DD273829A1 - MEANS FOR INHIBITION BZW. REGULATION OF NITRIFICATION OF AMMONIUM NITROGEN - Google Patents

Abstract

The invention relates to a means for inhibiting or regulating the nitrification of ammonium nitrogen, especially in mineral and organic fertilizers in Kultursoeden. The aim of the invention is to modify the nitrification inhibitor 3 (5) -methylpyrazole (MP) in such a way that an MP-based inhibitor is present, which can be used universally with liquid and solid fertilizers. It has been found that the volatility of the MP is reduced and the container corrosion is reduced when a reaction product of MP, formaldehyde and phosphorous acid is used. Such reaction products are obtained by reaction of MP and H3PO3 with formalin and have a comparable with MP nitrifizide effect. The liquid reaction products readily dissolve in liquid fertilizers and are also useful as nitrifying agents for other fertilizer additives in solid fertilizers.

Description

Field of application of the invention

The invention relates to means for inhibiting or regulating the nitrification of ammonium nitrogen, in particular of mineral and organic fertilizers in cultivated soil.

Characteristic of the known state of the art

To inhibit the ongoing in the ground microwave nitrogen conversion processes of the amide or ammonium nitrogen of handp'süblichen nitrogen fertilizer such. As urea or ammonium sulfate in nitrate nitrogen, the use of nitrification inhibitors is increasingly proposed daduich to achieve a more effective use of nitrogen while preventing nitrate accumulation in the plant and the nitrate leaching into the groundwater. The use of the previously known effective nitrification inhibitors is carried out either by fertilizer-independent application or bound to solid fertilizers together with these. The introduction of the inhibitors in liquid fertilizer solutions is difficult because of insufficient inhibitor solubility or insufficient stability. Due to the growing importance of nitrogen-containing fertilizer solutions, the use of nitrification inhibitors is indispensable, especially for highly concentrated fertilizer solutions - but also for manure and manure. The known nitrification inhibitors 4-amho-1,2,4-triazole hydrochloride (ATC), 1-carbamyl-3-methylpyrazole (CMP), nitrapyrin, dicyandiamide (DCC) dissolve unmodified only poorly in aqueous fertilizer solutions and do not meet the required stability requirements. The use of DCD in fertilizer solutions is not possible in simple cases due to the low rate of dissolution and agglomeration tendency . In addition, the required Mengenmeng 3 when using DCD or DCD derivatives as an inhibitor is relatively high and must be at least 10% of the amide and ammonium nitrogen of the fertilizer to develop the nitrified effect (DE-OS 2702284). Furthermore, DCD-containing concentrated fertilizer solutions tend to reduced stability and have a low shelf life.

Among the Pyra / olnitrifiziden is considered highly effective nitrification inhibitor 3 (5) - ^M othylpyrazol (MP). MP is a liquid, immiscible with water substance. Due to the high volatility and the resulting occupational hygiene disadvantages MP is not universally applicable. There are drug losses in MP application in both solid and liquid fertilizers. The use of MP salts, such as. As MP sulfate or MP phosphate is not justifiable due to the associated increased corrosion effect of the strongly acidic solutions.

The MP bond to polymers gem. DD-WP 210025 leads to water-insoluble, film-forming solids, whereby a complex production and expensive raw materials are required.

Object of the invention

The aim of the present invention is to chemically modify the nitrification inhibitor 3 (5) -methylpyrazole such that the high degree of nitrified activity is retained and the modified inhibitor can be introduced into liquid fertilizer solutions without additional expense by simple mixing without impairments such as volatilization. young of the active ingredient or insufficient storage stability of the fertilizer solution occur.

Explanation of the essence of the invention

It is an object of the invention to develop an inhibitor preparation based on 3 (5) -methylpyrazole, which can be introduced without difficulty into liquid fertilizer solutions without the disadvantages described. Inhibitor preparation is to be understood as meaning a reversible chemical binding of the MP to suitable substances. According to the invention this is achieved by reacting MP with formaldehyde (FA) and phosphorous acid 'H ₃ PO ₃ ) to give an MP-FA-H ₃ PO ₃ reaction product.

