DE3237905A1 - Nitrogen fertilisers containing a nitrification inhibitor - Google Patents

Abstract

Nitrogen fertilisers containing a nitrification inhibitor allow a particularly high utilisation of nitrogen when the fertilisers are in the form of granules of particle size 3 to 16 mm, preferably 6 to 10 mm, which are prepared by compressing or granulating. The nitrification inhibitor used is dicyandiamide.

Description

Nitrogen fertilizers containing a nitrification inhibitor

The invention relates to fertilizers with the addition of a nitrification inhibitor in the form of large-grain granules.

When using nitrogenous mineral fertilizers, more and more occurs or less cast a loss of nitrogen. Especially when using Urea are various sources of loss to be considered. To Certain amounts of nitrogen escape from the urease to break down the urea into ammonia in the form of gaseous ammonia. The ammonia remaining in the soil is caused by nitrifying bacteria converted into nitrite and nitrate, with some of the nitrogen being denitrified escapes in elemental form and is thus lost for plant nutrition. Furthermore, considerable amounts of nitrate are released into the groundwater by the rain flushed what is not wanted for environmental reasons on the one hand, and on the other hand to further Leads to nitrogen losses.

A wide variety of measures are taken to avoid these losses taken, such as B. the conversion of urea into poorly soluble reaction products by reaction with formaldehyde or isobutyraldehyde, the coating of urea granules with plastics or with sulfur. Another measure that is particularly important in m Use of urea in rice cultivation to reduce nitrogen losses is the use of large-grain granules. The success shows in one higher harvest trough when using such granules compared to usual Urea prills with a grain size smaller than 3 mm.

There was therefore the task of using large-grain fertilizer granules to further increase the success achieved in terms of improved nitrogen utilization, to further reduce nitrogen losses and to increase the crop yield or in order to achieve the same yields by reducing the amount of fertilizer.

This task is solved by using a fertilizer in granulate form a nitrification substance, the granules having a grain size of 3 to 16 mm.

By using particularly large granules with a content of a nitrification inhibitor, such as. B. Dicyandiamide was surprisingly found that not only the formation of nitrates in the soil with increasing granulate size continuously decreases, but that the nitrification-inhibiting effect also over time is relocated. Overall, surprisingly, the result is that the incorporation of dicyandiamide in a medium of more than 3 mm grain size a higher than just that expected nitrogen utilization, and thus delivers higher crop yields.

Such large fertilizer granules are produced by wrapping of the fertilizer grain with dicyandiamide, which is achieved, for example, by rolling can be. However, a homogeneous mixture of the fertilizer with dicyandiamide is preferred pressed or granulated. However, dicyandiamide can also be used during the granulation process or evenly added to the fertilizer immediately before the pressing process.

Urea, ammonium sulphate and ammonium nitrate are preferred as nitrogen fertilizers used.

Example 1: To determine the effect of the nitrification inhibition the following test variants are selected, using urea as the fertilizer became 1. Granulate sizes: - 1 mm grain diameter (sorting 1 - 1.6 mm) - 4 mm grain diameter (Assortment 3 - 5 mm) - 8 mm grain diameter (Assortment 7 - 9 mm) - 12 mm grain diameter (Assortment 11 - 13 mm) - 16 mm grain diameter (Assortment 15 - 17 mm) 2. Dicyandiamide - without dicyandiamide - with 10% dicyandiamide-N / total-N 3rd examination dates - 14 days after fertilization - 31 days after fertilization - 64 days after fertilization The Vessels were filled with 2/3 soil and 1/3 sand (approx. 8 kg).

The fertilizer (1.0 g N) was placed at a depth of 5 cm.

The temperature during the experiment was approx. 20 OC and the floor humidity approx. 60% of the maximum water capacity.

At the examination appointments, the vessels were filled with about 1 liter of water percolated. NO2, NO3t NH4, urea and dicyandiamide were determined in the percolate.

Test results: The conversion of urea to nitrate in the soil is slowed down by the increasing size of the urea granules.

14 days after fertilization, this effect is only seen from a grain size of 12 mm or 31 days after the thinning for the largest granules (16 mm) established. 64 days after the fertilization is practically between the urea granules there was no difference in terms of nitrate formation (Table 1).

