USE OF ETHYNYLPYRIDINE COMPOUNDS AS NITRIFICATION INHIBITORS

Abstract

The present invention relates to the use of novel nitrification inhibitors of formula I, which are ethynylpyridine compounds. Moreover, the invention relates to the use of compounds of formula (I), Formula (I) as nitrification inhibitors, i.e. for reducing nitrification, as well as agrochemical mixtures and compositions comprising the nitrification inhibitors of formula (I).

##STR00001##

Claims

1. (canceled)

2. The method of claim 10, wherein in said compound of formula I R.sup.1 is Cl.

3. The method of claim 10, wherein in said compound of formula I R.sup.2 is C.sub.1-C.sub.4-alkyl; and n is 0 or 1.

4. The method of claim 10, wherein in said compound of formula I n is 0.

5. The method of claim 10, wherein the compound of formula I is a compound according to formula I.1* or I.2* ##STR00027##

6. A composition for use in reducing nitrification comprising at least one compound of formula I ##STR00028## or a salt, stereoisomer, tautomer or N-oxide thereof as a nitrification inhibitor, wherein in the compound of formula I R.sup.1 is halogen; R.sup.2 is halogen, CN, NO.sub.2, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-haloalkyl, or C.sub.2-C.sub.4-alkenyl, wherein each substitutable carbon atom in the aforementioned groups is independently unsubstituted or substituted with one or more, same or different substituents R.sup.A; wherein R.sup.A is CN, halogen, OR.sup.a, NR.sup.bR.sup.c, C(O)R.sup.a, C(O)OR.sup.a or C(O)NR.sup.bR.sup.c; R.sup.a is H, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-haloalkyl, or phenylmethyl; R.sup.b and R.sup.c are independently of each other selected from H and C.sub.1-C.sub.4-alkyl; and wherein n is 0, 1, 2, or 3, and at least one carrier.

7. An agrochemical mixture comprising (i) at least one fertilizer; and (ii) at least one compound of formula I ##STR00029## or a salt, stereoisomer, tautomer or N-oxide thereof as a nitrification inhibitor, wherein in the compound of formula I R.sup.1 is halogen; R.sup.2 is halogen, CN, NO.sub.2, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-haloalkyl, or C.sub.2-C.sub.4-alkenyl, wherein each substitutable carbon atom in the aforementioned groups is independently unsubstituted or substituted with one or more, same or different substituents R.sup.A; wherein R.sup.A is CN, halogen, OR.sup.a, NR.sup.bR.sup.c, C(O)R.sup.a, C(O)OR.sup.a or C(O)NR.sup.bR.sup.c; R.sup.a is H, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-haloalkyl, or phenylmethyl; R.sup.b and R.sup.c are independently of each other selected from H and C.sub.1-C.sub.4-alkyl; and wherein n is 0, 1, 2, or 3.

8. The method of claim 10, wherein said compound of formula I is used in combination with a fertilizer.

9. The method of claim 10, wherein said reduction of nitrification occurs in or on a plant, in the root zone of a plant, in or on soil or soil substituents, and/or at the locus where a plant is growing or is intended to grow.

10. A method for reducing nitrification, comprising treating a plant growing on soil or soil substituents and/or the locus or soil or soil substituents where the plant is growing or is intended to grow with at least one compound of formula I ##STR00030## or a salt, stereoisomer, tautomer or N-oxide thereof as a nitrification inhibitor, wherein in the compound of formula I R.sup.1 is halogen; R.sup.2 is halogen, CN, NO.sub.2, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-haloalkyl, or C.sub.2-C.sub.4-alkenyl, wherein each substitutable carbon atom in the aforementioned groups is independently unsubstituted or substituted with one or more, same or different substituents R.sup.A; wherein R.sup.A is CN, halogen, OR.sup.a, NR.sup.bR.sup.c, C(O)R.sup.a, C(O)OR.sup.a or C(O)NR.sup.bR.sup.c; R.sup.a is H, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-haloalkyl, or phenylmethyl; R.sup.b and R.sup.c are independently of each other selected from H and C.sub.1-C.sub.4-alkyl; and wherein n is 0, 1, 2, or 3.

11. The method of claim 10, wherein the plant and/or the locus or soil or soil substituents where the plant is growing or is intended to grow is additionally provided with a fertilizer.

12. The method of claim 11, wherein the application of said compound of formula I and an optional fertilizer is carried out simultaneously or with a time lag.

