Mixture for treating fertilizers containing urea

Abstract

The invention relates to a synergistic mixture of urease inhibitor and nitrification inhibitor for the treatment of urea-containing fertilizers, more particularly having an improved urease-inhibitory effect, to the use thereof, and to urea-containing fertilizers comprising said mixture.

Claims

1. A mixture for the treatment of urea-containing fertilizers, comprising component A and component B, wherein component A comprises: a) at least one (thio)phosphoric triamide of the general formula (I)
R.sup.1R.sup.2N—P(X)(NH.sub.2).sub.2  (I) wherein X is oxygen or sulfur, R.sup.1 is C.sub.1-10 alkyl or C.sub.3-10cycloalkyl, and R.sup.2 is hydrogen, and component B comprises: b) a salt of 2-(N-3,4-dimethylpyrazole)succinic acid, where component A and component B are in a weight ratio in a range from 1:1.5 to 1:5.

2. The mixture of claim 1, wherein component A comprises N-(n-butyl)thiophosphoric triamide (NBPT) or N-(n-propyl)thiophosphoric triamide (NPPT).

3. The mixture of claim 2, wherein component A is N-(n-butyl)thiophosphoric triamide.

4. The mixture of claim 1, wherein the salt of 2-(N-3,4-dimethylpyrazole)succinic acid is selected from the group consisting of alkali metal salts, alkaline earth metal salts, and ammonium salts.

5. The mixture of claim 4, wherein the salt of 2-(N-3,4-dimethylpyrazole)succinic acid is an alkali metal salt.

6. The mixture of claim 1, wherein component A and component B are in a weight ratio in the range from 1:2 to 1:4.5.

7. The mixture of claim 1, wherein component A and component B are in a weight ratio in the range from 1:2.5 to 1:4.

8. The mixture of claim 1, further comprising component C, wherein component C comprises: c) at least one compound containing an amino group or a substituted amino group and having a boiling point of more than 100° C., selected from methyldiethanolamine, tetrahydroxypropylethylenediamine, trimethylaminoethylethanolamine, N,N,N′,N′-tetrarnethyl-1,6-hexanediamine, N,N′,N″-tris(dimethylaminopropyl)hexahydrotriazine, 2,2′-dimorpholinyldiethyl ether, or mixtures thereof in at least 0.2 times the molar amount of component A.

9. The mixture of claim 1, further comprising: (x) component D, wherein component D comprises a solvent for the (thio)phosphoric triamides, and/or (y) component E, wherein component E comprises a polymer in dissolved or dispersed form.

10. The mixture of claim 1, further comprising component C, component D, and component E, wherein: component C comprises at least one amine having a boiling point of more than 100° C., component D comprises a solvent for the (thio)phosphoric triamides, and component E comprises a polymer in dissolved or dispersed form, wherein each of component A, component B, component C, component D, and component E form 100% by weight of the mixture.

11. A method for reducing the nitrogen losses in a soil treated with a fertilizer, said method comprising delivering the mixture of claim 1 in the form of a formulation, solution or dispersion to the soil separately or simultaneously to the fertilizer.

12. A method for reducing the nitrogen losses or lowering ammonia load in a substrate, said method comprising delivering the mixture of claim 1 to the substrate, wherein the substrate is an organic fertilizer, harvest refuse, grazed land, liquid manure, or an animal stall.

Description

EXAMPLES

(1) In the examples below, the following abbreviations have the following meanings: NBPT N-(n-butyl)thiophosphoric triamide=urease inhibitor UI DMPSA 2-(N-3,4-dimethylpyrazole)succinic acid=nitrification inhibitor NI

EXAMPLES

A. Preparation Examples for 2-(N-3,4-dimethyl-pyrazole) succinic acid (DMPSA)

Example 1

(2) 9.6 g of 3,4-dimethylpyrazole (0.1 mol) and 9.8 of maleic anhydride (0.1 mol) were heated in 50 ml of 50% acetic acid to 100° C. After 16 hours, the reaction mixture was evaporated to dryness. When the residue is taken up in diethyl ether, the product (2-(N-3,4-dimethylpyrazole)succinic acid) precipitates in pure form and is isolated by filtration: white crystals in a yield of 92%. In the NMR spectrum there are a number of methyl signals apparent, which is in agreement with the elimination of the 3,5-tautomerism as a result of the substitution on nitrogen.

Example 2: Preparation on the 200 kg Scale

(3) Starting materials used for the experiments were maleic anhydride from CVM with a purity of more than 99.5%, and an 80% aqueous solution of 3,4-dimethylpyrazole (3,4-DMP) from BASF SE. According to the NMR spectrum, the solution of 3,4-DMP used contained about 2% of otherwise uncharacterized impurities.

