Growth and yield response of grain legumes to different soil management practices after rainfed lowland rice

Field experiments were conducted over a 3-year period (1992-1995) in Sulawe si, East Java and the Philippines to investigate the response of post-rice (Orzya sativa L.) soil managements on growth and yield of legumes after low land rice under rainfed conditions. Grain Legume yields ranged from complet e crop loss due to excessive rainfall after sowing to a maximum of 1.08 Mg ha(-1) fur mungbean (Vigna radiata (L.) Wilzek), 1.33 Mg ha(-1) for soybean (Glycine max L. Merr.) and 2.3 Mg ha(-1) fur peanut (Aracis hypogaea L.). The response and magnitude of the effects from different management systems on legumes were closely related to the climatic conditions prevailing duri ng the crop establishment phase. Correct timing of legume sowing was seen a s the most important factor determining successful moderate crop production , followed by the availability of subsoil water reserves. Tillage was consi dered a potential method to improve yields because sowing could be carried out later during the dry season when rainfall was more predictable. Tillage , provided it is carried out at suitable soil water contents, could probabl y partially overcome the adverse soil physical condition induced during the rice phase. Fertiliser application tended to increase food legume in wette r areas showing that residual fertiliser effects from the previous rice cro p could he limiting. In drier areas, fertiliser application had little effe ct on grain legume yields. Mulch as a soil amendment tended to increase yie lds in drier areas due to its water conservation effect. In wetter areas mu lching was not necessary and could even lead to yield reduction if conditio ns were too wet. (C) 2000 Elsevier Science B.V. AU rights reserved.