أثر الری التکمیلی على رفع إنتاجیة أشجار البن وتقدیر کفاءة إضافته تحت نمط ری محسن

Abstract

Water dilemma is the biggest care facing Yemen now and will be more difficult on close future. There are a lot of solutions to treating this problem , such as decrease the water loses by using pipes for water transfer; prohibit the flood irrigation system; determination the actual water consumption for all crops and using the modern irrigation systems. The objectives of this study were knowing the effect of supplement irrigation on rise the production of coffee trees and the irrigation addition efficiency under beneficent irrigation pattern (pips to rings). The study was carried out on farmer field at Wadi Terrs, Al-Shaoba, Taiz governorate. Field soil was heavy texture, light salt and medium fertility. The coffee trees were 15 years old. Four supplementary irrigation head were applied (15, 30, 38 and 45 mm.) and each water head was repeated five times, in other words 20 coffee trees were used in completely randomized design (CRD). The supplemental irrigation was added according to the trees need as seeing by the farmer. It is added through a net which content of reservoir has 4.2 m3 capacity, plastic pipes (PVC), 2 inches diameter and soil rings surrounding the trees. The water transfer efficiency through plastic pipe was 90% and the supply efficiency of this system was 81%. The total rainfall for 2006 season was 846 mm. and the effective rainfall was 518.4 mm. (5184 m3/h). Eight supplementary irrigation were added during the season, so the total volume were 1200, 2200, 2780 and 3300 m3/h. The total water consumption (effective rainfall and supplementary water) were 6384, 7384, 7964 and 8484 m3/h for 15, 30, 38 and 45 mm. water head, respectively. The coffee fruits were collected five times, the first collection was on 28 Aug. 2006 and the last one was on 10 Jan. 2007. Coffee yield weight had been taken at 12% fixed moisture, so it were 1.77, 3.33, 3.57 and 2.83 t/h for 15, 30, 38 and 45 mm. water head, respectively. The statistical analysis showed that there are significant differences just for yield weight and husks percentage, while the general averages of the husks and beans percents for all treatments were 57 and 43%, respectively. The result of this study clarified that the best water head was 38 mm., which gave the highest average yield (3.57 t/h), while the better water use efficiency was 0.46 kg/m3 for 30 mm. head treatment. Finally the average of irrigation addition efficiency which obtained it under the followed irrigation pattern was 81%.