Chemical attributes of a remineralized Oxisol

Abstract

Remineralizers are comminuted rocks that are applied to soil, and their use as an agricultural amendment was regulated in Brazil in 2013. However, mechanisms of action of these materials must be better known to enable them to be best used in agricultural fields. Soil chemical attributes of an Oxisol were monitored after the application of a diabase remineralizer. The increase in exchangeable Na observed was associated with the dissolution of the border of the plagioclase crystals where this element is highly concentrated (albite). Therefore, it was inferred that the time since the application of the remineralizer (1 to 2 years depending on the treatment) was not sufficient to exhaust this crystal volume. Unfortunately, the presence of several sources of Ca-containing minerals in the remineralizer did not allow to infer if the calcic nuclei was dissolving. An increase in effective cation exchange capacity was observed without the concurrent increase in the pH of the soil. The two non-exclusive hypotheses proposed to explain this result were that an extra surface charge has originated on the surface of the newly precipitated oxidic phases and/or from the dissolution of the remineralizer grains. Rapid precipitation of amorphous solids (as measured by the increase in Alo and Feo) would also explain the lack of increase in exchangeable Fe and Al despite the large amount of Al2O3 (11.90%) and Fe2O3 (14.45%) in the remineralizer.

Successive off take of elements by maize grown in pure basalt powder

“…According to Hinsinger et al (2001), the amount of Fe released from basalt under leaching conditions using maize plants reached a maximum increase of about 100-500 times the release without plants (control). Non-absorbed iron ions in solution are then precipitated as low crystallinity iron oxides (especially ferrihydrite and amorphous ferric hydroxide) (Silva et al, 2017).…”

“…E-mail: luisekrahl@yahoo.com.br Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License is an attempt to reduce agricultural costs and dependence on imported fertilizers. Many works showed positive results for crop productivity and increases in soil quality, whereby basalt powder, for its composition and abundance in spread areas over the world, may assist massively in quality building of soils (Anda et al, 2015;Nunes et al, 2014;Silva et al, 2017). In Brazil, an existing network of basalt quarries, already producing construction aggregates at low cost, has the potential to supply crushed material to agricultural regions (Lefebvre et al, 2019).…”

“…Plants rhizosphere and their associated microbial populations play a major role in the silicate minerals weathering (bioweathering) by increasing acidity, absorbing and releasing elements and organic ligands, as well as siderophores (Burghelea et al, 2015). Plant roots, ultimately, contribute to increase the dissolution rates of Ca and Mg silicates present in basaltic minerals (Akter and Akagi, 2005;Anda et al, 2015;Hinsinger et al, 2001;Silva et al, 2017).…”

“…Basalt minerals undergo a congruent dissolution whenever its bulk chemical composition is rich in iron (Fe), and alkaline earth elements, such as Mg and Ca (Silva et al, 2017). The susceptibility of basalt minerals to weathering, generally follows the sequence: glass > olivine > pyroxene > amphibole > plagioclase > Kfeldspar (Eggleton et al, 1987).…”

Effect of basalt rock powder associated with different substrates on the initial development of aroeira seedlings (Myracrodruon urundeuva)

“…However, their use requires planning so that the application is economically viable and environmentally sustainable. Mineral extraction of basalt rock produces as residue rock powder, which contains macro and micronutrients, contributing to soil fertility as a function of the predominance of minerals which are easily weatherable and rich in cations, allowing their gradual release (Silva et al 2017). In addition, there are other advantages, such as pH correction, the absence of soil salinization and excess potassium absorption, benefiting the absorption of calcium and magnesium, and a reduction of soluble phosphorus fixation by the presence of silica.…”