Development of new measurement and analytical method to trace 41K for long-term

To establish a control technique of fertilizer application for resource-saving and environmental conservation, non-radiative 41K tracer method in the field has been developed. In this paper, potassium silicate fertilizer, one of slow-release fertilizer, was synthesized and marked by 41K. Potassium silicate fertilizer with natural abundance of 41K/39K was prepared by mixing 76.2 g fly ash, 23.4 g potassium carbonate and 7.2 g magnesium hydroxide and colicinating the mixture for 47 min at 850degC. The product was satisfied the conditions of potasium silicate fertilizer. Then, the potassium silicate fertilizer marked with 41K was synthesized by calicinating the mixture 1.85 KCl (6.77% 41K and 93.23% 39K) and 11.45 g 41KCl under the above conditions. 41K excess% of product fertilizer was about -2.00%, which is possible to trace 41K of crop plant of soil culture pot test during the growing process. (S.Y.)