cycling in red soil upland, long-term straw mulching can alleviate soil carbon limitation and significantly boost the activity of nitrogen and phosphorus acquisition enzymes, and the long-term use of hedgerows in conjunction with straw mulching can alleviate soil microbial phosphorus limitation. The results provide a theoretical basis for the ecological restoration research on carbon-nutrient (e.g., nitrogen, phosphorus) processes for red soil on eroded sloping farmland.