Effect of contrasting sources of organic and inorganic fertilizers on growth and yield maize in dry agro-ecology in Northern Ghana

Declining maize yields due to a myriad of factors such as inherently poor soils, continuous cropping of cereal after cereal, high cost and unavailability of chemical fertilizers, continuous crop residue removal and soil erosion and run-off have all had their toll low soil fertility and reduced maize yields in northern Ghana. To address this negative trend a field trial was conducted at the Manga Agricultural Research Station in the Upper East Region of Ghana, which represents a Sudan Savanna agro-ecology in the country. The experiment was established as a complete block design with 4 replications with plot dimension of 4.5 m x 5 m. The experimental treatments comprised available sources of both organic and chemical fertilizers currently being used by peasant farmers in Ghana. The experimental factors studied were nitrogen fertilizer rates: 0 kg N/ha; 40 kg N/ha and 80 kg N/ha; length of tied ridges were: 2 m and 4 m wide and crop residue management practices were: total crop residue removal; 50% crop residue removal; 100% crop residue retention and 50% crop residue retention. The trial was established as a randomized complete block design with 4 replications. The results of this study revealed that the chemical fertilizers with micro nutrients such as S, Zn and Mg produced taller plants with superior stem dimensions and also produced tassels and silk significantly earlier than their counterparts. They also produced the best grain and straw yields, due to higher cob numbers, bolder grain and higher harvest indices. Poultry manure and sheep manure were the best amongst the organic sources evaluated.