Evaluation of Wood Ash as Additive for Cow Manure Composting

This study was conducted to produce high-quality compost using both cow manure and wood ash that can specifically be used to increase the fertility of soils in tropical regions. Increased proportions of wood ash were co-composted with cow manure. During composting, the composts produced presented the classical composting temperature curve and attain a thermophilic composting phase (about 60 oC). After 117 days of composting, the produced composts (CMA 0%; CMA 5%; CMA 10% and CMA15%) had a C/N ratio between 16 and 30, and their pH, was basic, indicating maturity.  They were rich in minerals (Mg; Ca; K+; and Na+) and poor in heavy metals (Zn; Cu and Pb). Wood ash addition raise the fungal communities except for CMA 0% and did not impair significantly on bacteria communities; however, addition of high amounts of wood ash could reduce the metabolism of the microbial communities including cellulase activity that showed a proportional decrease according to the added amount except for CMA 15%. The composts showed a germination index greater than 80% at all concentrations, indicating the absence of phytotoxicity. Therefore, co-composting of cow manure with wood ash (<15%) allowed to obtain a good organic fertilizer with higher liming potential, nutrient content, and less hazardous material which could be used in farms to remediate acidity of tropical soils

Effects of Cattle Manure Wood-Ash Compost on Some Chemical, Physical and Microbial Properties of Two Acid Tropical Soils

A field study was conducted to assess the potential of cattle manure wood-ash compost in order to improve soil fertility and productivity in two areas in the centre region of Cameroon distant of 200 km. The farms were amended with four types of compost, C1 (100% cattle manure compost), C2 (95% cattle manure with 10% wood ash admixture), C3 (90% cattle manure compost and 10% wood ash admixture), and C4 (85% cattle manure compost and 15% wood ash admixture).  Soybean was the growing plant during the experiment which lasted three months. After the harvesting, physical, chemical, biological and plant parameters were evaluated. The compost significantly increased soil pH, Electrical conductivity, total organic carbon, total nitrogen, concentrations of Ca2+, Mg2+, K+, Na+, and total phosphorus. The composts also had a stimulatory effect on the total soil bacteria and fungi, cellulase and protease activities. Improvement soil physical, chemical and microbial parameters enhanced biomass production and yield. In summary, cattle manure wood-ash composts could be used for alleviating soil acidity and improve soil fertility of tropical acid soils. Future research is needed to address its sustainability in a long-term study