Soil Detachment with Organic Mulching Using Rainfall Simulator in Comparison with a Short Duration Natural Rainfall for Effective Soil Conservation

Abstract

The impact of raindrop on sandy soil was studied using rainfall simulator and natural rainfall to determine average soil detached. Erosion by rainfall is one of the major hazards threatening the productivity of farmlands. This study determined the rate of soil detachment in comparison between natural rainfall and simulated rainfall for effective soil conservation measure. The height of the simulator was varied considering the diameter of the nozzles which were considered during the design stage of the rain simulator. Two plots of dimensions 2 m × 2 m each were cleared with one considered for bare and treated soils for both the natural rainfall and simulated rainfall. Splash cups were installed on each of the plots at half depth of the cup after the clearing of the area at 0.4 m × 0.4 m apart. Two sets of rain gauge were placed at the experimental site to note the volume of natural rainfall on the farm. The average soil detached was analysed using statistical analysis where t-test was also carried out to know the difference in mean. There was a significant difference in the degree of soil detachment between bare and treated soil under natural rainfall experiment; t(18) = 8.917, p < 0.01. The mean of the natural rainfall for the bare soil was 11.6910 compared to that of the treated soil of 7.75. Size of effect (Eta-square (η2) = 0.8154) reveals that the nature of soil accounted for 81.5% variance in the average detachment rate. For simulated experiments with a mean value of 7.3360 have higher tendency of detachment than treated soil with a mean value of 4.2240. Size of effect (Eta-square (η2) = 0.630) reveals that the soil types accounted for 63% variance in the average detachment. It was concluded that 40.33% soil was found to be conserved using the cow dungs mixed with bare soil to compact the soil. The nozzle size, simulator height, rainfall intensity and other rainfall parameters all contributed to the amount of average soil detached.