EVALUATION OF WETTING FRONT DETECTOR TO DETERMINE WATER DEMAND, WATER AND CROP PRODUCTIVITY OF SEECTED FODDER VARITIES UNDER SUPPLIMENTAL IRRIGATION (CASE STUDIES IN LEMO AND ANGEACHA AREAS OF SNNP REGION

Abstract

Crop water estimation is relevant to address issues such as proper utilization of water, prediction of crop productivity to design irrigation systems, resources, farm irrigation scheduling and environmental assessment. An experiment was conducted during April to July in 2015 at Jawe and Kerekicho Kebeles in SNNP. The aim was to measure ETc, Kc of Desho grass, oats and vetch fodder crops; with objective of evaluating the WFD (scheduling tool) in terms of biomass yield and water productivity. The study was among two treatments with three replicated plots at each of the study areas and each plot size prepared was 10 m X 10 m. Data collected during the study were: plant height, soil moisture content of the soil, irrigation depth and biomass yield. To determine the ETc of the fodder crops, water balance method was used. Kc of desho grass and oats & vetch fodder crops were computed from measured ETc and ETo which was calculated from weather data. Seasonal ETc of desho grass and oats and vetch was 206 and 186 mm, respectively. K c values of desho grass at early, vegetative, mid and late stages were 0.4, 0.71, 0.89, and 0.72 respectively whereas for oats & vetch was 0.29, 0.89, 1.01, and 0.71, respectively. Evaluation of WFD was tested by one way ANOVA software at a significant level of (p<=0.05). At the mid and late stages of Desho grass, the plant height under WFD treatment was higher than the local practices by 28% and 23% respectively whereas the plant height of oats and vetch under WFD treatment was higher than the local practices at the mid and late season by 23% and 9% respectively. The biomass of desho grass and oats and vetch at the WFD treatment was higher than the local practices by 19% and 21% respectively. The irrigation water productivity difference of desho grass and oats and vetch under WFD treatment was higher than the local practices by 13.5 % and 24% respectively. In conclusion, WFD was better to save time, to have better yield, and to use the water resource effectively and efficiently.