Improving the Fertilizer Value of Cattle Manure for Sustaining Small Holder Crop Production in Ghana

摘要

A study was conducted through composting to evaluate the potential of Chromolaena odorata, Stylosanthes guianensis and maize stover mixture as sources of nutrients, for improving the fertilizer quality of cattle manure. Composting was done in a ratioof 1:1 and 2:1 plant materials mixture: manure. Mass loss and nutrient release from the composts were determined, using the leaching tube and litter bag techniques, respectively. Decomposition and nutrient release constants were estimated by fitting a single exponential model to the data. Composting significantly improved the nutrient content of cattle manure and thus its fertilizer value. The N content for instance was increased by 53 and 102%, respectively for the 2:1 and 1:1 composts which, suggeststhat the composting materials are potentially good organic amendments for improving the fertilizer value of cattle manure. Peak total N mineralization rates for the 1:1 and 2:1 compost types were observed on the 6th and 4th week of incubation, respectively. The association between C: N ratio and N and P releases were positively correlated with R-squared values of 0.33 and 0.35 and 0.70 and 0.74 for N and P respectively of the 1:1 and 2:1 compost types. The 2:1 compost had a higher decomposition rate (k= 0.02) than the 1:1 compost (k = 0.03) and half-life values were 35 and 23 days for the 2:1 and 1:1 compost types, respectively. This suggests that any of the compost types can be effectively used together with or without a small amount of mineral fertiUzer to produce maize, which is a major cereal in Ghana.