Green sand (K feldspar?) is considered a natural source of potassium (K) and is acceptable to organic farming. However, its K ( about 5 - 6%) is released very slowly. Are there any treatments/amendments that could increase/speed up its K release?
Dearest Nguyen, yes it is possible to increase or catalyze the release of K by treating the soil with farm produced lactobacillus/probiotics to aid in digestion and nutrient release. You can produce your own farm base lactobacillus/probiotics. To find out how, please check in one of my paper: Economic and Market Analysis of Swine Rearing and Pork Production in Ghana.
By chemical modification to hydroxy syenite, as in http://mpc-www.mit.edu/component/k2/item/392-reconstituting-feldspar-for-fertilizer_ Shall you get in touch with the MIT lab for technical detail that involve very fine milling and Ca exchange.
I think there are some strains of micro organisms can do this action using different doses