Farming Practices and Implications for Water Quality and Sustainability at S’ang, Kandal, Cambodia

Abstract

In Cambodia, the primary water issue is the pollution of surface water by organic and inorganic pollutants linked to agricultural and non-agricultural activities. The objective of this study was to investigate the pressing issue of decreasing water quality linked to agricultural activities using cooperative methods to monitor water quality as influenced by farmer practices. Overall, the goal was to assess the relationship between agricultural runoff and sediment and nutrient levels in local water bodies. As such, this study analyzed the impacts of agricultural practices on water quality in S’ang, Kandal, Cambodia, focusing on farm irrigation, fertilizer application, and manure management via water quality testing, Geographical Information System (GIS) mapping, and qualitative insights from farmer interviews. There were three periods of water sampling, which commenced in May (dry season – with irrigation & fertilizer), August 2024 (wet season – rain-fed period with reduced fertilizer), and March 2025 (dry season – harvest & post-harvest period) to ensure the data captured the complete farming practice and management scenarios. Five farmers participated in the focus group interview. Water samples were analyzed in a laboratory, while Excel was used for data visualization and trend analysis. Nonnumerical Unstructured Data Indexing, Searching, and Theorizing software (NVIVO) facilitated qualitative analysis, identifying themes and patterns from interviews. I found while most parameters such as total nitrogen (TN), total phosphorus (TP), total dissolved solids (TDS), total suspended solids (TSS), and chlorophyll remained within acceptable standards, potassium (K) and turbidity levels frequently exceeded thresholds, particularly during the dry season when fertilizer use and irrigation respectively were most intensive. These elevated K and turbidity levels suggested a strong link between seasonal farming practices and nutrient runoff, although potential contributions from domestic wastewater and industrial sources cannot be ruled out. This study underscored the long-term risks of unmanaged agricultural practices on water quality, potentially affecting both human and ecological health. Promoting best management practices, providing knowledge incentives for sustainable farming, and fostering community-led monitoring programs could help mitigate water contamination. This study provided a critical foundation for improving water resource management in Cambodia and similar agricultural regions globally.