(4) The experiments were first conducted in a 20 L reaction vessel, which in further experiments was replaced by a 25 L reaction vessel.

(5) In the first experiment, 41.608 mol of maleic anhydride were introduced and were dissolved in 11 liters of distilled water. During this procedure, the temperature rose by 10° C. Then 41.608 mol of 80% 3,4-dimethyl-pyrazole solution were added, the temperature rising by a further 12° C. When the addition was over, the reaction mixture was heated to an internal temperature of 100° C. When this temperature was reached, the reaction mixture was stirred at 100° C. for 24 hours and then allowed to cool. After the reaction mixture had cooled to 90° C., a sample was taken for reaction monitoring by NMR spectroscopy, and the reaction mixture was subsequently seeded with 1 g of product (crystals of 2-(N-3,4-dimethylpyrazole)succinic acid. At this temperature there was as yet no crystallization, but the crystals added also no longer dissolved. On further cooling, starting at around 85° C., crystallization slowly began. The major amount of the product only crystallized at just below 80° C. with an increase in temperature. For complete crystallization, the reaction mixture was left to cool overnight with stirring. The precipitated solid was isolated by filtration using three 8 l G3 glass suction filters, using a suction flask and membrane pump, under reduced pressure, then washed with a total of 8 liters of distilled water, and subsequently dried under reduced pressure at a bath temperature of 60° C. The dried product thus obtained was placed into a vessel, thoroughly mixed, and sampled for investigation by NMR spectroscopy. In the subsequent experiments, in place of the distilled water, a corresponding amount of the combined filtrates was used as the reaction medium. The excess quantity of the combined filtrates was discarded.

(6) Monitoring of the reaction by NMR spectroscopy after 24 hours revealed a relatively constant conversion of around 92% with a relatively constant isomer ratio P1/P2 (2-(3,4-dimethyl-1H-pyrazol-1-yl)succinic acid/2-(2,3-dimethyl-1H-pyrazol-1-yl)succinic acid) of around 3.3. The ratio was slightly higher only at the start of the serial experiment. However, that was also to have been expected, since the use of the filtrate instead of the distilled water as reaction medium introduced a larger amount of P2 (P1/P2 ratio in the filtrates is around 1.0) into the subsequent experiments.

(7) The composition of the reaction mixture after a reaction time of 24 hours attained constant values after just a few experiments. Similarly, the compositions of the products isolated in the individual experiments differ only slightly from one another.

(8) The solids, obtained on average with a yield of 90.22%, possessed a purity of 99.9% and an isomer ratio on average of 4.0 (2-(3,4-dimethyl-1H-pyrazol-1-yl)succinic acid to 2-(2,3-dimethyl-1H-pyrazol-1-yl)succinic acid). Impurities of 3,4-DMP, maleic acid and rac-malic acid were undetectable or detectable only in traces (<0.1%) in the 1H NMR spectra.

B. Use Examples

(9) Screening trials were conducted to evaluate the effect of DMPSA and NBPT in the inhibition of urease and inhibition of nitrification, and to find suitable quantities for use. Serving for this purpose was a two-factorial trial design including an unfertilized control sample. For the urease inhibitor NBPT and for the nitrification inhibitor DMPSA, in each case 0%, 33%, 66% and 100% of the application rates recommended for the individual compounds when used alone were used (in this example, 0.6 g of NBPT per kg of urea and, respectively, 3.6 g of DMPSA per kg of urea), giving 16 trials (0%-0% to 100%-100%), in addition to the unfertilized control sample.

(10) Urea fertilizer was delivered in an amount of 200 kg nitrogen per ha, corresponding to 0.51 mg of urea nitrogen per g of soil. The soil used was Filder loam with a pH of 6.8. The incubation trials were carried out at 20° C. For the investigation of trace gases, air supply was passed first through a gas sample, then through a 250 ml capacity glass bottle containing 150 g of soil, subsequently through a gas sample for the outgoing air and through an acid trap, in order, for example, to determine amounts of ammonia. For the measurement of nitrogen, about 20 g of soil were incubated; for the measurement of urea, about 5 g of soil.

(11) The percentages of the active compounds are based on the normal application rate when using only one of the components (NI or UI).

(12) 1. Results—Ammonium

(13) % of applied urea (13 mg N)

(14) A determination was carried out 28 days after application of the urea, with the percentage recovery in the form of ammonium being reported.

(15) TABLE-US-00001 UI Days after appl. 28 0 ⅓ ⅔ 1 NI 0 1 9 21 28 ⅓ 62 66 67 70 ⅔ 63 66 66 66 1 69 68 68 80

(16) From the results it is apparent that 33% of DMPSA are sufficient to inhibit nitrification throughout the trial. NBPT had no supplementary influence after 28 days.

