Rice (Oryza Sativa L.) Tolerance to Drought Can Be Improved by Silicon Application

The aims of this work were to assess the effect of drought and silicon on rice growth and productivity. A completely randomized design pot experiment with three replications was conducted in a clay soil with five levels of soil moisture content (SMC) (70, 80, 90, 100, and 120% of the soil saturation point) and five rates of Si (0, 2.1, 4.2, 6.3, and 8.4 mg Si/10 plants). When SMC was reduced from 120% to 70%, plant height, rice straw, root yield, and grain yield significantly reduced with 32, 52, 36, and 27%, respectively; however, when Si rate increased from 0.0 to 8.4 mg/10 plants, they significantly increased by 38, 97, 49, and 106%, respectively. At the SMC of 70%, when Si rate increased from 0.0 to 6.3 mg/10 plants, N, P, K, and Si concentrations in straw increased by 42, 59, 36, and 53%, respectively.