Effects of Using Different Organic Sources in Combination with Mineral Nitrogen Fertilizer on Soil Fertility, Grain Yield, and Maize Quality

Integrated soil fertility management is critical for crop productivity and soil health management. The study was carried out to determine the effects of different organic sources with mineral nitrogen application on soil fertility, grain yield, and maize quality on the Andisols of Sidama, Ethiopia. The treatments were: control, 100% of RNP-(138 N and 92 P), 100% of RN from vermicompost, 100% RN from conventional compost, 25% RNP +75% of RNP from vermicompost, 50% of RNP + 50% of RNP from vermicompost, 75% of RNP+25% of RNP from vermicompost, 25% of RNP +75% of RNP from conventional-compost, 50% of RNP+50% of RN from conventional-compost, and 75% of RNP +25% of RN from conventional-compost. The treatments were arranged in a randomized complete block design and replicated three times. The highest maize grain yield (7494.3 kg ha-1) and biomass yield (18718.0 kg ha-1) were obtained from the applications of 50% recommended NP fertilizer plus 50% vermicompost, which is based on recommended N equivalent respectively. The soil fertility analysis result shows that the combined application of organic with mineral fertilizer had brought significant changes to soil fertility and showed a positive effect on the soil pH, organic carbon content, total nitrogen, CEC, available P, available K, and CEC. Similarly, the use of organic fertilizer in conjunction with mineral fertilizer resulted in a significant change in the protein and oil content of maize. The protein content % and oil content % ranges from 7.1%-13.9%-4.2%-7.2% respectively. These results suggest that an appropriate proportion of organic fertilizer with mineral fertilizer not only provides enough nutrients but also improves the soil environment, leads to increased yields, and plays an important role in maize quality. Therefore, the combined application of this 50% recommended NP fertilizer plus 50% vermicompost (based on N equivalent rate) can be recommended to farmers for production that increases maize yields with an assurance of sustainable soil fertility and quality maize production in, Sidama of Ethiopia. Keywords: Grain yield, Maize, protein and oil content, Organic and Mineral fertilizers DOI: 10.7176/ALST/92-02 Publication date: February 28th 202