CULTAN

from Wikipedia, the free encyclopedia
Incorporation of manure into the field; Such fertilization is also being examined by the JKI in the CULTAN department , but the advantages and disadvantages of the summer and manure incorporation methods must be considered separately
Punctures of the tail wheels in the soil, ASL can etch depending on the pH value

CULTAN ( Controlled Uptake Long Term Ammonium Nutrition , German: controlled long- term ammonium nutrition ) is a rather rare form of underfoot fertilization for the nitrogen supply of crops. It was developed by the agricultural scientist Karl Sommer from Bonn in the late 1960s and is used, among other things, in grassland , in arable farming for grain, maize, potatoes and beets as well as in viticulture and tree nurseries . It costs more than calcium ammonium nitrate (including application).

With this method, nitrogen fertilization of the plants is carried out - unlike conventional fertilization methods - only once for a vegetation period with ammonium (NH 4 + ) instead of nitrates (NO 3 -N). The fertilizer is not applied to the soil or worked into it over a wide area, but rather it is introduced into the soil at points or in strips.

A special injection technique is used to try to place the fertilizer solution seven to 20 cm deep in the soil, slightly offset to the side of the rows of seeds or plants. For row crops with larger row spacings such as potatoes, beets or maize, this can be technically solved with some effort. As a rule, however, the cultan method is used for grain and oilseed rape that have row spacings of around 10 cm. There is no laterally offset application possible, on the contrary, a - albeit small - proportion of plants is hit and destroyed by the injection technique.

Mechanism of action

Uniform root pattern after conventional nitrogen fertilization with nitrate
Radial root pattern after nitrogen fertilization with ammonium in the CULTAN process (growth around the depot)

With nitrogen fertilization , only part of the fertilizer is absorbed by the plant. Nitrogen washed out by water or released into the air is lost and leads to considerable environmental problems ( eutrophication , nitrous oxide ). Karl Sommer sees advantages in applying highly concentrated ammonium fertilizer near the roots. The effect of the ammonium deposits is based essentially on the phytotoxicity of the ammonium. Ammonium, evenly distributed in the root space, can be absorbed by the plants both actively and passively. If it is actively absorbed, it is taken over directly into the metabolism of organic N-compounds at the roots. In the case of passive uptake, on the other hand, it can be enriched in mature leaves, where even low concentrations cause growth disorders. At higher concentrations, ammonium would cause necrosis on the leaf margins. In addition, ammonium in the root space reduces the uptake of other cations .

These negative effects of ammonium would not occur with the CULTAN process, since it is not evenly distributed in the soil, but in limited, highly concentrated depots . The depots only take up a small part of the volume of soil that a plant can root. The rest of the root space remains relatively free of ammonium ions, so that a stable supply of other nutrients can take place there.

In contrast to the evenly distributed ammonium, only a few roots would come into contact with the ammonium at the interfaces in depots. There, these roots would only absorb ammonium from the depots if they were adequately supplied with carbohydrates from the shoot . The ammonium ion is absorbed directly into the metabolism of the organic nitrogen compounds. The ammonium uptake is therefore self-regulated by the plant according to its current “ assimilatory performance”. From this the conclusion can be drawn that the growth potential of the plant is always fully exploited according to the weather conditions and at the same time no oversupply is possible.

The plants would grow specifically towards and around the interfaces of the depot. If the nitrogen in the border areas were consumed, the root tips would grow back and the entire depot would grow until it was completely emptied. A root network around the depot can be recognized using a root image created by Sommer. There are no other such pictures yet.

Under the conditions of nitrogen uptake from the concentrated ammonium depots, the entire metabolism changes as a result. Since the location of the nitrogen incorporation is shifted from the leaves to the roots, the concentrations of the substances and the resulting osmotic pressures also change . These changes, known in biology as source-sink effects, led to an improvement in the growth and quality of the plants.

General doctrine vs. CULTAN

A direct uptake of ammonium contradicts the current state of science. Due to the nitrification in the soil, according to conventional doctrines, it is assumed that regardless of the fertilized nitrogen forms ammonium, nitrate or urea, the nitrogen is ultimately available to the plants as nitrate (see also: nitrogen cycle ).

