Comparison of Soil Chemical Properties in Five Different Land Use Systems after Flooding: a Case Study from South India

Climate change is visible as climatic events like flood and drought. Floods have a major impact on soil properties by altering them through dilution, transporting and deposition of minerals. Kerala had a flood on August 2018 with a different duration or temporal variation from three to seven days due to heavy and unexpected rain from June to mid of August 2018, that triggered large landslides on that month. The current study was focussed on the impact of flood on soil chemical properties (pH, soil EC, organic carbon, available NPK) at Thrissur district of Kerala in forest, rubber, nutmeg (homegarden), coconut and open land use systems. Soil samples were collected from flood affected and adjacent non flood affected of these land use systems from 0–20 cm depth after six months of flood and analysed chemical properties according to standard methods. The result of soil pH analysis showed a greater significant decrease in coconut plantation (6.28 to 4.94) after flood. Forest, rubber and homegarden showed an increase in organic carbon (OC) (0.22, 0.77, 0.45% respectively), available P (36.85, 32.6, 38.42 kg/ha respectively). Forest showed a higher amount of available N (84 kg/ha) after flood while rubber, nutmeg and open land use systems showed a decrease in available nitrogen (201.6, 107.1, and 207.9 kg/ha decrease respectively. Forest (196.6 kg/ha), rubber plantation (299.4 kg/ha), nutmeg plantation (292 kg/ha), coconut plantation (421.4 kg/ha) and open condition (125.7 kg/ha) showed a decrease in available K content after flood. Tree based land use systems showed a remarkably better resilience or masked the ill effect of flood very quickly compared to other systems. Integration of shade tolerant species ( Grewia robusta, Ailanthus triphysa and Vateria indica ) in coconut plantation would help the plantation to adapt flood like situation from soil nutrient loss, also it would increase the productivity of land by maximum utilisation of land resources.