Silicon and nutrition in cereals
Silicon (Si) is one of the most abundant elements in the earth’s crust; however, its assimilable form is limited in most agricultural soils. It is generally found in the form of insoluble oxides or silicates, which makes its absorption by plants difficult. This limitation is particularly relevant in hyperaccumulating crops such as wheat, barley or rice, where silicon plays a crucial physiological and structural role. In this context, foliar application of formulations enriched with silicon and nutrients has been consolidated as an effective strategy to improve yield, optimize nutritional efficiency and increase resistance to stress and pathogens.
How silicon strengthens plant structure
In cereals, silicon is deposited as phytoliths in the cell walls, especially in the epidermis, forming a double layer next to the cuticle. This plant “armor” reinforces the rigidity of stems and leaves, reducing the risk of lodging, a common problem in high-density plantings or with excessive nitrogen fertilization. In addition, this more upright and efficient architecture allows greater light capture, improves photosynthesis and favors nutrient redistribution.
At the functional level, silicon stimulates photochemical activity and improves net photosynthetic rate, transpiration and intracellular CO₂ concentration. This has a direct impact on improved nutrient use efficiency, particularly nitrogen, which translates into greater vegetative vigor and productivity.
Protection against diseases and pests
In addition to its structural effect, silicon acts as a physical barrier that reinforces tissues against the entry of pathogens such as Fusarium spp. or Magnaporthe oryzae (piricularia in rice). In addition, it activates induced defense responses, stimulating the synthesis of lignin, phenolic compounds, peroxidases and chitinases, essential mechanisms for slowing the advance of diseases. This effect is reinforced by integrating silicon in fungicide treatment programs, especially at critical moments of crop development.
In terms of pests, silicon has been shown to reduce the incidence of chewing and sucking insects. In rice, for example, a lower presence of Eysarcoris ventralis (chinch bug or pudenta) has been recorded, due to tissue hardening that hinders stomatal perforation and feeding of these insects.
Silicon and Resilience: Water, Salt and Solar Stress Under Control
One of the most valuable benefits of silicon is its ability to mitigate different types of abiotic stress. Under drought conditions, it reduces transpiration by modulating stomatal closure, improves water retention and favors cell homeostasis. In salinity, it limits the accumulation of ions such as Na⁺ and Cl-, and promotes proper ionic balance by enhancing the uptake of potassium, calcium and magnesium.
This protective effect is complemented by the activation of the antioxidant system, through enzymes such as ascorbate peroxidase (APX), which mitigate oxidative damage produced by reactive oxygen species (ROS), preserving the integrity of cell membranes. In high radiation environments, frequent in rice-growing areas during flowering. Silicon also acts as a natural photoprotector, dissipating excess light energy and preventing photosynthetic collapse.
Yield, fertilization and sustainability
Several studies have confirmed that the application of silicon (Si) in cereal crops improves the formation of ears or panicles, increases the number and weight of grains, and reduces flower sterility, especially in rice. This last point is key to improve yields in seasons with unstable weather conditions.
From an agronomic perspective, silicon allows a better efficiency in the use of nitrogen fertilizers, opening the possibility of reducing doses without reducing yields. This means not only an economic benefit for the farmer, but also a reduction in the environmental impact derived from nitrate leaching.
The future of silicon in cereals
Silicon (Si) is no longer considered a secondary element but a key tool in modern agriculture. Its role as a biostimulant, physiological regulator and shield against abiotic and biotic stress factors positions it as an essential resource in the management of strategic crops such as wheat and rice. With a safe profile and no toxicity risks, its inclusion in fertilization programs contributes to more sustainable agricultural systems, improving crop efficiency and productivity.
