EFFECT OF IRRIGATION INTERVAL , LEVEL OF IRRIGATION WATER AND EMITTER DISCHARGE ON INFILTRATION RATE IN CLAYEY SOILS

Al-sheikhly, A.H.; Abdul-Rahman, J.N.

	EFFECT OF IRRIGATION INTERVAL , LEVEL OF IRRIGATION WATER AND EMITTER DISCHARGE ON INFILTRATION RATE IN CLAYEY SOILS
The Iraqi Journal of Agricultural Science
Article 1, Volume 42, Issue 0, 2011, Pages 108-125
Authors
A.H. Al-sheikhly; J.N. Abdul-Rahman
Abstract
A field experiment was performed to study the effect of irrigation interval, irrigation level and emitter discharge on infiltration rate in clayey soil, which was planted with okra by using drip irrigation system. The study was designed as a factorial experiment within split-plot design using RCBD in three replicates, A(irrigation interval) was put in main plots and combination between B(irrigation level) and C ( emitter discharge) was put in sub-main plots. The results showed a decrease in infiltration rate and accumulative infiltration at the end of growing season in all treatments in comparison with infiltration rate and accumulative infiltration before planting. Decreasing ratios were 58.7% - 63.7 and 60% - 64% for 3 days and 5 days irrigation interval treatments, respectively. The values of cumulative infiltration were15.5 – 17.3 cm and 14.9 – 16.7 cm for 3 days and 5 days irrigation interval treatments , respectively . the results showed a decrease in the infiltration rate (i) of 5 days irrigation interval in comparison with 3 days irrigation interval . Bulk density of soil profile (0 – 50 cm deep) increased at the end of growing season for all treatments in comparison with their values before planting. Increasing ratios of bulk density for treatments irrigated every three days (3 days irrigation interval) were 10.2% - 12.4% . On the other hand, the increasing ratios of bulk density of soils of the treatments irrigated in 5 days interval, were 11.7% – 14.6%. Saturated hydraulic conductivity (Ks) (as soil profile depth average) decreased in treatments of 3 and 5 days irrigation intervals in comparison with hydraulic conductivity of soil profile befor planting. The decreasing ratios of Ks were 64.7% - 68.9% and 66.6% - 69.9 for both irrigation intervals, respectively. Mean weight diameter decreased at (0 – 30 cm deep) of soils treatments in comparison with MWD values befor planting. The decreasing ratios ranged from 4.4% - 19.6% and 8% - 36.1% in irrigation intervals of 3 days and 5 days, respectively . The values of sorptivity (S) were 0.194 – 0.243 cm min -½ and 0.177 – 0.233 cm min -½ for 3 days and 5 days irrigation interval treatments . The results showed a decrease in (A) values in comparison with Ks .
Main Subjects
Kirkuk University

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