Agro-ecological Assessment of the Preponderance of Rill Erosion Channels under Different Land Cover Types in Humid Tropics of Akamkpa, Southeastern Nigeria

Abstract

Agro-ecological assessment of proliferation of rill erosion channels in the humid tropic was conducted between January and July 2022. The purpose of the study was to seek possibility of preventing proliferation of rill erosion channels using a variety of crops; vetiver grass, potato plant, groundnut and fallow vegetation in erosion control. Different land slopes of 4, 5 and 6 per cents representing blocks 1,2 and 3 were used for the study. Soil samples were collected from each unit for laboratory determination of soil textural characteristics. Plots dimension of 10m x 80m were delineated on each slope to form a block. Sub plots of 10m x 10m were delineated from each block for each crops cover types. In-situ measurement of parameters, viz; number of rill erosion channels, length, width and depth of channels were accomplished. The total number of rill channels from each crops’ plot was statistically analyzed to determine their Coefficient of Variation (CV). The CV values for vetiver, potatoes, groundnut, fallow vegetation and control plot indicated; 40.50%, 31.11%, 60.62%, 38.00% and 62.50% respectively. Result of channel characteristics showed that fallow plot recorded the lowest number of channels of 1.8, width of 2.3cm and length of 142.5cm respectively. Average length and depth recorded in vetiver plots are 143cm and 1.6cm, Potatoes has a total depth of 2.2cm and length of 194.3cm. Similar result was recorded in fallow plot, indicating that vetiver, potatoes and fallow vegetation exhibited similar erosion control potential. Conversely, the highest length, width and depth and number of rill channels were traced to control plot with a mean of 3.8 spillways, depth of 4.8cm, width of 25.8cm and mean length of 312.5cm seconded by groundnut plot. Implying, soil protection as well as crop production can be guaranteed with the right choice of crops in the humid tropics