U. Kafkafi
B. Bar‐Yosef
Large areas of the world consist of marginal desert soils. Introducing these soils to agricultural production requires development of new irrigation and fertilization techniques. This study was conducted to test the hypothesis that such soils can be used provided one can control soil water content and nutrient concentration of the soil solution in the root zone by supplying nutrients daily through a trickle irrigation system.
Six fertilizer combinations at two irrigation levels were tested on a tomato crop of a determinate type of growth (Lycopersicum esculantum var. S‐5), grown on a virgin desert soil containing 85% calcium carbonate and EC of 7 mmho/cm. The highest yield, 80 tons/ha, was obtained with 400 mm water (40% of evaporation from a Class A pan) plus KNO3, superphosphate, and KH2PO4 fertilizers. In the root volume of this treatment the nitrate concentration in the soil solution was about 160 ± 30 ppm NO3‐N throughout the season. A total soil water potential of about −2 to −4 bars during the first month of growth resulted in a lower canopy yield but earlier fruit ripening as compared with total water potential of −1 to −2 bars.
