English

Abstract

Application of farmyard manure (FYM) alone or in combination with inorganic fertilizers helps in proper nutrition and maintenance of soil fertility in maize fields when applied at proper doses replenishing the most deficient macro and micro nutrients which in turn help in getting the highest grain yield and harvest index in hybrid maize varieties. The harvest index determines how many photosynthates are transformed into economic yield. It is the ratio of economic yields to biological yield. A study was conducted at the Haramaya University Chiro Campus to determine the effect of enriched FYM and inorganic fertilizers on grain yield of maize and harvest index. FYM was used either alone or in combination with inorganic fertilizers as follows: control (zero fertilizers and FYM), 10 tons/ha FYM, 8 tons/ha FYM and 25 kg/ha of (Nitrogen (N) + 20 kg/ha Potassium (P), 6 tons/ha FYM, 50 kg/ha N + 40 kg/ha P, 4 tons/ha FYM, 75 kg/ha N + 60 kg/ha P, 2t ons/ha FYM , 100 kg/ha N+80 kg/ha P 100 kg/ha N + 100 kg/ha P. The treatments were arranged in randomized complete block design with four replications from 2008 to 2010. Result from the combined analysis of variance on hybrid maize (BH-140) yield and harvest index over years showed the presence of no significant difference among treatments with 10 tons/ha FYM and 100 kg/ha N +100 kg P/ha (p < 0.05). The pooled analysis of variance over years also revealed the existence of no significant differences among Treatments 2, 6, and 7 viz (10 t/ha FYM + 0 N and P, 2 t/ha FYM and 100 kg/ha N + 80 kg/ha P and100 kg/ha N + 100 kg/ha P), respectively at (p < 0.05) on grain yield of hybrid maize (BH-140) and the harvest index. But 4 tons/ha FYM and 75 kg/ha N + 60kg/ha P increased maize yield from 5.1 tons/ha in 2009 to 8.15 tons/ha in 2010. Similarly, the harvest index has increased from 0.33 to 0.58 (33 to 58%) at this rate. From this finding it was noted that, enriching FYM with inorganic fertilizers can boost hybrid maize grain yield significantly through improving the physico-chemical properties of the soil and contribute to the highest value of harvest index. Therefore, on the basis of these results, it can be concluded that, enriched FYM could be used for hybrid maize production at western Hararghe in order to get maximum grain yield and the highest value of the harvest index. Thus, it is recommended that, application of 4 tons/ha FYM incorporated with 75 kg of N and 60 kg of P at Chiro can significantly increase hybrid maize (BH-140) yield and sustain its productivity over years. Besides, it also contributes in reducing the cost of inorganic fertilizers which has been a bottle neck to smallholder farmers of eastern Ethiopia. However, profitability of this technology needs to be tested at different locations and in different seasons. Key words: Farmyard manure, soil fertility, hybrid maize (bh-140), harvest index, inorganic fertilizers, biological yield, photosynthates.