The Role of Tree Fertilizer in Enhancing Maize Production and Mitigating Soil Acidity at Haro Sebu On-station, Kellem Wollega Zone of Oromia, Western Ethiopia

Abstract

Declining soil fertility is identified as one of the main limiting factor in smallholder cropping systems. The strategy of using inorganic fertilizers for this problem is being highly constrained by high cost, low purchasing power of smallholders and limited access to credit. Thus, a judicious integration of both organic and inorganic sources of nutrients may be envisaged as one of the options.  a biomass transfer study on Cajanus Cajun in combination with different rates of inorganic fertilizer was conducted  for two consecutive years  in 2014/15 and 2015/16 cropping season at Haro Sebu  Agricultural Research Center, Kellem Wollega, Oromia, Ethiopia. The objective of the study was to investigate the role of tree biomass fertilizer in promoting maize production in Kellem Wollega zone of Oromia, Ethiopia, and also to assess the potential of tree biomass fertilizer for mitigating the problems of soil acidity in western Ethiopia. The experiment was tested on maize variety (BH-661), and it was also repeated during the 2015/16 cropping season to assess the possible residual effect of applying inorganic fertilizer and Cajanus biomass. Results indicated that maize grain yield was significantly affected by varying rates of Cajanus biomass (p < 0.0001) and inorganic fertilizer (p <0.0001) during the first cropping season. the interaction effect of Cajanus biomass and inorganic fertilizer was also significant(p<0.02) ,but no significant difference in maize yield was noticed for both factors during the second year when no any external input was added indicating that nutrients from Cajanus biomass was used and  lost in the first year. Maize grain yield varied from 3417kg/ha to 6284 kg/ha during the first year and from 3143.3 kg/ha to 3609.3kg/ha during the second year. From this finding, integrated Cajanus biomass and inorganic fertilizer application seems promising alternative for maize production in the area by improving soil  fertility, and made available to crops during the year of application. However, the economic analysis to assess the profitability of using this organic fertilizer with or without inorganic fertilizer was  studied. The economic evaluation, on the other hand, revealed that the highest net benefits were obtained from treatments in the experiment, 4T+0.5Frt would be the best recommendation for farmers followed by 6T+0.5Frt and 6T+FullFrt respectively. Hence, it is likely to conclude that integration of organic and inorganic fertilizer application would be ecologically, friendly and economically justifiable

Keywords: Soil fertility improvement, Maize yield (BH-661), Cajanus biomass, and inorganic fertilizer