WO2001028957A1

WO2001028957A1 - Rehabilitating sites which are poor in or do not contain humus

Info

Publication number: WO2001028957A1
Application number: PCT/EP2000/009837
Authority: WO
Inventors: Stephan Von Tapavicza; Doris Bell; Bettina Kopp-Holtwiesche; Sven Welper
Original assignee: Cognis Deutschland Gmbh & Co.Kg
Priority date: 1999-10-16
Filing date: 2000-10-07
Publication date: 2001-04-26
Also published as: AU7662900A; AR026168A1; DE19949979A1; GT200000175A

Abstract

The invention relates to the use of C sources which can be easily broken down by soil organisms in order to rehabilitate sites which are poor in or do not contain humus, and to a method for rehabilitating sites which are poor in or do not contain humus by using C sources of this type. According to the invention, agents can be added which improve the soil either simultaneously or in a time-delayed manner and/or which stabilize or compact the soil.

Description

Recultivation of humus-poor or humus-free locations

The present application relates to the use of carbon sources which can easily be digested by soil microorganisms for the recultivation of humus-poor or humus-free sites, and to a method for recultivating such sites using such carbon sources.

The recultivation of soil includes all measures that contribute to the restoration of a soil capable of cultivation, whereby the original topsoil has been removed or rendered unusable by human intervention. Such measures are of increasing importance from a variety of locations around the world, as growing populations lead to increasing land use, particularly in developing countries. Uncontrolled tillage regularly results in the destruction of valuable cultivated soils that can only be recultivated through complex measures. But there are also large areas in developed countries that need to be recultivated, such as mining heaps (opencast mines), garbage heaps, industrial wastelands, dumps and dredged material.

Another problem is the cultivation or recultivation of desert soil and of erosion areas, which are caused, for example, by agriculture not adapted to the climatic conditions or by deforestation. Another starting point for recultivation is so-called land (Reclaimed Soil), which is used for land reclamation in many countries, especially the developing countries. For this purpose, soils from quarries etc., which are barely humus-free or humus-free and only have a negligible microfauna, are heaped up and there is the problem of providing such a soil with a layer of humus in order to use this soil for agriculture.

The object of the present invention was to carry out recultivation measures in humus-poor or humus-free soil. In the context of the present application, humus is understood to mean the entirety of the dead, plant and animal substances present in the soil. Humus formation (mineralization and herdification) is the common work of soil, animals and microorganisms. On average, one liter of a Central European forest floor contains two earthworms, 50 bristle worms, 100 small spiders, crabs, millipedes and insects, 500 erasers and barnacles, 1000 springtails, 2000 mites, 30,000 roundworms and 1 million amoebas, flagellates and other unicellular organisms. The ingredients from animals and plants released by microbial decomposition are generally summarized as non-humic substances. These are compared to the humic substances, which are understood to mean the humins and humic acids created by various chemical degradation mechanisms. The chemical composition of the humus is not uniform. It is striking that the carbon-nitrogen ratio in plant residues is approx. 40 to 1, in humus, on the other hand, 10 to 1. Soil poor in soil means that the total carbon content in the soil (after incineration) is in the range of at most 1% by weight , Typically, however, only a maximum of 0.2 to 0.5% by weight of carbon is found. The soils are often practically free of carbon (e.g. pure sand soils). The basic problem of recultivation is that, on the one hand, the mechanical-physical properties of the soil have to be adjusted so that plant growth is possible; here, in particular, rootability, aeration and water penetration are among the essential criteria, but it must also be ensured that the properties of the soil are adjusted so that the microorganism flora and fauna that are essential for successful plant growth can develop. In addition to the physical parameters already mentioned, certain chemical compounds with nutritional character must therefore also be Ground. The entry of nutrients into the soil thus represents one of the foundations for recultivation. In the case of soils that are poor in or low in humus, there is the additional problem that particularly large amounts of carbon have to be introduced into the soil. A cultivable soil typically has a carbon content of 1.0 to 2.5% by weight. Commercial considerations must therefore also be taken into account, ie those compounds are to be used which are inexpensive in order to be able to carry out the recultivation of large areas of land at low cost. It has been found that the above requirement can be met by selecting certain carbon sources.

