REDUCTION OF NITRATE LEACHING OF CULTIVATED SOILS It is generally known today that, within the framework of the cultivation of plants, a sufficient supply of nitrogen has a determining importance. Under conditions of use, water-soluble nitrogen compounds and / or initially insoluble in water are common parts of both organic fertilizers and inorganic fertilizers.
In all the areas in question here, such as for example agriculture, forest management, landscape care or gardening, large quantities of growth aids based on nitrogen are provided, among others, to cultivated soils. With reference to the importance and function of the various current types of nitrogen fertilizers, we can refer to the technical literature. We mention in this connection, for example, the publications "Agrarwirt-schaft" (Agriculture), Grundstufe 1, Fachteorie für Bodenkunde, Chemie, Pflanzenernáhrung ua, BLV Verlagsgesellschaft München, Landwirtschaftsverlag Münster-Hiltrup, especially pages 110 to 113, subchapter 3.1.3"Stickstoffdüngemittel" (Nitrogen Fertilizer), as well as GARTENBAULICHE BERUFSSCHULE, volume 1, Grundwissen des GSrtners, (Basic knowledge of the gardener) Verlag Eugen Ullmer, Stuttgart, 7th. edition, especially pages 216 to 219, subchapter "Stickstoffdünger" (Nitrogen Fertilizers) as well as the corresponding table 39 on page 218. Most types of plants take nitrogen mainly in the form of nitrate ions (N03 ~). soluble in water. Other forms of easy supply or hardly soluble in water are subjected after their introduction into the soil to complex nitrification processes, caused especially by populations of bacteria, so that finally in the soil all forms of N are transformed into nitrate - often also known as nitro. These easily soluble forms of nitrogen have a determining importance for the growth of the plants nevertheless they present simultaneously the problem of the leaching of the nitrate of the area of the roots of the plants towards deep zones of the ground and finally in the water table. This process, which has an important effect on the environment today and is therefore undesirable, is the forced result of the irrigation processes that determine the growth of plants through natural and / or artificial spraying of the root zone. the plants. The teaching in accordance with the present invention described below is based on the surprising discovery that by introducing selected ecologically compatible components with surfactant effect that are preferably mixed with additional components identified below that are applied to the ground there is possible a Substantial reduction of nitrate leaching from the root zone of plants. Before presenting details of the teaching in accordance with the present invention, we refer to the technical teaching of a previous patent application not yet published. The above-mentioned unpublished document DE 19701127.6 discloses concentrates of surfactants with limited foam formation for use in promoting the growth of plants. With details are described crosslinking aids in the form of an aqueous concentrate that can flow and be emptied, highly concentrated, based on surfactants to intensify the penetration and diffusion of water in the root zone of plants at the time of irrigation, containing ecologically compatible surfactant components alkyl (poly) glycoside compounds of oil-in-water (O / W) type preparation - also known below as ".APG compounds" - and in admixture with olefinically unsaturated fatty alcohols as well as optionally additional partial esters of fatty acids with polyfunctional alcohols such as foaming limiters / foam removers and additional water-soluble lower alcohols as viscosity regulating agents.
