Macro and Micro-Nutrients Concentrations and Uptake by Maize Seedlings Irrigated with Fresh or Saline Water as Affected by K-Silicate Foliar Fertilization

摘要

Silicon was reported to play a role in increasing plant resistance to biotic and abiotic stress. Pot experiment was conducted in the greenhouse of the "Micronutrient Project", Fertilization Technology Department, National Research Centre, Dokki, Cairo, Egypt with (Zea maize L. var. Pioneer) grown on silty loam soil to study effect of K-silicate foliar fertilization on concentrations and uptake of nutrients by plant seedlings. The plants were sown on mid May, 2012 in Mitscherlich pots contained 7.0 kgsandy sod. The experiment followed the Randomized Complete Block Design (RCBD) with nine treatments, in three replicates. The K-sdicate was foliar sprayed two times in the concentrations of 300, 600 and 900 mg L-1. The first spray was 21 days after sowing and the second was 10 days after the first one. One third of the experimental pots was irrigated with tap water, the second third was irrigated with water contains 4134 mg L"1 saline ions and the last third of pots was irrigated with water contains 5594 mg Lr1 saline ions. Data revealed that despite the increase of sodium concentrations in the seedling tissues due to irrigation with saline water, other nutrient concentrations were slightly affected (p = 0.05). The K-silicate foliar fertilization found also to significantly affect concentrations and uptake of the determined micronutrients iron (Fe), zinc (Zn), manganese (Mn) and copper (Cu). Iron concentration was increased as K-silicate was added in the tissues of both plants irrigated with fresh orsaline water. The best dose was 600-900 mg Lr~(-1). The same trend was almost found with Zn and Mn while Cu showed no trend, however, its concentrations were higher than that determined for control plants. The best dry weight accumulation (4.1 g per plant) was achieved by the treatment 600 mg L~(-1) K-sdicate on the plants irrigated with fresh water. The best dose gave the highest dry matter accumulation with the plants irrigated with saline water was also 600 mg L~(-1)K-silicate with low level salinity (2.8 g per plant) and 300 mg L~(-1) K-silicate with the higher level salinity in irrigation water (2.13 g per plant). Despite K-silicate could keep the concentrations of nutrients in the normal ranges, however, salinity of irrigation water found to interfere with dry matter synthesis and negatively affect dry matter accumulation. Thus, silicon treatment can be only partially alleviating salinity stress on maize plants.