Evaluation Of Irrigation Scheduling Strategies For Enhanced Irrigation Efficiency And Water Conservation – In Perkerra Irrigation Scheme, Kenya

Abstract

Irrigation scheduling refers to the process of defining the most desirable irrigation frequencies and depths. It helps the farmer to know when to irrigate, water flow rate(quantity), and duration of water supply to the farm. It is meant to avoid negative effects of under or over-irrigation. 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. Proper irrigation scheduling will increase farm output and efficient use of water by; minimizing loss of water through runoff and deep percolation, optimizing yield and quality of crops, optimizing costs of pumping that will then save on the energy required and finally reducing the operation and maintenance cost. There is a need to carry out irrigation scheduling study in order to come up with appropriate prediction methods and other measures of reducing leaching of important minerals by percolation and soil erosion (siltation) through surface runoff in the irrigation fields. The main objective of this research is to investigate the most appropriate irrigation interval taking rainfall into consideration. Data collection will include measurements of the soil types, crops sampling, evapotranspiration, soil water monitoring, meteorological data and bed level surveys. The determined results will then be used to determine the most efficient and reliable schedule for future irrigation and also to provide needed information for improvement of irrigation interval for Perkerra Irrigation scheme. The knowledge acquired from the research with Perkerra Irrigation Scheme will also be applied to the real operational potential of schemes with similar conditions as Perkerra Irrigation Scheme. In this study, I briefly review irrigation strategies used in the past/currently used for conserving water in the irrigation fields. Then we define the major strategy that suits the Perkerra region. These measures incorporate the water supply, the amount of water to be conserved, time and space. Knowing the crop water requirements (CWR) is necessary for better irrigation practices, scheduling and efficient use of water since the water supplied by rainfall is very minimal. I will use a CROPWAT model in this project to develop an efficient irrigation schedule for the main crops being grown in Perkerra Irrigation Scheme.