Fertilising composition which includes a plant-assimilable phosphorus and calcium potentiator and use thereof.

Abstract

The invention provides a fertilising composition which includes a plant-assimilable phosphorus and calcium potentiator, said assimilable phosphorus potentiator being glyceric acid, a combination of said fertilising composition together with other fertilisers and / or biostimulants, as well as its use in the form of a hydrosoluble powder, granulate or liquid prior dissolution in water for direct application by fertigation or foliar application.

Description

[0001] DESCRIPTION

[0002] FERTILIZER COMPOSITION INCLUDING A PHOSPHORUS AND CALCIUM ENHANCER AVAILABLE TO PLANTS AND ITS USE

[0003] The present invention relates to a fertilizer composition that includes a phosphorus and calcium enhancer assimilable by plants, as well as to the use of said fertilizer composition.

[0004] More specifically, in a first aspect, the invention provides a fertilizer composition that includes glyceric acid as an enhancer of phosphorus and calcium assimilable by plants, where the glyceric acid improves the levels of total phosphorus in the plant, its application constituting an alternative to conventional phosphate fertilizers.

[0005] In a second aspect, the invention relates to a combination of the described fertilizer composition together with another additional fertilizer and / or biostimulant.

[0006] Phosphorus is an essential macronutrient for plant growth and a determining factor in crop productivity. Plants absorb it in its soluble forms, primarily H₂PO₄. 2' and H2PO4 ' However, despite the high applications of phosphate mineral fertilizers, phosphorus deficiency is a common problem in agricultural soils due to the low solubility (<1%) of total organic and inorganic phosphorus present in them (Bünemann et al., “Assessment of gross and net mineralization rates of soil organic phosphorus - A review”, Soil Biology and Biochemistry. 89:92-98, 2015). This is because much of the phosphorus applied in fertilizers is immobilized by sorption processes, by precipitation with Fe ions. 3+ and Al 3+ in acidic soils and with Ca ions 2+in calcareous soils, or by its transformation into organic forms (Liao et al., “Phosphorus and aluminum interactions in soybean in relation to aluminum tolerance. Exudation of specific organic acids from different regions of the intact system”, Plant Physiol. 141, 674-684, 2006). Therefore, the biggest problem in plant nutrition related to phosphorus is not the total concentration of this element in the soil, but its bioavailability to plants.

[0007] Furthermore, the overuse or inappropriate use of phosphate fertilizers and their low uptake efficiency by crops (around 45%) lead to decreased soil fertility, significant environmental pollution, primarily in rivers, lakes, and aquifers, and increased production costs for farmers (Tilman et al., “Agriculture: sustainability and intensive production practices”, Nature. 418: 671-7, 2002). Moreover, phosphate rock, the main raw material used industrially in the production of phosphate fertilizers, is a non-renewable source of phosphorus, meaning its reserves are limited and gradually declining (Saeid et al., “Phosphorus Solubilization by Bacillus Species”. Molecules. 23, 2897, 2018).

[0008] In this regard, the main solutions designed to address the problems mentioned above consist of the use of metal ions complexed with amino acids to improve phosphorus solubilization by microorganisms present in the soil (EP3181538A1) or the application of inoculum of phosphorus-solubilizing microorganisms (Hu et al., “Development of a biologically based fertilizer, incorporating Bacillus megaterium A6, for improved phosphorus nutrition of oilseed rape”, Can J Microbiol. 59:231 -

[0009] 6, 2013; US5256544A; WO2014082167A1 ).

[0010] For the reasons outlined above, there is currently a need in the plant nutrition sector to seek alternatives to conventional phosphate fertilization that would increase the utilization of both phosphate fertilizers and the total phosphorus reserves accumulated in soils (Zhu et al., “Phosphorus activators contribute to legacy phosphorus availability in agricultural soils: A review”, Science of the Total Environment 612 (2018) 522-537, 2018) and sustainably increase crop productivity. In fact, some authors suggest that the phosphorus accumulated in agricultural soils could be sufficient to maintain global crop yields for 100 years if it were in available forms (Khan et al., “Role of phosphate-solubilizing microorganisms in sustainable agriculture - a review”, Agron. Sustain. Dev. 27, 29-43, 2007).

