|Author:||Ragab, R. ; Malash, N. ; Abdel Gawad, G. ; Arslan, A. ; Ghaibeh, A.|
|Book Group Author:||NA|
Following its successful calibration, the SALTMED model was subjected to testing against field data of a portion of 2002 and all of the 2001 and 2000 growing seasons in both Egypt and Syria. The model proved its ability to handle several hydrodynamic processes acting at the same time. Using data of five complete growing seasons from Syria and Egypt, the model successfully predicted the impact of salinity on yield, water uptake, soil moisture and salinity distribution. The results obtained from the observed and simulated data indicate that tomato cv Floradade is salt tolerant and suitable to grow in the Mediterranean region. The results indicated that a 7 dS/m irrigation water only reduced the yield by 50%. The results indicated that the relation between both yield and water uptake as a function of irrigation water salinity is non linear and is better described by a polynomial function of the fourth order. The use of normalized yield and water uptake obtained by simply dividing the given values by the equivalent values obtained under 100% fresh water eliminates the effect of external factors (seasons, climate, soil, etc.) and produces more consistent and reliable results as originally proposed for normalized yield by Maas and Hoffman [Maas, E.V., Hoffman, G.J., 1977. Crop salt tolerance — current assessment. J. Irrig. Drain., Division ASCE 103, 115–134] and adopted as an accepted practice for both normalized yield and water uptake by many authors Letey et al., 1985 and Shalhevet, 1996. The scaled water uptake can be described by almost the same equation as the one derived for yield. As such, one can use the scaled water uptake function to predict the yield under a given salinity level of irrigation water. The water uptake can be estimated from soil moisture profiles using different techniques. The results proved that the SALTMED model can be considered a useful tool in the management of water, crop and soil under field conditions. The model was developed to be generic, easy and friendly to use. The model is PC based and can run under Windows 95, 98, 2000 and Windows XP operation systems. It is a physically based model and has three built-in databases for soils, crops and irrigation systems. It can be applied on any irrigation system, any soil type, any water quality and any crop. It accounts for soil heterogeneity. It calculates evapotranspiration, bare soil evaporation, plant water uptake, leaching requirements, soil salinity profiles, soil moisture profiles and yield. The model provides academics with a research tool and field managers with a powerful tool to manage their water, crop and soil in an effective way to save water and protect the environment.
|Pages:||89 - 107|
|Journal:||Agricultural Water Management|
crop management, crop yield, irrigation, models, salinity,soil management, soil water, testing, tomatoes, water uptake, Egypt,Syria, Lycopersicon esculentum, West Asia, Asia, Mediterranean Region,Middle East, Developing Countries, Threshold Countries, North Africa,Africa, Lycopersicon, Solanaceae, Solanales, dicotyledons, angiosperms,Spermatophyta, plants, Mathematics and Statistics (ZZ100), Plant WaterRelations (FF062), Soil Physics (JJ300), Plant Production (FF100),Horticultural Crops (FF003) (New March 2000), Soil Water Management(Irrigation and Drainage) (JJ800) (Revised June 2002) [formerly SoilWater Management], Soil Management (JJ900)