Nitrogen cycle (without absorption of ammonium by plants as claimed by Sommer)

Field trials

To what extent the positive effects observed in summer can be attributed to the mostly unnaturally high amount of sulfur (around 150 kg / ha), he leaves it unclear. In fertilization tests, sulfur compensation up to a level of 80 kg / ha of network sulfur is sometimes given, which showed significantly more positive effects than the sulfur application via injection fertilization.

A three-year study by the Agriculture Department at the Breisgau-Hochschwarzwald District Office expects results similar to those of Sommer, and to speak of reliable scientific findings when the results are only expected is simply wrong. Researchers at the University of Bonn, where Sommer taught, were also unable to achieve equivalent yield results in vegetables.

If CULTAN is characterized on the one hand by a well-developed theoretical foundation, on the other hand the meager available figures with regard to the required investment costs and yield raise considerable doubts about suitability in practice, marketability and acceptance by the agricultural producers.

Just as astonishing is the inadequate flow of information about the growth conditions in which cultan fertilization resulted in higher yields.

  • So simple yields of rapeseed are compared without going into the important oil yields per hectare. The Cultan method is compared with fertilization that is customary in practice, but without going into the amount of fertilizer, type of fertilizer, stage of growth or application dates, and rapeseed varieties that are unusual in practice are also used
  • In other experiments, liquid manure is injected using the Cultan method and compared with horn meal. The fact that manure is a complex fertilizer is not mentioned here; beets in particular react positively to the use of potash and phosphorus.
  • Cultan fertilization was also tested in brewing barley. Here, summer malting barley was sown on a wheat field damaged by geese. Since the cultivation was done without a plow, differences due to uneven goose feeding can have a major impact. In addition, as a comparison to the pure nitrogen cultan fertilizer, full mineral fertilizers were used, which cause the salt concentration to rise to unfavorable levels due to the potassium component. For reasons of comparability and reliability of the results, basic seed or at least certified seed is used in field trials . In this case, replica seeds were used. Sulfur compensation did not take place.

In a test carried out in 2010, Cultan fertilization performed worse in all disciplines: Regardless of whether it was the raw protein content or yield, quantity yield and regardless of the amount of nitrogen fertilizer, no advantages of an ammonium-sulfur injection could be determined.

As early as 2004, the University of Bonn carried out a fertilization test with the starch potato variety Agria . With the same amount of fertilization, the starch content and market product yields were the same as with conventional fertilization with calcium ammonium nitrate . If the nitrogen supply was reduced, this had a direct effect in some cases with yield losses in terms of quantity and starch yield.

In the years 2008–2009 Cultan fertilization was checked by the Lower Saxony Chamber of Agriculture at three locations. Even with the same nitrogen fertilization level, the significant yield increases promised by some contractors did not occur. Here, too, there is talk of luxury consumption at the first cut of grass and dangerously high nitrate levels.

Scientific studies on the effects of injection fertilization on the health of plants and ammonium nutrition are still lacking.

Research and Development

Seed drill with fertilizer coulters (right) and seed coulters (left / rear)

Work on the CULTAN process has been going on for many decades, the beginnings being seen around the 1970s. The essential foundations were laid by the university professor Karl Sommer at the University of Bonn , where research on injection fertilization (especially liquid manure injection) continues to this day, at the beginning of the 21st century. The application of the process is being researched in Germany in particular by the Braunschweig Julius Kühn Institute, Federal Research Institute for Cultivated Plants (JKI), Institute for Crop Production and Soil Science. Several research institutes are also working internationally with CULTAN injection fertilization.

Events on the topic take place occasionally in different countries, with field demonstrations, workshops and specialist conferences. The Julius Kühn Institute held an international symposium “Injection fertilization - current knowledge, new developments and experiences” with over 100 participants in February 2010 in Braunschweig. In this context, it should be noted that, among other things, liquid manure injection, which is customary in practice and prescribed in the Netherlands, also falls under this topic.

