DD288974A5 - MEANS OF INHIBITING NITRIFICATION - Google Patents

Abstract

The invention relates to an agent for inhibiting nitrification. The compositions of this invention can be used to inhibit the nitrification of ammonium nitrogen in crops. As active ingredient they contain 1,3-dithiolanes of the general formula in which R is alkyl (C1 to C4) or benzyl, or their salts with organic or inorganic acids. Formula {Inhibition of nitrification Ammonium nitrogen in cultivated soils; 1,3-Dithiolanes or their salts with inorganic or organic acids}

Description

in which R is alkyl (C ₁ to C ₄ ) or benzyl, or their salts with organic or inorganic acids.

Field of application of the invention

The invention relates to agents for inhibiting the nitrification of ammonium nitrogen, in particular from mineral and / or organic fertilizers, in cultivated soils.

Characteristic of the known state of the art

For the inhibition of the microbial conversion processes of ammonium nitrogen into nitrate nitrogen, nitrification inhibitors are increasingly being used. This ensures a more effective use of nitrogen while preventing nitrate enrichment in the plant and nitrate leaching into the groundwater. The utilization of the fertilizer nitrogen can be significantly improved by the inhibition or regulation of nitrification and thus the economic benefits of nitrogen fertilization can be increased. The use of the previously known effective nitrification inhibitors is predominantly by fertilizer-independent application or bound to solid fertilizers together with these nitrification-inhibiting effects are known from compounds of different classes; Thus, a number of pyridine, pyrimidine, triazole and pyrazole derivatives have been proposed for use. From DD-PS 217206 are e.g. substituted cyanoethylanilines from DD-PS 217693 halogenated acetophenones known as nitrification inhibitors.

Also, various S- or S, N-heterocycles, for example 3,5-di-alkyltetrahydro-i, 3,5-thiadiazine-2-thiones (DD-PS 107 664) or 1,2,4-thiadiazoles (DD- PS 229396) have been proposed for this purpose. However, the previously known nitrification inhibitors have certain disadvantages, such. B. too high volatility, too fast hydrolytic decomposition, high toxicity, elaborate production processes and the like, which preclude an economic application.

Object of the invention

The aim of the invention is to develop new means for inhibiting or regulating the nitrification of ammonium nitrogen in the soil, which are easy to prepare, have a sufficient residual action and allow the surface application.

Explanation of the essence of the invention

It was therefore the task of finding such active ingredients which are suitable to achieve the object of the invention.

This object is achieved in that the means for inhibiting the nitrification of ammonium nitrogen in cultivated soils in addition to conventional excipients and carriers as the active ingredient 1,3-dithiolanes of the general formula

OH ₂ - S _x

C = ER,

in which R is alkyl (C ₁ to C ₄ ) or benzyl, or the salts thereof contain organic or inorganic acids.

The active compounds can be prepared in a simple manner from monoalkyldithiocarbamates and 1,2-dichloroethane; the salts are formed by reaction with the corresponding acids in the presence or absence of a solvent.

The compositions of the invention may be in the form of a solid or liquid concentrate z. B. in water or in a mixture with

e.nem solid, ground or granulated carrier or mixture with solid and / or liquid mineral or organic fertilizers containing urea and / or ammonia and / or ammonium nitrogen, can be applied.

The compositions of the invention are useful shortly before, at the same time or shortly after the application of the fertilizer

an application rate of 0.5 to 200 kg / ha of active ingredient, preferably 10 to 60 kg / ha, applied.

embodiments

The examples are intended to illustrate in more detail the inhibition of the nitrification of ammonium chloride by the use of the agents according to the invention.

The compositions according to the invention are added as urea-active substance mixture to a black earth-like sandy loam soil and mixed uniformly with it. The concentration was 16ppm (based on soil mass) with a nitrogen input of 20mg N / 100g soil. After humidifying the soil to B0% of the maximum water capacity was incubated at 20 ^e C for 28 days and then determined the nitrate or nitrite nitrogen formed. The same urea addition to the bottom served as control as in the test variants. The calculation of the inhibitory effect in percent was carried out according to the formula

'a - b

«100 =% inhibition

a-c

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

Some of the active ingredients prepared are summarized in Table I.

Table I: 1,3-Dlthiolane of the general formula OH ₂ -S _n

= NR "HX CH ₂ -S ^

No · R HX Physo Const «(n _D , P)

1.6180

1.5890 1.5640 1.6340

133 - 4 140-2 141 - 3

H OH, ^ χ ^, ΟΟΟΗ 102 - 3

A η - GH, - B OH ₂ η - » O ₂ H ₃ O O ₄ H ₉ - D E F -G ₆ H ₅ O ₂ H ₅ HCl Hl G ^ l TT COOH I I COOH

OH ₃ HO-OH-OOOH I 111 - 3 I HO-CH-COOH O ₂ H ₅ COOH 94-5 COOH O ₂ H ₅ OC 65 - 7 O ₂ H ₅ HO OH OH \ ι y 157 - 9 POP HO OH ₃ OH O ₄ H ₉ OOH I 92-3 I OOOH - O ^ H _C COOH 125 - 6

N η -

Oh oh

COOH

The following were known in the examination of the agents according to the invention for their nitrification-inhibiting action Comparative substances included: P = 3,6-D! Methyltetrahydro-1,3,6-thiadazine azine-2-thione (Dazomet) Q = dichlorourea

^ - OH ₂ - ON

R = 01 -Q- IT _n (according to DD - PS 217 206)

00 - OH ₂ oil

0 S = O - (V 0 - OH ₂ O (according to DD - PS 217 693)

-Rjr-HHOO CH ₂ OlT = OHjS-I _x ^ N (according to DD - PS 229 396)

The results of testing the active ingredients for their nitrification-inhibiting activity are shown in Table II. TABLE II Nitrification-inhibiting effect of the agents according to the invention in comparison with known active substances

active substance % Inhibition A 45 B 79 C 67 D 70 e 98 F 34 G 84 H 75 I 83 K 100 L 96 M 88 N 78 O 98 P 18 Q 31 R 11 S 21 T 64

The name of the active substance corresponds to the information in Table I.

From Table II it can be seen that the inhibition of the nitrification of ammonium nitrogen by the agents A to O according to the invention is consistently better in relation to the comparison products P to T. The active substances E, K, L and O are particularly noteworthy; these are salts which have advantages in terms of application (water solubility) over the pure 1,3-dithiolanes.

Claims (1)

An agent for inhibiting the nitrification of ammonium nitrogen in cultivated soils, characterized in that, in addition to customary excipients and carriers, it comprises 1,3-dithiolanes of the general formula OH ₂ - S ^ I 0 s NO OH₂ -B ^ ·