[0011] Furthermore, plants exude a considerable portion of the organic compounds generated in photosynthesis (between 11 and 40%) through their roots in order to regulate the chemical composition of the rhizosphere and promote the growth of microorganisms that can provide benefits to the plant in a given ecosystem (Badri and Vivanco, “Regulation and function of root exudates”, Plant, Cell and Environment 32, 666-681, 2009; Zhalnina et al., “Phosphorus activators contribute to legacy phosphorus availability in agricultural soils: A review”, Science of the Total Environment 612 (2018) 522-537, 2018). The compounds present in root exudates include sugars, amino acids, organic acids, fatty acids and secondary metabolites (Bais et al., “The role of root exudates in rhizosphere interactions with plants and other organisms”, Annu Rev Plant Biol. 57:233-66, 2006).

[0012] In addition to the cultivated species and its phenological stage, the composition and quantity of these exudates are mainly influenced by environmental signals, such as the availability of nutrients in the soil. In fact, plants have adaptation mechanisms to soils with low available phosphorus, including the root exudation of metabolites that increase phosphorus solubilization and uptake and / or modulate the composition of soil microbial communities, favoring microorganisms capable of solubilizing inorganic phosphorus or mineralizing organic phosphorus. These exudates include carboxylic acids, sugars, phenolic compounds, amino acids, and even certain enzymes (Carvalhais et al., “Root exudation of sugars, amino acids, and organic acids by maize as affected by nitrogen, phosphorus, potassium, and iron deficiency”, J. Plant Nutr. Soil Sci.174, 3-11, 2011; Vengavasi and Pandey, “Root exudation index as a physiological marker for efficient phosphorus acquisition in soybean: an effective tool for plant breeding”, Crop Pasture Sci. 67, 1096-1109, 2016). High root exudation places an additional burden on the plant's carbon demand, diverting a greater amount of resources generated by its photosynthetic machinery to this end (Vengavasi and Pandey, supra). In the specific case of phosphorus deficiency, plants release around 30% of the carbon fixed through photosynthesis in the form of root exudates during phosphorus deficiency (Khorassani et al., “Citramalic acid and salicylic acid in sugar beet root exudates solubilize soil phosphorus”, BMC Plant Biol. 11, 121, 2011).

[0013] In light of the foregoing, the present invention is based on the aforementioned approaches such that, on the one hand, by regulating phosphorus transformation processes in soils, root exudates can increase the availability of this nutrient to plants and the efficiency of its use in agricultural soils and, on the other hand, constitute an alternative to the use of traditional phosphate fertilizers. Therefore, it would be desirable to have fertilizers that mimic root exudates and have a similar effect, allowing for the elimination or reduction of mineral fertilizer applications and mitigating environmental pollution, while simultaneously providing an alternative to conventional phosphate fertilization to reduce pollution resulting from its use and sustainably increase phosphorus use efficiency and crop productivity.

[0014] The present invention fulfills the two objectives mentioned above, providing a fertilizer composition that includes glyceric acid as an enhancer of phosphorus available to plants, where the glyceric acid improves total phosphorus levels in the plant. Furthermore, in alkaline soils (pH 8 or higher) and those with high limestone content, phosphorus precipitates due to the presence of calcium, resulting in calcium phosphates. In this type of soil, the solubilization of insoluble phosphorus will not only release phosphorus available to plants, but also available calcium (Rietra RPJJ, et al., “Interaction between Calcium and Phosphate Adsorption on Goethite”, Environ. Sci. Technol., 2001, 35 (16), pp. 3369-3374; Lei Y. et al., 2018, “Interaction of calcium, phosphorus and natural organic matter in electrochemical recovery of phosphate”, Water Research Volume 142, pp. 10-17; Tunesi S., et al., 1999, “Phosphate adsorption and precipitated in calcareous soils: the role of calcium ions in solution and carbonate minerals”, Volume 53, (3), pp. 219-227).

