Indirect Fertilizers

fertilizers used to change the reaction of the soil solution, to improve the physical properties of the soil, and to activate its useful microflora. Among the indirect fertilizers are lime fertilizers of all types (limestones, calcareous tuff, chalk, marl), which eliminate excess soil acidity; gypsum, an agent for chemical improvement of solonets soils; sulfur fertilizers, which reduce soil alkalinity; and sodium fertilizers, which create soil potassium by using sodium to force it out of the absorbing complex of the soil into solution.