The technical teaching of the additional development presented below uses the principles of technical education presented in the German patent application mentioned above. The disclosure of this older German patent application is hereby incorporated explicitly as an object of the disclosure of the present invention. The technical teaching of the previous application mentioned above is based on the following problem: the apparently simple measure of irrigating soil surfaces, especially in the case where there is a high density of plants, can present significant difficulties. An example is the case of pedestrian traffic and / or vehicular traffic on grass surfaces, where despite regular irrigation small or large areas of grass can dry. When you try to humidify. In these places, the water does not penetrate the soil and especially does not penetrate the root zone of the plants. As a result the corresponding lawn area can become sick due to dryness and lack of nutrients. It is known that by means of the combined use of auxiliaries with a crosslinking character with the water used for sprinkler irrigation, a better penetration of the aqueous phase in the soil zone and consequently also in the field of the roots of the plants is obtained. In accordance with the teaching of the aforementioned prior application, surfactant auxiliaries composed of .APG type O / W, which are used today on a large scale in totally different technical fields, must be used as auxiliaries. The APG compounds are surfactant auxiliaries in the field of washing and cleaning agents, including textile washing substances. The teachings of the above-mentioned prior application are based on the determination that aqueous APC-based crosslinking agents are also valuable crosslinking agents for increasing the growth of plants relative to soil irrigation. However, in this case the following problem must be solved: the APG-based surfactant auxiliaries of the type in question have a particularly high foam-forming capacity in aqueous preparations. For its use in the field of washing and cleaning agents this characteristic is generally desired by the consumer; however, in the field of work of the present invention this characteristic is not only not desired but can represent a major problem. Common auxiliaries for limiting the formation of foam are known in the field of washing and cleaning agents, however they are not suitable for use in the scope of the present invention for the promotion of the growth of healthy plants. The aforementioned technical teachings of the aforementioned prior patent application employ, together with the APG-based surfactant components, selected foam removers or foam delimiters, which do not affect the growth of the plants, and preferably promote the growth of the plants. said growth. In this case, these are fatty alcohols mentioned above and / or partial fatty acid esters with lower polyhydric alcohols. The teaching of the above application is also based on the purpose of being able to offer the combination of active substances desired here jointly in concentrated form easily dilutable with water, so that in addition the sufficient capacity of dilution of the concentrate should be ensured in the normal temperature range of use. The technical solution within the framework of the teaching of the above application is found in the combination of several aforementioned substances containing the O / W type .APG compounds together with foaming delimiters selected from the aforementioned technique in a aqueous concentrate, whose viscosity is regulated by the joint use of limited amounts of water-soluble lower alcohols. The additional development described below within the framework of teaching in accordance with the present invention is based on the following additional knowledge: crosslinking agents based on .APG of the type in question here promote not only the penetration of the spray water into the structure of the soil and therefore especially in the root zone of the plants, but the mixture of aqueous active substances applied here in the soil and / or in the aerial parts of the plants has an unexpected effect also in relation to the problem previously presented of the unwanted leaching of water-soluble nitrate in groundwater . OBJECT OF THE PRESENT INVENTION The object of the present invention is therefore the application of ecologically compatible surfactant compounds of the class of water soluble alkyl (oligo) glycoside compounds of the O / W type (APG compounds) through their application on the soil surface as an auxiliary to limit the nitrate leaching of the root zone of the plants of the cultivated soils due to spraying and / or irrigation. Details of teaching in accordance with the present invention The class employed in accordance with the present invention of APG compounds consists of ecologically compatible components with surfactant effect which are in the application form selected in accordance with the present invention under normal conditions of application, especially in the usual temperature ranges, surfactants of type O / W, that is to say, not soluble in water and in the range of temperatures in question, organic components that can flow through their mixing with water can be applied as preparations in the form of oil in Water. For the scope of application in accordance with the present invention, these .APG compounds and especially the aqueous preparations of these surfactants are applied either staggered and / or simultaneously with customary inorganic and / or organic fertilizers containing N on the surface of the ground. In the preferred application form according to the present invention, these APG compounds or their aqueous preparations are applied stepwise and / or preferably simultaneously with suppliers of C containing organic bonded carbon atoms for the increase of the growth of soil microorganisms populations and especially to reinforce the corresponding microorganism flora. As will be