Since the beginning of the 21st century, there seems to have been a slight increase in use in agricultural practice. In 2004 around 10,000 hectares were processed in Germany with 10 injection machines using the CULTAN method. In 2009/2010 it was around 70,000 hectares with the help of 44 machines. Other sources speak of around 100,000 hectares in Germany. Thus, the CULTAN process was used in 2010 on less than 1% of the German agricultural area.

technology

Corn seed drill with underfoot fertilizer

Depending on the plant culture, different types of depot (spherical, cup depots, etc.) are used, which require different application techniques. The best known form of ammonium fertilizer used as standard in Europe is under- root fertilization of maize.

Star wheel method

Sommer played a key role in developing tailwheel technology . It describes a CULTAN injection technique in which a star wheel injector supplied by a liquid fertilizer tank is driven over the area to be fertilized. However, this is only used by individual contractors.

Functional sketch of a star wheel:
1. Hub
2. Wheel tire
3. Spoke tube
4. Spoke
5. Pressure hose
6. Threaded piece

A single tail wheel consists of a metal tire with usually twelve hollow spoke tubes. On each of these pipes there is a hollow spur (also called a sting or spoke), which is supplied with the fertilizer from the fertilizer tank via a pressure hose, wheel hub and spoke tube. There is a side hole on the spur head through which the fertilizer is injected into the soil at 1.5 to 8 bar. After the respective spur has pierced the ground, the channel between the pressure hose and the spoke tube is opened mechanically.

In modern devices, a control device adjusts the amount of fertilizer to the different working speeds. The membrane pump and the control valves of the injector device are activated. The spurs and wheels from different manufacturers differ slightly, but function in principle in the same way and are based on the design by Karl Sommer.

Cultivator shares or harrows

In addition to the star wheel technology, cultan fertilization is also carried out with the help of harrows and shares , which means less technical effort. With the Duett coulter, the Horsch company has found a way to simultaneously apply seed and fertilizer.

Crop protection sprayer

With conventional spraying also may NH 4 -containing fertilizers are applied. You must have drag hoses for this, as some NH 4 fertilizers are not suitable for foliar fertilization. These drag hoses also lay depots in strips. However, the spray boom must be kept very low. In addition, weights are mandatory at the hose ends so that the hoses do not lose contact with the ground due to the vegetation. The driving speed must be reduced accordingly in order to prevent the hoses from jumping open and damage to the swinging linkage.

Used fertilizers

Winter wheat after two ASL administration to previous crops shows acidification symptoms over the entire area (growth inhibition (previous crop rape), moss)

Frequently, ammonium sulphate solution or Blue sulfates used. In addition, ammonium nitrate urea solution (AHL), NH3 strong water and monoammonophosphate (MAP) or diammonophosphate (DAP; commonly called 18 × 46 because of the content values) are used.

Criticism of ASL and blues sulfates

Above all, ASL and the similar bluesulfate are in the focus of critics.

  • Sulfur fertilizers, regardless of the form, consume the lime stocks, for every 100 kg of nitrogen fertilization by ASL, around 200 kg of CaO can be expected.
  • Among other things, ASL is obtained from exhaust air or exhaust gas purification. This substance is also produced in the production of hydrogen cyanide.
  • The sulfur contained in blues sulfates is around 9% by weight with around 8% nitrogen. Corresponding to a nitrogen fertilization of 150 kg / ha nitrogen for rapeseed, around 170 kg / ha sulfur are applied. The sulfur requirement of rapeseed is around 60 kg / ha. With constant use of blues sulfates, the risk of sulfur leaching into the groundwater is high. Calculations show that - with a new groundwater formation of 100 mm annually - a leaching of 80 kg / ha sulfur is sufficient to exceed the limit value in the groundwater.

