A water-holding
controlled release fertilizer for tobacco exclusively and a preparation method thereof are provided. The water-holding
controlled release fertilizer includes the following materials by the weight percentage: 2 percent to 4 percent of sand grains, 10 percent to 14 percent of lemery, 10 percent to 14 percent of
potassium nitrate, 10 percent to 14 percent of
diammonium phosphate, 22 percent to 26 percent of cake
fertilizer, 0 percent to 4 percent of
zinc sulfate, 0 percent to 0.4 percent of
sodium molybdate, 20 percent to 24 percent of
adhesive A, 10 percent to 14 percent of
adhesive B and 1 percent to 3 percent of
water retention agent. The invention adopts the method that the
water retention agent is at the outmost layer so that the
water retention layer absorbs water at first. The water retention layer does not contact chemical fertilizer directly. The influence of the chemical fertilizer on the absorbing effect of the water
retention agent is reduced. At the same time, according to the balanced fertilization principle of cured tobacco, the kind and the quantity of the deficient element of tobacco soil is supplemented. Hereby, the compound fertilizer especially for cured tobacco of the invention is designed and manufactured. By fixing the grain
diameter of a core,
nutrition dissolution property is changed by fertilizer enwrapping method in order to control the release of
potash fertilizer effectively. Moreover, the water
retention agent absorbs water, which consequently realizes the
dynamic equilibrium of fertilizer release and
plant absorption.