presented in more detail below, the suppliers of C especially suitable in this respect are saturated lipophilic and / or olefinically unsaturated hydrocarbon residues with a grease structure as well as organic compounds degradable by anaerobes, which together with the APG compounds are they apply to the soil in the form of their O / W emulsions and / or O / W dispersions mentioned above. In a particularly important embodiment of the teaching according to the present invention, APG compounds are used in mixture with fatty alcohols and / or partial fatty acid esters with lower polyfunctional alcohols conveniently in the form of the indicated aqueous presentations - on the ground and in this way in the upper layers of the ground. Before presenting these improvements in detail, we first mention detailed data of the individual components defined in accordance with the present invention of the preferred mixtures of multiple components employed. The APG compounds of type O / W Here we refer first to the technical knowledge and the extensive documents for the preparation and the obtaining of APG compounds, especially of the type in question in the present invention, such as for example the publication in book form by HILL et al "Alkyl Polyglykosides"
(Alkyl polyglycosides), VCH-Verlagsgesellschaft mbH, Weinheim 1997. The publication of EP 0 230598 Bl provides complete data for the preparation and obtaining of the class of substances in question in the present invention of APG compounds, to which we refer for simplicity. Preferred APG compounds according to the present invention are characterized in that they employ at least partially and preferably at least mainly alkyl (oligo) glucoside compounds whose alkyl radical is at least mainly derived from straight-chain fatty alcohols. Compounds of this type are surfactant auxiliaries of a wide range of uses. Many factors are currently considered for use in practice: crosslinkers based on APG can be based on natural substances in a known manner. They are obtained as reaction products by reaction of fatty alcohols with monosaccharides, oligosaccharides and / or polysaccharides. In the case of the use of higher polysaccharides and / or oligosaccharides with fatty alcohols, a depolymerization is caused in the course of the acid catalysis reaction first by hydrolysis and / or alcoholysis, before the formation of the desired APG compounds. Preferred saccharide components for the formation of APG are glucose or corresponding oligoglucoses or polyglucose. Suitable reagents are also saccharide compounds based on mannose, galactose, arabinose as well as additional monomer glycosides, oligoglycosides and / or polyglycosides. Suitable APG compounds for the present invention are obtained as products of the reaction of the general formula R-0- (G) x / wherein R represents an aliphatic hydrocarbon radical and preferably straight chain with at least 6 carbon atoms , preferably with 8 to 24 carbon atoms, and especially with 8 to 18 carbon atoms, and G represents a glycosa unit with 5 or 6 carbon atoms, preferably represents glucose. The degree of oligomerization x - and therefore the DP value - provided by the distribution of monoglycosides and oligoglycosides, in the class of surfactants in question is usually within a range between 1 and 10, and is found, for example, within a range of about 1.2 to 5, preferably within a range of about 1.2 to 4 and especially within a range of 1.2 to 2. The O / W type APG compounds, ie surfactant components of the specified technique, which they lead to the formation of oil-in-water emulsions - they present in a known manner a relatively high HLB value, which is preferably within a range greater than 7 and especially greater than 8 or 9, so that a HLB range of 10 to 18 it has a special importance. Fatty Alcohols Employed According to the Present Invention As described above, these blend components are employed in the multi-component mixtures according to the present invention with multifunctional significance. On the one hand, they are valuable components as foam delimiters for the practical use of multi-component mixtures in dilute aqueous preparations, on the other hand they are useful in the soil and especially in the root zone of plants as carbon suppliers. for the growth of microorganisms and especially for promoting the growth of organotrophic microorganisms. Fatty alcohols are degradable both by natural degradation processes and by aerobic and anaerobic degradation. As an important source of C in accordance with the present invention for. the organotrophic growth presents in its molecular structure lipophilic hydrocarbon radicals with a fatty structure and therefore a relatively high concentration of C-H groups that provide energy. The preferred fatty alcohols according to the present invention in the mixture of multiple components are characterized by having at least 6 to 8 carbon atoms in the molecule, wherein mono and / or polyunsaturated olefin fatty alcohols with 10 to 28 carbon atoms and especially corresponding fatty alcohols with 12 to 24 carbon atoms are especially preferred. A further preferred parameter for the choice of suitable fatty alcohols is the solidification temperature of these components of the mixture. Preferred components with a range of solidification temperatures equal to / less than 20 ° C and especially temperatures within a range equal to / less than 10 to 15 ° C. Although the use of fatty alcohols based on natural substances of the type mentioned herein is preferred in accordance with the present invention, the teaching in accordance with the present invention is not limited thereto. It is also possible to use fatty alcohols of synthetic origin which have a branched chain, and are suitable components of the mixture within the framework of the present invention. In this case, the coordination of the solidification range of this (these) alcohol component (s) can be especially influenced. Partial esters