Effect of sulphur added to phosphate rock on solubility and phytoavailability of phosphorus

Ewa Stanisławska-Glubiak,Jolanta Korzeniowska,Wiktor Jóźwiak,Helena Górecka,Grażyna Wiśniewska,Józef Hoffmann

doi:10.2478/pjct-2014-0014

Abstract

Abstract For ground phosphate rock (GPR) to be applied as phosphorus fertilizer, the availability of phosphorus to plants needs to be improved. One possible way to achieve this is by adding sulphur, which will accelerate decomposition of phosphate in soil owing to the activation of microbiological processes. This study involved granulation of fertilizers composed of phosphate and sulphur mixed at 38:1 and 10:1 ratios and two analogous fertilizer variants but with added molasses as a source of organic carbon for sulphur bacteria. A small-scale industrial installation for production of multi-component fertilizers was used to make granular fertilizer by the compaction method. The granular fertilizers were then tested in an agricultural experiment. The fertilizer in which the phosphate to sulphur ratio was 10:1 produced better effects. Addition of molasses to the fertilizers did not improve their fertilizing capacity

Highlights

Production of concentrated phosphate fertilizers known as superphosphates entails technological processes in which the raw material such as phosphate rock (PR) undergoes very expensive chemical processing
Phosphate rock and sulphur fertilizer (PRSF) with an adequate ground phosphate rock to sulphur ratio (GPR:S) is metabolized in soil owing to activation of microbiological processes
Several variants of PRSF were made from phosphate rock originating from Morocco and obtained from Phosphate Fertilizer Production Plant in Gdańsk and ground sulphur produced by the Siarkopol Chemical Plant

Summary

Introduction

Production of concentrated phosphate fertilizers known as superphosphates entails technological processes in which the raw material such as phosphate rock (PR) undergoes very expensive chemical processing. When developing new fertilizer manufacturing technologies based on the use of phosphate rock, it is important to raise the content of readily soluble forms of phosphorus. This can be achieved, for example, through an addition of sulphur to GPR6–10. The factors affecting the effectiveness of such fertilizers are: the quality of phosphate rock, the degree of its milling, ratio of GPR: S, and the type of crops and soil. The presumption is that the increase of sulphur will increase their agronomic effectiveness

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