Jessa May T. Malanguis1, Cheryl C. Batistel1* and Marlito Jose M. Bande2
Land use conversion affects soil ecosystem quality and balance, which can be reflected by microbial activities. This study was conducted to assess the effectiveness of microbial respiration as indicator of soil quality of different land uses, reforestation site, agricultural land and grassland, in Cienda, Gabas, Baybay City, Leyte. The amount of CO2 evolved after one, three and seven days of incubation was used to determine microbial respiration rate of different land uses and across relief. Relationship between microbial respiration on pH, organic matter, total nitrogen, and moisture content at field capacity were also examined.
Results revealed that microbial respiration varies significantly among land uses with the highest rate observed in grassland while the lowest was in the reforestation site. Across relief, amount of CO2 released was significantly higher in the lower slope compared to the upper and the middle. The process tends to be significantly influenced by soil organic matter and moisture content. Results suggest that there is an inverse relationship between microbial respiration and organic matter, and a direct relationship with moisture content. High soil respiration in the grassland and in the lower topographic relief implies that the soil organic matter is converted into inorganic forms which are available for uptake by plants. A significant interaction between land use types and relief was also observed in both organic matter and moisture content leading enhanced microbial respiration. Land use and relief showed no significant effect on total nitrogen and soil pH.
Keywords: microbial respiration, soil quality, land uses, organic matter, decomposition