Performance Comparison Between Open Drip and Sub-surface System a Case Study Mwea Irrigation Agricultural Development Center

Abstract

Around 75% of Kenya's population relies on agriculture for both sustenance and income. About Kenya's two-thirds of the land is semi-arid to arid. Conventional irrigation systems like furrow and has been largely adopted in Kenya due to low investment costs despite having demerits that include soil salinity, water logging, amongst others. From literature, it has been established that water storage, could be an ultimate solution to some of the aforementioned challenges. This therefore calls for investment in modern irrigation technologies like drip (both surface and sub-surface systems). A study on the performance comparison on stable sustenance of sub/surface soil moisture between buried and surface drip system was carried out in Mwea Irrigation Agricultural Development (MIAD) Centre and whose objectives were to investigate the wetting patterns in open and sub-surface systems and determine and recommend the better option of the two systems. The EC-5 Soil Moisture Sensor technique, along with the portable soil moisture monitoring system (TRIME FM), was employed to measure soil volumetric moisture. Water quantity changes (%) were determined through the emitters at 0 cm, 5 cm, and 20 cm depths for all experimental setups. Both irrigation systems underwent similar treatments, with the same water quality 2meters standardized head and 2 liters per hour discharge in all three cases. Frictional and other conveyance losses were assumed to be same in all scenarios. The findings indicated that soil water content increased following an irrigation regime, but gradually decreased over time. Comparatively, the results demonstrated that the moisture in soil was more stable for T2 (5 cm depth placement) in subsurface drip irrigation compared to T1 (open/surface placement) and T3 (20 cm depth dripper placement). Over the same irrigation duration, 20 cm placement had stable water profile than open drip. Mean moisture content for T1, T2 and T3 were 25.98%, 30.09% and 28.45% respectively. The study concluded that subsurface drip irrigation at 5 cm depth (T2) outperforms open drip (T1) and 20 cm depth (T3) in maintaining stable soil moisture. With a mean content of 30.09%, T2 proves superior, indicating its effectiveness for efficient water management in irrigation practices. It is recommended that future research may delve into analysis of performance of open drip vs sub-surface based on specific crop water requirements. The study's results are expected to serve as a valuable guide for water managers and farmers in selecting appropriate irrigation systems for sustainable production practices.