13. A method for treating a fertilizer, comprising application of a nitrification inhibitor of formula I ##STR00031## or a salt, stereoisomer, tautomer or N-oxide thereof as a nitrification inhibitor, wherein in the compound of formula I R.sup.1 is halogen; R.sup.2 is halogen, CN, NO.sub.2, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-haloalkyl, or C.sub.2-C.sub.4-alkenyl, wherein each substitutable carbon atom in the aforementioned groups is independently unsubstituted or substituted with one or more, same or different substituents R.sup.A; wherein R.sup.A is CN, halogen, OR.sup.a, NR.sup.bR.sup.c, C(O)R.sup.a, C(O)OR.sup.a or C(O)NR.sup.bR.sup.c; R.sup.a is H, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-haloalkyl, or phenylmethyl; R.sup.b and R.sup.c are independently of each other selected from H and C.sub.1-C.sub.4-alkyl; and wherein n is 0, 1, 2, or 3.

14. The method of claim 11, wherein said fertilizer is a solid or liquid ammonium-containing inorganic fertilizer, a solid or liquid organic fertilizer, or an urea-containing fertilizer.

15. The method of claim 10, wherein said plant is an agricultural plant vegetable, a silvicultural plant, an ornamental plant or a horticultural plant, each in its natural or in a genetically modified form.

16. The method of claim 14, wherein said fertilizer is selected from the group consisting of NPK fertilizer, ammonium nitrate, calcium ammonium nitrate, ammonium sulfate nitrate, ammonium sulfate, ammonium phosphate, liquid manure, semi-liquid manure, biogas manure, stable manure, straw manure, worm castings, compost, seaweed, guano, formaldehyde urea, anhydrous ammonium, urea ammonium nitrate (UAN) solution, urea sulphur, urea based NPK-fertilizers, and urea ammonium sulfate.

17. The method of claim 15, wherein said plant is selected from the group consisting of wheat, barley, oat, rye, soybean, corn, potatoes, oilseed, rape, canola, sunflower, cotton, sugar cane, sugar beet, rice, spinach, lettuce, asparagus, cabbage, and sorghum.

Description

EXAMPLES

[0522] The compounds of the invention have been tested as follows in terms of the inhibition of nitrification:

[0523] 100 g soil is filled into 500 ml plastic bottles (e.g. soil sampled from the field) and is moistened to 50% water holding capacity. The soil is incubated at 20 C. for two weeks to activate the microbial biomass. 1 ml test solution, containing the compound of formula I in the appropriate concentration (usually 0.1, 0.3 or 1% of nitrogen N), or DMSO and 10 mg nitrogen in the form of ammoniumsulfate-N is added to the soil and everything mixed well. Bottles are capped but loosely to allow air exchange. The bottles are then incubated at 20 C. for 0 and 14 days.

[0524] For analysis, 300 ml of a 1% K.sub.2SO.sub.4-solution is added to the bottle containing the soil and shaken for 2 hours in a horizontal shaker at 150 rpm. Then the whole solution is filtered through a filter (Macherey-Nagel Filter MN 807%). Ammonium and nitrate content is then analyzed in the filtrate in an autoanalyzer at 550 nm (Merck, AA11).

[0525] The inhibition (NI a specified concentration) is calculated as follows:

[00001]$\mathrm{inhibition}\mathrm{in}\%=\frac{\left(\mathrm{NO}3-N_{\mathrm{without}\mathrm{NI}\mathrm{at}\mathrm{end}\mathrm{incubation}}-\mathrm{NO}3-N_{\mathrm{with}\mathrm{NI}\mathrm{at}\mathrm{end}\mathrm{incubcation}}\right)}{\left(\mathrm{NO}3-N_{\mathrm{without}\mathrm{NI}\mathrm{at}\mathrm{end}\mathrm{of}\mathrm{incubation}}-\mathrm{NO}2-N_{\mathrm{at}\mathrm{beginning}}\right)}100$

[0526] The following compounds of general formula I have been tested:

