Nitrate Accumulation and Oxalate Formation in Spinach Plants (Spinacia oleracea, L.) as Affected by Nitrogen Fertilization levels and Iron Foliar Application.

Abstract

Two field experiments were organized at the Tag Elez Station Experimental Farm; Governorate of Dakahlya, during the two successive winter seasons of . Spinach seeds were sown on 2 nd and 6 th of December, seasons 2014 and 2015, respectively. Ten treatments were arranged in split plot design with 3 replicates to evaluate the combination effect of five levels of N-fertilizer {50, 75, 100, 125 and 150 %} from the recommended dose (RD) by the Ministry of Agric. and Soil Recl. (MASR) in the form of NH 4 NO 3 (33.5% N) as soil application in the presence and absence of Fe as foliar way FeSo 4 (20%Fe) was used as a source of Fe at the rate of 300 ppm Fe. The obtained results indicated that: * A nitrogen fertilizer application at the rates of this survey significantly increased the average values of dry weigh, chlorophyll contents, N, P, K, Fe and VC in the leaves of spinach plant tell the rate of 100% RD. increasing the rate of N-fertilizer from 100% to 150% RD significantly decreased the mean values of all the aforementioned traits during both seasons of the experimentation. At any level of N-fertilization; foliar applied of Fe has been recorded a pronounced high effects on the average values of all parameters under the current study. * Increasing the rate of N-fertilization from 50 to 150%RD sharply and significantly increased the average value of nitrate and nitrite accumulation in spinach leaves, while such effect significantly decreased the activity of nitrate reductase enzyme in spinach plant. Moreover, foliar application of Fe in combination with any rate of N-fertilizer has been corrected this trend. * A favorable effect on oxalate formation in spinach leaves due to an addition of iron in foliar way combined with any level of N-fertilization as compared to the plants treated with the same levels of nitrogen in single form.

Nutritional Value of Savory Herb (Satureja hortensis L.) and Plant Response to Variable Mineral Nutrition Conditions in Various Phases of Development

“…Wala [31], garden savory herb [30], and rocket leaves [37,38]. Plant nitrogen uptake preferences depend on the species and environmental factors [23,39]. An important issue is the synergistic and antagonistic relationship between the forms of nitrogen and the cations or anions taken up by plants [26,40].…”

“…They found a significant effect of the increasing doses of nitrogen (up to 300 kg N∙ha −1 ) on the content of nitrates and manganese in the plants in all development phases. It has also been shown that nitrogen fertilization not only increases the N content in plant tissues, but also changes the concentration of other nutrients [ 20 , 21 , 22 , 23 ].…”

Application of Bio-Stimulants in Comparison with Organic and Mineral N Fertilizers for Growth Promotion of Spinach and Common Bean Grown on Sandy Soil

“…Therefore, they represent modern and suitable alternatives to simple salts, and even to commercial synthetic chelates such as EDTA due to their cheaper price. On sandy clay loam soil under Egyptian conditions, Ghaly et al, (2017) concluded that nitrate accumulated in leaves of spinach was severely increased with increasing nitrogen fertilizer rates up to 150% of the recommended rate while the highest safe yield of spinach plant and the best quality parameters were realized for the plants treated with N-fertilization at the rate of 100% of the recommended rate.…”