TOMATO GROWTH IN CALCAREOUS SOILS IN RELATION TO FORMS AND LEVELS OF SOME MACRO- AND MICRONUTRIENTS

A pot experiment was carried out using two surface soil samples from north-western coast of Egypt, to study the effect of different levels and forms of phosphorus, iron and zinc on their availability in soils was as well as dry matter yield of vegetative growth and the total uptake of such nutrients by tomato plants. Obtained data reveal that increasing Fe or Zn levels either mineral or chelated form as well as P-level tended to increase their residual values in the studied soils. The highest residual values being obtained were by application of 100 ppm P + 40 ppm Fe as FeSO4 and 100 ppm P + 20 ppm ZnSO4. Therefore, application of Fe or Zn in chelated form resulted in low residual amount in soils and increased their uptake by plant growth. Concerning tomato seedlings, the dry matter yield is highly increased by application of tri-combination P x Fe x Zn in comparison with application of mono- or di treatments. Phosphorus concentration and its total uptake highly increased by mono-application of phosphorus. Moreover, applying high level of 100 ppm P in combination with Fe and Zn decreased the concentration and total uptake of Fe and Zn in those plants grown in Sedi-Henish area. Concerning P/Fe and P/Zn ratios in tomato plants were highly depended on the nutrient level and form as well as the optimum combinations between them.