Enhancing Soil Fertility, Maize Grain Yield and Nutrients Composition through Different Planting Time and Manure Sources in Farmers’ Fields of Southeastern Nigeria

Maize (Zea mays L.) has a good potential as a cereal crop side by side with rice and wheat. Irrespective of its local and industrial uses, the production is still challenged by some factors as environmental changes associated with different sowing date and a decline in soil fertility. A field experiment was conducted at the research farm of the Federal College of Agriculture, Ishiagu, Ebonyi State, during the 2015/2016 cropping season. The study used a split-plot in a randomised complete block design which aimed at evaluating the effect of different time of planting and manure sources on selected soil chemical properties, maize grain yield and its proximate nutritive values for enhanced food security. The soil amendments used and their combinations are poultry droppings (PD), NPK 15:15:15 fertiliser, rice husk dust (RHD), poultry droppings + rice husk dust, NPK + rice husk dust, poultry dropping + NPK + rice husk dust and control. The soil parameters studied include soil pH, organic carbon, total nitrogen and cation exchange capacity. The maize grain yield was determined at harvest and the grain nutrients analysed include moisture content, crude fat, crude protein and ash content percentages. Results showed significant differences among the two planting times and soil amendments in all the soil parameters studied including their interactions. Maize planted in April increased the fresh cobs weight (18.37%) higher than those planted in May (11.19%) as PD amended plots increased the fresh cobs weight (2.71 t/ha) significantly (P < 0.05) higher. Maize grain ash percent (1.431%) was improved higher in May than April (1.403%). However, the percentage of moisture contents (MC) and crude fat (CF) (10.46% and 4.237%), respectively, of the maize grain were significantly higher in PD amended plots. Integration of NPK + PD + RHD gave the highest (1.52%) significant (P < 0.05) ash percent in the two planting periods. Plots treated with NPK+PD+RHD in May improved the crude protein higher than other treatments. Proper dissemination of this integrated nutrient management approach to the rural farmers could promote sustainable management practices among smallholder farmers, and ultimately sustain and boost maize production.