Disadvantages and requirements

  • A reserve fertilization with the CULTAN method is viewed critically on grassland areas. The increased N supply could lead to critical nitrate levels in the growth. This can damage the health of animals. In particular on grassland, the subsequent supply of nitrogen from organic manure manure must be taken into account, as grassland areas are mostly cultivated by cattle-intensive farms.
  • The agricultural machinery required for CULTAN use are significantly more expensive than conventional fertilizer spreaders , so that the process is mainly offered by specialized contractors . This argument is often mentioned, but it is not reliable.
  • In the case of simple, strip-shaped storage, the concentration in the depot may decrease in the event of heavy precipitation and thus the CULTAN fertilizer will have an undesirably faster effect. This can be prevented by using a star wheel.
  • If the crop is broken up in between for other reasons (herbicide damage, economic increased yield through e.g. potato cultivation instead of grain), or if the nitrogen cannot be fully used for other reasons such as drought, the ammonium is distributed in the soil. As a result, leaching occurs. However, targeted cultivation fertilization can be advantageous on dry, sandy soils, as the nutrients are immediately available for the vegetation period and there is no need to wait for uncertain rainfall.
  • Stony soils seem to cause problems. It is reported that there are problems with sprayed CULTAN fertilizer if it fails to cut stones. In particular, the partially used ammonium sulfate solution (ASL) must be labeled with the addition not suitable for foliar fertilization at pH values ​​below 4 . Similar problems seem to arise in heavy and at the same time dry soils.
  • Depending on the technology used, there seem to be problems with sticky soil or when applied in the morning dew. In addition, there may be reduced yields in lanes.
  • Depending on the technology and conditions of use, the star wheel nozzles can become blocked or break off.
  • It is viewed critically that at the time of application it is not known how much the crop actually needs. Influencing factors include the course of the weather, which in turn affects the soil's nitrogen supply capacity, e.g. B. influenced by organic fertilizers.
  • In addition, it is unclear at the time of cultan fertilization which amounts of nitrogen will be withdrawn from the culture due to its different yields from year to year.
  • Modern sensor technology (N sensor, crop meter) or N min samples can no longer be used to reduce the amount of fertilizer required, as the entire nitrogen supply has already been carried out using the CULTAN process.
  • A site-specific nitrogen fertilization and thus corrections of soil differences and growth levels within a field are only possible to a very limited extent.
  • The prerequisite for potato fertilization is the correct timing and placement of the CULTAN fertilizer. So it must be ensured that the depot is created below the seed potatoes. In addition, this must be done at a time when the root systems have not yet been damaged by the injection coulters. The Nmin content of the soil should be low for success and the proportion of organic fertilization should not exceed a third of the requirement.
  • The results mentioned by Cultan sellers can only be expected if the soil has a low mineral nitrogen content at the start of the experiment and a low mineralization performance during cultivation. Both are seldom the case on soils that are mainly used for vegetable growing. In the reports of very high yields after CULTAN fertilization from practice, it should be noted that the quantities of nitrogen used are sometimes very high.
  • In the case of crops damaged by moisture, as most recently in Germany in the winter of 1998/1999, the current state of research was that they should be fertilized with nitrate. It is unclear to what extent CULTAN fertilization offers a possibility here.
  • It must be ensured that the application is very precise. Above all, imperfections and double treatments must be avoided at all costs, as the entire amount of nitrogen required in the year is usually applied. Otherwise there will be a lack of or double application of fertilizer on partial areas. In contrast to mineral fertilization, the risk of application errors is concentrated on one pass and one application of fertilizer. Re-fertilization is hardly possible in later growth phases with the mostly heavy equipment, and the roots of the stands that have advanced in growth would first have to grow to the depot. The application can be done with high-quality GPS systems or on smaller areas with the help of foam markers.
  • Contrary to statements made by the scientist Sommer, the application date must apparently also be in the area of the beginning of the vegetation for injection fertilization, so as not to endanger the ears of corn due to a lack of nitrogen. (comparative also statement of the journal praxisnah 1/2011)