of fatty alcohols suitable according to the present invention In addition to the fatty alcohols defined above and / or instead of the fatty alcohols defined above, partial fatty acid esters of lower polyfunctional alcohols can be important compounds of the mixture within the framework of the present invention. Suitable compounds are, especially on the side of the polyfunctional lower alcohols, corresponding compounds having 2 to 6 carbon atoms and especially 3 to 5 carbon atoms. Of particular importance, due to their ease of obtaining as a natural element, the corresponding partial glycerin esters. The fatty acids of the class mentioned here of partial esters usually belong to the group of the corresponding compounds with 10 to 24 carbon atoms, whereby corresponding monocarboxylic acids in the C? 2-2o range are especially suitable. Fatty acids of the type mentioned herein are known as materials based on natural substances and can be obtained easily. The use of olefinically monounsaturated and / or polyunsaturated fatty acids may be preferred. A particularly suitable class of the active substances in question here are partial glycerin esters with olefinically unsaturated C 16/18 monocarboxylic acids, whereby corresponding monoesters are of particular importance. A fatty acid ester of this type that can be obtained in large amounts is the glycerin monooleate. Fatty acid esters of the constitution described herein can be degraded by natural degradation processes in the soil both aerobic and anaerobic as the fatty alcohols described above. They are also important sources of C for the organotrophic growth of microorganisms in the area near the roots of plants. Also by means of its employment a reinforcement of the growth of the plants is obtained through the stimulation of the growth of microorganisms that are in the soil. Further details regarding the teaching of the present invention Within the scope of the present invention, only fatty alcohols or only partial fatty acid esters can be used as components of the mixture together with APG compounds. In one embodiment, however, combinations of fatty alcohols and partial fatty acid esters are used. Mixture ratios are preferred - relative to the parts by weight of the anhydrous components - which are within a range of about 1: 1 to 1:10. Mixing ratios between fatty alcohols and partial esters of fatty alcohols (parts by weight of anhydrous components) are preferred within a range of 1: 1 to 1: 5, with mixtures being especially preferred within a range of 1: 1 to 1: 3. . In the mixture of several components for use according to the present invention, the APG components are at least approximately equal in weight by weight in relation to fatty alcohols and / or partial ester., so mixing ratios between APG and fatty alcohol and / or partial ester are preferred within a range of 1: 1 to 5: 1, preferably from 1: 1 to 3: 1 and especially of 1.5 to 2.5: 1 . The values mentioned here refer each time to the parts by weight of the mixture of elements and each time in relation to anhydrous components of the mixture. However, the teaching of the present invention is not limited to a use of this type of excess APG components. Also mixtures of elements with a corresponding excess of fatty alcohols and / or partial esters of fatty acids which are used as foaming limiters are found within the teaching of the present invention. The mixtures of various components according to the present invention are provided in accordance with the data of the introduction of the aforementioned prior German application 19701127.6 usually in the form of fluid aqueous concentrates on the market and for the user, and these concentrates can be diluted with water additionally for the application of the mixture of the elements in the soil and in the plants. In order to be able to provide a combination of elements in the form of concentrates that are easy to dilute with water, sufficient cleavability must be ensured at normal temperatures as well. The teaching of the aforementioned prior application clearly states that in the case of a mixture of APG aqueous concentrates with foaming delimiters / foam removers based on fatty alcohol and / or partial ester easily dense gels are obtained which can no longer flow. Accordingly, it is proposed in the aforementioned document to maintain the flow and drainage capacity also in the range of ambient temperatures by the addition of limited amounts of lower monofunctional alcohols and especially by the addition of limited amounts of ethanol. The same applies in the case of mixtures of elements within the framework of the application of the present invention. Preferred lower monofunctional alcohols are corresponding compounds with up to 4 carbon atoms. The teaching according to the present invention contemplates in an important embodiment the use, in addition to the components mentioned above of the mixture of elements, of further lower polyvalent alcohols, and especially lower polyvalent alcohols which flow at room temperature as components of the mixture. Likewise, these polyvalent alcohols can have a polyfunctional importance within the framework of the mixture of several elements. As parts of the fluid mixture with relatively high boiling points they promote the desired fluidity especially for the handling of the concentrate and thus their diffusion, on the other hand these components, after their application to the soil have a nutrient character in the sense that they represent an additional source of C for the growth of microorganisms, especially in the rhizosphere and / or in the mycorrhiza zone. Preferred polyhydric alcohols are corresponding compounds with 2 to 6 carbon atoms, preferably with 2 to 4 carbon atoms, so glycerin and / or glycol can be mentioned here as especially * >; • * • relevant. The high solubility in water of the components mentioned here can be an additional aid within the framework of the practical use of mixtures of multiple