Combined Effect of some Nitrogen and Zinc Sources on some Quality Parameters of Spinach Grown on Salt Affected Soil التأثیر المشترک لبعض مصادر النیتروجین والزنک على بعض مقاییس الجودة للسبانخ النامی علی أرض متأثرة بالأملاح

Abstract

Salinity is a major problem affecting vegetable production in Egypt. Thus, the purpose of this investigation was to evaluate the influence of foliar applications of different sources of zinc [(Z1): Zn-EDTA, (Z2): ZnSO4 and (Z3): without Zn (control)] with both (NH4)2 SO4 and Ca(NO3 )2 combined together with one level as 6 mixed ratios of Ca(NO3 )2 : (NH4)2 SO4 [N1100% Ca(NO3)2 : 0.0% (NH4)2 SO4, N2 75% Ca(NO3)2 : 25% (NH4)2 SO4, N3 50% Ca(NO3 )2 : 50% (NH4)2 SO4, N4 25% Ca(NO3 )2:75% (NH4)2 SO4, N5 0.0% Ca(NO3 )2 : 100% (NH4)2 SO4 and N6 control treatment (without nitrogen)] on some quality parameters and chemical composition of spinach plants grown on salt-affected soil during the winter season of 2018. The experiment was designed in a split-plot design with three replicates. As for most determined parameters at both growth stages (30 and 55 days sowing), the findings indicate that the highest values were recorded with N1 treatment and foliar application of Zn- EDTA (Z1),while the lowest values were recorded under a combination of N6 treatment (without N-fertilization) and Z3 treatment (untreated plants). It can be concluded that; foliar spraying with Zn-EDTA in combination with soil addition of calcium nitrate as a source of N-fertilization is considered the most suitable treatment for overcoming salinity stress in some Egyptian soils and releasing the highest safe yield of spinach plant.