[0015] Glyceric acid, or 2,3-dihydroxypropanoic acid, is a trionic acid derived from the oxidation of glycerol that is found naturally in plants such as those of the genus Brassica (Kim et al., “Metabolic Differentiation of Diamondback Moth (Plutella xylostella (L.)) Resistance in Cabbage (Brassica oleracea L. ssp. capitata)”, J. Agrie. Food Chem., 2013, 61 (46), pp. 1 1222— 1 1230, 2013).

[0016] Alcohol

[0017] CHsOH CHO

[0018] CGOH dehydrogenase

[0019]

[0020] glycerol glyceraldehyde glyceric acid

[0021] As mentioned above, in one aspect, the present invention provides a fertilizer composition that includes glyceric acid as an enhancer of phosphorus and calcium available to plants. In one embodiment, the fertilizer composition of the invention consists of 100% by weight of glyceric acid in the form of a water-soluble powder. In another embodiment, the fertilizer composition of the invention comprises between 30% and 80% by weight of glyceric acid and between 5% and 30% by weight of other components selected from the group consisting of sugars, amino acids, organic acids other than glyceric acid, polyamines, glycerol, myo-inositol, adenine, uracil, cytosine, guanine, and combinations thereof, the fertilizer composition being in the form of a water-soluble powder.

[0022] When present in the present fertilizer composition, sugars are preferably selected from mono- and disaccharides such as sucrose, fructose, trehalose, glucose, arabinose, maltose, as well as mixtures thereof.

[0023] When present in this fertilizer composition, amino acids are preferably selected from threonine, sine, phenylalanine, glutamic acid, methionine, GABA, ornithine, glycine, glutamine, aspartic acid, serine, asparagine, tyrosine, tryptophan, valine, leucine, isoleucine, proline, 4-hydroxyproline, arginine, histidine, alanine, cysteine, and mixtures thereof. When present in this fertilizer composition, organic acids other than glyceric acid are preferably selected from lactic acid, succinic acid, oxalic acid, gluconic acid, threonic acid, fumaric acid, and mixtures thereof. Polyamines, if present in this composition, are preferably selected from putrescine, spermidine, spermine, and mixtures thereof.

[0024] The presence of these other components, different from glyceric acid, in the composition of the invention is based on the fact that such components are part of the root exudates in the crops tested in the absence of phosphorus, which are described below, or are described in the literature as components of said exudates under normal conditions for plant development (Zhalnina et al., “Dynamic root exudate chemistry and microbial substrate preferences drive patterns in rhizosphere microbial community assembly”, Nat Microbiol, 3(4):470-480, 2018), and are therefore desirable for the aforementioned purpose of having a fertilizer composition that mimics root exudates with an analogous effect that may allow for the elimination or reduction of the application of mineral fertilizers.

