Glauconitic siltstone as a multi-nutrient fertilizer for Urochloa brizantha cv. Marandú

Abstract

Potassium (K) is one of the most absorbed nutrients by forage plants and it is found at low levels in tropical soils, requiring large amounts of fertilizers. The use of glauconitic siltstone as multi-nutrient fertilizers is an economic alternative to improve pasture-based production systems due to their low-cost production and long-term nutrient release. This study evaluated the effect of the glauconitic siltstone (GS) powder on three successive crops of Urochloa brizantha cv. Marandú (Syn. Brachiaria brizantha). Two experiments were carried out under greenhouse conditions, one using a Typic Dystrustox and the other a Typic Quartzipsamment. Both experiments were arranged in a completely randomized design with one factor, i.e., five glauconitic siltstone doses (0, 5, 20, 40, and 80 mg dm-3 of K2O) and four replications. In addition, three additional treatments were used, as potassium chloride, wollastonite and manganese sulfate at doses of 80 mg dm-3 of K2O, 270 mg dm-3 of silicon (Si) and 2 mg dm-3 of manganese (Mn), respectively. The sources were incubated for 60 days on the two soil types and, after the incubation period, Urochloa brizantha plants were grown. Three consecutive cuts were performed at 68, 104 and 168 days after sowing. The application of the GS in tropical soils promoted increases in plant dry matter, as well as K, Si and Mn levels in soil samples and accumulated in plants. In general, greater effects were obtained following the application of GS after consecutive cropping cycles due to its long-term release. Results described in this study provide an important understanding of the use of glauconitic siltstone as multi-nutrient fertilizers in tropical soils, being an efficient alternative to improve soil fertility and increase tropical pasture productivity.

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

“…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).…”

Ediacaran/Early Cambrian Serra da Saudade Formation, Bambuí Group: the sedimentary record of a foreland basin in Southeastern Brazil

“…Later, Lima et al (2007) detailed the Serra da Saudade Formation lithotypes and the genesis of the phosphatic mineralization. The São Gotardo region was studied by Moreira et al (2016), who described the glauconitic siltstone unit with K 2 O concentrations of up to 10 wt%, used to produce potash fertilizers (Violatti et al 2019).…”

“…4E), which is responsible for a whole-rock K 2 O content of approximately 10 wt% (Nader and Ackroyd 2017, Moreira et al 2016Moreira et al , 2020. Although innumerous studies regard the evaluation of the green siltstone ("verdete") as potassium source for agriculture (Piza et al 2011), up until recently, only the glauconitic siltstone was confirmed to be a fertilizer (Violatti et al 2019). Both the green and the glauconitic siltstones were deposited by settling in an outer shelf context, in the absence of energy.…”

Chemical Extractors to Assess Potassium Availability in Glauconitic Siltstone

“…It is mostly composed of glauconite mineral (40-80%), K-feldspar (10-15%), quartz (10-60%), and muscovite (5%) (Moreira et al, 2016). Glauconitic siltstone is a promising K fertilizer, with about 10% K 2 O (Violatti et al, 2019). The production process for glauconitic siltstone fertilizers is based on mechanical activation technology (Singla et al, 2019).…”