Tahsina Sharmin Hoque

Having up-to-date knowledge on the mineralization of organic materials and release of nutrients is of paramount significance to ensure crops’ nutrient demands, increase nutrient use efficiency and ensure the right fertilizer application at the right time. This study seeks to evaluate the mineralization patterns of various manures viz. cowdung (CD), cowdung slurry (CDSL), trichocompost (TC), vermicompost (VC), poultry manure (PM), poultry manure slurry (PMSL), and mungbean residues (MR). The objective being to establish their efficiency in releasing nutrients under aerobic (field capacity) and anaerobic (waterlogging) conditions. The incubation experiment was designed using a Completely Randomized Design (CRD) that took into account three variables: Manures, soil moisture, and incubation period. The mineralization of carbon (C) and nitrogen (N) ranged from 11.2 to 100.1% higher under aerobic conditions rather than anaerobic ones. The first-order kinetic model was used to mineralize both elements. C mineralization was 45.8 to 498.1% higher in an amount from MR under both moisture conditions. For N release, MR and PM exerted maximum amounts in anaerobic and aerobic scenarios, respectively. However, the rate of C and N mineralization was faster in TC compared to other manures in both moisture conditions. Although TC was 1.4 to 37.7% more efficient in terms of rapidity of mineralization, MR and PM performed better concerning the quantity of nutrient release and soil fertility improvement. PM had 22–24% higher N mineralization potential than PMSL while CDSL had 46–56% higher N mineralization potential than CD. C and N mineralization in soil was greater under aerobic conditions compared to what occurred in the anaerobic context. Depending on mineralization potential, the proper type and amount of manure should be added to soil to increase crops’ nutrient use efficiency, which in turn should lead to better crop production.

A good understanding of nutrient release from manure or compost after application through mineralization is important to assure meeting the nutrient demand of crops, to secure timely fertilizer application and to enhance nutrient use efficiency. The current study was done to evaluate phosphorus (P) and sulphur (S) release patterns from different types of manures viz. cow dung, cow dung slurry, tricho-compost, vermicompost, poultry manure, poultry manure slurry and mungbean residues. The mineralization study was performed under aerobic (field capacity) and anaerobic (waterlogging) conditions for 180 days at 25 ± 1 °C in the laboratory. The release of P and S showed the highest values within 75–180 and 75–150 days, respectively, and was always higher in aerobic conditions than in anaerobic conditions. The first-order kinetic cumulative model was a good fit for mineralization, which was significantly influenced by manure type, soil moisture level and incubation period. Poultry manure slurry exerted the highest P and S release under both moisture conditions. Both slurries showed higher potential mineralization, with a lower rate constant for these elements compared to that in their manure states. Hence, appropriate manures should be chosen and applied in the proper quantity to provide exact amounts of nutrients, to increase crops nutrient use efficiency and to formulate correct fertilizer recommendations.