SK8370Y1 - Sulfur and boron-containing liquid fertilizer - Google Patents

Abstract

Disclosed are solution-liquid NPK fertilizers containing hydrogen and potassium dihydrogen phosphate, as well as sulfur and boron. The source of sulfur in fertilizers is sulphate - thiosulphate anion. Boron contained in liquid fertilizers is bound in the form of any of the alkylamine complexes. It is preferred if as the source of sulfur is used ammonium sulphate - thiosulphate and as the alkylamine complex boron is used boronate ethanol complex. Fertilizers are suitable for preventive and supplementary fertilization in the form of off-root application.

Description

The solution concerns liquid NPK fertilizers containing sulfur and boron, which are intended primarily for extracorporeal - foliar application, but can also be used for plant nutrition via soil.

BACKGROUND OF THE INVENTION

The function of sulfur in plant nutrition and its link with metabolism, especially nitrogen, is generally not appreciated. In the interest of studying the basic physiological processes of nitrogen and phosphorus, it is striking how the issue of sulfur is circumvented in plant physiology, although its importance is in many ways classified as nitrogen and phosphorus. Abroad (mainly in the US, Canada and Australia) sulfur is usually classified as a basic plant nutrient. It has been scientifically proven that sulfur in the form of sulphates is needed for plants as much as phosphoric acid (e.g. Hofrnan, E. 1959).

It is noteworthy that although the importance of sulfur fertilization in the past has been unequivocally proved in our conditions, the unambiguous results of agronomic research have remained very little used in our agricultural practice. At least two statements from former VŠP workers in Nitra can be cited for practical documentation: "In field trials, we found that new winter wheat varieties are more sulfur intensive than phosphorus." Or elsewhere, JN Sulfur fertilization is sensitive to spring barley, (Ivanič, J. - Benko, V. - Report of VUI. Slovak Seminar on Rational Use of Industrial Fertilizers, Michalovce, 27th - 29th January 1982 - Proceedings of l.150).

In the past, sulfur was classified as a so-called sulfur. secondary plant nutrients, where they formed one group together with calcium, magnesium and iron In the 1970s, however, sulfur was increasingly considered to be a basic plant nutrient - along with nitrogen, phosphorus and potassium. nutrients sulfur rather than phosphorus, even though the total amounts of sulfur in soils are less than half the phosphorus reserves.

In general, with and as the main reasons for the sulfur deficit, they consider:

• increasing crop yields, • increasing concentrations of industrial fertilizers used, which in most cases no longer contain any sulfur, • replacement of sulfuric acid with phosphoric acid in fertilizer production, • reducing the use of fossil fuels with high sulfur content, • increasing pressure to reduce industrial emissions , • decreasing proportion of pesticides - mainly fungicides and insecticides containing sulfur, • constantly decreasing proportion of organic fertilizer use, • decreasing proportion of organic content in soils.

Sulfur (S) is present in plants in various compounds, in both oxidized and reduced forms. Probably the most important role of sulfur in a plant cell lies in its structural function in proteins. The most important sulfur amino acids cysteine and methionine are found in plants both in the free state and as a building component of proteins, while the amount of sulfur, e.g. in legumine 0.38 was determined and in maize was up to 0.60%. Cysteine is an essential part of the glutathione tripeptide, it is a precursor of taurine and coenzyme A. Methionine in turn participates in the synthesis of cysteine and cystine, choline, creatine and adrenaline. The main function of sulfur in proteins is the formation of disulfide (- S - S -) bonds from the sulfohydryl (- SH) groups of cysteine. Said disulfide bond serves to link two chains of polypeptides or to link two sites of a single chain - thus it is important in the context of stabilizing the structure of the polypeptides. The formation of disulfide bonds in proteins is one of the essential functions of sulfur in plant cells. Conversion of cysteine to cystine and vice versa creates an oxidation-reduction system in the plant cell that is capable of releasing or receiving a hydrogen atom depending on metabolic conditions (under reducing conditions - in excess of hydrogen cations and in the presence of reducing enzymes cysteine is formed) cysteine is formed under cystine conditions. Thus, the cysteine-cystine system functions both as a donor and as a hydrogen cation acceptor.

