Silicon in the earth’s soil
Silicon (Si) is the second most abundant element in the earth’s crust, accounting for 28.8% of its total mass (Sommer et al., 2006). Second only to oxygen, silicon (Si) stands out as one of the most common elements on our planet. However, its large presence contrasts with its limited availability, since most of the chemical forms in which it is found in soil are insoluble.
The importance of silicon in agricultural crops
Until recently, silicon (Si) was not considered an essential fertilizer element in fertilizer programs, which has led to very low levels of this element in most crops.
Silicon (Si) deficiency has a direct impact on the growth and metabolism of plants, preventing the complete completion of their life cycle. In addition, its function in the plant cannot be replaced by another element.
Under optimal growing conditions, the application of silicon (Si) shows beneficial effects on plant development, especially when administered via foliar. This practice results in a notable increase in production and an improvement in the quality and post-harvest life of the fruit.
In addition, the application of silicon (Si) leads to a significant increase in the absorption efficiency of all essential nutrients. This suggestion indicates that using it could greatly enhance the effectiveness of fertilizers used in agriculture, especially those rich in nitrogen.
Crops requiring a higher percentage of silicon (Si), identified as accumulators (>1% Si) (Ma and Takahashi, 2002), include species such as wheat, rice or tomato (Hodson, 2005).
A natural shield against stress in crops
Throughout their evolution, plants have evolved diverse responses and adaptations to survive under stressful conditions. Among these adaptations, the fundamental role of silicon (Si) in the tolerance to the stresses they face stands out.
Silicon (Si) acts in multiple ways to strengthen plant resistance to various stresses. From strengthening cellular structures to modulating biochemical and hormonal responses, it plays a crucial role in improving the health and yield of agricultural crops.
The application of silicon (Si) often significantly improves crop resistance to a variety of abiotic and biotic stresses (Epstein, 1999). Specifically, silicon (Si) demonstrates its effectiveness in mitigating damage caused by insect pests and fungi, these being the main biotic stresses.
It also contributes significantly to counteract the adverse effects of abiotic stresses such as drought, salinity and the toxicity of certain metallic elements.
Silicon against salt and water stress
Silicon (Si) has been shown to be effective in mitigating these effects by inducing the plant’s antioxidant system, protecting and activating photochemical activity, and modifying the hormone profile to generate greater accumulation of growth hormones and reduce stress hormones. In addition, Silicon (Si) increases the concentration of essential nutrients, which benefits plant responses and decreases the impact of stress, improving their water relations and contributing to maintain an optimal water balance in plants.
In the specific case of salt stress, Silicon (Si) also proves to be an effective tool to reduce its toxic effect. By producing a significant reduction in the accumulation of sodium and chloride ions in the leaves, it contributes to mitigate the negative effects of this type of stress.
Silicon for an agriculture of the future
The use of Si-rich products improves both yield and crop resistance to various stresses, boosting sustainability and food security in a world increasingly affected by climate change and environmental degradation.
This practice not only ensures more profitable agricultural production, but also promotes a more sustainable and resilient agricultural model, which is key to facing future challenges in agriculture.
