Plant Archives Volume 20 No. 2, 2020 pp. 7763-7771 e-ISSN:2581-6063 (online), ISSN:0972-5210 *Author for correspondence : E-mail: marwannasr91@yahoo.com THE EFFECT OF LASER LAND LEVELLING, TILLAGE AND DISCHARGE ON THE PERFORMANCE INDICATORS OF BORDER STRIP IRRIGATION AND THE REFLECTION OF THAT ON THE DEPTH OF WASTED IRRIGATION WATER Marwan Musa Nasr 1 *, Alaa Salih Ati 1 and Abdul Khalick Salih Nima 2 1* Department of Soil and Water Sciences, College of Agriculture Engineering Sciences, University of Baghdad, Iraq. 2 Ministry of Agriculture, Office of Agricultural Research, Iraq. Abstract A field experiment was conducted in the field of the national program for wheat development in Iraq-The Ministry of Agriculture in the Al-Rashid-Adwaniyah region, located on latitude 33° 13' 93.59" N, and longitude 44° 37' 91.37" E, at an altitude of 31 m above MSL, during the autumn season of the year 2018 AD, to know the effect of laser land leveling, tillage and discharge on the performance indicators of border strip irrigation and the reflection of that on the depth of wasted irrigation water. The experiment consisted of three treatments. The first was the slope percentage of the soil surface leveling, with three levels: the conventional leveling (L 0 ), the leveling with the slope percentage of 0.15% (L 1 ), and the leveling with the slope percentage of 0.30% (L 2 ). The second was the tillage equipment with two levels: the mold board plow (T 1 ) and the chisel plow (T 2 ). The third was the discharge rate with two levels: discharge rate of 16 L sec -1 (Q 1 ), and discharge rate of 24 L sec -1 (Q 2 ). The experiment was designed according to the design of randomized complete block design RCBD with three replicates. The gravimetric method was adopted for measuring soil water. The most important results obtained can be summarized by the irrigation performance indicators: adequacy, Christiansen’s coefficient, distribution uniformity and storage efficiency, recorded their highest indicators with the leveling slope ratio treatment, with L 1 level at 86.09, 89.48, 84.51 and 86.09%, Respectively. With the tillage equipment treatment, the highest irrigation performance indicators were recorded, with T 1 level of 87.36, 88.10, 82.07 and 87.36%, respectively. With the discharge rate treatment, the highest percentage was recorded in Christiansen’s coefficient and the distribution uniformity with Q 1 level of 88.61 and 83.23%, respectively. And in the adequacy and storage efficiency with Q 2 level of 84.71 and 84.71%, respectively. Key words : laser leveling, tillage, discharge, performance indicators of irrigation, depth of wasted irrigation water. Introduction The gap between water supplies and water demand is increasing in many areas of the world: in those areas already suffering water lacking, increasing drought will be the major constraint to agricultural growth and development. Climate changes will cause, above all, a decrease in annual water availability in many areas of the world. Water availability will decrease more and more due to the continuous decline of summer rainfall and in the face of high water demands for cultivations. More than 60 per cent of irrigation water is lost during the conveyance and application in the field. Farmers either under or over irrigate their fields resulting into loss of yield, low water use productivity and low fertilizer-use efficiencies. The determined crop water requirements indicate that there is enormous potential for water saving if it is applied according to crop’s requirement. Understanding the indicators of irrigation performance helps us to know the depth of wasted water and take arrangements to reduce the depth of wasted water. So this review paper was made to know measuring the depth