International Journal of Science and Research (IJSR) ISSN: 2319-7064 SJIF (2019): 7.583 Volume 10 Issue 4, April 2021 www.ijsr.net Licensed Under Creative Commons Attribution CC BY Evaluation of the Effectiveness of the Current Irrigation Scheduling Strategies in Perkerra Irrigation Scheme, Kenya Kennedy O. Okuku 1 , Japheth O. Onyando 2 1 Masters graduate in Water Engineering, Pan African University Institute of Water and Energy Sciences (including climate change) –PAUWES, Tlemcen, Algeria okukukennedy[at]yahoo.com 2 Professor of Soil and Water Engineering, Chairman of Department – Agricultural Engineering Department, Egerton University P. O. Box 536, NJORO-KENYA jonyando[at]gmail.com Abstract: Irrigation scheduling helps the farmer to know when to irrigate, water flow rate (quantity), and duration of water supply to the farm. Improper irrigation activities can lead to irrigation water loss by percolation and surface runoff, soil erosion due to surface runoff, leaching of the useful minerals through percolation, high energy consumption in pumping irrigation water and increase in operation and maintenance cost. Irrigation scheduling can help in reducing such problems and boost productivity. The main objective of this study was to evaluate the effectiveness of the irrigation scheduling strategies that are currently being practiced in Perkerra irrigation scheme. Four fields of 0.5 ha in average cultivated with maize crop, were selected to assess and compare irrigation water use efficiencies. Data collection included soil types, crops grown, soil water monitoring, meteorological data, irrigation system, discharge received per plot level and a total times irrigation is done. The average interval for applying irrigation water was found to be 2 to 3 days irrespective of rainfall. Over- irrigation to saturation is common in Perkerra Irrigation Scheme. Measurements carried out on the Perkerra irrigation scheme showed that there can be losses of more than 100%. The water use efficiency in PIS is very low and there should be improvements. The determined results were then used to evaluate the most efficient and reliable schedule for future irrigation and also to provide needed information for improvement of irrigation interval for Perkerra Irrigation scheme. Keywords: Evaluation of performances; Irrigation scheduling; Water scarcity; Irrigation efficiency; Evapotranspiration. 1. Introduction Irrigation is the artificial application of water to the soil to supplement water required for plant growth (FAO, 1996). Scheduling refers to the sequence of events in a chronological order in which water application is intended to take place. Therefore, Irrigation scheduling refers to the process of defining the most desirable irrigation frequencies and depths. It is meant to avoid negative effects of under or over-irrigation while maximizing on the crop yield (Kamble et al., 2013). Irrigation scheduling entails the determination of the right amount of water required by crops and estimation of the sequence to apply the water to crops. Water scarcity has been a major problem in many African countries. The scarcity may be due to theclimate change, increasing demand for freshwater by the competing users in various sectors like industries and the problems caused by the environmental destruction such as desertification and over- exploitation of the water resources (Adeboye et al., 2009). Kenya has one of the most skewed distributions of income amongst low-income economies in the world (Ngigi, 2002). Approximately 56% of its entire population live below the poverty line out of which 80% are living in the rural areas. More than 75% of the entire population in the rural area depends on agriculture for their livelihoods (FAO, 1996). Rainfall has been insufficient to grow crops in most parts of the world as rain-fed food production is affected by the change in rainfall (Levidow et al., 2014). Therefore, to increase crop production irrigation is the only option to be adopted. Irrigation infrastructure has increased over the quarter of the past century, for example, limited surface water has been diverted and groundwater exploited for irrigation purpose. The area under irrigation has escalated by 25% over a period of three decades (FAO, FIDA, and PMA, 2015). However, in recent times, the irrigation expansion rate has reduced because of the unreliable surface water and over-exploitation of the groundwater resources (Smith, 2000). There is an immediate need to decrease losses of water for irrigation and establish an effective irrigation strategy and management. This implies that water abstracted for irrigation is not efficiently used for crop growth due to losses. Only 45% of the water supplied to crops is taken up by the crop, with an estimated 15, 15 and 25% being lost in the water conveyance, water field channels and inefficient application on the agricultural land respectively (FAO, 2012). Paper ID: SR21423005511 DOI: 10.21275/SR21423005511 1192