Soil reaction and absorption of silicon by rice

Abstract

The solubility and availability of silicon can be influenced by soil reaction. A pot experiment with a clayey textured Rhodic Acrustox was conducted under greenhouse conditions to evaluate the effect of soil reaction on silicon availability to rice plants. The experiment was set up in a completely randomized design, using a factorial scheme (4 × 4) with four materials (calcitic lime, calcium and magnesium silicate, pure silicic acid, and wollastonite), four rates (0, 2500, 5000 and 7500 mg per 5 kg-pot) and four replicates. After 60 days, dry matter yield and silicon absorption by the rice shoot plants, pH CaCl2 , and soluble silicon (0.5 mol L -1 acetic acid and 0.01 mol L -1CaCl 2 ) in the soil were evaluated. The materials increased soil pH as the applied rates increased, except silicic acid. Soluble silicon extracted by 0.5 mol L -1 acetic acid also increased with applied rates. For calcium chloride, soluble silicon increased in the soil only with wollastonite and calcium and magnesium silicate, agreeing with its total content. Silicon absorption by the above-ground part of the rice plants was linearly correlated with rates of wollastonite, followed by calcium and magnesium silicate, silicic acid and calcitic lime. Soil pH increase with lime was not sufficient to provide silicon to the rice. The 0.01 mol L -1 CaCl 2 soluble silicon had the best correlation with silicon absorption by plants. More studies are necessary under field conditions and other soils to corroborate the presented results. Key words: Oriza sativa, soil, calcitic lime, silicate REAÇÃO DO SOLO E ABSORÇÃO DE SILÍCIO PELO ARROZRESUMO: A solubilidade e disponibilidade de silício podem ser influenciadas pela reação do solo. Com o objetivo de estudar o efeito da reação do solo sobre a disponibilidade de silício para a cultura do arroz, foi conduzido experimento em Latossolo Vermelho álico textura argilosa em casa-de-vegetação. O experimento foi conduzido em fatorial 4 × 4, delineamento em blocos inteiramente casualizados e quatro repetições. Quatro materiais (calcário, silicato de cálcio e magnésio, ácido silícico puríssimo e wollastonita) foram aplicados em doses equivalentes a 0, 2500, 5000, 7500 mg por vaso de 5 kg. Após 60 dias, foram avaliadas produção de matéria seca, absorção de silício da parte aérea do arroz, pH CaCl2 , silício extraído em ácido acético (0,5 mol L ) no solo. Os materiais aumentaram o pH do solo com as doses, exceto o ácido silícico. O silício solúvel em ácido acético foi crescente com as doses dos materiais. Para o CaCl 2 , apenas houve aumento de silício solúvel no solo com as doses de wollastonita e silicato de cálcio e magnésio, concordando com seu teor total. A absorção de silício pela parte aérea do arroz foi linearmente crescente com as doses da wollastonita, seguida do silicato de cálcio e magnésio, ácido silícico e calcário. O aumento do pH do solo com calcário não foi suficiente para fornecer silício ao arroz. O silício extraído com CaCl 2 0,01 mol L -1 apresentou maior correlação com a absorção de si...

Silicon fertilization improve yield and quality of rice and pearl millet in cerrado soils

“…Soluble Si content was greater in LV than in RQ (Figures 1 and 2), and was classified as medium and low, respectively (KORNDÖRFER et al, 2001). Higher values for the loamy sandy soil make sense given its higher clay content which is a source of soluble Si, in agreement with Raij;Camargo (1973), Camargo et al, (2007a), Camargo et al (2007b), and Pereira et al(2010).…”

“…However, they focused on the evaluation of the acidity correction and Ca, Mg, and Si supply under field conditions (BARBOSA FILHO et al, 2001;KORNDÖRFER et al,2001;CARVALHO-PUPPATTO et al,2003) and pots (PEREIRA et al,2004;KORNDORFER et al, 1999;CAMARGO et al, 2007b) and only a few studies (RAMOS et al, 2008) have evaluated the benefits of Si supply for the rice crops on its uptake, yield and quality without the additional effects (increasing on pH and Ca and Mg content in soils) of silicate applied in tropical soils. The Ca and Mg levels in soil had to be used in the same quantities when different silicate rates were applied in soil, as already done in incubation studies of Si sources and rates (CAMARGO et al, 2007a;PEREIRA et al, , 2010.…”

Silício na nutrição mineral e acúmulo de alumínio em plantas de arroz de terras altas

“…A reação do SiO 3 -2 , formando H 2 SiO 3 - (Prado et al 2003), poderia reduzir a concentração do H + presente na solução do solo (Ramos et al 2012). No entanto, a não alteração de pH observada neste experimento está de acordo com Camargo et al (2007). Esses autores demonstraram que o ácido silícico não foi capaz de alterar o pH do solo, mesmo em doses crescentes.…”

Effects of silicate application on soil fertility and wheat yield

“…However, other materials may be applied for acidity correction, as long as the product is constituted by neutralizing components such as calcium and/or magnesium oxides, hydroxides, carbonates and silicates. Calcium and magnesium silicates are similar to carbonates in composition; so, those sources can potentially replace lime even more advantageously (CASTRO;CRUSCIOL, 2013;CAMARGO et al, 2007;CARVALHO-PUPATTO et al, 2004). Thus, studies have shown that the calcium/magnesium silicates can be used as corrective of soil acidity and as silicon (Si) source (CASTRO;CRUSCIOL, 2013;CRUSCIOL et al, 2009;PULZ et al, 2008;CARVALHO-PUPATTO et al, 2004), in addition to increasing Ca, Mg, CEC values and base saturation soil (SARTO et al, 2014a).…”