EFFECT OF WHEAT CROP RESIDUE INCORPORATION WITH THE SOIL AND NITROGEN FERTILIZER RATES ON PRODUCTIVITY OF MAIZE (ZEA MAYS L.) VARIETY IN GIBE DISTRICT HADIYA ZONE, SOUTHERN ETHIOPIA

Abstract

Maize is an important cereal in human diets and animal feed, providing adequate energy and protein. Even though many biotic and abiotic factors can contribute to the big yield gaps, soil fertility depletion, and poor organic and inorganic nutrient management are among the major factors contributing to low productivity. Therefore, this research aims to determine the effect of wheat crop residue incorporation with the soil and nitrogen fertilizer rates on the productivity of maize variety in the study area. The study was conducted in Gibe District, Hadiya Zone, Southern Nations Nationalities, and People Regional State at farmers’ fields during the main cropping season in 2022. The treatments consisted of two factors, namely, four levels of nitrogen rates (75 kg ha-1, 100 kg ha-1, 125 kg ha-1, and 150 kg ha-1 of N in the form of urea) and five-level wheat residue application rates (control, 2.5t/ha, 3t/ha, 3.5t/ha and 4t/ha). The experiment was laid out in randomized complete block design (RCBD) in 4 x 5 factorial arrangements with three replications. The analysis of variance showed that the maximum grain yield (4.863 t ha-1) was obtained with the highest N rate (150 kg N ha-1), which applied 4 t ha-1 of residue incorporation with the soil. While the least value grain yield (2.877 t ha-1) was recorded in plots that received (75 kg N ha-1) applied at 4 t ha-1 of residue incorporation with the soil. Like grain yield, the total biomass yield of maize also increased linearly with an increase in nitrogen fertilizer rates. Thus, the results suggested that using 150 kg N ha-1, which applied 4 t ha-1 of residue incorporation with the soil, increased the yield of maize in the study area.