Influence of Silicon and Soil Texture on Phosphate Fertilization Efficiency of Rainfed Rice Grown in Tropical Soils

Abstract Backgrounds and Aims Silicon (Si) is a beneficial element known to attenuate biotic and abiotic stress in plants. The objective of this study was to verify whether Si increases the efficiency of phosphate fertilization and improves the yield components of rainfed rice grown in tropical soils. Methods The experiment was conducted in a randomized block design and in a 4 × 4 × 2 factorial scheme, with four P levels (0, 50, 100 and 200 mg kg −1 ) four Si levels (0, 240, 480 and 960 mg kg −1 ) and two soil texture types [clay and sandy clay loam (referred to as sandy texture soil)], with four replication. In the flag leaf emergence growth stage to determine shoot biomass, concentrations of Si and P and photosynthetic and water regime parameters and at the end of the experiment to determine grain yield components and pH and available Si and P in soils. Results The applying 960 mg kg⁻ 1 of Si improved the efficiency of phosphate fertilization, specifically at P concentrations of 100 and 200 mg kg⁻ 1 . The Si increases the photosynthesis rate and rice yield components. Conclusion Si can enhance soil-available P and plant P status under acidic conditions without changing soil pH, but these effects were mainly observed at high Si supply and were strongly modulated by soil texture. Si also improved selected yield components.