Non-pressure nitrogen carrier fertilizer solutions and dispersions and process of manufacture

摘要

A "non-pressure" liquid fertilizer containing nitrogen and sulfur can be prepared by a process comprising (a) mixing sulfuric acid in water, (b) dissolving urea into the resulting solution, and (c) adding anhydrous ammonia in an amount sufficient to bring the pH of the solution to between about 6 and 8. The resulting liquid fertilizers can typically contain in the range of about 19 to about 25% nitrogen and in the range of about 3 to 6% sulfur and remain substantially free from crystals when stored at temperatures above about 40 DEG F. A 19-0-0 liquid fertilizer containing about 3% S (as sulfate) remained crystal free when stored for about a month at about 32 DEG F. The "non-pressure" liquid can be blended with dispersion-type fertilizers. Dispersion-type fertilizers of low phosphate content can be made by substituting phosphoric acid for some or all of the sulfuric acid.