| Summary: | Food security issue has been one of the focuses in sustainable development goals due to growing global population. One of the resolutions in respond of this challenge is through efficient agricultural, land and crop management. Therefore, evaluation of soil health is crucial. Research was organized to characterize the physical, chemical and biological properties of sandy soil based on five treatments (0, 5, 15, 25 and 35 %) of food waste compost (FWC) amended soil. The experiment was conducted in laboratory to assess severity of soil properties in particular soil texture, pH, electric conductivity (EC), moisture content, soil organic matter (SOM), total carbon (TC), total nitrogen (TN) and C/N ratio effect the soil respiration (Rs) which involve in carbon cycling. In addition, germination index was conducted to determine the root growth for all five treatments. These data were used to evaluate the performance of five different Rs models in predicting the soil CO2 efflux. The models included are: 1) CASA model for total carbon (TC), 2) Stanford and Epstein model for soil moisture (SM), 3) Rs C/N model that incorporates C/N ratio, 4) linear regression between Rs and pH and EC (Rs pH EC), 5) Rs SOM model. The results showed that 25 % FWC amended soil (w/w) with indigenous microorganisms (6.1 x 107 colony forming unit (CFU)) produced the best results for C/N ratio (11.9) and enhanced the soil respiration. In addition, 25 % FWC amended soil shows higher germination index (125 %). A balance of carbon and nitrogen is required for microorganism to carry out their metabolic processes effectively. Organic material with high C/N ratio tends to reduce nitrogen from soil due to microorganism activities that consume nitrogen to compensate the carbon-rich material, potentially affecting plant growth. For the correlative models, the results showed that the Rs SOM model performed the best by capturing the variations of Rs quite well and having model testing average coefficient of determination (R2) of 0.74. Performance of the Rs pH EC was also adequate with average testing R2 of 0.71. This study highlights the challenges and significance of environmental controls such as organic matter, pH and EC on the simulation of Rs in FWC amended soil. Furthermore, this study can be used as tools for future development of in-situ microbial indicator for monitoring and managing sustainable soil health in Malaysia region.
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