The role of moisture depletion of the two tillage depths and the type of emitters on some physical properties of the soil and water productivity of the yellow maize crop

A field experiment was conducted to determine the role of moisture depletion percentages, two tillage depths, and two types of emitters and their interactions on some soil physical properties and water productivity of yellow maize crop during the fall season of 2024 at the Agricultural Research and Experiment Station - University of Kirkuk. The experiment included three main factors: moisture depletion percentage 45% and moisture depletion 65%, the second factor was two tillage depths (20 and 30) cm, and the third factor was two types of emitters (GR and T-Tape). A split-split plot design with a randomized complete block arrangement (RCBD) was used. The results of the experiment showed that the 45% moisture depletion led to an improvement in the physical properties and showed significant differences in both the total porosity and the weighted average diameter, as the total porosity values reached 48.74% for the 45% moisture depletion, while they reached 38.99% for the 65% moisture depletion. The weighted average diameter values were 1.63 mm for the 45% moisture depletion and 0.85 mm for the 65% moisture depletion. Significant differences were found when using 30cm tillage depth in growth characteristics, crop yield and water productivity. It was found that depth 30 gave the highest values for (leaf area, biological yield and crop water use efficiency) which reached (5088.57cm2, 28.863Mg ha-1 and 3.16kg m-3) respectively, compared to depth 20cm which reached (5930.62cm2, 24.530Mg ha-1 and 2.65kg m-3) respectively. It was also found from the evaluation of the drip irrigation system before and after planting that the values of hydraulic characteristics which include two characteristics, namely the difference in discharge qvar% and the absolute field emission uniformity FEUa% were significantly better before planting compared to the values after planting