Relation of Water and Gypsum Movement in Soil with Different Discharges of Drip Irrigation.

Abstract

Field experiment was conducted to study the relation between movement of water and gypsum and discharge of drip irrigation in gypsifereous soil .Emitters with discharge of 2 , 4 and 8 (L.hˉ¹) were used . Soil samples with gypsum from 85 g. Kgˉ ¹ of surface, soil layer(0-5 cm) and subsurface soil layer (5 - 40 cm) were taken from the field of College of Agriculture -Tikrit university. The samples were air dried and passed through a sieve with 0.2 cm opening .The soil samples were packed and stratified to simulate field conditions in a PVC columns with 18.8 cm inner diameter and 55 cm length . The drip irrigation system was installed and calibrated under pressure of 100 kPa . The efficiency of drip system were 90 , 97 and 97 % for emitters of 2 , 4 and 8 (L.hˉ¹) . The experiment was carried out into two separate groups of columns . in the first group the distribution of water in the soil columns were studied . Volumetric water content (