Organic amendment of an ultisol: effects on soil properties, growth, and yield of maize in Southern Guinea savanna zone of Nigeria

Background: The Southern Guinea savanna zone of Nigeria is characterized by inherently low soil fertility statusand rapid nutrient depletion especially soil organic matter. However, this zone is characterized by abundantagricultural land and is a potential for crop production. Field experiments were conducted in order to evaluate theeffects of integrated use of agricultural waste materials and compound mineral fertilizer on soil and plant nutrientstatus, growth, and yield of maize in ultisol in the Southern Guinea savanna zone of Nigeria.Results: Application of organic waste alone and in combination with mineral fertilizer enhanced root and shootbiomass, leaf area development, and yield and components of maize. Treatment effects were significant on growthcharacteristics of maize (stem girth, leaf area, plant height and days to 50% tasselling, root and shoot biomass). Soleapplication of NPK fertilizer (400 kg/ha) was not significant over the combined use of poultry manure and NPK ongirth, leaf area, and plant height. Mean values of stem girth, leaf area, and plant height ranged between 2.05 and3.8 cm, 0.26 and 0.54 m2, and 84.7 and 209.4 cm, respectively. Root and shoot dry weights were highest under soleNPK application compared with plots where either sole wastes or wastes in combination with reduced NPK wereapplication of NPK fertilizer (400 kg/ha) was not significant over combined use of poultry manure and NPK on stemapplied. Integrated use of agricultural wastes and NPK also enhanced root and shoot dry weights compared withsole application of wastes as well as seed weight per plant, 100-seed weight, and number of seeds per cob andgrain yield. Among the agricultural wastes applied, poultry manure enhanced the growth and seed yieldcharacteristics of maize. This treatment increased the seed weight per plant, number of seeds per cob, 100-seedweight and seed yield by 55.6%, 66.5%, and 55.4%, respectively over Chromolaena and neem seed cake.Chromolaena and neem seed cake produced similar grain weight per plant, 100-seed weight, number of seed percob, and seed yield. Poultry manure significantly enhanced the growth and seed yield characteristics of maize overChromolaena and neem seed cake.Conclusions: Integrated use of organic wastes and mineral NPK fertilizer showed promising potential for improvingsoil fertility, growth, and yield of maize in the Southern Guinea savanna agroecological zone of Nigeria. It isrecommended that poultry manure at 7 t/ha plus NPK fertilizer at 200 kg/ha be adopted for maize cultivation inthe study area.

Keywords:

Tropics , Savanna , Soil , Organic , Amendment , Maize