PARENT SESSION
Special Session 9: Restoration of Mesopotamian Marshes of Iraq
Organized by: CJ Richardson and BG Warner
Tuesday, August 9, 1:30 PM - 5:00 PM, Exhibit Hall 210a-e, Level 2, Palais des congrès de Montréal
Effect of tillage and nitrogen fertilizer on some physical properties of marsh soils and on yields of rice and corn.
Hussain, T.*,1, Al-Ani, A.*,2, Nedawi, I.*,3, 1 Marsh Research Centre, Thee Kar, Iraq2 Ministry of Agriculture, Baghdad, Iraq3 College of Agriculture, Basra, Iraq
ABSTRACT- Marsh soils cover a large area in the southern part of Iraq. Development of agriculture in the area will depend greatly on the optimum use and the efficient management of these soils. This study was conducted in a field site located about 15 km south-west of Sug-Alsheuke town in Thee Kar governorate. The sub-surface layers of these soils have high content of clay and silt which may cause them to act as hardpans. Changes in the soil profile characteristics and yield of rice and corn as affected by deep plowing (0-35 cm) and nitrogen application was investigated in a factorial experiment. The rate of nitrogen application ranged between 0-165 kg/ha and between 0-120 kg/ha for corn. Deep plowing significantly reduced soil bulk density, but increased both mean weight diameter and saturated hydraulic conductivity. Nitrogen rate did not influence bulk density and hydraulic conductivity of all soil layers, but increased the mean weight diameter of the surface layer. Deep plowing, nitrogen application rate, and their interaction increased significantly the yield of rice and corn. Average yield of rice and corn was 3670 and 4978 kg/ha, respectively for surface plowing, but increased to 5375 and 9712 kg/ha, respectively for deep plowing. Nitrogen application increased the average yield of rice from 3825 in the control to 5225 kg/ha when 165 kg of N/ha was added. The yield of corn increased from 5847 in the control to 8368 kg/ha when 165 kg N/ha was added to the soil. The interaction of plowing depth with nitrogen application significantly increased the yield of both crops.
Key words: marshes, Mesopotamia, Iraq, soils