The Design, Construction and Testing of a Semi-Automated Drainage Lysimeter in Bambili, North West Region of Cameroon

Water is a critical resource in agriculture, and supplying the right amount is essential for healthy plants and optimal productivity. With insufficient water, plants become stressed, unproductive, and may eventually die. In contrast, excess water can lead to diseases, nutritional disorders, and waterlogged soils. To estimate the crop evapotranspiration of carrots, a semi-automated drainage lysimeter with a surface area of 150 cm by 140 cm and a depth of 90 cm was designed, constructed, and tested under the climatic and soil conditions of Bambili in the Northwest Region of Cameroon. The materials used for construction included 12 mm thick metal sheets, soil pebbles/gravel, stones, and a soil moisture tool. The lysimeter was tested by using it to estimate the crop evapotranspiration of carrots (Daucus carota) through the water balance equation. The crop was irrigated daily using a watering can, and the lysimeter was used to monitor rainfall, drainage, and soil moisture. The daily data collected were used to calculate crop evapotranspiration (ETc Lysimeter) using the water balance equation from early June to late August 2022 at three different growth stages: initial, mid, and late. The average crop evapotranspiration from the semi-automated drainage lysimeter (ETc Lysimeter) using the water balance method was 2.6 mm, 3.5 mm, and 3.2 mm for the initial, mid, and late growth stages, respectively. Based on the results of this study, the soil monitoring tool and the weighing lysimeter setup proved to be effective, providing an easy opportunity to estimate crop water use. Hence, the lysimeter can be used to determine the crop evapotranspiration of other related crops.