The study looked at how different types of land use affect the quality of soil in the Naban River watershed. They found that converting natural forests to farmland or rubber plantations changed the distribution of soil aggregates, which are important for soil structure. Cornfields and rice-paddy fields had lower levels of certain soil aggregates compared to natural forests. Rubber plantations also showed decreases in soil aggregates after being converted from natural forests for different lengths of time. Overall, the study showed that the type of land use can significantly impact the stability and quality of soil aggregates in the watershed.