In addition to amino acids, sulfur is also involved in the synthesis of several important organic compounds. It is a component of plant essential oils such as alliin (isolated from garlic, enzymatically formed from alicin with a strong antimicrobial effect), methyl- and propylthiosulonates (antibacterial substances contained in onions and garlic), isothiocyanic acid esters contained in mustard oils (the largest antimicrobial) antifungal activity has benzyl isothiocyanate), it is also a part of several important glycosides (eg in carrot plants), vitamins (in the tram - vitamin B 1 sulfur is an essential element of the thiazole ring) and so on. Sulfur has been shown to affect root growth and also play an important role in chlorophyll formation. The assimilation of sulfur by plants is characterized by the reduction of the sulphates received and the synthesis of amino acids and proteins. This process is particularly pronounced in ripening seeds. In the case of butterfly plants (le

With K 8370 Υί guminoses) enough sulfur increases the usability of nitrogen. It has also been shown that sulfur increases the efficiency of enzymes and increases the utilization of non-protein nitrogen and nitrates.

It is clear that sulfur has a number of important functions and is obviously an irreplaceable element for plants. Depending on the species and part of the plant, from 0.05 to 0.6% of sulfur is present in the dry matter of the plants. Most sulfur contains oilseeds, legumes, siliceous plants and plants of the cabbage and vetch families. Most sulfur accumulates in the leaves, less in seeds and least in plant stems.

The literature indicates these sulfur contents in the grain, respectively. seeds of some plants:

barley ........................ 0,18%, oats ................... ......... 0,18%, wheat ....................... 0,17%, corn ...... ............... 0,17%, beans ......................... 0,24% , peas .......................... 0.27%, soya ................ ............. 0,32%, oilseed rape ................ 1,0%, mustard ........ ................ 1.4%.

Sulfur deficiency leads to functional disorders similar to the lack of essential nutrients, but mainly nitrogen - growth slows down and chlorophyll formation is also reduced. Accordingly, sulfur-deficient plants are characterized by "stunted" growth, with clear greenish and whitish leaves in the event of a large sulfur deficiency. The formation of anthocyanin in herbs and leaves is also significant, and in addition to reducing the assimilation area as a result of slowed growth, woody stems of the plants are also reported. The external symptoms of sulfur deficiency are similar to nitrogen deficiency and therefore it is usually difficult to ascertain which of the two elements is causing the malfunctions. However, it may be helpful to know that the lack of sulfur occurs predominantly on young parts of plants (in the case of Brasica oleracea oilseed rape, the leaves are small in the case of sulfur deficiency and the stems are upright).

Sulfur deficiency in flax, lucerne and oats was manifested by a decrease in the percentage of protein nitrogen, but an increase in the percentage of non-protein nitrogen. In addition, slower growth, smaller tuberous roots and poor reaction to the added nitrogen were observed in the lantern in the absence of sulfur.

The sulfur requirements of different types of agricultural crops vary considerably. This requires a differentiated approach to sulfur fertilization.

According to data published in the United States, approximate phosphorus and sulfur donations for some selected crops are as follows:

Collection of plant nutrients:

Crop: Yield: Phosphorus (P) Sulfur (S) [Lbs./Acre][kg/ha] [Lbs / Acre] [kg / ha]

Clover, hay 10 t 60 67.5 55 61.9 cabbage 20 t 14 15.8 44 49.5 Sweet corn 200 bu (7048 lit.) 48 54 33 37.1 oats 80 bu (2819 lit.) 20 22.5 15 16.9 Groundnut oil 2 t 15 16.9 25 28.1 Potatoes (white) 600 bu (21,143 liters) 30 33.8 14 15.8 Rice 100 bu (3524 lit.) 22 24.8 15 16.9 soy 50 bu (1762 lit.) 23 25.9 20 22.5 tobacco 1 t 22 24.8 18 20.3 wheat 60 bu (2114 lit.) 20 22.5 15 16.9

It follows that the lack of assimilable sulfur affects not only the yield but also the quality of agricultural production. Scientific literature, in particular the American literature, states that sulfur is necessary to achieve the quality parameters of cereals. Sufficient sulfur-acceptable plants are necessary to achieve the desired bread wheat quality. Sulfur-deficient wheat is of low quality - flour is dough, high in ash and has poor grindability, low gluten content and unsuitable 'baking' properties. Several studies have shown that high levels of applied nitrogen without a corresponding dose of sulfur greatly reduce flour quality.