A first object of the present invention relates to the use of carbon sources (C sources) which can be easily digested by soil organisms for the recultivation of humus-poor or humus-free locations, in particular in deserts and in piled-up, preferably stony land. Easily digestible carbon sources are understood here to mean those carbon-containing compounds which can be metabolized anaerobically or aerobically by soil microorganisms without the addition of catalysts or elevated temperatures under normal site conditions. Long-chain, linear hydrocarbon compounds are particularly important. A selection of such compounds that can also be used in the sense of the present invention can be found in DE 197 48 884 by the applicant. Particularly important representatives of the substance class mentioned here are corresponding hydrocarbon compounds which are at least partially functionalized with oxygen as a hetero atom. Typical examples of components of this type are fatty alcohols and / or fatty acids or their derivatives and / or salts. Suitable fatty alcohol or fatty acid derivatives are their esters, ethers and / or amides. Of particular importance in the context of the invention are the fatty alcohols and the esters of fatty acids with monofunctional and / or polyfunctional alcohols. The term fatty acid esters includes both the use of polyfunctional alcohols Fullest like partial esters. Which special components are the preferred representatives in the respective specific individual case is determined, if appropriate, by secondary effects and thus by the presence of any desired synergisms within the overall system. The aim of the older teaching is to improve the living conditions for soil microorganisms which, as already described above, are essential for plant growth, in particular root growth, in the soil. However, DE 197 48 884 makes no statements as to the extent to which such C sources can be used to improve / support the recultivation of soils that are free of humus or poor in humus.

It has been shown that residues from the production of oleochemical raw materials are suitable as the preferred C source in the sense of the teaching according to the invention. In the extraction of fats and oils from native sources, a large number of waste materials accumulate, for example the husks of oil-containing seeds in the processing of oil seeds etc., but also in the refining of the raw fats and oils, residues are formed which are within the meaning of the present invention can be used. Chemically speaking, these are preferably fatty substances selected from the groups of fatty alcohols, fatty acid esters of lower alcohols, fatty acids, triglycerides and / or waxes. It should be emphasized that mixtures of such compounds are generally obtained, the composition of which can contribute to the particular suitability as a C source. In connection with the present invention, residues from the production of Palmol and Pal kernol are particularly preferred. These are preferably methyl esters, preferably the fatty acid residues C ₂ -C ₁₈ in admixture with triglycerides, likewise preferably the chain length of the fatty acid residues C ₂ -C ₈ . Such residues contain on average 20 to 50% by weight of methyl ester and 40 to 70% by weight of glycerides. Furthermore, those waste materials are obtained from the palmol extraction, which contain 40 to 60 wt .-% fatty acids of the section C ₁₂ -Cι ₈ and 20 to 35 wt .-% methyl ester. In addition to the fatty substances, which usually make up at least 90% by weight of the residues, they also contain Water in amounts of less than 10, preferably less than 5 and in particular less than 8% by weight. The production residues also contain trace elements, preferably copper, iron and zinc in amounts of up to 1000 ppm. Typical amounts are in the range between 100 and 300 ppm. Production backlogs that are predominantly or completely from the production of vegetable oleochemical raw materials are particularly preferred. Production residues which are liquid at room temperature are also preferred. According to the present technical teaching, the production backlogs represent the C sources for microorganisms in the soil area.

Further suitable C sources are, for example, castor meal, animal manure, green compost, clear sludge or champingon compost.

For the purposes of the present invention, it is generally sufficient to apply suitable amounts of such production backlog to the soil to be recultivated. 0.5 to 5 t / ha, in particular 1.0 to 2.5 t / ha and particularly preferably 1.0 to 2.0 t / ha, of soil to be recultivated are preferably used.

