Iron-zinc and phosphorus relationship in the nutritional status of tomato seedlings grown on sandy soils

A surface sandy soil from Wardan (North of Giza Governorate) was treated by mono, di- or tricombinations of 50 and 100 ppm-P, 20 and 40 ppm-Fe as FeSO4, 10 and 20 ppm Fe as Fe-EDDHA, 10 and 20 ppm-Zn as ZnSO4 and 5 and 10 ppm Zn as Zn-EDTA. The main objective of these treatments is to study the availability of such nutrients as well as the growth and nutrient uptake by tomato seedlings grown on sandy soils. The obtained data revealed that the available-P was high in the sandy soil under investigation and that may be due to previous management. Moreover, mono-applications of P, Fe or Zn tended to increase their residual content in the sandy soil after tomato growth. Also, the application of mineral iron or zinc resulted in increase of their residual amount in comparison with the application of the same level of the chelated form. It was clear that applying of 100-P resulted in highly significant increase in the dry matter yield and phosphorus uptake of tomato seedlings. Also, applying of 40 ppm-Fe as FeSO4 in combination with 10 ppm Zn as Zn-EDTA resulted in high concentration and uptake of both Fe and Zn by tomato plants. Also, P/Fe and P/Zn ratios in vegetative growth of tomato plants ranged from 3.06 to 9.82 and 15.28 to 95.65, respectively. These ratios depend on not only nutrient level and form but also on their combinations.