[0025] The fertilizer composition of the invention is formulated as a water-soluble powder, as previously indicated, but it can also be formulated as a liquid composition by dissolving it in water or in granular form by adding granulating agents known to the skilled trade. With respect to the second aspect, the invention relates to a fertilizer composition as described above in combination with another fertilizer selected from nitrogen fertilizers, phosphate fertilizers, potassium fertilizers, calcium fertilizers and amendments, micronutrients, boric acid, and leonardite, as well as combinations thereof, and / or in combination with one or more biostimulants selected from the group consisting of amino acid hydrolysates, humic extracts, seaweed extracts, live microorganisms, microbial extracts, and combinations thereof.Live microorganisms or extracts of microorganisms shall preferably come from the species Pichia guilliermondii, Azotobacter, chroococcum, Bacillus megaterium, Bacillus aryabhattai, Oceanobacillus picturae, or from bacteria belonging to genera recognized for their phosphorus solubilization capacity: Pseudomonas, Bacillus, Rhizobium, Burkholderia, Achromobacter, Agrobacterium, Micrococcus, Aerobacter, Flavobacterium, Mesorhizobium, Azotobacter, Azospirillum, Erwinia, Paenibacillus and Oceanobacillus (Rodriguez and Fraga, “Phosphate solubilizing bacteria and their role in plant growth promotion”, Biotechnology Advances 17 (1999) 319-339, 1999;El-Tarabily and Youssef,“Enhancement of morphological, anatomical and physiological characteristics of seedlings of the mangrove Avicennia marina inoculated with a native phosphate-solubilizing isolate of Oceanobacillus picturae under greenhouse conditions”, Plant Soil (2010) 332:147–162, 2010;

[0026] In this case, the composition of the invention is present in the combination in a proportion of 0.5 to 10% by weight.

[0027] In one embodiment, the additional nitrogen fertilizer is present in the combination in a proportion of 5 to 90% by weight and is selected from urea, ammonium nitrosulfate, potassium nitrate, ammonium sulfate, ammonium nitrate, calcium nitrate.

[0028] In another embodiment, the additional phosphate fertilizer is present in the combination in a proportion of 5 to 90% by weight and is selected from phosphate rock, triple superphosphate, single superphosphate, concentrated superphosphate, phosphoric acid.

[0029] In yet another embodiment, the additional potassium fertilizer is present in the combination in a proportion of 5 to 90% by weight and is selected from potassium chloride, potassium sulfate, potassium magnesium double sulfate, potassium hydroxide.

[0030] In another embodiment, the additional calcium fertilizer is present in the combination in a proportion of 5 to 90% by weight and is selected from calcium chloride, calcium cyanamide, calcium sulfate, dolomite, limestone, calcium oxide, calcium hydroxide.

[0031] In yet another embodiment, the additional micronutrient fertilizer is present in the combination in a proportion of 1 to 30% by weight and is selected from ferric sulfate, magnesium sulfate, zinc sulfate, manganese sulfate, copper sulfate, ammonium molybdate, and cobalt chloride. In a further embodiment, boric acid as an additional fertilizer is present in the combination in a proportion of 1 to 30% by weight. In another embodiment, leonardite as an additional fertilizer is present in the combination in a proportion of 5 to 90% by weight.

[0032] In the case of combining the fertilizer composition of the invention with biostimulants as described above, preferably the biostimulants are present in the combination in a proportion of 5 to 90% by weight.

[0033] The invention also includes the use of the fertilizer compositions described herein in the form of a water-soluble powder, in granular form or in liquid form after dissolving in water for application by fertigation or via foliar application.

[0034] In the case of use of the composition of the invention in the form of a water-soluble powder by fertigation or via foliar application after dissolution in water, preferably it is applied in an amount of 0.5 to 20 kg / ha and 0.06 to 1 kg / ha respectively.

[0035] When using the composition of the invention in combination with another fertilizer in granular form, this combination is preferably applied directly at a rate of 75 to 1,500 kg / ha. When using the composition of the invention in combination with liquid biostimulants for application by fertigation or foliar spray, this is preferably applied at a rate of 0.5 to 20 kg / ha and 0.06 to 1 kg / ha, respectively. Examples 1. Test for obtaining and identifying root exudates in the absence of phosphorus

[0036] With the aim of characterizing in detail the response of crops to phosphorus deficiency and identifying the root exudates that have the greatest influence on phosphorus dynamics in the soil, the Applicant analyzed the differential exudate profile of two agronomically important crop species, maize and tomato, in the absence of phosphorus. The assay for determining root exudates emitted in the absence of phosphorus is briefly described below.