In the context of the present technical teaching, however, it has proven advantageous to use, in addition to the inexpensive oleochemical raw materials, other auxiliaries and additives known to the person skilled in the art. These are preferably agents which stabilize and solidify the soil and agents which improve the soil microorganism growth in or on the soil of the site to be recultivated. The use of wetting agents is also preferred. It is particularly preferred to use, in addition to the oleochemical production residues, ecologically contractually wetting agents of the O / W type; these are preferably alkyl polyglycosides (APG). Such wetting agents are also described, for example, in DE 197 48 884 above. The APGs are natural product-based compounds of the general formula R-0 (G) _x , in which R is a primary, preferably straight-chain and aliphatic hydrocarbon radical with at least 6 C atoms, preferably with 8 to 24 C atoms and in particular 8 means up to 18 carbon atoms and G represents a glycose unit with 5 or 6 carbon atoms, preferably glucose. The degree of oligomerization x - and thus the DP value - which indicates the distribution of monoglycosides and oligoglycosides, is usually a value between 1 and 10 in the surfactant class concerned and is, for example, in the range from about 1.2 to 5, preferably in the range from about 1.2 to 4 and in particular in the range from 1.2 to 2. Reference can be made to the extensive specialist knowledge and literature for the production of APG compounds, see for example the publication by Hill at. al. "Alkylpolyglycosides, VCH-Verlagsgesellschaft mbH, Weinheim 1997". In addition to the APG compounds mentioned above, other biodegradable and contractual components with comparable properties in the sense of the teaching according to the invention can also be used. For example, sugar partial esters of monocarboxylic acids and in particular 8 to 24 carbon atoms, sorbitan esters, for example of the type of sorbitan monostearate or sorbitan monooleate or also surfactants of biological origin are suitable here. Examples include sophorose lipid, trehalose lipid or lipopeptides as they are known as metabolites or membrane components of a multitude of microorganism strains.

Anionic surfactants, for example soaps, but also biodegradable alkyl sulfates, in particular fatty alcohol sulfates, can also be used as wetting agents. The teaching of the above-mentioned DE 197 488 84 mandates the use of compounds of phosphorus and / or nitrogen which have lipophilic residues. In the context of the present technical teaching, there is no compulsory use, but it has also proven to be advantageous to use such connections. It should be noted here that these are optional components, ie both the wetting agents and the lipophilic compounds containing N and P can be used together or independently of one another. The compounds having lipophilic residues are preferably phospholipids, in particular lecithin, lecithin hydrolyzates or chemically modified lecithins. Such compounds are known from the older DE 44 37 313 AI by the applicant for use in improving plant growth and stimulating the microorganisms living in the substrate. The teaching of this application is therefore also the subject of the present technical teaching.

The phospholipids used according to the invention are amphiphilic substances which are obtained from plant or animal cells. Preferred phospholipids are the glycerophospholipids, which are usually also referred to as lecithin. The sphingophospholipids are less preferred. Known and usable substances here are the diacylphospholipids, phosphatidylcholines, phosphatidylethanolamines,

Phosphatidylinositols, phosphatidylservines, phosphatatidylglycerols, phosphatidylglycerol phosphates, diphosphatidylglycerol, N-acylphosphatidylethanolamine and phosphatidic acid. The monoacylphospholipids, lysophosphatidylcholines,

Lysophosphatidylethanolamines, lysophosphatidylinosines,

Lysophosphatidylserines, Lysophosphatidylglycerols, Lysophosphatidylglycerophosphate, Lysodiphosphatidylglycerols, Lyson-acylphosphatldylethanolamine and Lysophosphatidinsaure. Because of the accessibility, the person skilled in the art will primarily resort to industrially available phosphatidylglycerides, which are commercially available as vegetable or animal lecithins and zephalins. These preparations are mostly obtained from oils such as corn oil or cottonseed oil or soybean oil. Preferred within the scope of the invention are the enzymatically hydrolyzed glycerophospholipids (enzymatically hydrolyzed lecithin), which have a more hydrophilic character due to the elimination of a fatty acid ester. The only exceptions are products that have lost their phosphoric acid residue due to the enzymatic hydrolysis.

As natural substances, the phospholipids are completely degradable to C0 ₂ and H ₂ 0 and biomass, with the result that no inert or ecotoxicologically questionable degradation products accumulate in the soil in the process according to the invention. The phospholipids themselves move slowly in the soil and are therefore not washed out into the groundwater. They are also non-toxic, so that their use is also possible for this reason.

Although the use of the phospholipids is also possible in solid form, liquid preparations are usually used. This is done in particular in such a way that 0.5 to 30 g, preferably 1 to 20 g, of phospholipid are applied per m ^{2 of} substrate surface in dilute aqueous preparation. The aqueous preparation preferably contains 1 to 20 g, in particular 2 to 9 g, of phospholipid per liter. The aqueous preparation can be prepared in this form immediately before use, but it has proven expedient to carry out the preparation of this preparation intended for use in such a way that a more concentrated preparation is first adjusted to the use concentration by dilution with water. This can be a solid concentrate, for example in powder or granule form; however, liquid concentrates are preferably used. It has also proven expedient to stably emulsify the phospholipids in the aqueous preparations in order to prevent segregation during storage and during use. If the phospholipids are not self-emulsifying, so that they can be converted into the emulsion form using physical methods alone, surfactants are added to support the formation of the emulsion. Anionic surfactants or mixtures of anionic surfactants and nonionic surfactants are particularly suitable, but also nonionic surfactants alone, with biodegradable and completely degradable surfactants being preferred in any case.

