Response of Two Soybean Varieties to the Application of Organic Fertilizers

Abstract

The national demand for soybeans is increasing in response to increasing population. Consequently, the cultivation of soybeans should be extended to new areas, including those of marginal fertility, and under various farming systems. Because farmers may have limited access to supplies of inorganic fertilizer and pesticides, and limited funds with which to buy them, organic farming can be a viable option. Farmers can use on-farm inputs that are normally available at the production site. An organic farming system may be able to ensure food security at the local level because continuity of plant production is possible. This study was conducted to investigate the response of two soybean varieties to different types of organic fertilizer in an organic farming system. The experiment was carried out at IPB experimental station, Bogor, Indonesia, in December 2009-July 2010. Split plot design was used with types of organic fertilizer as the main plot (poultry manure, Centrosema pubescens Benth, and Tithonia diversifolia Hemsl.) and soybean varieties as the sub plot (Anjasmoro and Wilis). The results showed that the application of Centrosema sp. and Tithonia sp. increased plant height and productivity, and reduced plant pest and disease intensity compared to poultry manure. Production of soybean applied with poultry, Centrosema sp., and Tithonia sp. manures was 1.16, 1.33, and 1.48 t/ha-1, respectively. On rainfed land, Anjasmoro was higher in vegetative characteristics and productivity compared to Wilis. The production of Anjasmoro and Wilis was 1.57 and 1.07 t/ha-1 respectively