components. Preferred amounts for the blend components discussed herein are usually at a maximum of 30 to 35% by weight, preferably at a maximum of 20 to 25% by weight, and especially within a range of 5 to 15% by weight , each time they are percentages by weight in relation to the mixture of several elements in the form of the concentrate described above, which can then be diluted with water for application in the areas of the soil to be treated. In addition to the unsaturated fatty alcohols described above as components of the mixture or instead of said fatty alcohols, olefinically unsaturated terpene alcohols can also be used as foam scavenger / foam scavengers. In the case of terpene alcohols, these are acyclic or monocyclic, bicyclic or tricyclic alcohols of various olefinically unsaturated alcohols containing between 10 and 40 carbon atoms. The terpene alcohols are preferably used in the form of their natural mixtures as foam delimiters / foam removers. A preferred representative here is what is known as pine oil, a mixture of several terpinoles such as a- and β-terpinoles, a-fencialcohol, borneol and isoborneol as described in Rompp's Dictionary of Chemistry, page 3451, volume 4, 9a. edition, 1991. In addition, pine oil also contains in minor amounts other non-alcohol compounds, for example, camphor, anethole and estragole. The pine oil is also obtained from pieces containing resin and from the roots of various types of pines by extraction for example with benzene or chloroform and subsequently by fractionation and distillation. The foam removal components are as mentioned before usually in small amounts as the components of APG - each time in relation to the active substance. Mixtures are preferred in which the foam removal components can be used in markedly smaller amounts. Accordingly, concentrates of various elements are suitable within the framework of the present invention whose content of foam remover is within a range of about 10 to 25% by weight and preferably within a range of about 15 to 20% by weight . The lower water-soluble monofunctional alcohols which are used as viscosity regulators are determined in terms of type and amount by the above-mentioned principal components, the lower water soluble polyvalent alcohols optionally employed as well as the amount of water found. globally in the mixture of several elements. Additional amounts of viscosity regulator are especially suitable within a range of at least about 5 to 7% by weight as the lower limit and from 12 to 25% by weight as the upper limit. Amounts of ethanol within a range of about 5 to 20% by weight and especially 10 to 15% by weight in general have a sufficient influence on the viscosity in the direction of flowability and the desired emptying of the mixture of several components also in the range of ambient temperatures. The water content of the concentrates of various elements generally reaches at most about 50% by weight, and yet is in preferred embodiments at lower levels. For the water content of the mixture of multiple component ranges from a maximum of about 30 to 45% by weight are especially suitable. In general, the water content is selected in such a way that it has a clearly lower level and such that it is for example within a range of 10 to 20% by weight, preferably within a range from 10 to 15% by weight. In practice, the multi-component mixtures containing surfactants according to the present invention are applied in the soil in aqueous form diluted in amounts of at least about 0.5 to 1 g / m2 and preferably at least about 3 to 5 g / m2 of multi-component mixture containing APG - in relation to the anhydrous active ingredient mixture. The preferred upper limits for the applied amount of mixtures of active substances - again in relation to the anhydrous mixture - are within a range of 25 to 30 g / m2, but the use of higher quantities, for example up to 40 g / m2 'or up to 50 g / m2 are important embodiments of the teaching of the present invention. The application of combinations of active substances containing surfactants in the sense of the teaching of the present invention may be unique or may be repeated during the course of the year and especially during the course of the growth phase. The time of the application of the mixture of multiple substances within the meaning of the present invention can be established in terms of type and quantity in relation to the process of fertilizer application. The solution to the problem of unwanted leaching of nitrate by the use of the auxiliaries defined in accordance with the present invention is obviously influenced especially due to the available amount of nitrate. While there is currently no clear explanation of the technical effects found at the basis of the teaching of the present invention, it is assumed that they are due to the horizontal expansion and consequently to the fine division of the soluble nitrate parts. in water in the upper structure of the soil under the influence of the mixture of several substances based on surfactants applied in accordance with the present invention which is co-responsible for the positive effects pursued. EXAMPLES In the following examples, comparative tests were carried out and the results obtained are presented in a confronted manner, where in identical working conditions the elution behavior of aqueous test solutions is determined in relation to the nitrate leaching of the soil used for agriculture. . As APG compounds of type O / W in the sense of the teaching according to the present invention, aqueous preparations of the commercial product known as "Magic Wet", registered trademark of the applicant, were used. Magic Wet is a mixture of active substances of the type defined above which, in the form of an aqueous concentrate, in addition to the APG surfactant compounds of the O / W type also contain frothing delimiters selected from fatty alcohols and partial fatty acid esters together with a viscosity regulator.
