Rapid estimation of nutrients in chicken manure during plant-field composting using physicochemical properties

Regression equations which relate livestock and poultry manure nutrient content to its several physicochemical properties have been reported by previous researchers. This study explores the feasibility and efficiency to determine the nutrients (TN; TP; TK; Cu and Zn) in chicken manure during composting using physicochemical properties (pH, EC and DM), and compares the performances of regression equations in this study with those in the literature. The results show that DM is the best predictor to construct the single linear regressions for all the nutrients (R2 ⩾ 0.84, p < 0.001). In addition, the multiple linear regression equations based on DM and pH are all notable. These findings show the potential of physicochemical models for TN, TP, TK, Cu and Zn with more convenience and rapidness, but further research is needed to develop better models with higher accuracy for the above and other more nutrients.