(17) 2. Results—Nitrate

(18) % of the urea applied (13 mg N)

(19) 5 Days after Application:

(20) TABLE-US-00002 UI Days after appl. 5 0 ⅓ ⅔ 1 NI 0 16 10 11 11 ⅓ 4 6 6 6 ⅔ 5 6 5 6 1 6 5 5 5

(21) 28 Days after Application:

(22) TABLE-US-00003 UI Days after appl. 28 0 ⅓ ⅔ 1 NI 0 57 58 64 52 ⅓ 20 15 14 15 ⅔ 17 17 14 16 1 14 19 14 20

(23) In the results it is apparent that 33% of the DMPSA is sufficient to inhibit nitrification during the entire period.

(24) 3. Results—Ammonia Emission

(25) % of the urea applied (77 mg N)

(26) 4 Days after Application:

(27) TABLE-US-00004 UI Days after appl. 4 0 ⅓ ⅔ 1 NI 0 0.3 0.3 0.1 0.0 ⅓ 0.6 0.0 0.0 0.0 ⅔ 0.9 0.0 0.1 0.2 1 0.7 0.0 0.0 0.4

(28) 9 Days after Application:

(29) TABLE-US-00005 UI Days after appl. 9 0 ⅓ ⅔ 1 NI 0 1.3 1.1 0.2 0.0 ⅓ 3.7 1.1 0.2 0.0 ⅔ 2.4 1.2 0.2 0.0 1 2.2 0.8 0.2 0.0

(30) From the results it is apparent that with an increasing fraction of NBPT it is possible to reduce the ammonia losses. At just 66% NBPT there was a notable and almost complete reduction in ammonia emissions, especially 9 days after application.

(31) The addition of DMPSA causes the ammonia emissions to rise.

(32) By addition of NBPT it was possible to prevent the increase in ammonia emission by the nitrification inhibitor.

(33) 4. Results—Laughing Gas

(34) 77 mg N applied

(35) Results—N.sub.2O—N cumulative

(36) TABLE-US-00006 μg N.sub.2O—N Bottle.sup.1 Days after UI-0_NI-0 UI-0_NI-1 UI-0_NI-2 UI-0_NI-3 UI-1_NI-0 UI-1_NI-1 UI-1_NI-2 UI-1_NI-3 UI-2_NI-0 appl. 2 3 4 5 6 7 8 9 10 0 0 0 0 0 0 0 0 0 0 0.5 0 0 0 0 0 1 0 2 0 1 1 3 1 1 2 2 2 3 1 2 4 3 1 1 3 4 2 3 2 3 10 4 2 1 4 5 2 4 3 4 17 4 2 2 5 5 2 4 3 5 23 4 2 2 7 5 2 4 4 6 45 5 2 2 16 8 3 5 8 8 59 6 3 3 32 11 5 5 16 10 83 5 3 2 48 11 5 5 36 12 115 5 3 3 75 13 5 5 67 14 141 6 3 3 122 14 6 7 125 17 152 6 3 3 144 15 6 7 145 18 172 5 1 2 179 15 4 6 190 20 211 5 2 2 203 12 2 4 215 22 264 7 3 2 238 13 2 3 249 24 320 7 4 3 343 12 3 6 312 28 371 8 6 4 497 12 2 6 397 % of appl. 0.48 0.01 0.01 0.00 0.65 0.02 0.00 0.01 0.52 μg N.sub.2O—N Bottle.sup.1 Days after UI-2_NI-1 UI-2_NI-2 UI-2_NI-3 UI-3_NI-0 UI-3_NI-1 UI-3_NI-2 UI-3_NI-3 appl. 11 12 13 14 15 16 17 0 0 0 0 0 0 0 0 0.5 0 0 0 0 0 1 1 1 1 2 1 2 1 2 4 2 2 2 1 7 1 4 8 3 2 2 1 10 1 5 11 4 2 2 1 11 1 5 13 5 2 2 1 12 1 6 14 6 5 3 2 13 2 8 18 8 4 3 3 20 3 8 20 10 4 3 5 31 4 10 23 12 4 3 4 52 3 10 23 14 5 2 5 90 4 13 25 17 5 2 5 99 4 14 26 18 4 3 5 125 7 13 28 20 2 1 3 141 4 11 26 22 4 3 6 156 7 12 26 24 9 6 11 174 7 12 28 28 13 5 12 194 7 11 29 % of appl. 0.02 0.01 0.02 0.25 0.01 0.01 0.04

(37) From the results it is apparent that just 33% of DMPSA drastically reduces the emissions of laughing gas.

(38) From the results it is apparent overall that the combination of 33% of the usual amount of DMPSA with 66% to 100% of the usual amount of NBPT leads to an optimum effect. Nitrification is adequately inhibited, laughing gas losses and ammonia losses are sharply reduced, and the urea is stabilized for longer.