US 5,476,528 A · System for improving material release profiles

Abstract

Improved release profiles which can, for the first time, be customized to match requirements of systems including crop nutrient uptake are realized by providing a plurality of heterogeneous particles comprised of water-soluble constituents set in a matrix of water-insoluble materials, and further providing a continuous homogeneous barrier of same, or a different water-insoluble material, juxtaposed the peripheral surface of each such heterogeneous particle. A first alternate embodiment includes forming in situ reaction products to reduce the specific gravity of such heterogeneous particles. In a second alternate embodiment, there is substituted for all, or a portion of such water-soluble material, organic media comprised primarily of composted poultry litter wherein soluble iron values remain available for substantial periods of time without incorporating or utilizing expensive conventional synthetic chelating agents.

Claims8

Dependent claims

A slow release fertilizer having improved release profiles of substantially water-soluble constituents therein, said fertilizer comprising:

a plurality of heterogeneous particles with each of said heterogeneous particles comprising a plurality of homogeneous particles of at least one substantially water-soluble, nitrogen-containing constituent set in a matrix of water-insoluble material, said at least one substantially water-soluble constituent selected from the group consisting of urea, urea phosphate, ammonium phosphate, or mixtures thereof, and said water-insoluble material comprising polyethylene, said polyethylene having a molecular weight ranging from about 3,000 to about 18,000 and said polyethylene in combination with from about 50 to about 90 weight percent wax wherein the proportion of said wax, relative to said polyethylene, is directly, but inversely, proportional to the molecular weight of said polyethylene;
and
a substantially continuous and homogeneous film of a water-insoluble material juxtaposed the surface of and encapsulating each of said heterogeneous particles, said water-insoluble material comprising polyethylene, said polyethylene having a molecular weight ranging from about 3,000 to about 18,000 and said polyethylene in combination with from about 50 to about 90 weight percent wax wherein the proportion of said wax, relative to said polyethylene, is directly, but inversely, proportional to the molecular weight of said polyethylene.

Dependencies are inferred from the claim text.

System for improving material release profiles

Life of this patent

System for improving material release profiles

Life of this patent

Abstract

Claims8