An experiment was conducted for identifying the most efficient tillage method using the sub-soiling plough for enhancing some of physical properties of the heavy clayey soils. The experiment was conducted on a heavy clayey soil of an area 1800 m² located in Serewa village -Belqas -Daqahlia. This area divided into 4 adjacent plots, each one has a dimensions of (9m x50m) and was allocated only, for one treatment. The surface irrigation was the system applied and the amount of irrigation water added was equal for each plot (22.5m³) and was applied at the same time for all plots. Furthermore, an accounting for the rate of water flux in mm/day beneath soil profile along subsequent ten days from saturation was the last objective of this research. Only, four treatments were involved in this research as (Treat.1): subsoiling plough at 40cm depth with a lateral spacing of 150cm, (T2): sub-soiling plough at 60cm depth with a lateral spacing of 150cm, (T3): sub-soiling plough at 40cm depth with a lateral spacing of 300cm and (T4): sub-soiling plough at 60cm with a lateral spacing of 300cm. For all plots, the sub-soiling plough was followed by chisel plough at 20cm depth and laser-controlled leveller at the dead level. All the data obtained clearly indicated that, the second treatment (T2) achieved the highest mean value of soil infiltration rate (2.2 mm/h) over all treatments and the lowest mean values for the cone penetration resistance, water content and bulk density at the surface layer of soil profile after tillage (2.41 M.Pa), (17.74 % w/w) and (1.17 g/cm³), respectively. Whereas, at saturation, it achieved the highest mean value of the water content (62.78 %w/w) and the lowest mean value of penetration resistance (.01 M.Pa). On the other hand, the mean value of the water content rested in the soil of the second treatment at the tenth day from saturation was (24.68 %w/w), producing the highest water flux (4.29 mm/day). Also, the second treatment achieved the shortest period of time needed until all amount of the deluge imposed on the soil surface after irrigation be completely infiltrated (20 h.).

Scarce water resources management makes accurate measurements of different parameters of water requirements very critical. Therefore, the values for crop evapotranspiration and crop water requirement are identical. Crop water requirements refer to the amount of water that is needed to be supplied efficiently. Therefore, there are many models and tools which were used in this study are used in this study as a practical tool to calculate actual evapotranspiration such as the CROPWAT model. Moreover, Eddy Covariance and ET-Watch model are methods used to estimate evapotranspiration. The main goal of the study was to assess daily and decadal actual evapotranspiration using Eddy covariance and ET-Watch model under arid land conditions then compare results with CROPWAT model result. Egypt was used as an example. Results showed that Eddy covariance ETa values for both crops were lower than ETa values from CROPWAT, while ET-Watch values were somewhat close to CROPWAT values. For cotton, the intercept of the linear relationship for daily ETa were 1.737 and 2.15, respectively between Eddy covariance and CROPWAT. For decadal ETa were 1.91, 2.039 ETWatch and CROPWAT. While for wheat crop, the intercept of the linear relationship for daily ETa were 1.09 and 0.663, respectively between Eddy covariance and CROPWAT, ETWatch and CROPWAT. For decadal ETa were 1.101 and 0.69. Its highly recommended to use ETWatch when predicting daily ETa, while for decadal ETa both Eddy covariance and ETWatch could be used with no big differences.