Application of Soil and Water Assessment Tool (SWAT) to evaluate the fates of nitrogenous fertilizer in subtropical mountainous watershed tea farms.

Extensive nutrient loss is one of the most challenging issues faced by agricultural production regions worldwide. However, diffuse pollution in the subtropical mountainous watersheds is rarely simulated. A watershed model with regional parameter values is essential for watershed management.

Efficiency of a multi-soil-layering system on wastewater treatment using environment-friendly filter materials.

The multi-soil-layering (MSL) system primarily comprises two parts, specifically, the soil mixture layer (SML) and the permeable layer (PL). In Japan, zeolite is typically used as the permeable layer material. In the present study, zeolite was substituted with comparatively cheaper and more environmentally friendly materials, such as expanded clay aggregates, oyster shells, and already-used granular activated carbon collected from water purification plants.