Evaluation of an optimal productivity crop production index as a result of Salinity and sodicity control of alluvial soils of West Nile Nubian plants

Soluble salts commonly encountered in salt-affected soils include those of alkaline metals (sodium and potassium) and alkaline earth metals (calcium and magnesium). Some of these salts are sparingly soluble (carbonates of calcium and magnesium), others are slightly soluble (calcium sulphates) and yet others are moderately to highly soluble (chlorides, nitrates and bicarbonates of calcium and magnesium and all salts of sodium and potassium). The study area has been divided into classes of salinity and sodicity Critical salinity (ECe) and sodicity (SAR) levels have been set for the range of crops being contemplated for the study area. Assuming that a potential yield reduction of 25% is the maximum reduction that could be tolerated for most of the crops, then the permissible ECE level should not be more than 12 DSM-1 and the permissible SAR values should not be more than 24. It is worth mentioning that even at these ECE and SAR values some of the salt sensitive crops might suffer from a reduction in yield that can amount up to 50%. On the other hand, salt tolerant crops will be little affected. Just as crops differ in tolerance to high salt concentrations, they also differ in their ability to withstand high sodium concentrations. Crop growth and development problems on sodic soils can be nutritional (sodium accumulation by plants), associated with poor soil physical conditions, or both. Plants on sodic soils usually show a burning or drying of tissue at leaf edges, progressing inward between veins. General stunting is also common. Crops differ in their ability to tolerate sodicity, but if sodium levels are high enough, all crops can be affected. Generally, soybeans are quite sensitive, corn and grain sorghum are intermediate and wheat and alfalfa are more tolerant. Few sorghum-Sudan hybrids are very tolerant, able to grow on soils with exchangeable sodium percentages above 50%. The above mentioned assumptions are even more important when one has in mind the fact that the Norht Sudan State has more than 16 million ha of arable land areas.