Korean Journal of Soil Science and Fertilizer ISSN:0367-6315(Print) 2288-2162(Online) 한국토양비료학회 학회지

The release of mineral nutrients from green manure residues of mowed weeds affects the nutrient supply from soil to fruit crops. Litterbags filled with the residues of two weed species, Elymus tsukushiensis var. transiens (Gramineae) and Vicia hirsuta (Leguminosae), were periodically examined after being deposited on the soil surface in a persimmon orchard in mid-May 2011 and 2012. The residues within the litterbag decomposed faster during higher rainfall in 2011 than in 2012. There was no significant difference in the decomposition rate of the residues between the two weed species. In 2011 - 2012, DM remaining (% of initial DM) decreased to 69 - 92% during the first month, 26 - 43% after 2 months, and then it gradually decreased to 17 - 23% after 5 months of deposition. Releases of N, P, and K from the residue were also faster during the first two months in 2011 than in 2012, regardless of the weed species. N remaining (% of initial content) in the residues of the two weed species decreased to 48 - 82% during the first month, 26 - 44% after 2 months, and remained under 25% after 4 months. P from the residue released faster in V. hirsuta than E. tsukushiensis var. transiens during the first month, decreasing to 33 - 67% and 66 - 90% of the initial contents, respectively. It was notable that K remaining rapidly decreased to 66 - 91% during the first month and 4.6 - 14.7% after 2 months of deposition in both years. The results indicated that summer fertilization should be adjusted depending on patterns of nutrient release from weed residues under persimmon trees, considering new weed growth.

Change in dry matter remaining (% of initial content) from residue of two weed species within a litterbag deposited on the soil surface under tree canopy of a persimmon orchard on May 13 in 2011 (A) and 2012 (B).