Soil Salinity and Crop Yield at El-Salam Canal Area, Egypt

Soil salinity and solute movements through the soil are considered the most important challenge facing agriculture in Arid and Semiarid regions (e.g., Egypt). The objective of the present study is to investigate soil salinity problems and different strategies to control or reduce them, and increase crop yield at a national project called the El-Salam Canal service area in north-eastern Egypt. Moreover, the study of solute transport through different types of soil will help in understanding the risk of ground water.

In order to achieve the objectives, one laboratory experiment and two field experiments were conducted. The laboratory experiment investigated the accuracy of the WET sensor compared to the commonly used time domain reflectometry (TDR) technique. In the field experiments, five sites were investigated using both dye as a tracer and the WET sensor for measuring soil salinity. Two sites were investigated concerning the effects of salinity on crop yield using the WET sensor for soil salinity measurements.

The laboratory experiment showed that the WET sensor gave highly accurate dielectric permittivity and bulk soil salinity measurements when compared to TDR. The field experiments showed that the western cultivated clay soil land is more saline than the eastern cultivated loamy sand and sandy soil land. Effects of clay patches resultingfrom deep tillage of a loamy sand soil decreased solute transport and increased soil salinity heterogeneity. Results proved that the fish farming technique is not effective for reducing soil salinity and improving soil properties. Using the DLA model for describing dye penetration resulted in accurate predictionsfor different soil types with different land uses.

The salinity effect on crop yield experiment concluded that a wide distance between ditches or between ditches and canals will make the saline ground water level to rise approaching the soil surface in the middle distance between ditches. This results in increasing soil salinity and decreasing crop yield. A new technique for decreasing distances between ditches by using filled ditches together with open ditches proved to be successful for decreasing soil salinity and improving yield quantity and quality in heavy clay soil.