In comparative tests that were carried out under otherwise identical working conditions, the elution behavior of aqueous preparations of APG with various concentrations of APG relative to nitrate leaching is determined. These tests were compared with the use of APG-free water as an elution medium. Two additional investigations were carried out where once was used as an aqueous elution medium an aqueous preparation of a commercially available liquid fertilizer and on the other hand the same liquid aqueous phase, however with additional use of Magic Wet in the phase liquid Below we present details of this experiment: as a liquid fertilizer, the commercial product "Substral", a registered trademark, was used.
15 for a N-P2? 5-K20 ratio of 6-4-4. In the tests mentioned here, an aqueous preparation at tfk 3% by weight of these liquid fertilizers was used each time. With details the following procedure was followed: Loess type soil useful for agriculture purposes,
20 fresh, humid was homogenized in a mortar and sieved through a 5 mm mesh. The soil used contains N due to its past and contains especially soluble nitrate. The dry weight of the soil used is determined with 86.5% by weight. Each 50 g of moist soil is filled into glass frits
25 of 10 cm long which are held vertically in supports in such a way that each glass frit receives from above the test solution. The products obtained in each case were collected under the glass frits. Each glass frit receives 1 ml of test solution from above and 5 ml of water or active substance solution drop by drop. Within a period of 5 to 10 minutes this volume of liquid has passed through the floor in the glass frit and is absorbed. The next elution step is carried out by supplying each time 5 ml of water in the upper part of each of the glass frits to be eluted. The eluate is collected. The amount of eluted product collected is determined as well as the concentration of nitrate in mg / ml that is contained in the eluted product. Each test of the following Examples 1 to 6 is repeated three times at different times in accordance with the following: a first series of tests determines the liquid elution practically immediately after application and the distribution of the test solution used in each case on the floor inside the glass frit in question. A second series of tests is carried out after a period of 7 days after the application and penetration of the test solution to be determined in each case. The third - series of tests finally increases the period of time between the application of the test solution in the soil and the elution at 14 days. Below we present details of each of the examples: Example 1: blind test, pure water is used as a test solution here. Example 2: a 1.25 wt% aqueous solution of Magic Wet is used as a test solution. Example 3: 2.5 wt% aqueous solution of Magic Wet is used as a test solution. Example 4: 5.0 wt% aqueous solution of Magic Wet is used as the test solution. Example 5: A 3% by weight aqueous solution of Substral is used as the test solution. Example 6: the aforementioned aqueous solution of Substral is used here with the use of Magic Wet 1.25% by weight as a test solution. While in Examples 1 to 4 no additional nitrogen is introduced into the soil samples to be studied, examples 5 and 6 contemplate the addition of 9 mg of nitrogen per 50 grams of soil. In a first determination the elution volume is determined in ml after 0 day, after 7 days and after 14 days. The following values are obtained: Table 1 Example volume of elution in ml after after after 0 day 7 days 14 days 1 5 3.3 3.0 2 6.5 2.3 2.1 3 6.5 2.0 3.1 4 6.5 2.4 2.4 5 6.0 3.0 2.8 6 6.5 2.1 2.2
