Interactive Effects of Silicon and Soil pH on Growth, Yield and Nutrient Uptake of Maize

Priming crop seeds with silicon (Si) to withstand various abiotic stresses is a novel approach. As soil pH affects dissolution of Si pools and Si uptake by plant, evaluation of this approach in relation to soil pH is needed to understand the effectiveness of this method in different types of soil. Pot experiment was conducted to evaluate the interactive effect of seed priming with Si and soil pH on growth, yield and nutrient uptake of maize. Completely randomized design with factorial arrangement was employed where treatments consisted of three Si doses (0, 1 and 2 mM) and four levels of soil pH (5.3, 6.3, 7.4 and 8.1). Overall, Si seed priming with 1 mM provided better performance of maize than did the control (about 11% higher cob length, about 47% more kernel number cob(-1) and about 11% higher grain yield and shoot Si). Soil pH from slightly acidic (6.3) to neutral (7.4) was more favorable for growth, yield and nutrient uptake. Across Si doses, maize produced about 21% more kernel number cob(-1) and about 8% higher grain yield at pH 7.4 than at pH 8.1, whereas plants grown at pH 8.1 had about 60% lower shoot P, about 12% lower soil K and about 21% lower shoot Si than that grown at pH 7.4. The interactive effect of Si and soil pH was mostly nonsignificant indicating the feasibility of Si application across diverse soil pH ranges. Maize performed poorly at extremely low and high soil pH; the recommendation of Si addition should also take this soil parameter into account.