The Use of Dual and Surge Irrigation to Improve The Efficiency of Surface Irrigation

Abstract

A field experiment was conducted in a farm(5km northwest of Ramady City) during Autumn Season in a silty clay loam sedimentary soil. The ground water table depth is 120 cm. Field has divided into 10 strips(2.40x80)m with spaces 1m between strips and 2 m between replicates each strips has divided into 3 furrows (20 cm in depth, 80 m length,with 0.2% slop) with each others.Study factors included Contineous Irrigation (conventional), Dual Contineous irrigation, Contineous irrigation with two phases, Surge irrigation, Dual Surge irrigation Cycle ratio was 0.25 with time On-time 4 minutes and off-time 12 minutes for both dual surge irrigation and surge irrigation with discharge of 2 litter/sec. for both advance phase while the discharge after completing advance phase was 0.8 litter/sec. The plots were planted with corn(Zea mays L)and irrigated drainage water with salinity 5.8-6.2 ds/m, and Euphrates water (1.1-1.3 ds/m). Consumptive water use was calculated by Evaporation Pan method. Twenty test has been carried out for advance and recession of flow along furrow by using eight observation stations. Apportinity time and absorbed water depth in each middle furrow was calculated at each station. Practical and Theoretical relative yield of corn were calculated.Results showed that Dual Surge Irrigation system reduced of salty water used to complete advance phase with rate of 12.41% comparing with Dual Contineous irrigation system, The efficiency of Salt- water displacement proceeses downward increased by 11.56%. by the effect of fresh water under Dual surge irrigation system compared with Dual Contineous Irrigation system, The percentage fresh water saving reached to 44.94% and 51.30% in dual surge and dual Contineous irrigation system respectively, Insert Surge Irrigation technique on Dual Contineous Irrigation system leads to reduce salt- water advance phase time, late in recession time in Dual surge Irrigation and Surge Irrigation with the other treatments during advance and post- advance phase, distribution of Dual surge Irrigation system as compared with dual Contineous irrigation system in salt- water distribution efficiency during advance phase and uniformity of total absorption depth along the furrow for all testing months during the season, theoretical relative yield (RY%) has decreased gradually with increasing in depended depth for calculating the average soil salinity (ECe) with assumption of no mixing between fresh and saline water, practical relative yield exceeds the theoretical relative productivity when assuming the condition of mixing between fresh water and salt water, the practical relative yield has distinction on the theoretical yield at depth of 0-90-cm in Maas 1984 equation.