Physicochemical Properties of Soil in Flood Affected and Non-affected Areas of Rajapur, Bardiya

Flood is one of the most frequently occurring natural disasters that affect billions of people worldwide. In Nepal, flood causes destruction of life and property in Terai region due to heavy seasonal rainfall. Flood changes the soil quality by altering the nutrient composition and by heavy sediment transport. In Rajapur, Bardiya, Karnali River in the west causes floods and inundation in fertile and cultivable land. Specific objectives of this research were to assess the physicochemical and biological properties of soil and compare the properties in flood-affected areas and non-affected areas. Soil nutrients were analyzed in lab, using Kjeldahl method for nitrogen, Modified Olsen’s bicarbonate method for phosphorus, Flame photometric method for potassium, Walkley and Black method for organic matter, pH meter for pH and moisture content, and Bouyoucos hydrometer method for soil texture. In this research, the results showed that flood changes physicochemical properties in soil but the extent of the damage depends upon different factors like landforms, texture, and land use land cover. More specifically, the data reflected that nutrient contents were significantly different in agricultural area in active alluvial plain, where nitrogen decreased by 0.03 % in 0- 15 cm depth, phosphorus decreased by 4.12 kg/ha in 0-15 cm depth and 6.8 kg/ha in 15-30 cm, potassium increased by 102.14 kg/ha in 0-15 cm depth, and organic carbon decreased by 0.29% in flood-affected areas. But the nutrients were not significantly different in recent alluvial plain. The conclusion showed that flood did not necessary decrease the nutrient content and the impact was not consistent across different landform. This research provided a brief picture of nutrient content in soil in Rajapur, Bardiya, which can be a valuable tool for local farmers to determine the type of crops and need of suitable fertilizer for desired outcome.