While the surfactants listed above improve the supply of water to the soil and the phosphorus and nitrogen-containing compounds are to be regarded as nutrients for the soil microorganisms, it has also proven to be useful for recultivating soil-stabilizing agents, preferably those based on polyvinyl alcohol esters Cι_ ₅ monocarboxylic acids in Use in combination with plasticizers based on triesters of glycerin. Such agents are known in principle for soil stabilization, for example from DE 44 28 249 AI by the applicant. In the sense of the present technical teaching, it is particularly preferred to use, in addition to the organic oleochemical production residues as the C source, preferably compounds of phosphorus and / or nitrogen having a lipophilic residue in combination with wetting agents and, at the same time or with a time delay, to carry out soil stabilization preferably with the polyvinyl alcohol esters already described , Furthermore, it has proven to be advantageous, for example, to add seeds to the soil to be recultivated, together with the active components described above. In addition, conventional fertilizers known to those skilled in the art can also be used. These are inorganic or organic substances, either immediately or after chemical decomposition in the soil on which the plants grow, the elements required by the plants, in particular nitrogen, phosphorus, potassium, magnesium but also trace elements such as iron, manganese, zinc , Copper and boron in a form that can be absorbed by the plants. For example, fast-acting nitrogen fertilizers, ammonium salts, nitrate and urea are used, while certain organic nitrogen compounds, for example cyclodiurea, release the nitrogen only slowly and are to be regarded as depot active substances. In a similar manner, the other elements are usually used in the form of more or less water-soluble salts. Examples include ammonium, potassium, magnesium and calcium phosphates, potassium sulfate, potassium chloride, potassium magnesium sulfate, magnesium sulfate, ammonium molybdate, zinc sulfate and boric acid. In the aqueous preparations of the phosphorolepids used according to the invention, urea, ammonium nitrate and potassium nitrate are preferably used as the active ingredients. The amount of fertilizer depends on the needs of the respective plants whose growth is to be improved. In the case of recultivation, only careful, low-dose fertilization can be assumed at first, and not through high Concentrations cause an impairment of the growth of microorganisms in the soil.

To further solidify the soil, it has proven to be advantageous to introduce fibrous solids, preferably straw or coconut fibers, but also sawdust, into the soil or onto the soil.

Another object of the present invention relates to a method for the recultivation of humus-poor or humus-free sites, wherein easily accessible C sources are introduced into and / or on the soil of the site for soil microorganisms, and optionally at the same time or with a time offset, further soil-improving and / or the soil stabilizing or consolidating agents can be entered. The C sources described above are preferably used. Also preferred is a process design in which ecologically contractual wetting agents of the O / W type, preferably APG compounds, are introduced together with the entry of the C sources. Embodiments of the method according to the invention are of particular importance, in addition to the introduction of the C source in combination with wetting agents, nutrients and / or agents for soil stabilization / stabilization - as described above - are used in a separate step. According to the invention, the wetting agents are used in amounts of from 0.01 to 1.0 t / ha, in particular from 0.02 to 0.5 t / ha and very particularly preferably in amounts of from 0.02 to 0.1 t / ha. The agents for increasing growth are used in amounts of 0.1 to 2.0 t / ha, preferably 0.2 to 1.5 and in particular 0.2 to 0.8 t / ha of the soil.

In order to recultivate a soil with a low humus content in the sense of the present invention, the soil is first exposed to the C source, possibly in admixture with a wetting agent, it being also possible to add agents which increase the growth of microorganisms. Such a mixture is preferably applied in the form of an aqueous solution or emulsion. Subsequently treatment of the soil with mineral fertilizer and / or soil stabilizing agents follows. At the same time or with a time delay, seeds of annual, herbaceous plants are then preferably applied to the soil, which contribute to the stabilization of the soil by their growth and, if appropriate, to a desired nitrogen fixation in the soil (for example when using legumes). Depending on the development of the humus layer, the application with the C sources, wetting agents or growth-increasing agents is carried out several times a year. However, depending on the nature of the soil, the method according to the invention generally leads to the formation of a sufficiently thick humus layer after 2 to 5 years.