See also

literature

  • Literature by and about CULTAN in the catalog of the German National Library
  • Konrad Steinert: Permanent no-till in trials - experiences with no-till in a Saxon market fruit farm . In: Agriculture without a plow . No. 2 , 2008, p. 5-13 ( online ).
  • Karl Sommer: CULTAN fertilization. Physiologically, ecologically and economically optimized fertilization process for arable crops, grassland, vegetables, ornamental plants and fruit trees. AgroConcept GmbH, Bonn (ed.). Verlag Th. Mann, Gelsenkirchen, 2005. ISBN 978-3-7862-0151-9 .
  • Karl Sommer, C. Leufen, HW Scherer: Cultivation of potatoes using the “CULTAN” method. In: Potato growing. No. 56, 2005, pp. 148-153.
  • Karl Sommer: Perspectives of the CULTAN process. In: VLN-INFO sheet. No. 4, 2002, pp. 12-16.
  • Karl Sommer, HW Scherer, Antje Kunert: CULTAN process in maize. In: Mais, the magazine for the corn grower. No. 1, 2002, pp. 20-23.
  • Karl Sommer: CULTAN and agriculture without a plow. In: Agriculture without a plow. No. 6, 2001, pp. 11-16.
  • Karl Sommer: CULTAN fertilization for grain with no alternative? In: Agriculture without a plow. No. 3, 2010, pp. 23-27.
  • H.-J. Schumacher: Increase in yield and quality for brewing barley; Successfully growing summer cereals with the CULTAN method. In: Agriculture without a plow. No. 1, 2009, p. 26.
  • D. Baget fries: Controlled use of pesticides and safeners in combination with the N supply according to the "CULTAN" method. Diss. Bonn. 2002.
  • Ernst Viehausen: Nitrogen mobilization and nitrogen utilization as well as regulation of vegetative growth in winter wheat on heated soils . Bonn 1983, DNB  840648863 (dissertation, University of Bonn).

