Long-term experiments comparing the impact on soils and field crops of potassium chloride vs. potassium sulfate.

摘要

Soil salinization is a major source of concern in Mediterranean area. Among the different countries, Egypt represents a unique example in the region. Before the construction of the High Dam in the early 60's, salinization was prevented by annual floods from the Nile, which used to leach out salts naturally contained in the parent rock material. Since that construction, farmers have had to adapt their cropping systems and to use more fertilizers. The choice of fertilizers in that situation is a keyfactor in order to limit salinization. More, the necessary enlargement of cropping acreage in the so-called new reclaimed land is widely based on drip irrigation that increases the risk of salinization. In order to measure the effect of grades of potashon yield and soil salinity, a series of field experiments have been conducted between 1995 and 2000 by the Soil & Water Research Institute of Agricultural Research Center (SWRI-ARC) in cooperation with K+S and SCPA, major European potash producers. Thisfive-year project based on field experiments has been set up in six different locations. Two crops per year were cropped in the same plots, on the base of local rotation practices. The results from the experiments located in the new reclaimed land area shows clearly the detrimental effect of potassium chloride on yield through an accumulation of salts in the soil, while potassium sulfate increases yield and has no incidence on soil.