Enhancing the Chemical Properties and Recovery Rates of Organic Fertilizer through Carbon-to-Nitrogen (C/N) Ratio Manipulations of Biomass Wastes

This research explored the impact of varying carbon-to-nitrogen (C/N) ratios in different organic biomass wastes on compost recovery and chemical properties.Using a split-plot design within a completely randomized setup, the study investigated the outcomes of compost derived from combining poultry manure (PM) with rice straw (RS) and carbonized rice hull (CRH) at different C/N ratios, ranging from 15:1 to 35:1.Chemical analyses revealed distinct characteristics for each biomass waste.CRH exhibited the highest organic carbon (OC) content, followed by RS and PM.PM showed the highest total nitrogen (N) and total phosphorus (P), while CRH had the highest total potassium (K) due to the ash component from its heat treatment.Additionally, PM exhibited the highest total nitrogen-phosphorus-potassium (NPK) content, followed by CRH and RS.CRH displayed the highest C/N ratio, followed by RS and PM.Over a twomonth composting period for the PMRS and PMCRH biomass mixtures, it was observed that increasing C/N ratios enhanced compost recovery but decreased pH, OC, total P, total K, total NPK, and the final C/N ratios of PMRS.Similarly, increasing C/N ratios lowered the pH, total P, total K, and total NPK of PMCRH.Despite these variations, both biomass mixtures consistently produced composts with notably high levels of nitrogen, phosphorus, potassium, and overall NPK.