Example 1

[0527] ##STR00019##

TABLE-US-00001 NI NI @ 1% @ 0.1% 83% 46%

Example 2

[0528] ##STR00020##

TABLE-US-00002 NI NI @ 1% @ 0.1% 76% 74%

Example 3

[0529] ##STR00021##

TABLE-US-00003 NI NI NI @ 1% @ 0.3% @ 0.1% 94% 84% 68%

Comparative Example

[0530] ##STR00022##

TABLE-US-00004 NI NI @ 1% @ 0.3% 54% 35%

[0531] Example 2 was additionally tested in terms of the reduction of N20 emission Corn seeds (Zea mais, cultivar Shorty) were planted 1 seed/pot in 8 cm pots in standard greenhouse soil (mixture of peat, loam and sand) and grown in a greenhouse at 20 C. and 60% humidity. Plants were grown for ten days in a completely randomized set-up. On day 6, plants were watered but not fertilized to 50% water holding capacity then left to dry out. On day ten, the plants were separated out and each pot set onto a plant saucer designed with an inner compartment for the pot and an outer ring that is filled with water. At time 0 water with or without 100 ppm ammonium sulfate and with or without the given concentration of nitrification inhibitor (1% and 0.3%) was applied to the plant such that the water holding capacity of the soil was around 50-60%. Then a gas sampling chamber was placed over the plant saucer such that the rim fit into the ring filled with water to create a gas-tight chamber and 20 cc air from the chamber were drawn into a syringe and immediately emptied in to a Vacutainer (Labco, 12 ml volume). This equals the Time Zero measurement for each pot. The same procedure was performed with all pots in the experiment. After one hour incubation time, again 20 cc air samples were taken from the gas chambers and emptied into Vacutainers as described above. Plants were then returned to their positions in the climate chamber. The procedure was repeated at precisely the same time of day for the next two weeks.

[0532] Samples were analyzed in a Shimadzu 2014 GC equipped with an ECD system. Data was calculated as the cumulated emissions over the measurement period and the % reduction of N20 emissions relative to the untreated but fertilized control was calculated.

##STR00023##

TABLE-US-00005 % reduction of N2O relative % reduction of N2O relative to control @ 1% to control @ 0.3% 97 91

[0533] The compounds according to the invention have been further tested in terms of their % NH.sub.4N recovery from fertilized NH.sub.4N.

[0534] The compounds according to general formula I were tested as follows in terms of the inhibition of nitrification:

[0535] 100 g soil (soil Limburgerhof with pH(CaCl.sub.2) 6.8; 73% sand, 23% silt, 4% clay, which is classified according to FAO as a sandy loam) is filled into 500 ml plastic bottles and is moistened to 50% water holding capacity. The soil is incubated at 20 C. for two weeks prior to the experiments to activate the microbial biomass. 1 ml test solution, containing the compounds of formula I or the comparative compounds in the appropriate concentration (0.1, 0.3 or 1% (w/w) of fertilized NH.sub.4N), and 10 mg nitrogen in the form of ammoniumsulfate-N(NH.sub.4N) is added to the soil and everything mixed well. Unfertilized controls received 1 ml pure water. Bottles are capped but loosely to allow air exchange. The bottles are then incubated at 20 C. for 14 days and 28 days.

[0536] For analysis, 300 ml of a 1% K.sub.2SO.sub.4-solution is added to the bottle containing the soil and shaken for 2 hours in a horizontal shaker at 150 rpm. Then the whole solution is filtered through a filter (Macherey-Nagel Filter MN 807%). Ammonium content is then analyzed in the filtrate using an autoanalyzer. Ammonium was quantified via an indophenol blue dye at 660 nm.

[0537] The nitrification inhibition is expressed as % of NH.sub.4N recovery from fertilized NH.sub.4N(100%) after subtraction of unfertilized control soil. The number of replicates is 4.

[0538] The following compound of general formula I has been tested in terms of the % NH.sub.4N recovery:

Example 4

[0539] ##STR00024##

TABLE-US-00006 wt.-% relative to NH.sub.4N 0.1 0.3 1 % NH.sub.4N recovery after 74.00 68.50 72.00 14 days % NH.sub.4N recovery after 59.0 56.0 28 days

[0540] The following comparative compounds have been tested in terms of the % NH.sub.4N recovery:

Comparative Example A

[0541] ##STR00025##

TABLE-US-00007 wt.-% relative to NH.sub.4N 0.1 0.3 1 % NH.sub.4N recovery after 46.50 60.30 67.80 14 days % NH.sub.4N recovery after 51.2 68.1 28 days

Comparative Example B

[0542] ##STR00026##

TABLE-US-00008 wt.-% relative to NH.sub.4N 0.1 0.3 1 % NH.sub.4N recovery after 20.94 44.40 59.90 14 days % NH.sub.4N recovery after 11.1 61.0 28 days

[0543] For comparison of the % NH.sub.4N recovery of the compound of the invention, i.e. Example 4, with the comparative compounds as shown above from different trials, the standard deviation of a common treatment of all trials with DMPP (3,4-dimethylpyrazole phosphate) was calculated. As the standard deviation was low, data from different trials were pooled together to compare the average % NH.sub.4N recovery for the compound of the invention and the comparative compounds as shown above.