Table 1 NO3 content / G. barrel FERTILIZATION days after fertilization 1 g N / jar 14 31 64 Ha 1 mm 485 597 499 Ha 4 mm 443 523 495 Ha 8 mm 523 634 513 Ha 12 mm 344 500 557 Ha 16 mm 312 393 477 Ha / DCD 1 mm 310 500 545 Ha / DCD 4 mm 297 405 445 Ha / DCD 8 mm 312 383 458 Ha / DCD 12 mm 213 351 429 Ha / DCD 16 mm 204 320 364 Ha / DCD = urea + 10% by weight of dicyandiamide N The incorporation of dicyandiamide into the fuel granules, with 10% by weight of dicyandiamide-N based on urea-N, increases the size of the granules. reduced nitrate formation again. At all three times of the investigation, when fertilizing with fertilizers containing dicyandiamide, the nitrate formation in the soil decreases continuously with increasing granulate size.

If one carries the difference of the nitrate content of the soil after the urea and urea-dicyandiamide manure as the mean of the three study times on, the nitrification inhibition is effectively obtained with the exclusion of the grain sizes by dicyandiamide. If you consider the smallest granulate size as a control, see above it turns out that with larger granules a stronger effect of the dicyandiamide occurs than in the control (synergism). An optimal effect intensity is Achieved with small medium granules with a diameter of 8 mm (see Fig. 1).

With regard to the duration of the nitrification inhibition, the best effect will be achieved with the largest urea granules. The results show that when thinning with a urea-dicyandiamide granulate 1 - 4 mm in diameter approximately that the same but somewhat longer-lasting inhibition of nitrate formation in the soil was achieved than when fertilizing with urea supergranules (12-16 mm with urea dicyandiamide granules of 12 - 16 mm grain size leads to intensive and sustained inhibition of nitrate formation as illustrated in Table 2.

Table 2 Nitrate formation (mg N03-N / vessel in the soil after fertilization with small and super granules Fertilizer granule size days after fertilization 14 31 64 small 464 560 497 507 Urea super 328 446 517 430 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Urea small 303 452 487 414 + 10% Dicyan- super 208 335 404 316 diamid-N small = 1 - 4 mm super = 12 - 16 mm x - 3 examination dates Example 2: In a series of incubation tests, the effect of dicyandiamide was tested with increasing granulate sizes of urea and ammonium sulfate.

Test variants: 1. Granulate sizes: - 1 mm - 4 mm 8 8 mm - 12 mm # - 16 mm # 2. Dicyandiamide: - without DCD - 5% DCD - 10% DCD - 20% DCD 3. Fertilizer: - Urea - Ammonium sulphate Incubation took place at a constant temperature - (20 0) and humidity conditions (60% water capacity). According to standardized incubation period the NO3 and NH4-N content in the soil was determined Results The The results of the incubation tests essentially correspond to the results in the example 1 described vessel tests. With increasing amounts of DCD (5 to 20%), the Nitrate formation from urea and ammonium sulfate can be prevented to a greater extent (Table 3).

Table 3 Influence of dicyandiamide on nitrate formation (mg N03-N / vessel) in the soil Wt% DCD fertilizer Ammonium sulfate urea 54.2 154.6 5 18.5 133.2 10 13.9 116.7 20 14.2 99.4 % By weight DCD means the amount of dicyandiamide-N added based on the total N-content of the fertilizer.

Also the synergism of dicyandiamide and the size of the granules Fertilizer was confirmed by the breeding tests, the optimal intensity of action of dicyandiamide was also achieved here with a granulate size of 8 mm; the However, the synergistic effect is more pronounced with urine than with ammonium sulfate (Fig. 2) Blank page

Claims (6)

Patent claim 1. Nitrogen fertilizer with a nitrification inhibitor in granulate form, characterized in that the granulate has a grain size of 3 - 16 mm. 2. fertilizer according to claim 1, characterized in that the granules has a grain size of 4 - 12 mm. 3. fertilizer according to claim 1 and 2, characterized in that the granulate has a grain size of 6-10 mm. 4. DUngemittel according to claims 1 - 3, characterized in that that the nitrification inhibitor is dicyandiamide and 1-30% by weight of the fertilizer nitrogen amounts to. 5. A process for the production of a fertilizer according to the claims 1-4, characterized in that a mixture of 1-30 parts by weight of dicyandiamide and 99-70 parts by weight of urea is granulated or compressed in a known manner 6. A method for the production of a DUngemitteis according to claims 1-4, thereby gekennzeichnot that a mixture of 1-30 parts by weight of dicyandiamide and 99-70 Parts by weight of ammonium sulfate is granulated or compressed.