Silicon Sources for Agriculture

Abstract

This chapter overviews the major silicate fertilizers commercially available and describes briefly their manufacturing processes. Silicon (Si) sources for agricultural use range from chemical products to natural minerals to by-products of steel and iron industries. All these products are shown to be effective in improving crop growth and yield. Slag-based silicate fertilizers are cost-effective, but more attention should be paid to their potential environmental risks which may arise from the heavy metals contained in the fertilizers. Soluble potassium or sodium silicates are completely water soluble and can be used as foliar fertilizers, but are usually too expensive for soil application. Slow-releasing potassium-containing or potassiumrich silicates that are manufactured using feldspar as raw materials are not only cost-effective and agriculturally effective but also environmentally friendly.Keywords Potassium silicate • Slag-based silicate • Slow-releasing potassium silicate • Sodium silicate

Silicon modifies leaf nutriome and improves growth of oak seedlings exposed to phosphorus deficiency and Phytophthora plurivora infection

“…On the other hand, severe deprivation of Si (in hydroponic experiments) can induce very complex changes as an increase of Ca, Mg, K, S, Mn and Zn in wheat, and a decrease in N and Mo in oilseed rape ( D’Oria et al., 2021 ). Our work further demonstrated that the stronger the stress, the clearer was the response to Si addition, though even in –Si treatments the available soil Si (about 40 mg kg -1 ) was far beyond its deficiency threshold ( Liang et al., 2015 ). The application of Si to oak seedlings under the most severe stresses (P deficiency + P. plurivora root infection) resulted in the strongest improvement of biomass accumulation ( Figure 2 ), root damage ( Figure 3 ) and visual symptoms ( Figure 1 ), and also had the strongest statistical signal of altering leaf nutriome profiles ( Tables 2 and 3 ) affecting thus leaf accumulation pattern of 11 out of 13 nutrients ( Table 4 ; Figure 5 ).…”

Wildfires in the western United States are mobilizing PM2.5-associated nutrients and may be contributing to downwind cyanobacteria blooms

“…20,105,106 Phosphate/phosphorus actively adsorbs to solid surfaces in soil. 107 Silicon, an element commonly found in soil and fertilizers, 108,109 was statistically elevated for many of the same years as phosphorus, thus supporting this hypothesis.…”

Effect salicylic acid and silicon on physiological and phytochemical indices of Scrophularia striata L. under water stress

“…Amino acids such as alanine (Ala), arginine (Arg), aspartic acid (Asp), glycine (Gly), glutamic acid (Glu), histidine (His), leucine (Leu), isoleucine (Ileu), methionine (Met), and serine (Ser) exhibited an increase in the control treatment. Concomitant with the decline in the uptake of nutrient compounds like NO₃ by the roots and their transfer to the shoot, amino acid synthesis also decreased [23]. Water deficit stress, through the reduction of the plant's transpiration rate, diminishes the transfer of nitrogen from the root surface to the shoot.…”