Claims

claims

1. Use of carbon sources (C sources) that are easily digested by soil microorganisms for the recultivation of humus-poor or humus-free locations.

2. Use according to claim 1, characterized in that the C sources are selected from residues from the production of oleochemical raw materials.

3. Use according to claims 1 to 2, characterized in that the C sources are selected from residues of the production of vegetable oleochemical raw materials.

Use according to claims 1 to 3, characterized in that the production residues contain fatty substances selected from the groups of fatty alcohols, fatty acid esters of lower alcohols, fatty acids, triglycerides and / or waxes.

Use according to claims 1 to 4, characterized in that the production residues contain fatty alcohols of chain length C _i2 to Ciβ.

6. Use according to claims 1 to 5, characterized in that the production residues contain fatty acid methyl esters of chain length C _i2 to Cι ₈ .

7. Use according to claims 1 to 6, characterized in that the production residues triglycerides with fatty acids

Chain length C _i2 to C ₁₈ included.

8. Use according to claims 1 to 7, characterized in that the production residues contain in amounts of <10, preferably <5 and in particular <1 wt .-% water.

9. Use according to claims 1 to 8, characterized in that the C sources contain trace elements, preferably copper, iron and zinc in amounts up to 1000 ppm.

10. Use according to claims 1 to 9, characterized in that the C sources are liquid.

11. A method for the recultivation of humus-poor or humus-free locations, characterized in that easily accessible C sources are introduced into and / or on the soil of the site for soil microorganisms, optionally at the same time or with a time delay, other soil-improving and / or soil stabilizing agents or solidifying agents can be registered.

12. The method according to claim 11, characterized in that additional ecological contractual wetting agents of the O / W type are introduced into and / or on the floor.

13. The method according to claims 11 and 12, characterized in that alkyl (oligo) glycosides (APG compounds) are used as ecologically compatible wetting agents.

14. The method according to claim 11 to 13, characterized in that additional agents for increasing the growth of soil microorganism growth are introduced in and / or on the soil of the site, the lipophilic compounds containing phosphorus and / or nitrogen and, if desired, further macro and / or contain micronutrients for plant growth.

15. The method according to claims 11 to 14, characterized in that phospholipids, preferably lecithin, lecithin hydrolyzates or chemically modified lecithins are added to the soil of the site to increase the growth of soil microorganisms.

16. The method according to claims 11 to 15, characterized in that additional means for stabilizing the soil of the site are introduced, the esters of polyvinyl alcohol with C _ι - ₅ - s monocarboxylic acids in combination with plasticizers based on triesters of glycerol, contain.

17. The method according to claims 11 to 16, characterized in that additional seeds and / or organic or inorganic fertilizer 0 are applied in and / or on the ground of the site.

18. The method according to claims 11 to 17, characterized in that further fibrous materials such as straw or coconut fibers are introduced into and / or on the floor. 5

19. The method according to claims 11 to 18, characterized in that in a first stage in and / or on the floor of the site C sources are applied together with ecologically contractual wetting agents of the O / W type and in a second step the soil is treated with an agent of the site for soil stabilization, preferably based on Polyvinyacetatestern with C _ι _ ₅ monocarboxylic acids.

20. The method according to claims 11 to 19, characterized in 5 that the C sources in amounts of 0.5 to 5 t / ha, preferably of

1.0 to 2.5 and in particular from 1.0 to 2.0 t / ha of the soil to be recultivated can be used.

21. The method according to claims 11 to 20, characterized in that the ecological contractual wetting agents in amounts of 0.01 to 1.0 t / ha, preferably from 0.02 to 0.5 and in particular from 0.02 to 0 , 1 t / ha of the soil to be recultivated.

5 22. The method according to claims 11 to 21, characterized in that the means for increasing the growth of the soil Microorganism growth in amounts of 0.1 to 2.0 t / ha, preferably from 0.2 to 1.5 and in particular from 0.2 to 0.8 t / ha of the soil to be recultivated are used.

23. The method according to claims 11 to 22, characterized in that the means for soil stabilization in amounts of 0.1 to 2.0 t / ha, preferably from 0.2 to 1.5 and in particular from 0.2 to 0, 8 t / ha of the soil to be recultivated can be used.