Influence of Different Heat Units and Supplementary Irrigation on Barley Production Under Matruh Conditions-Egypt

This study was carried out at Marsa Matruh governorate - western north coast Egypt (31° 15´ 35ʺ N, 27° 9´ 43ʺ E) in the 2017/2018 growing season. The experiment was conducted to assess the different heat units or Accumulative of growing degree-days (AGDD) under various factors [sowing dates, tillage operation and different Supplementary irrigation strategies] on biomass and grain yield production for barley. Thus; the factor of sowing date comprise into three treatments (15th Nov, 30th Nov and 15th Dec). Second factor is tillage with two treatments (no tillage”NT” and tillage 20cm”T”) and the third factor is Supplementary irrigation with three treatments (0, 70and 140mm). thus; The results revealed that the (1 Ton.Fed-1) for (BY)  needs for (585.3, 578.73 and 626.64) heat units (AGDD) as an average under different sowing dates (15th Nov, 30th Nov and 15th Dec.) respectively with tillage treatment “T” . Further; the (1 Ton.Fed-1) from grain yield (GY) needs for (1518) heat units if sowing on the (15th Nov.), for (1531.85) heat units on (30th Nov.) and for (1468.7) heat units on (15th Dec.). on the hand; with no tillage (NT)  the BY and GY need for more heat unit to get (1 Ton.Fed-1) by (683.7,729.7 and 807.6) heat units for BY and (1845.1,1904.1 and 2099.5) heat units for GY under different sowing date (15th Nov, 30th Nov and 15th Dec). Notable; that the highest value for heat uses efficiency (HUE)  observed with (140mm) and tillage operation (T)  under sowing date 15th Nov by (2.06 & 0.76 Kg. fed -1 C-1day-1) for both (BY) and (GY) respectively. However; under sowing date 30th Nov there is not any significant differentiation for heat uses efficiency (HUE) value compare with sowing date 15th Nov which recorded (2.03 & 0.73 Kg. fed -1 C-1day-1) for both (BY) and (GY) respectively. On the other hand; The Aqua Crop model adequately simulated the biomass yield (BY), and grain yield (GY) for barely under different treatments. The simulated (BY) agreed well with the measured (BY) across different treatments where (R2= 0.98 & E = 0.95 & RMSE = 1.17%) for barely under different treatments of (sowing dates and supplementary irrigation strategies) with tillage process. measured and simulated (GY) were also closely related. The Aqua Crop model calibrated the GY with the prediction statistics error by (R2= 0.90 & E = 0.51 & RMSE = 1.18%) with tillage process. Consequently; these results suggest that the good value recorded with tillage (T), (140mm) and 15th Nov. In addition, AquaCrop model could be used to predict BY and GY of barely with a high degree of reliability at western north coast conditions. Thus; using Aqua Crop helps to determine the plantation day which records a highest efficiency for heat units and water productivity. Keywords:  Aqua Crop; Barley production; Heat unit; Sowing date; Supplementary irrigation and Tillage DOI: 10.7176/JNSR/9-14-04 Publication date:July 31st 201