DE4018395A1 - Inhibition of nitrification of ammonium nitrogen in soils - Google Patents

Abstract

An agent for inhibiting and regulating the nitrification of ammonium-N contains, in addn. to conventional auxilliaries and carriers, 1-guanyl-3-methyl pyrazole of formula (I) or its acid addn. prods. or coordination cpds. as the active ingredient.

Description

Field of application of the invention

The invention relates to the prevention or regulation of nitrification of ammonium nitrogen, in particular from mineral and organic Fertilizers, in cultivated soils.

Characteristic of the known prior art

Ammonium nitrogen is subject to the microbial in the soil in a relatively short time Conversion via the intermediate stage of nitrate nitrogen. This The process is largely determined by the temperature, the soil moisture, the pH and the biological activity of the soil affected.

In contrast to ammonium nitrogen, nitrate nitrogen is not Sorption carriers of the soil, clay and humus sorbed. The consequence of this is that nitrate nitrogen during the winter half year and in strong Precipitation or intensive irrigation even during the summer half-year, especially on light soils that are subject to leaching. The washout losses can average up to 20% of fertilizer nitrogen annually be.

The washed out nitrogen is not only for the nutrition of crops lost, but also leads to the enrichment of nitrate nitrogen in the groundwater. This can be related to the drinking water supply lead to damage to human and animal health.  

In addition to the washout losses, under certain conditions, in particular with high humidity or soil compaction, annually considerable gaseous nitrogen losses due to denitrification of the nitrate nitrogen occur. By inhibiting or regulating nitrification can significantly improve the use of fertilizer nitrogen and thus increases the economic benefits of nitrogen fertilization will.

It is already known that for these purposes, in addition to substituted Pyrazoles (US-PS 34 94 757, JP-PS 7 24 718, DD-PS 1 31 063, DD-PS 1 33 088) and their azolium salts (US-PS 36 35 690, JP-PS 72 47 182, JP-PS 72-47 183), Substances such as dicyandiamide (DOS 27 02 284, DOS 27 14 601, DOS 3 54 482), Nitrapyrin (US-PS 34 24 754, SU-PS 10 85 966) and guanylthioureas as well whose salts (JP-PS 5 852/59, JP-PS 5-60 02 958) can be used. However, these compounds have disadvantages such as low activity, too low thermal and hydrolysis stability, too high toxicity, too high Volatility and complex manufacturing processes that are economical Oppose application. Too high a volatility and a low one thermal and hydrolysis stability of the active ingredients limit the Application methods very strongly and only allow an introduction in the floor too.

Aim of the invention

The aim of the invention is to provide active substances for inhibiting or regulating nitrification of ammonium nitrogen in the soil, which have a sufficient residual effect and which are based on their low volatility all application methods, especially surface application, allow.  

State the nature of the invention

It has surprisingly been found that 1-guanyl-3-methylpyrazole (GMP) corresponds Formula I,

whose acid addition products or coordination compounds nitrification inhibit or regulate ammonium nitrogen.

Table 1 gives an overview of some substances.

Table 1

The agents according to the invention have the advantage of being very low Volatility, which means less loss of active ingredient in surface application occur. In addition, the invention Medium characterized by a high thermal and hydrolysis stability, which a Incorporation into the fertilizer allowed and previous mixing processes or bypassing the separate application of active ingredient and fertilizer.  

The agents according to the invention can be mixed with or together with solid or liquid mineral or organic fertilizers that contain the nitrogen in a reduced form. they can also be melted in solid mineral ammonium fertilizers are as well as in the form of a solid or liquid concentrate, for. B. in water or in a mixture with a solid, ground or granulated Carrier to be used.

If the new agents are used together with solid or liquid fertilizers, so you can apply with 0.1-50 wt .-% of the fertilizer nitrogen be, preferably with 0.2-15 wt .-%.

The following examples serve to explain the invention.

Embodiments example 1

The agents according to the invention were used as ammonium sulfate active ingredient mixtures added to a black earth-like sandy loam soil and evenly mixed.

The concentration was 16 ppm (based on soil mass) when nitrogen was added of 20 mg N / 100 g soil.

After wetting the soil to 50% of the maximum water capacity was incubated at 20 ° C for 28 days and then the nitrate or nitrate nitrogen formed certainly. The same ammonium sulfate addition served as a control to the floor as in the test variants.

The inhibitory effect in percent is calculated according to:

a = nitrite and nitrate content of the control
b = nitrite and nitrate content of the samples with active ingredient
c = nitrite and nitrate content of the soil used

The results are shown in Table 2.

Table 2

Inhibition of nitrification in percent after 28 days of incubation

Example 2

The agents according to the invention were one as a urea-active ingredient mixture black clay-like sandy loam soil added and mixed evenly.

The concentrations were 4.2 and 1 ppm (based on soil mass) a nitrogen dose of 20 mg N / 100 g soil. After moistening the floor to 50% of the maximum water capacity was incubated at 20 ° C and in Nitrate and nitrite nitrogen intervals determined every 14 days. As a control served the same urea addition to the floor as in the test variants.

The inhibition was calculated analogously to Example 1.

The results are shown in Table 3.

Table 3

Table 3, continued

Example 3

3 mg of the agents according to the invention were superficially on 10 g of a sand rust, which was set to 10% of the maximum water capacity. A serving dish with 4 mg 0.1 n H₂SO₄ served as an adsorption vessel, in which the volatile loss of active ingredient was adsorbed. The whole was incubated in a glass vessel with a ground glass cap at 20 ° C and the Active substance content on the corresponding sampling days by UV spectroscopy determined. 3 mg of 3-methyl-pyrazole applied on the surface served as a comparison.

The advantage over 3-methylpyrazole is shown in Table 4.

Table 4

Volatility in a sand rust soil

Example 4

1.25 mg of the agent according to the invention was dissolved in 100 ml 0.1 n H₂SO₄ and the active substance content was determined by UV spectroscopy as a function of time. The results the drug stability in dilute sulfuric acid are from table 5 can be seen.

Table 5

Hydrolysis stability in dil. H₂SO₄

Example 5

The agents according to the invention were melted as a urea active ingredient (2% and 4% active ingredient in the melt) a black earth-like sandy loam soil added and mixed evenly. The concentrations were 4.2 and 1 ppm active ingredient (based on soil mass) in one additional nitrogen addition of 20 mg N / 100 g soil.

After wetting the soil to 50% of the maximum water capacity was Incubated at 20 ° C and every 14 days nitrate and nitrite nitrogen certainly. The same urea addition served as a control to the floor as in the test variants. The inhibition was calculated analogous to example 1.

Table 6

Melting in urea with 2% active ingredient

Table 7

Melting in urea with 4% active ingredient

Claims (1)

Agents for inhibiting or regulating the nitrification of ammonium nitrogen, characterized in that they contain 1-guanyl-3-methylpyrazole according to formula I in addition to conventional auxiliaries and carriers, whose acid addition products or coordination compounds contain.