ABSTRACT
Rice (Oryza sativa L.) is the main crop after wheat in Iran, and these two are the main suppliers of calories for the Iranian people. Overusing fertilizers and toxins of chemicals has caused environmental pollution. One of the applied methods for reducing this status is using silicon fertilizer in the paddy field. The process of exchange and absorption of nutrient elements is used in the rhizosphere environment. Silicon absorption was independent of the water absorption rate in rice plants. The state of the dissolved silicon differs depending on the pH of the solution and nutritional status. Addition of calcium silicate increased the levels of silicon, phosphorus, calcium, and copper, and reduced the levels of nitrogen, potassium, manganese, and zinc in the leaf of rice. It has been held that an abundant portion of silicon is needed for rice to grow, indicating the predominant role of silicon in rice production. Photosynthesis produces 90% of dry matter and is influenced by diverse factors, including light, CO2, water, and mineral nutrients. Leaf area increases are augmented by silicon; furthermore, silicon causes the leaves to be erect, positively influencing crop photosynthesis. The addition of silicon does not play a role in the photosynthesis rate, stomatal conductance, and transpiration. However, it has been observed that the amounts of chlorophyll a and b and total chlorophyll are augmented in flowering stage. These amendments could be correlated with an enhancement in the level of sodium and potassium silicate fertilizers. Silicon at the cellular scale increased the cuticle thickness and cell diameter of the parenchyma, xylem, and vessel phloem. Silicon decreased the protein, Fe, Mn, and Zn of leaves of the Shiroodi variety. Application of 250-500 kg·ha-1 silicon fertilizer also decreased the amount of stem borer pollution and blast, and as a result, yield improved about 5% in the field and 24% in pot
18.1 Introduction ..........................................................................................................................344 18.2 Paddy Soils ...........................................................................................................................344 18.3 Rice Rhizosphere ..................................................................................................................344 18.4 Silicon in Paddy Soil ............................................................................................................ 345 18.5 Silicon in Rice Plants ............................................................................................................ 345 18.6 Silicon Uptake ......................................................................................................................346 18.7 Factors Affecting Silicon Uptake .........................................................................................346 18.8 Recent Advances of Silicon in Improving the Growth and Yield of Rice in Iran ................346 18.9 Future Perspectives ............................................................................................................... 351 References ...................................................................................................................................... 352
experiment. Therefore, it is recommended that silicon fertilizers like granule, ligules, and nanosilicon be used in the paddy fields of north Iran to improve the growth and yield and reduce the biotic and abiotic stresses in paddy fields.
