Indigenous Soil Fertility Knowledge of Rainfed Lowland Rice Farmers in Central Laos Indigenous Soil Fertility Knowledge

Abstract

Knowledge of the soil fertility is an important factor in determining crop yield under low or in the absence of chemical fertilizer application and is even more critical under rainfed conditions than in irrigated areas. Here, we report a case study conducted in central Laos in which we identified the criteria farmers use to perceive and evaluate their soils and related their perceptions of soils to both scientific indicators of soil fertility, such as the chemical and physical properties, and rice productivity. In a zoning of paddy fields was performed quickly and accurately, rezoning was unnecessary for conducting the subsequent interviews. The farmers use robust criteria to differentiate their fields. When the farmers’ descriptors of soil quality were compared to the soil analyses, a significant correlation was found only for the topographical land levels. The farmers estimate soil fertility from a holistic viewpoint based on soil descriptors. In the same way on upland rice farmers, lowland rainfed rice farmers use the soil color for soil classification. However, they distinguish the soil fertility from yield levels, indicating that their concept of fertility is related to minimum yield in the area. There were no significant relationships between the farmers’ soil classifications and a scientific understanding of soils in case soil fertility inferred based on soil physico-chemical analyses was low. It is considered that farmers include the water conditions in their concept of paddy field fertility.