Frequently, the irrigation water is the cause of many management problems. Almost all waters used for irrigation contain inorganic salts in solution. These salts may accumulate within the soil profile to such concentrations that they modify the soil structure, decrease the soil permeability to water, and seriously injure plant growth. Crusting of the surface may affect not only infiltration and soil aeration but also the emergence of seedlings. Cemented conditions of the subsoil layers may hamper root development and water movement characteristics.
Calcareous soils tend to be low in organic matter and available nitrogen.
There may be also problems of potassium and magnesium nutrition as a result of the nutritional imbalance between these elements and calcium. Summary Calcareous soils are soils rich of calcium carbonate which occur mainly in the semi-arid subtropics of both hemispheres. Potential productivity of calcareous soils is high where adequate water and nutrients can be supplied. The management of water and nutrients is the main production challenge. Optimal amounts of water for plant growth have to be provided without wastage, and salts which may affect plant growth have to be controlled.