Scientific literature recommends ensuring that the sulfur content of the soil does not fall below 22.5 kg S per hectare. In relation to fertilizer application, it is necessary to ensure that the nitrogen to sulfur (N / S) ratio is at least 5: l and the phospho

With K 8370 sulfur (P205 / S) was at least 3: 1. The presence of sulfur has been shown to positively affect the acceptability of phosphorus, especially by young plants, and also helps to keep phosphorus in the plants in acceptable form - protecting it from retrogradation.

Sulfur deficiency in flax, lucerne and oats results in a decrease in the percentage of protein nitrogen, but an increase in the percentage of non-protein nitrogen. In addition, in the case of lanterns, in the case of a sulfur deficiency, slower growth, smaller tuberous roots and poor reaction to the added nitrogen are usually observed.

Very high demands on sulfur are sown lantern. Scientific literature suggests that sulfur fertilization results in an increase in harvest of 500 to 1000%, with an increase in lantern yield of 50 to 500% due to the application of a suitable sulfur fertilizer.

Nowadays, mainly sulphates, especially ammonium, potassium, magnesium, calcium and iron sulphate, are used as sources of plant-assimilable sulfur.

The stoichiometric content of biogenic elements in these sulphates is as follows:

21.20% N,

54.06% K2O,

16.35% MgO,

23.28% Ca

20.09% Fe,

24.26% S,

18.40% S,

13,01% S,

18,60% S,

11.53% S.

ammonium sulfate, (NH4) 2SO4 potassium sulfate, K2SO4 magnesium sulfate, MgSO4.7 H2O calcium sulfate, CaSO4.2 H2O ferrous sulfate, FeSO4.7 H2O

Ammonium sulphate is a source of sulfur in a number of mixed, granular and liquid fertilizers produced today. Among the solid fertilizers, one of the most important fertilizers containing plant-acceptable sulfur is the mixed granulate of nitrate and ammonium sulphate containing 26 wt. % total nitrogen and 13 wt. % of total sulfur (DASA 26/13).

Liquid fertilizers are mainly liquid liquid fertilizers based on the thematic system: water-urea-ammonium sulphate (eg type 18,5-0-0 + 7,5 S, known under the name SAM) and quaternary system: water-ammonium nitrate urea-ammonium sulfate (e.g. type: 25.5-0-0 + 3.3 S, known as SADAM).

Recently, the offer of special sulfur-containing liquid fertilizers has also been suitably enriched by liquid sulfur concentrates prepared on the basis of: polysulphides, in particular dipotassium four-sulphide, K2S4 and alkaline hydrolysates of collagen materials. According to the current technical conditions, the type of liquid sulfur concentrate of the present type currently produced contains at least: 2 wt. % nitrogen, 8 wt. % K 2 O and 9 wt. % of total sulfur (as S).

Based on favorable results with the use of liquid fertilizers abroad (mainly in the USA) containing sulfur bound predominantly in the silane - thiosulphate form, liquid fertilizers of ammonium silane type (NI 14) 282 () are increasingly used in our country as well. and / or K2S2O3.

Boron plays an important role in the biochemical processes occurring in plant organisms and microorganisms. Its effect is related to oxidative reduction processes in plant organisms. Boron improves oxygen supply of plant tissues, especially roots. The action of boron in plants is closely related to the activity of meristem tissues, the so-called. meristem, for cell wall development, development and physiological maturation of fruits and transport of sugars. Boron activates dehydrase enzymes with some decrease in oxidase activity and increase in catalase activity. Boron also increases the hydrolytic activity of the invertase enzyme and facilitates the movement of sugars - for example, from sugar beet to foliage or, in the case of vine, from foliage to grapes and the like.