[0037] The procedure, similar to that used by other authors (Naveed et al., 2017, “Plant exudates may stabilize or weaken soil depending on species, origin and time”, European Journal of Soil Science), was the same for both maize seeds (variety LG 34.90) and tomato seeds (variety Agora Hybrid F1). The seeds were surface-sterilized by washing them for 5 minutes with 96% ethanol, followed by 10 minutes in 5% bleach. They were then thoroughly washed and soaked in sterile MilliQ water for 4 hours. For germination, the seeds were placed on a bed of filter paper moistened with sterile MilliQ water. The seeds were allowed to germinate in the dark for 4 days, after which the seedlings were transplanted into hydroponic trays, with their roots immersed in standard Hoagland nutrient solution.Twelve plants were placed in each tray, with three trays (each corresponding to a biological replicate) designated for the control treatment and the other three for the absence of phosphorus. The plants grew under a temperature and photoperiod of 25°C and 16 h light / 22°C and 8 h dark and a light intensity of 4,000 lux on the surface.

[0038] The nutrient solution was replaced with fresh solution every three days and kept aerated at all times using bubble tubes. After 10 days of growth, the plants underwent phosphorus depletion treatment. For this purpose, three trays were incubated for three days with phosphorus-free modified Hoagland solution, while the remaining three trays were incubated with the complete solution. After incubation, root exudates were collected. The plants were carefully removed from the culture trays and washed thoroughly with water, followed by a final wash with distilled water. The plants from each tray were placed in wide-necked flasks containing 200 ml of MilliQ water, with the roots submerged. The plants were incubated in the flasks for 6 hours. Subsequently, the plants were removed, and the insoluble material was removed from the solution by filtering through 0.20 µm filters.The filtered material was flash-frozen in liquid nitrogen and subjected to lyophilization. The resulting dried material was weighed and analyzed by Gas Chromatography-Mass Spectrometry after derivatization with methoxyamine and N-methyl-(thmethylsilylthfluoroacetamide).

[0039] Table 1 shows the metabolites exuded by the plants and their ratios under phosphorus-free conditions compared to control conditions.

[0040] Table 1

[0041]

[0042] Based on these results, the 11 metabolites found in the exudates of both crops were selected. These metabolites were: gluconic acid, glyceric acid, lactic acid, glucose, threonic acid, fructose, aspartic acid, serine, glycerol, arabinose, and glutamine. Each metabolite was applied separately at a dose of 1 kg / ha in a pot containing 3 kg of soil. Corn plants were sown (4 pots per treatment with one plant per pot), and the effect on their dry weight was observed after 6 weeks. The effect of the metabolites was compared with a negative control (no treatment) and a positive control with a conventional phosphate fertilizer (triple superphosphate at a dose of 100 phosphorus fertilizer units -P₂O₅- per hectare).The soil came from an agricultural soil with a sandy loam texture and an available phosphorus content of 0.5 ppm, considered a very low level of this element for agricultural practices (Practical Guide to Rational Crop Fertilization in Spain, MAPAMA 2009). This level of available phosphorus corresponds to 4.5 kg of P2O5 per hectare (considering 30 centimeters of arable soil and an average density of 1,300 kg / m³). 3 The mass per hectare would be approximately 3,900 tons). The total phosphorus level in this soil, including that not available to plants, was 252 ppm (2,251 kg of P2O5 / ha).

[0043] The selected metabolites improve maize growth to varying degrees, as shown in Table 2 below. Table 2

[0044]

[0045] The previous results indicate that glyceric acid is the metabolite that most improves corn growth, achieving the same result as conventional phosphate treatment with triple superphosphate.

[0046] 2. Application of the fertilizer composition and combination of the invention

[0047] Three fertilizer compositions in the form of water-soluble powder were prepared according to the invention with the following composition:

[0048] A: 100% by weight of glyceric acid

[0049] B: a combination of between 30 and 80% by weight of glyceric acid and between 5 and 30% gluconic acid, between 5 and 30% lactic acid and between 5 and 30% glutamine;

[0050] C: a combination of between 30 and 80% by weight of glyceric acid and between 5 and 30% glucose, between 5 and 30% fructose and between 5 and 30% glycerol.

