Regularities of Decompostion and Nutrients Releasse of Amaranthus hypochondriacus Green Manure Under Woodland of Camellia oleifera

To explore the regularity of decay and nutrient release for Amaranthus hypochondriacus green manure in Camellia oleifera at different growth stage. The paper set up covering the surface and burying ground in 2 ways, by measuring the release rule of carbon, nitrogen, phosphorus and potassium at the stage of budding and mature. The findings indicated that at budding stage, A.hypochondriacus had high decomposing speed and less residual amount of dry matters, returning on the soil surface or underground the release rate was 68.18% and 71.11% respectively, both had the equivalent decomposing speed of dry matter. A.hypochondriacus at budding stage had fast releasing of nitrogen and potassium, and low speed in phosphorus. While at mature stage, the decomposing speed was slowdown with mass of residual dry matters, the fertilizer effect of returning underground was better than that returning on the surface soil, the release rate was 70.66% and 54.05% respectively. The release of nitrogen and potassium was lower than that application at the budding stage, but the release of phosphorus was relatively high. Using A.hypochondriacus as green manure, the effect of A.hypochondriacus nitrogen fertilizer is good at budding stage, and it can be used as topdressing in C.oleifera. At mature stage, buried A.hypochondriacus in the soil can be used as base fertilizer for C.oleifera after October.