Necrosis of parenchymal root tissues, which usually occurs in the absence of boron, also suggests that boron also affects the synthesis of adenosine triphosphate (ATP). Boron also speeds up the intake of sugars to plant peaks, roots and plant reproductive organs. In this context, boron has been shown to regulate the transport of assimilates from leaves to generative organs and plant roots.

Boron deficiency in plant nutrition slows the synthesis of protein compounds. Boron has also been found to regulate the osmotic processes and hydration of plasma colloids, and also has a positive effect on plants by disturbing the optimal relationship between mineral nutrients in the soil, for example between nitrogen and potassium or between calcium and magnesium. able to draw the necessary amount of calcium from the soil.

LARGE.R.L. (Fertilizer Solution 6/1976) stated that boron activates cells that ensure the formation of mainly generative organs - flowers and fruits, thus strongly affecting the crop and its quality. During growth, in the case of boron deficiency, several typical symptoms appear on the plants, such as infertility of ears of corn, so-called. glue sticking, heart rot of beet, so-called. grape peas, shape deformities of pome fruit and the like.

Sugar beet rot, as a typical manifestation of boron deficiency, was first described in the early 1930s, but currently the characteristic symptoms of this micronutrient deficiency are known for a number of diverse plants grown in different geographical zones.

In the soil, boron is present in various compounds whose plant and micro-organism accessibility varies. Plants may receive boron from its water-soluble compounds and those that are soluble in weak acids. It is known that boron contained in the soil is incorporated into the crystalline lattice of soil minerals.

S K 8370 Υί

However, this crystalline lattice can only be destroyed by the action of strong acids or alkalis. For these reasons, even if the boron content of the soil is high enough, this does not mean that the soil contains the necessary amount of plant-accessible boron. Plant-boron deficiency usually occurs when the boron content washed out with hot water is close to 0.5 ppmB in moderate soil and 0.3 ppmB in sandy and light soil. In heavy and calcareous soils, an acceptable boron content is usually required to be greater than 0.8 to 1.0 ppm

In agricultural practice, boron fertilization can be carried out in the soil before sowing, but usually in the form of extracorporeal so-called. foliar application, which is significantly more effective. Less frequently but also used in practice is seed dressing or dressing.

According to needs and objectives, boron fertilization can be divided into: basic, supplementary (optimization, prophylactic) and preventive. Basic boron fertilization should always be carried out on the basis of a well-defined boron deficit at a specific site. When applied to the soil, not only does the need for boron for the crop being grown are usually met, but its content is corrected so that further fertilization with boron is required at the earliest after 2-6 years.

Supplementary - optimization fertilization with boron is usually carried out in the absence of significant deficiency, but high crop yields are expected due to the fact that other vegetation factors are in optimum. In supplementary fertilization, boron is usually applied to the leaf in amounts corresponding to about 1/30 of the recommended fertilization rate.

Preventive boron fertilization is fertilization in which the loss of boron expected by the crop is mainly eliminated. This type of fertilization is usually carried out even if precise data on the content of boron in the soil are not available.

Although all plants require a certain amount of boron, the demands on it vary from one plant species to another. With considerable simplification, monocotyledons have lower boron requirements than dicotyledons. Also, the sensitivity to boron deficiency is different for individual plant species. While root crops, most vegetables and many fruit trees are sensitive, while most cereals respond poorly to boron fertilization.

Currently, in addition to the limited use of boron and boron phosphorous frits, the primary source of boron for plants is mainly borohydride (H3BO3), tetraborates, especially sodium borohydride (NaCl 10 H2O) or some of the boron-containing minerals such as colemanite, pandermit , boronatrocalcite, acharite and the like.

The use of various boron fertilizers based on various sodium octaborates, mainly Na2BsOi3 · 4 H2O and NazBsOiô, has also been widely applied in agricultural practice. 3 to 4 H2O. Octoborates are a suitable source of boron for fertilization into the soil as well as for the preparation of solid fertilizers containing boron. However, their use together with liquid fertilizers greatly limits their relatively low solubility. For example, only about 5 wt. % boric acid, about 3 wt. % anhydrous sodium borohydride and only about 7.5 wt. % sodium octaborate. It goes without saying that the solubility of said boron sources in liquid fertilizers is significantly lower.

