Study on Preparation of Sustained-Release Potassium Fertilizer with Bentonite as Carrier and Slow Release Performance of Potassium

Using natural, cheap and porous mineral bentonite as the carrier, adding some urea-formaldehyde resin as binder and preparing the slow-release potassium fertilizer with electric pressure machine, the experiment gave a preliminary study on the sustained release effect of the self made slow-release fertilizer by the method of water dissolution rate, the sand column leaching solution and soil column leaching test. And the research gets the expected slow-release effect. The paper explored the influence and the influence degree of the type of bentonite, the amount of urea formaldehyde resin, the rate of soil and fertilizer on the performance in nutrient release of the prepared slow-release fertilizer tablets by the perspective of a single factor analysis and the orthogonal test. Considering the nutrient release properties and the economic issues, there comes to the conclusion, the best condition for preparing slow release fertilizer is: soil and fertilizer ratio 8:2, 15% the amount of urea-formaldehyde resin, potassium-based soil by the method of semi-dry.