Impact of Different Soil Amendments on Carbon and Nitrogen Mineralization in Ultisols

Quantifying the nutrient mineralization in soils amended with different materials is vital for understanding the nutrient availability for plant uptake. It helps to improve nutrient management by minimizing nutrient loss from the soil. The present research was conducted as a laboratory incubation to assess the nitrogen (N) and carbon (C) mineralization in Ultisols amended with cattle manure, spent poultry layer litter, Gliricidia leaves (Gliricidia sepium), leaf litter compost, urea, and Siam weed leaves (Chromolaena odorata). A Completely Randomized Design (CRD) was used with four replicates, and means were compared with Duncan’s multiple range test (DMRT) after analyzing the data with the SPSS 25 statistical package. CO2-C evolution in amended soils increased up to day 14 of incubation and became stable as incubation progressed. The highest total flux of CO2-C (171.89 g/kg) was obtained in cattle manure-amended soil. Compost-amended soil showed significantly higher (p=0.05) release of mineralized nitrogen (1530.31 mg/kg) over unamended control. The pH in all the amended soils increased over time, with the highest pH in soil amended with compost. Thus, the present study indicated rapid C and N mineralization when different amendments are integrated into the soil.