Effects of poultry litter and inorganic fertilizer on growth and productivity of Rhizobia inoculated and non-inoculated beans

Abstract

Agriculture has been the most contributing sector towards Uganda’s economy. However, its output has always been hampered by declining soil fertility leading to reduced yields, increased agricultural losses, and malnourishment among low-income earners. In Uganda, there is scanty research about the effectiveness of either organic or inorganic fertilizers in crop production. Therefore, there was a need to establish the effectiveness of inorganic fertilizer (N: P: K; 17:17:17) and organic fertilizer (poultry manure/litter) on the growth, and productivity of rhizobia inoculated and non-inoculated bio-fortified NAROBEAN 2 variety, which is rich in iron and zinc, high yielding and drought resistant.  A randomized complete block design experiment was conducted at Mbarara Zonal Agricultural Research and Development Institute (MBAZARDI). Poultry litter was applied at the rate of (10t/ha), N: P: K 17:17:17 at 20.3 kg ha^-1, and Rhizobia at 250g per 15 kg of beans. Treatments were; Rhizobia + N: P: K 17:17:17 (M 1), Rhizobia + Poultry litter (M 2), Rhizobia only (M 3), Poultry litter only (M 4), N: P: K 17:17:17 only (M 5) and the control (M 6). Growth parameters included the number of leaves, branches, and shoot height; and productivity parameters included the number of pods produced per plant and economic yield. Statistical analyses were done at 5% level of significance. The growth parameters showed no significant difference (P > 0.05) while the bean grain yield and productivity were significantly different (p < 0.05) under the various treatments. Rhizobia + Poultry litter and N: P: K 17:17:17 only, produced the highest effect on both growth and productivity as compared to other treatments. Application of rhizobia with poultry manure was the best soil treatment for increasing the growth and productivity of NAROBEAN 2. This will increase production, food security, abate malnutrition, and sustainably improve soil quality.