The volume of eluble water, ie the soil water holding capacity, is slightly increased in Examples 2 to 6 compared to Comparative Example 1 immediately after the application of the corresponding test solutions, after 7 days and after 14 days this effect is no longer noticeable. In the eluted products obtained in accordance with the data in Table 1, the nitrate content effectively removed is determined in each individual case in an analytical manner. The following table 2 presents a summary of the values determined within the framework of the conformation of Table 1. Table 2 Example content of nitrate determined in mg eluted then eluted after eluted after 0 day of 7 days of 14 days 1 0.2 0.132 0.21 2 0.065 '0.03 0.095 3 0. 013 0. 012 0.028 4 0. 013 0. 012 0.02 5 13. 5 6. 513 7.08 6 12. 35 4. 032 4.33 The comparison of the values provided here shows that the amount of nitrate removed with the water of elution by the addition of Magic Wet is significantly lower. For example, by using a 1.25 wt.% Solution of Magic Wet, the nitrate leaching of 0.2 mg in the control sample of example 1 (after 0 day) is reduced to a value of 0.065 mg and consequently the 32% of the original nitrate leaching. With higher applied amounts of Magic Wet this effect is further increased, for example with a 2.5 wt.% Solution of Magic Wet, nitrate leaching is reduced to 6.5% of the original level. The nitrogen applied additionally through a liquid fertilizer (9 mg of N per 50 g of soil, which corresponds to 3 0.6 mg of N03) is conserved in a reinforced way in the soil thanks to the co-use of Magic Wet in liquid phase of elution (see the comparative values of examples 5 and 6). Example 7 Several different fertilizers were studied in an additional test within the framework of a leaching test to determine their nitrogen release capacity, as well as the effects of a decreased leaching by the mixture of active substances according to the present invention. For this purpose soil monoliths (soil columns) almost without disturbance were taken from a soil used for agriculture, and were placed in a meter-long lysimeter equipped at the bottom with a layer of gravel drainage. The soil corresponded to a light soil (sL = sandy silt). As fertilizer, two fertilizers were used in standard granules (nitrous ammonium lime or Floranid Master). The amount used in both cases reached 200 kg of pure nitrogen per hectare. Each variant was repeated four times. The mixture according to the present invention known commercially as "Magic Wet" of the applicant was applied in an amount of 2 g / m2 (20 kg / hectare) with a ten times greater amount of water. As controls, monoliths not fertilized with the natural nitrogen content were used. During the entire study time the containers were exposed to natural climatic conditions. During the day the temperatures were within a range of 15 to 25 ° C, and during the night of 14 to 18 ° C. At the beginning of the study the fertilizers and / or the test substance according to the present invention were provided. on the surface of the earth monoliths. A precipitation of 40 mm of rain per week was simulated. The filtration water was collected. 10, 20 and 30 days after the start of the test, the filtration water was investigated to determine the nitrate content (analysis by injection) and the average release of nitrate was determined. The filtering water of the monoliths fertilized with nitrous ammonium lime presented a significantly higher load of nitrate than the non-fertilized controls or the monoliths fertilized with Floranid Master (Table 3). In each case the one-time application of the mixture of active substances according to the present invention "Magic Wet" produces a dramatic reduction of nitrate leaching in the filtration water. For example, the leaching of nitrate from monoliths fertilized with Floranid Master was reduced from 58 mg NO3 / I to 45 mg NO3 / I. Table 3 Nitrate in water without Magic Wet with Magic Wet filtration reduction in mg / l to control "without fertilizer" 44.2 25.6 58%
Floranid Master 58.6 45.2 77% Cal ammonium nitro 64.8 52.1 80%
In the test substrate it is a soil used for agriculture, irrigated naturally. It can be seen that the mixture of active substances according to the present invention can limit nitrate leaching also in the practice of agriculture. The mixture according to the present invention protects the ground water against an additional load of nitrate, and on the other hand maintains an expensive fertilizer in the root zone of the cultivated plants and therefore contributes to the effective use of the fertilizers .