Increasing groundnut yield on dryland Alfisols in Indonesia

East Java is the major groundnut (Arachis hypogaea) producing province in Indonesia. It produces 68.7% (487,800 t) of the national groundnut production from 27 % (176,800 ha) of the total area under the crop in the country (BPS 2001). The majority of this crop is planted on dryland Alfisols. In central production area, 65 % of the total farmer’s income comes from groundnut (Sumarno and Adie 1995). Increased productivity of groundnut will increase farmers ’ income and regional and national production of the crop. Groundnut on dryland is usually grown during February–May and June–September. The traditional groundnut cultural practices at farmers ’ level are narrow plant spacing (20 cm × 20 cm), no fertilizer and pest and disease control, and use of local variety. Because of thes