It has surprisingly been found that such a reaction product has a comparable with MP high nitrifying effect in the soil sowia a much lower MP-FIOchtigkeit. It is further surprising that such reaction products markedly reduce the corrosive effect of fertilizer solutions on the usual transport and storage containers made of unalloyed steels.

The liquid i.iP-FA-H3PO ₃ reaction products according to the invention are obtained by reaction of MP with formalin and H ₃ PO ₃ . Such a reaction product has a molar ratio of the reaction components MP, formaldehyde and H ₃ PO ₁ of 1-4: 0.5-2: 1.5-2. The molar ratio of 1: 1: 1 is preferred, with different viscous reaction products being obtained as a function of the reaction temperature and time. The preparation of the reaction products is carried out in a simple manner by mixing the components, wherein MP and phosphorous acid are initially introduced and formalin is slowly added. The labor and energy consumption of the manufacturing process is low. It is also of particular importance that no by-products, whose disposal or recovery would require additional effort, incurred.

If the components are only briefly heated (up to 10 min ä 100 ⁰ C), water-soluble products are obtained, resulting in N-Düngerlösungeii such. As ammonium nitrate-urea solution or urea solution quickly and without residue solve and are virtually unlimited shelf life.

A further possible application of the MP-FA-H ₃ PO ₃ -PrOdUkIe according to the invention is that these are used as adhesives with nitrifizider effect on solid amide and / or ammonium fertilizers in the form of fertilizer granules or fertilizer crystals for powders, PSM or as nitrifying combination components can be.

For this purpose, advantageously higher-viscous reaction products in which part of the reactivity was removed by distillation.

embodiments

example 1

Preparation of MP-H ₃ PO ₃ -formaldehyde reaction product

126 g of aqueous, 65% technical phosphorous acid (1 mole) were placed in a flask with 82.5 g of 99.5% 3 (5) -methylpyrazole 1 mole) and then 120 g of 25% formalin (1 mole). added with stirring and cooling so that the temperature was not above 4O ⁰ C (reaction product A). Reaction product B was formed by distilling off 25 g of reaction fluid in vacuo. Are obtained liquid MP-Ha-POrFormaldehyd reaction products containing 25% and 27% MP and have a pH of 3-4. They are readily soluble in water and N fertilizer solutions.

Example 2

Evidence of nitrification inhibition

The compositions according to the invention were added to a sandy loam soil in a concentration of 1 or 2 ppm, based on their content of MP. As N fertilizer, urea was used. After humidifying the soil to 50% of the maximum Wesserkapazität the soil was incubated at 2O ⁰ C and the formed nitrite and nitrate nitrogen determined at several intervals.

As a criterion for the effectiveness, the inhibition of nitrification in percent was calculated according to the following formula:

g U

100 =% inhibition

a - c

a = nitrite and nitrate content of the sample without active substance (control) b = nitrite and nitrate content of the sample with active substance c = nitrite and nitrate content of the soil used The results are shown in Table 1.

Table 1

Inhibition of nitrification

Sample effort% inhibition by days

Quantity (ppm) 14 28 43 50 63 70 77

MP I 100 100 85 53 34 _ _ (Comparison) 2 100 100 97 63 47 5 - reaction I 100 100 93 85 35 35 17 prod.A 2 100 100 100 100 84 65 30 reaction 1 100 100 92 24 15 5 - prod.B 2 100 100 97 84 60 50 -

annotation

MP-HjPO ₃ -FA reaction product A / B acc. example 1

Example 3

Detection dor reduced volatility Din volatility of the MP in the ertindungsgemäßen agents was determined by MP-stripping with a stream of air at 40 C ^c.

A defined air stream is passed over the 0.5 g MP sample for 1 h. In 2 downstream fritted washing bottles, the volatile MP is collected in water and determined by UV spectroscopy.