[0051] These products (A, B, C) were tested in field trials with corn and tomato plants, compared to a negative control (no treatment) and a positive control of conventional phosphate fertilization consisting of triple superphosphate (D). The doses and application method were as follows:

[0052] - For corn:

[0053] · A: 10.0 kg / ha via fertigation.

[0054] • B: 10.0 kg / ha via fertigation.

[0055] • C: 10.0 kg / ha via fertigation.

[0056] • D: Triple superphosphate: 100 units of phosphorus fertilizer (P2O5) per hectare

[0057] - For the tomato:

[0058] • A: 8.0 kg / ha via fertigation.

[0059] • B: 8.0 kg / ha via fertigation.

[0060] • C: 8.0 kg / ha via fertigation.

[0061] · D: Triple superphosphate: 80 units of phosphorus fertilizer (P2O5) per hectare

[0062] The treatments significantly improved the yield and phosphorus content of maize (Tables 3 and 4), as well as of tomato (Tables 5 and 6).

[0063] Table 3

[0064]

[0065] Table 4

[0066] Table 5

[0067]

[0068] Table 6

[0069]

[0070] In order to determine whether the increase in phosphorus content in the studied treatments is due to an increase in the availability of assimilable phosphorus for plants, phosphorus balances were carried out in the trials with corn and tomato plants.

[0071] In trial 2, the same agricultural soil was used as in trial 1, with an available phosphorus content of 0.5 ppm (corresponding to 1.95 kg / ha of phosphorus and 4.5 kg / ha of P₂O₅ fertilizer units) and a total phosphorus content of 252 ppm (corresponding to 983 kg / ha of phosphorus and 2,251 kg / ha of P₂O₅ fertilizer units). No phosphorus fertilizer units were applied in treatments A, B, and C, as none of the molecules used in these treatments contained this element. Considering the dry weight of the maize and tomato plant biomass (see Tables 7 and 8) and the percentage of total phosphorus in the plants (Tables 4 and 6), the kg of phosphorus present in the biomass obtained per hectare can be calculated. As can be seen, the amount of phosphorus in the dry biomass is much higher in all cases than the amount of phosphorus available in the soil.Therefore, the increase in phosphorus content in plants is necessarily due to an increase in the availability of assimilable phosphorus for plants thanks to the fertilizer composition with an assimilable phosphorus enhancer. Table 7.

[0072]

[0073] Table 8

[0074] In all the trials conducted, the soil used had a pH of 8.4 and an active limestone content of 14%. These conditions are typical of calcareous soils, in which phosphorus precipitates with calcium to form calcium phosphates. Thus, in this type of soil, the solubilization of insoluble phosphorus will release not only phosphorus available to plants, but also calcium.

Claims

CLAIMS 1. Fertilizer composition including a phosphorus and calcium enhancer assimilable by plants, characterized in that said phosphorus and calcium enhancer assimilable is glyceric acid.

2. Fertilizer composition according to claim 1, characterized in that it consists of 100% by weight of glyceric acid in the form of a water-soluble powder or in the form dissolved in water.

3. Fertilizer composition according to claim 1, characterized in that it comprises between 30 and 80% by weight of glyceric acid and between 5 and 30% by weight of other components selected from the group consisting of sugars, amino acids, organic acids other than glyceric acid, polyamines, glycerol, myo-inositol, adenine, uracil, cytosine, guanine and combinations thereof, the fertilizer composition being in the form of a water-soluble powder.

4. Fertilizer composition according to claim 3, characterized in that the sugars are preferably selected from sucrose, fructose, trehalose, glucose, arabinose, maltose, as well as mixtures thereof.