The problem of low boron concentration in solution mixtures for plant nutrition is particularly acute, bearing in mind also the effect of low relative atomic weight of boron on the content of this biogenic element in its compounds (eg boric acid, H3BO3 contains only 17.42% boron, tetraborate) sodium-borax only 11.34 wt% B and sodium octaborate, which is one of the most concentrated boron sources, contains only about 20.5 wt% B).

In the past period, considerable attention has been paid to research and subsequent technology of liquid boron concentrates, which would address the limitations already outlined in the application of boron in agricultural practice. It has also been sought to ensure that the boron contained in these concentrates is bound in a complex form which would be a prerequisite for its higher biological activity.

From successful solutions, which were applied in production and consequently also in agricultural practice, we can mention complex boron compounds in terms of AO ČSSR no. 223 678 and 259 578. Liquid concentrate of complex bound boron according to the solution contained about 63 g of boron and about 64 g of ammoniacal nitrogen per liter, while the complexing agent in its production were mixed carbohydrates, mainly pentoses (d-xylose), carboxylic acids and polybasic acids. alcohols of natural (vegetable) origin (so-called wood sugars).

Especially in forestry, concentrates of solution type were used, based on the theme of the system: B2O3 - K2O - water. A certain disadvantage of these concentrates was their considerable alkalinity (pH about 12 and more), which greatly limited the possibilities of their practical use.

A significant breakthrough in the chemistry and technology of liquid boron concentrates was the use of boron complexes with alkanolamines and / or alkylamines, the research of which was mainly carried out in the former VÚAgT in Bratislava (AO ČSSR No. 236 641 and ÚV SR No. 2929). These solutions have enabled the production of liquid boron concentrates, which have been widely used in manufacturing and application practice, and are characterized by their unusually high concentration of biogenic element, usually about 150 g of boron per liter. exploitation

With K 8370 týchtoί these boron concentrates also made it possible to produce multi-component liquid fertilizers with a relatively high content of basic plant nutrients.

It follows from the above that considerable progress has been made in the field of liquid fertilizer research and production in the past period, with the use of both basic, secondary and micronutrients in their solution form already widely used in agricultural practice. However, in an effort to achieve optimal representation of biogenic elements, at their highest concentration, even while maintaining the required phase stability of fertilizers, non-traditional combinations of raw material components used in their preparation are still sought. Further progress in this area is based primarily on the knowledge of the phase systems of the raw material components used and the establishment of limit values of equilibrium systems not yet published.

The solution-type liquid multicomponent fertilizers currently produced and used are characterized by a relatively high content of basic plant nutrients, but usually do not provide sufficient additional biogenic elements such as sulfur and boron in this case.

The essence of the technical solution

This solution is a contribution to the knowledge base of liquid multicomponent fertilizer technology.

The solution liquid fertilizers according to the solution are characterized by being not only a source of basic plant nutrients, the source of the phosphorus and potassium contained therein is potassium hydrogen phosphate (K2HPO4) and dihydrogen potassium phosphate (KH2PO4), but also contain at least 8% by weight. and at least 0.5 parts by weight of boron, which is present in the fertilizer in the form of one of the alkanolamine complexes of boron, in the form of a silane (thiosulfate) anion (S2O3) 2-. It has also been shown experimentally that it is advantageous to use ammonium (II) sulphate ((NI 14) 282 () 3) or potassium (IIS2O3) as the source of silate in the preparation of solution liquid fertilizers. Both these salts are very soluble in water and allow the preparation of concentrated solutions which are characterized by high phase stability even at temperatures below 0 ° C. Moreover, in addition to an efficient source of sulfur-available plants, they are also sources of other essential plant nutrients - nitrogen, resp. potassium, in its chloride-free form. Said simates are also effective as inhibitors of urease and nitrification and are also fungicidally effective due to the sustained release of elemental sulfur. A study of phase equilibrium in the system found that, in order to guarantee the optimum properties of the solution liquid fertilizers according to the solution, it is expedient if these in 100 parts by weight contain 17.8 to 33.5 parts by weight of ammonium silate - (ΝΗ4) 2δ2θ3 ·

In order to ensure the desired boron content in liquid type fertilizers of the solution type, it is expedient to use some of the alkanolamine complexes of boron in their preparation. For economic as well as ecological reasons, the use of ethanolamine complex of boron prepared using the already mentioned solutions protected in the past period (AO ČSSR no. 236 641 and ÚV SR no. 2929) proved to be successful in this respect.

