Hydroponic Water Requirement Estimation for Cucumber Using FAO-CROPWAT Model in Awka, Anambra State, Nigeria.

Abstract

Anambra State faces water scarcity which mostly occurs in many communities, particularly in Ifite Awka, and agricultural water use is progressively becoming more limited in the light of growing water demands of these various communities.Consequently, available water has not been satisfying demand both in quantity and quality in relation to the booming population of the nation for domestic, industrial and agricultural purposes. The aim of this study was to use CROPWAT model in estimating the water need for cucumber using10-year climate data (2008-2018) of Awka. This study was carried on Cucumber (Cucumis sativusL. ‗Loeica‘) which was grown in a specifically designed urethane based recyclable plant growth substrate (UBS) during nursery stage and carbonized rice husk during post nursery stage in a Dutch Bucket Hydroponic production system using gravity-fed drip fertigation techniques. The performance of the test crop in a controlled environment was determined with data analyzed in a completely randomized design (CRD). Crop water requirement was determined using 10-year climate data in CROPWAT version 8 software. Reference crop evapotranspiration (ETo) was also determined using the Food and Agricultural Organizaton (FAO) Penman-Monteith method. Four crop growth stages: initial stage, development stage, mid-season and late season stage were considered. The study shows that reference evapotranspiration (ETo) varies from 2.5 to 3.36 mm/day for the area under study. The gross water requirement was 342.42 mm/year with an application efficiency of 70%. Thus the drip irrigation set up can conveniently supply the water required for crop use in the area. In this way the locally fabricated gravity-fed drip irrigation system was found significant to conveniently supply the water required for irrigation in the area but there is need for automating the setup by adding a timer that will detect when to apply water.