Weed communities of gogorancak and walik jerami rice in Indonesia and reflections management

摘要

Dry-seeded bunded rice (gogorancah) followed by minimum-tillage transplanted rice (walik jerami) is an annual rain-fed crop production system that underpins rice production in Indonesia on sloping lands. Adaptive research to investigate points of intervention for improved yields in both crops was conducted by survey to characterise the weed flora and by on-farm experiment comparing nutrient addition and intensive weeding. Rice yields in weed-free researcher-managed trials in both crops varied between3 and 6 t ha depending on toposequence position, and tended to be greater in gogorancah. The highest yields were found in lower toposequence positions with differences of approximately 1 t/ha being recorded across toposequence. Average on-farm yields were significantly lower. The greatest yield improvement resulted from additional fertiliser. Canonical correspondence analysis indicated that the weed flora after farmer weeding was diverse, with weed densities up to 100 plants / m~2 and showed no strongrelation to soil fertility.