Web links

Commons : CULTAN  - collection of images, videos and audio files

Individual evidence

  1. ↑ North Rhine-Westphalia Chamber of Agriculture: Nitrogen fertilizers (Guide 2012; PDF; 77 kB).
  2. ↑ Bluesulphate.de: Blue-Sulphate not suitable for foliar fertilization
  3. ↑ Page no longer available , search in web archives: FAT report Switzerland Cultan in Mais@1@ 2Template: Dead Link / www.agroscope.admin.ch
  4. ↑ K. Sommer, HW Scherer: Source / Sink - relationships in plants depending on ammonium as "CULTAN", nitrate or urea as available nitrogen fertilizers ; Presentation, Königsberg, 2007.
  5. ↑ Forage production and climate change: grassland management as a sink and source of greenhouse gases . In: C. Berendonk, G. Riehl (Hrsg.): Communications of the working group for grassland and fodder cultivation in the Society for Plant Cultivation Sciences eV Volume August 10 , 2009 ( online [PDF]).
  6. ↑ terraquat.com (PDF; 460 kB)
  7. ↑ Uni Bonn, Liu, Jiancun (1996), page 11 (PDF; 201 kB)
  8. ↑ Christoph Felgentreu: Influence of the injection fertilization method (cultan method) on the yield and quality of winter rape in Brandenburg . In: Communications from the Society for Crop Science . tape 16 , 2004, DNB  015479919 , p. 193–194 ( online [PDF]).
  9. ↑ Agroscope Switzerland: Horn meal + slurry cultan in organic beets ( Memento from December 25, 2015 in the Internet Archive )
  10. ^ Hermann-Josef Schumacher: Yield and quality advantages for brewing barley . In: Agriculture without a plow . No. 1 , 2009, p. 26–28 ( online [PDF]).
  11. ↑ FLV Frankfurt: Test field results 2010 , p. 13.
  12. ↑ Uni Bonn page 19 (PDF; 1.3 MB)
  13. ↑ Grassland - News about nitrogen fertilization. (PDF; 302 kB) In: Rundbrief AG FUKO. Hansa-Landhandel, 2010, p. 5 , archived from the original on December 19, 2013 ; Retrieved January 9, 2011 .
  14. ↑ Julius Kühn Institute on the important role of sulfur on plant health
  15. ↑ a b Gerlinde Nachtigall: Injection fertilization - a fertilization method with a future! Science Information Service , March 3, 2010, accessed on July 2, 2010 .
  16. ↑ cultan.de information on distribution. July 16, 2010. Retrieved July 16, 2010 .
  17. ↑ DLR RLP spreading technology shares (PDF; 39 kB)
  18. ↑ LVG Straelen: CULTAN method in arable farming ( Memento of October 16, 2007 in the Internet Archive ) (overview Cultan fertilizer devices)
  19. ↑ LVG Straelen: CULTAN method in arable farming ( Memento of October 16, 2007 in the Internet Archive ), page 18.
  20. ↑ Lime fertilization. Rönner GmbH & Co. KG, July 18, 2010, archived from the original on December 19, 2013 ; Retrieved July 18, 2010 .
  21. ↑ Chamber of Agriculture NRW origin and etching behavior of ASL. (PDF; 77 kB) July 18, 2010, accessed on July 18, 2010 .
  22. ↑ LWK Luxembourg Sulfur demand for rapeseed ( Memento from September 2, 2011 in the Internet Archive )
  23. ^ DLR: Sulfur leaching. (PDF; 83 kB) July 18, 2010, accessed on July 18, 2010 .
  24. ↑ Hansa-Landhandel: Does the CULTAN fertilization match the grassland? ( Memento from October 20, 2013 in the Internet Archive ) (PDF; 929 kB)
  25. ↑ Stefanie Hahn ( JKI ): New nitrogen fertilization process saves costs and helps to reduce the nitrate content in drinking water. Science Information Service , March 20, 2008, accessed on July 9, 2010 .
  26. ↑ Tine injectors cause problems, tail wheel is recommended. (PDF; 720 kB) Accessed July 13, 2010 .
  27. ↑ Adaptation strategies for regional crop production. (PDF; 2.7 MB) Regional Climate Adaptation Program Model Region Dresden, July 1, 2011, accessed on June 16, 2017 .
  28. ↑ high pressure injection. (PDF; 8.3 MB) Julius Kühn Institute , July 16, 2010, p. 26 , archived from the original on March 30, 2014 ; Retrieved July 16, 2010 (from a presentation template).
  29. ↑ nitrogen fertilizers. (PDF; 77 kB) Chamber of Agriculture NRW, July 16, 2010, p. 2 , accessed on July 16, 2010 .
  30. ^ Landhandel Nord-West: Abolition of the Cultan injector. (PDF; 92 kB) (No longer available online.) July 16, 2010, p. 1 , formerly in the original ; Retrieved July 16, 2010 .  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.@1@ 2Template: Toter Link / www.lnw2.de  
  31. ↑ Kennco Injection Wheel. (PDF; 8.3 MB) Julius Kühn Institute, July 16, 2010, p. 22 , archived from the original on March 30, 2014 ; Retrieved July 16, 2010 (from a presentation template).
  32. ↑ Thuringian State Agency for Agriculture (page 8). (PDF; 8.3 MB) July 16, 2010, archived from the original on March 30, 2014 ; Retrieved July 16, 2010 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.jki.bund.de
  33. ^ ALB Bayern: Disadvantages of the system (page 34). (PDF) (No longer available online.) July 16, 2010, formerly in the original ; Retrieved July 16, 2010 .  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.@1@ 2Template: Toter Link / www.alb-bayern.de  
  34. ↑ Leufen: Abstract: Potato fertilization with Cultan. (PDF; 31 kB) July 16, 2010, accessed on July 16, 2010 .
  35. ^ Agriculture MLR Baden-Württemberg
  36. ↑ top agrar 2/1999 Nu-Agrar, Hansgeorg Schönberger, Fertilize wet-damaged stocks with nitrate
  37. ^ Agricultural Office Mecklenburg-Western Pomerania, page 5 ( Memento from January 15, 2015 in the Internet Archive ) (PDF; 273 kB), accessed on January 9, 2011