Abstract
The increasing world population has led into big food and raw material demand, with high pressure on agriculture. In Brazil, potassium fertilizers are mostly imported rising interest on rocks and mining rejects as alternative sources. The objective of this work was to evaluate the effect of crushed rocks over mineral nutrition, yield and efficiency of potash fertilization in rice. The experiment was carried out under greenhouse conditions in pots with 3.7 kg of Oxisol soil samples. The experimental design was completely randomized, in a factorial layout 4 × 6, comprising six crushed rocks used as alternative multinutrient fertilizer (breccia, biotite schist, ultramafic, Chapada byproduct, mining byproduct and phlogopite), and four doses based on potassium (0, 200, 400, 600 kg K2O ha-1), with four replications. The concentration and accumulation of potassium, copper, zinc and nickel in rice shoot dry mass were determined. These data were used to evaluate the efficiency index of K-source rocks on fertilization. It was shown that crushed rocks promote alterations in mineral nutrition, grain yield and potassium use efficiency, remarking their potential to be used as alternative fertilizer in rice cropping systems. Key words: Alternative nutrient source, micronutrient, fertilization efficiency, plant nutrition, soil conditioner.
Highlights
In Brazil, the first studies on materials with low nutrients dissolution kinetics were carried out in the 1970’s
The experimental design was a completely randomized in 4 × 6 factorial scheme with six crushed rocks utilized as alternative multinutrient fertilizer, and four doses based on potassium supply (0, 200, 400 and 600 kg K2O ha-1), with four replications (Table 1)
Manganese ore waste found in Belo Horizonte, MG, Brazil, originated from metallurgical process of manganese extraction
Summary
In Brazil, the first studies on materials with low nutrients dissolution kinetics were carried out in the 1970’s. New technological methods have been tested in order to increase nutrient solubility from the variable content in rocks. Among these methods, crushing, thermal processes of melting, acidification and microorganisms inoculation were tested. High energy demand in processing the materials and the competition with potassium chloride. The methods to turn these rocks soluble have shown unfeasible due to their low nutrients release and Brazilian agricultural context has changed, as well as the consumption rates of potassium chloride (Lopes, 2005). The increase in potassium consumption by agriculture, leading to high importing dependence of K fertilizers and
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