5. Fertilizer composition according to claim 3, characterized in that the amino acids are selected from threonine, sine, phenylalanine, glutamic acid, methionine, GABA, ornithine, glycine, glutamine, aspartic acid, serine, asparagine, tyrosine, tryptophan, valine, leucine, isoleucine, proline, 4-hydroxyproline, arginine, histidine, alanine, cysteine, and mixtures thereof.

6. Fertilizer composition according to claim 3, characterized in that the organic acids other than glyceric acid are selected from lactic acid, succinic acid, oxalic acid, gluconic acid, threonic acid, fumaric acid and mixtures thereof.

7. Fertilizer composition according to claim 3, characterized in that the polyamines are selected from putrescine, spermidine, spermine and mixtures thereof.

8. Combination of the fertilizer composition according to any of claims 3 to 7 with another additional fertilizer selected from nitrogen fertilizers, phosphate fertilizers, potassium fertilizers, calcium fertilizers and amendments, micronutrients, boric acid and leonardite, as well as combinations thereof.

9. Combination according to claim 8, characterized in that the fertilizer composition according to any of claims 3 to 7 is present in the combination in a proportion of 0.5 to 10% by weight.

10. Combination according to claims 8-9, characterized in that the additional nitrogen fertilizer is present in the combination in a proportion of 5 to 90% by weight and is selected from urea, ammonium nitrosulfate, potassium nitrate, ammonium sulfate, ammonium nitrate, calcium nitrate.

11. Combination according to claims 8-9, characterized in that the additional phosphate fertilizer is present in the combination in a proportion of 5 to 90% by weight and is selected from phosphate rock, triple superphosphate, single superphosphate, concentrated superphosphate, phosphoric acid.

12. Combination according to claims 8-9, characterized in that the additional potassium fertilizer is present in the combination in a proportion of 5 to 90% by weight and is selected from potassium chloride, potassium sulfate, potassium magnesium double sulfate, potassium hydroxide.

13. Combination according to claims 8-9, characterized in that the additional calcium fertilizer is present in the combination in a proportion from 5 to 90% by weight and is selected from calcium chloride, calcium cyanamide, calcium sulfate, dolomite, limestone, calcium oxide, calcium hydroxide.

14. A combination according to claims 8-9, characterized in that the additional micronutrient fertilizer is present in the combination in a proportion of 1 to 30% by weight and is selected from ferric sulfate, magnesium sulfate, zinc sulfate, manganese sulfate, copper sulfate, ammonium molybdate, and cobalt chloride.

15. A combination according to claims 8-9, characterized in that boric acid as an additional fertilizer is present in the combination in a proportion of 1 to 30% by weight.

16. Combination according to claims 8-9, characterized in that leonardite as an additional fertilizer is present in the combination in a proportion of 5 to 90% by weight.

17. Combination of the fertilizer composition according to any of claims 3 to 7 with one or more biostimulants selected from the group consisting of amino acid hydrolysates, humic extracts, seaweed extracts, live microorganisms or microorganism extracts and combinations thereof.

18. Combination according to claim 17, characterized in that the biostimulants are present in the combination in a proportion of 5 to 90% by weight.

19. Use of the fertilizer composition according to claims 1 to 7 in the form of a water-soluble powder, in granular form or in liquid form after dissolving in water for application by fertigation or via foliar application.

20. Use according to claim 19, characterized in that it is applied in quantities of 0.5 to 20 kg / ha and 0.06 to 1 kg / ha in the form of a water-soluble powder by fertigation or via foliar application after dissolution in water, respectively.

21. Use of the combination according to claims 8 to 18, in the form of a water-soluble powder, in granular form, or in liquid form after dissolution in water for application by fertigation or via foliar application.

22. Use according to claim 21, characterized in that it is applied directly in an amount of 75 to 1,500 Kg / ha in granular form.

23. Use according to claim 21, characterized in that it is applied by fertigation or via foliar application in an amount of 0.5 to 20 kg / ha and 0.06 to 1 kg / ha, respectively.