Background Studying green manure decomposition in various returning methods can establish a scienti c foundation for farmland nutrient management.Methods In a rubber plantation on Hainan Island, China, utilized the nylon mesh bag method to imitate the decomposition of kudzu (whole plant, stem, and leaf) under two returning methods (mulching and burying) in two different sites (young and mature rubber plantations). The decomposition rate and nutrient release dynamics of kudzu and investigated the impact of kudzu returning on various soil properties such as soil pH, soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), nitrate nitrogen (NO 3 − -N), ammonium nitrogen (NH 4 + -N), available phosphorus (AP), and enzyme activities were analyzed.Results Compared with mulching, the burying returning method signi cantly increased the kudzu decomposition rate and nutrient release proportions. After 270 days, more than 80% of the C, N, and P in different components of kudzu were released. The decomposition rate was found to be more affected by the initial soil factors than by the endogenous nutrients of kudzu. Compared with CK, all kudzu treatments led to signi cant increases in soil enzyme activities and soil pH, SOC, NO 3 − -N, and AP concentrations in two rubber plantations. The TN and NH 4 + -N concentrations were signi cantly increased in mature rubber plantations, while the TP was the opposite.
ConclusionThe kudzu returned can effectively alleviate soil acidic, improve soil nutrient availability, regulating soil enzyme activities of the rubber plantation in the short-term. These results provide a scienti c basis for the rational application of kudzu in rubber plantations.