Potential Slow Release Fertilizers Based on K2MgSiO4 Obtained from Serpentinite

Abstract

In this work, a potassium magnesium silicate mineral based on phase K 2 MgSiO 4 was prepared from serpentinite rock and studied as a potential K and Mg slow-release fertilizer. The material was prepared by impregnation of serpentinite/KOH and calcination at 700 °C to produce K 2 MgSiO 4 phase, olivine and forsterite. The release patterns of K and Mg in the stirred-flow trial and leaching through the soil columns showed that K 2 MgSiO 4-based materials released K on lower rates than KCl and MgSO 4 .7H 2 O, however, there was no evidence of Mg release. The extraction with 1 mol L-1 NH 4 OAc showed a considerable content of Mg and K for K 2 MgSiO 4-based materials, due to exchange of NH 4 + and Mg 2+. X-ray diffraction (XRD) analysis of materials impregnated with K and calcined showed peaks relative to K 2 MgSiO 4. After leaching, the peaks intensity diminished, supporting that part of K leached. Therefore, the samples showed great potential as slow-release K-fertilizers when compared with KCl source.

Do enhanced efficiency potassium sources increase maize yield in soil with high potassium content?

“…Changes in K release rate are verified when comparing enhanced efficiency K fertilizer sources and conventional sources (Ballotin et al, 2020). It is essential to highlight that, regardless of the treatments tested, LKC was within the range from 17 to 35 g kg -1 , which are values established as adequate for leaf analysis of K in maize (Cantarella et al, 1997).…”