EFFECT OF SUBSURFACE DRIP IRRIGATION METHODS ON SOME PHYSICAL PROPERTIES OF SOIL, GROWTH AND YIELD OF POTATOES

Abstract

A field experiment has been conducted in Silty Loam soil during agricultural season 2020 in Al-Hamdiya Research Center, north of Ramadi city, located at latitude 33° 27' 10.8" N, longitude 43° 23' 2.4" E. Three methods of subsurface drip irrigation were used, they are partial root-zone drying PRD, subsurface border irrigation SBI and conventional subsurface drip irrigation SDI, and moisture depletion rates are 25% and 50%. The results of the study showed that the PRD irrigation method had a significant effect on the bulk density values both of depths 0-15 and 15-30 cm, as it was 1.28 and 1.32 Mg m-3 respectively, and it had a significant effect on the values of the MWD at a rate of 0.39 and 0. 29 mm, respectively. The moisture depletion was 25% for a depth of 15-30 cm, with the highest MWD of 0.22 mm. The PRD method achieved the highest average values for plant height and leaf area of 45.5 cm and 39.5 dm2 compared to 44.3 cm and 33.9 dm2 when treating the SDI, while it was 45.10, 44.4 cm and 38.33, 33.83 dm2 for the moisture depletion treatments 25 and 50%, respectively. The PRD method achieved the highest average of the total yield when depleting 25% of field capacity with a value of 28.60 Mg ha-1 and the lowest average of 27.08 Mg ha-1 when depleting 50%, while the PRD treatment gave the highest value of total yield amounting to 29.75 Mg ha-1 when depleting 25% of field capacity.