Study of water productivity of wheat and moisture distribution under the influence of center pivot irrigation and different tillage systems for desert soils

A field experiment was conducted to grow the wheat crop during the fall season 2020 in Karbala province, north of Ain Al-Tamr District in two locations of different textures and parent materials. The first site (calcareous soil) with a sandy loam texture, is located at (44° 40' 37') east longitude and (32° 41' 34') north latitude, at an altitude of 32 m above sea level, and an area of 20 hectares. As for the second location (gypsum soil) with a loam texture, it is located at a longitude (45° 41' 39') east and a latitude (33° 43' 34' north) and at an altitude of 33 m above sea level and an area of 20 hectares. To find out the effect of different tillage systems on water productivity and wheat yield under center pivot irrigation system. Two treatments were used in the experiment, The first treatment: four-level tillage systems: zero tillage (T1), Spike pin harrows (T2), disc harrows (T3), and Moldboard plows (T4). As for the second treatment: Soil type with two levels: gypsum soil (G) and calcareous soil (C). The experiment was designed according to a randomized complete block design with three replications. The highest yield of crop and field water was with treatment C with the productivity of 10.40 and 9.82 kg m^-3, respectively and with T1 treatment with yields of 10.10 and 9.50 kg m^-3, respectively. And with the GT1 bi-interaction treatment with yields of 9.30 and 8.80 kg m^-3, respectively and with CT2 treatment with yields of 11.70 and 11.10 kg m^-3, respectively. The treatment of calcareous soil (C) gave the highest value of grain yield, biological yield and 7657 kg ha^-1, 18167 kg ha^-1, respectively. Tillage treatment T1 gave the highest value of grain yield and biological yield of 7735 kg ha^-1 and 18475 kg ha^-1, respectively. The bi- interaction treatment GT1 gave the highest value for grain yield, biological yield 7520 kg ha^-1, 17,980 kg ha-, respectively. The interaction CT2 treatment gave the highest value for grain yield, biological yield 8660 kg ha^-1, 19270 kg ha^-1, respectively. The T1 and T2 tillage system under center pivot irrigation is better in terms of moisture content at all depths and time periods.