Glauconitic Siltstone as a Source of Potassium, Silicon and Manganese for Flooded Rice

Abstract

The objective of this study was to evaluate the efficiency of glauconitic siltstone as a multi-nutrient source for flooded rice. Two experiments were carried out under greenhouse conditions, one using a Ferralsol and the another an Arenosol. Glauconitic siltstone was applied in different doses (0, 5, 20, 40, and 80 mg dm-3 K2O) and potassium chloride, wollastonite, and manganese sulfate were respectively used as standard sources, at doses of 80 mg dm-3 K2O, 270 mg dm-3 Si, and 2 mg dm-3 Mn. The sources were incubated for 90 days on the two soil types and, after the incubation period, rice plants were sown, and two consecutive rice growths were performed. The application of glauconitic siltstone in tropical soils promotes increases in the plant and grain dry matter of rice plants, as well as K, Si and Mn contents in soil samples and accumulated in plants. Greater effects following the application of glauconitic siltstone are obtained after the second rice growth due to its gradual release.

Agricultural use of phonolite and verdete rocks as a source of k for corn crop

“…For the treatment that the source of K was verdete with coffee husk (VCH), the highest amounts of P contents were observed in the control treatments with KCl and the treatment with the verdete in mixture with coffee husk calcined at 600 °C. KCl is used as a standard source of K, thus, treatments that present results similar to its application are considered as an alternative source of K (Arrieta et al, 2020).…”

“…To optimize the efficiency of the use of these rocks and take advantage of their potential to supply K content to plants (Violatti et al, 2019;Arrieta et al, 2020), processes such as grinding to increase the contact surface with the soil, calcined at different temperatures with or without the addition of flux such as CaO that alters the crystalline structure of the minerals, the acidification with acids of low molecular weight associated with incubation times or even the mixture of rocks with organic matrices rich in K 2 O such as coffee husk, could demonstrate positive results in the solubility and K 2 O release capacity from the mineral matrices (Martins et al, 2015;Pessoa et al, 2015;Santos et al, 2015).…”