Effects Of Spraying Iron And Magnesium Solutions On Physiological Metabolism And Growth Of Maize And Wheat Seedlings

There are different degrees of iron deficiency, magnesium deficiency phenomenon in alkaline soils of northern China, hence, soil fertilization or foliar spraying of trace elements are effective pathways to promote the crop nutrient balance and enhance crop stress resistance and yield. In this study, we sprayed different concentrations of single and combined FeSO₄?7H₂O solution（250 mg/L、500 mg/L、750 mg/L） and MgSO₄?7H₂O（0.5 g/L、1 g/L、1.5 g/L） on potted seedling stage corn and wheat. And two weeks later, in order to analysis the effects of spraying Fe and Mg liquid fertilizer on carbon metabolism and growth of seedling stage maize and wheat, we measured the physiological indexes of corn and wheat,such as photosynthetic parameters, photosynthetic pigment in leaves,soluble sugar, starch, free amino acids and soluble protein, and we also tested the proline, glutathione, ascorbic acid content and antioxidant enzymes（superoxide dismutase, peroxidase, catalase） activity. The results showed that:（1） Spraying an proper concentrations of Fe and Mg liquid fertilizer not only to promote the leaf area and increase the aboveground biomass of maize leaves, but also significantly increased root biomass, shoot ratio, and promote root growth which had the positive meaning to the growth and late stage development of corn. In physiological and biochemical metabolism, spraying an appropriate concentrations of Fe and Mg liquid fertilizer, it could effectively improve the chlorophyâ…¡ content, photosynthetic capacity and the content of soluble sugar and starch, promote carbon metabolism maize. The most suitable concentration applied for maize seedlings in this experiment is 500 mg/L FeSO₄?7H₂O, 1 g/L MgSO₄?7H₂O, or the mixture of 250 mg/L FeSO₄?7H₂O and 0.5 g/L MgSO₄?7H₂O.（2） After spraying on wheat, an appropriate concentrations of Fe and Mg liquid fertilizer, increased wheat aboveground and root biomass,but had little impact on shoot ratio. In physiological and biochemical metabolism, spraying Fe and Mg liquid fertilizer can increase the content of wheat chlorophyâ…¡ a, chlorophyll b, soluble sugar, starch, soluble protein, promoted carbon metabolism of wheat, which was good for production and accumulation of carbohydrates, the growth and development of wheat seedling. Although the content of wheat glutathione（GSH） and ascorbic acid（ASA） was not changed significantly, but proline content, superoxide dismutase（SOD）, and catalase（CAT） activity were significantly improved, which could improve cold tolerance t, survival ratio of wheat in winter. Spraying Fe and Mg liquid fertilizer can increase wheat tillers significantly, the number of spikelets, per panicle, grain weight and production. The most suitable concentration applied for maize seedlings in this experiment is 500 mg/L FeSO₄?7H₂O, 1.5 g/L MgSO₄?7H₂O, or the mixture of 500 mg/L FeSO₄?7H₂O and 1 g/L MgSO₄?7H₂O.In summary, during the growth of maize and wheat seedlings, spraying appropriate concentrations of FeSO₄?7H₂O solution or MgSO₄?7H₂O solution, could promote its growth and development, improve photosynthetic efficiency, enhance the physiological metabolism; meanwhile, wheat can improve cold tolerance, survival ratio of wheat at low temperature in cold winter, thereby improving yields, thus contributing to next spring wheat growth and yield improvement.