EFFECT OF VARIABLE WATER APPLICATION RATES ON YIELD OF FLAX AND IRRIGATION WATER USE EFFICIENCY

Abstract

Two field experiments were conducted at the Experimental Farm of Sakha Agric. Res. Station during the two successive seasons 2006/2007 and 2007/2008. The aim of this work is to study the influence of irrigation intervals (traditional, irrigation at 60 %depletion of available soil moisture and irrigation at 100 and 80 % of cumulative pan evaporation) and applied irrigation water at flow rates (30 and 60 L/sec) on productivity of flax and some irrigation efficiencies. The design of the experiments were split-plot design. The obtained results could be summarized as follows: Seed yield and other plant parameters such as plant height, , capsules number per plant and protein content had significantly affected with various irrigation treatments. Irrigation at 100%, 80% from cumulative pan evaporation and 50%depletion of available soil moisture were superior to traditional treatment, respectively. Irrigation at 100 % pan evaporation recorded the highest values of flax seed yield (540.8 and 539.4 kg/fed.), straw yield(3.545and3.767ton/fed.),plant height(114.9 and 116.2cm), technical length (101.8 and 100.5cm)and capsules number per plant(13.93and14.89)in the first and second seasons, respectively Irrigation of flax plants at 60 % depletion of available soil moisture resulted in the highest oil content (41.98 and 40.4 %) in the first and second seasons, respectively. Irrigation at high flow rate( 60 L/sec) increased values of plant height, technical length, number of capsules per plant, seed yield, straw yield, oil and protein contents compared to low flow rate (30L/ Sec.)in the two growing seasons. ● The interaction between irrigation intervals and flow rate (I x F) had significant effects on the technical length in the 1st season, while in the2nd season, the interaction had a significant effect on all parameters except seeds yield and protein content. - The lowest values of water applied (1914.83 and 1967.6m3 /fed.) were found under irrigation at 100 % pan evaporation , while the highest values of water applied (2463.5and 2530.5 m3/fed.) were recorded with traditional irrigation in the 1st and 2nd seasons, respectively. - The amount of water applied (2266.23 and 2334.2m3/fed.) with flow rate of 30 L/sec. was higher than that 2087.9 and 2140.1m3/fed. with flow rate of 60 L/sec in the 1st and 2nd seasons, respectively. - Water consumptive use (m3/fed) generally behaved the same trend of water applied for all treatments. - Water application efficiency values were higher with treatments which irrigated at 100% and 80% from cumulative pan evaporation and 60%depletion from available water than traditional treatment. Also, the values were increased with increasing flow rate. Irrigation losses had almost the opposite trend to that encountered with water application efficiency. - The highest average values of CWUE and FWUE were recorded under irrigation at 100 % pan evaporation and flow rate of 60 L/sec. in the two growing seasons. - Irrigation at 80 % from cumulative pan evaporation achieved the highest value of water application efficiency (77.00 and 76.91%) in the 1st and 2nd seasons, respectively. It can be recommended to use evaporation pan class A in irrigation scheduling (proper time and amount of water) to maximize the return from unit of water applied and save irrigation water.