The effect of diammonium phosphate (DAP) and organic manure (goat manure) on the performance of soybean.

Abstract

Production of soybean in Uganda is steadily increasing but yields have remained low averaging 990-1150kg/ha in farmers’ fields (FAQ 2002). These low yields are attributed to several factors including low soil Fertility, inappropriate management practices and attack by pests and diseases (Oloka, Tukamuhabwa and Sengooba, 2005). Use of synthetic fertilizers is being discouraged worldwide as they are known to affect soil health by killing the important soil micro-organisms. Because of this there is increasing advocate for the use of organic manure such as goat dung to increase crop productivity and farm yields. This research investigated the effect of DAP and goat manure on the performance of soybean. It was carried out from September 2014 to January 2015 in a randomized complete block design. Goat manure (0.4-0.5 nitrogen, 0.3-0.4 phosphorous 0.3-0.4 potassium) that is according to Chandra (2005), was applied in each block at three levels excluding the control blocks that is 0.83tons/ha, 1.7tons/ha and 2.510ns/ha. The same blocks were at the same time treated with DAP at three levels as well i.e. 0.01 tons/ha and 0.03tons/ha. 'The research showed that DAP and organic manure increases soybean yield on average by 5.2% however, M4D3 (2500kg manure combined with 20kg of DAP) increases it by up to 25.1% and increases the profit margins by 24.9%. This implied that DAP and organic manure improves soybean performance and increases profits. Keywords: Soybean, Diammonium phosphate, Organic manure, Growth yield