Chemical Properties and Nutrient Composition of Composted Cow Dung as Affected by Duration of Composting and Bulking Plant Materials

A composting experiment was conducted at the Institute of Agricultural Research And Training (I.A.R&T), Moor plantation, Ibadan to evaluate the effects of duration of composting (DC) of cow dung with four plant materials on the chemical properties and nutrient composition of composts. Four cow - dung based composts were made on-farm with siam weed (Chromolaena odorantum L), Tridax (Tridax procumbens L), guinea grass (Panicum maximum L.) and maize (Zea mays L.) stover as composting plant materials (CPM) using the indore method. Composts were sampled at 1, 2, 3, 4 and 5 months after composting and analysed for the pH, organic carbon, effective cation exchange capacity (ECEC), water soluble carbon (WSC), total N, available P, exchangeable cations (K, Ca, Mg and Na). Results showed significant effects of both DC and CPM on chemical properties of composts except available P. The pH, total N, organic carbon and WSC and C: N ratio of compost decreased with increasing DC. Highest levels of total N (6.7 g kg-1) were observed in compost at three months DC. Guinea grass compost (GGC) was highest in pH and WSC. Compost materials and duration of composting therefore need to be considered in formulating compost for organic fertilizers in organic farming.