The Flüchiigke't was following the following forms! calculated:

a ·

=% MP volatility

a = MP determined in do η templates (in mg) from MP reaction products. b = MP determined in the templates (in mg) boi use of 0.5 g MP alone. The results are shown in Table 2.

table

Determination of MP volatile substance

No sample

MP content

MP Flüchtif / ness

MP 98.0

MP-FA 73.2

MP-H ₃ PO ₃ 45.5

Roactionprod.A 25.0

Reaktionsprod. B 27.0

100 18.0 26.3

Remarks:

No. 1-3 Comparative Samples No.4-5 MP-H ₃ PO ₃ -FA reaction product A or B according to Example 1

tJeisplel 4 proof Koi. Reduction of Sion In ammonium nitrate-urea.toff solutions (mixture of ammonium nitrate, urea and water in the weight ratio 4: 3: 3) with and without addition of the agent according to the invention. In Example 1, sheets of St 38 were completely immersed and held for 32 days at a temperature of 20-25 ° C.

After this test time, the following were determined or calculated:

- The linear removal (V _L ) from the occurred by corrosion weight loss

- The protection value (S) as a measure of the anti-corrosive effect of the additive

the light transmission (D) to evaluate the turbidity and coloration properties of the solution

- The Fe content of the solution as a measure of corrosion.

table

Stability of carbon steel St 38 in ammonium nitrate-urea solution with various additives

Mass (mg) Additional additive medium Linear removal VI (mm / a) Protection value S (%) Translucency D (%) Fe content of the solution (%) 0.02583 - 65.5 0.04 25 50 100 MP 0.01584 3.27345 3.35497 38.7 0 0 72.0 U U 0.04 0.55 0.75 25 50 100 H ₃ PO ₃ 0,01279 1,80879 3,00550 50.5 0 0 59.1 U U 0.04 0.88 0.84 25 50 100 Reaktionsprod. A 0.00512 0.00402 0.00365 80.2 84.4 85.9 82.0 76.9 80.4 0.04 0.02 0.02

Remarks: u = impermeable

ΔM

, 3650

ATJ

tt

(τι: mass difference in <j

A: area in cm ²

ζ ι Material density in g / cm³

t; Test duration in d

^{1 L} ; | .0Γ '· V. °:. ^Ί . iwo ,. rur. '.! .. l j r j o'iiio Lua.'c: \

'' - V '! ¹ : liiin ^ i-or. "Btivrj nit ZuG.it j

D: Photometric Boüimmung the light transmittance of the ammonium nitrate-urea solution in a 5-cm K'üvette at 400nm

Example 5

Use of MP-HaPO3-FA reaction product as an adhesive

10kg of prilled urea (90% of the prills with a grain diameter of 1-2.5rnm) were mixed in a mixing drum at 20 ° C with 70g of the MP-H ₃ P0 ₃ -FA reaction product B gem. Example 1 offset. After a mixing time of 2 minutes, that had

Reaction product was distributed to the grain surface, and there was the addition of 231 g of powdered dicyandiamide (particle size 0.1 mm), the skh distributed within 5 minutes on the urea prills and adhered.

Obtained was a non-caking urea fertilizer with a nitrification inhibitor combination of MP and

Dicyandiamide (DCD) in the mass ratio 1:10 containing 0.5% MP and 5% DCD (based on urea nitrogen). The inhibitors are fat and permanently bound to urea, MP volatilization during transport, storage and application does not occur.

Claims (5)

1. An agent for inhibiting nitrification based on 3 (5) -methylpyrazole (MP), characterized in that they contain, among other excipients and excipients, the active ingredient MP in the form of reaction products of MP, phosphorous acid and formaldehyde. 2. Nitrification inhibiting agent according to claim 1, characterized in that it can be used in ammonium-containing liquid fertilizers or in manure and manure. 3. means for inhibiting nitrification according to. 1, characterized in that they can advertise as a nitrifying agent for the binding of powdered additives to ammonium fertilizer granules applied. 4. Nitrification inhibiting agents according to claim 1 and 2, characterized in that they can be applied at a rate of 0.5-25 kg / ha of reaction product, preferably 1-10 kg / ha. 5. A nitrification inhibiting agent according to claim 1, characterized in that it can be added to the fertilizer containing ammonium in amounts of from 0.5 to 15% by weight of the fertilizer nitrogen.