US4073633A
Expired / Lapsed
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Topical nitrogen fertilization method
Assignee: Union Oil Company of California
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Filing: 1976-05-17
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Granted: 1978-02-14
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Expires: 1996-05-17
Abstract
Abstract Volatilization loss of surface broadcast urea is reduced by combining the urea with an acid generating compound in a concentration sufficient to maintain a neutral or slightly acidic environment in the immediate vicinity of the urea particles.
Inventors
- 👤 Donald C. Young
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:24
CPC Classifications
C; C05; C05C; C05C9/00; Y; Y10; Y10S; Y10S71/00; Y10S71/903
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
125 words
The method of topically fertilizing soils containing urease enzyme with urea particles under conditions in which a basic environment having a pH of at least about 7 would exist immediately adjacent said particles in the absence of the acid generator hereinafter defined, and minimizing the nitrogen lost by volatilization of said urea, including the steps of surface broadcasting said urea particles on said soil as a particle form combination of urea and at least one acid generator in an amount sufficient to maintain a pH below 7 in the soil immediately adjacent said urea particles, and maintaining (1) said particles on the surface of said soil, and (2) a pH below 7 in said soil immediately adjacent said particles for at least about 24 hours.
Claim 2
Independent Claim
125 words
The method of topically fertilizing soils containing urease enzyme with urea particles under conditions in which a basic environment having a pH of at least about 7 would exist immediately adjacent said particles in the absence of the acid generator hereinafter defined, and minimizing the nitrogen lost by volatilization of said urea, including the steps of surface broadcasting said urea particles on said soil as a particle form combination of urea and at least one acid generator in an amount sufficient to maintain a pH below 7 in the soil immediately adjacent said urea particles, and maintaining (1) said particles on the surface of said soil, and (2) a pH below 7 in said soil immediately adjacent said particles for at least about 24 hours.
Claim 3
Dependent Claim
61 words
The method of claim 1 wherein said soil is a basic soil having a pH above 7 and said acid generator is present in said combination in an amount sufficient to generate at least about 0.02 molar equivalents of acid per mole of urea present in said combination and maintain a pH in said adjacent soil of about 6.5 or less.
Claim 4
Dependent Claim
33 words
The method of claim 2 wherein said acid generator comprises elemental sulfur in an amount sufficient to generate between about 0.05 and about 1 molal equivalent of acid per mole of said urea.
Claim 5
Dependent Claim
21 words
The method of claim 2 wherein said basic soil has a pH above 8 in the absence of said urea particles.
Claim 6
Dependent Claim
41 words
The method of claim 4 wherein said acid generator is selected from the group consisting of (1) elemental sulfur; (2) sulfuric, nitric, hydrochloric and phosphoric acids; and (3) mono- and dicarboxylic acids having 1 to about 10 carbon atoms per molecule.
Claim 7
Dependent Claim
69 words
The method of claim 5 wherein said urea particles are maintained on said soil surface for at least 48 hours after said surface broadcast application, and said acid generator is combined with said particles in an amount sufficient to prevent the volatilization loss of more than 20 percent of the urea that would otherwise be lost by volatilization within said 48 hours in the absence of said acid generator.
Claim 8
Dependent Claim
100 words
The method of claim 1 wherein said acid generator is selected from the group consisting of (1) elemental sulfur; (2) sulfuric, nitric, hydrochloric and phosphoric acids; (3) mono- and dicarboxylic acids having 1 to about 10 carbons; (4) salts of which the conjugate acid has an ionization coefficient at least about 10 percent greater than the ionization coefficient of the conjugate base and which produce a solution having a pH below about 5 in distilled water in a concentration of 0.1 molar; and (5) salts of cations which form hydroxides or carbonates having solubility products below about 10 -10 .
Claim 9
Dependent Claim
49 words
The method of claim 1 wherein said particles are left on the surface of said soil for at least 24 hours and said acid generator is combined with said particles in an amount sufficient to prevent the loss of more than 10 percent of said urea within 24 hours.
Claim 10
Dependent Claim
71 words
The method of claim 1 wherein said urea particles are maintained on the surface of said soil for at least about 48 hours following said surface broadcast application, and the amount of said acid generator combined with said urea is sufficient to prevent the volatilization loss of more than 20 percent of the urea that would otherwise be lost by volatilization within 48 hours in the absence of said acid generator.
Claim 11
Dependent Claim
35 words
The method of claim 9 wherein said acid generator is selected from the group consisting of ammonium phosphates, sulfates and fluorides and the nitrates, phosphates, sulfates and chlorides of iron, zinc, copper, magnesium and manganese.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-13 | 1981-08-15 | 1982-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-13 | 1985-08-15 | 1986-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-13 | 1989-08-15 | 1990-02-14 | $7700.00 | Window Closed / Lapsed |