The solution liquid fertilizers of the present invention are also characterized by a virtually neutral or weakly basic chemical reaction (pH: 6-8).

Although the solution liquid fertilizers can also be used for fertilization in soil, its composition and exceptional properties predetermine it especially for extracorporeal - foliar application. They are usually used, after appropriate dilution with water, in connection with supplementary or preventive fertilization to ensure readily available sulfur and boron-treated plants

EXAMPLES

The following examples illustrate and document the present invention, but do not limit the claims for protection thereof.

Example 1

In order to prepare 1000 liters of liquid liquid fertilizer containing sulfur and boron in addition to nitrogen, phosphorus and potassium, 519.75 kg (ca. 390.8 liters) of concentrated aqueous ammonium thiosulfate containing at least 58 wt. % (Cca4) 2δ2θ3 · This solution contained approx. % total sulfur (as S) and about 12 wt. % ammonia nitrogen (as N). The solution had only a weakly basic chemical reaction (pH ca. 7.5) and its specific gravity at room temperature was close to 1330 kg / m ³ .

533.25 kg (ca. 378.2 liters) of aqueous hydrogen (K 2 HPO 4) and potassium phosphate dihydrogen - KH 2 PO 4 were added to the soda solution under stirring. The phosphate-potassium solution used contained approximately 18 wt. % phosphorus (as P2O5) and about 21 wt. % potassium (as K2O) in chlorine free form

SK 8370 meί me. The lead source of phosphorus and potassium was characterized by its relatively high density - density (at room temperature about 1410 kg / m ³ ). The phosphate-potassium solution used had only a weakly basic chemical reaction (pH about 7.5).

Furthermore, 189 kg of urea fed and 108 kg (about 79.1 liters) of boron monoethanolamine concentrate containing about 150 g of boron (as B) per liter were added to the mixed solution while stirring. The liquid boron concentrate used was prepared by reacting boric trihydrogen acid with monoethanolamine, the so-called. colamine

Thorough mixing resulted in 1350 kg (about 1000 liters) of liquid fertilizer solution according to a solution containing 154.3 g of total nitrogen (as N), 95.8 g of phosphorus (as P2O5), 111.9 g of potassium (as K2O), 135 g of sulfur (as S) and 11.9 g of boron (as B) per liter. The liquid fertilizer prepared had the character of a colorless, practically clear solution, practically odorless. The product was characterized by its neutral or weakly alkaline chemical reaction (pH: 6.5 to 8.0, usually 7.3). Its density - density at room temperature was close to 1350 kg / m ³ . The phase stability of the undiluted concentrate was at least up to 0 ° C.

Example 2

In order to prepare 2000 kg of liquid liquid fertilizer according to a solution characterized by a high content of potassium in the chlorine-free form, the following steps have been taken:

A 2000 liter tank equipped with stirring was charged with 900 kg of a concentrated aqueous solution of potassium thiosulfate (thiosulfate) containing about 50.5 wt. % K2S2O3. The content of the monitored plant nutrients in this raw material was: 20.75 wt. % potassium (as K), respectively. about 25.0 wt. % (as K 2 O) and about 17.0 wt. % of total sulfur (as S). Subsequently, 700 kg of an aqueous solution of potassium phosphates - hydrogen (K2HPO4) and dihydrogen (KH2PO4) containing about 18 wt. % phosphorus (as P2O5) and 21 wt. % potassium (as K 2 O). Furthermore, 300 kg of urea to be added and 100 kg of liquid boron concentrate prepared in the manner described in the Office of the Government of the Slovak Republic no. 2929, by reacting the monoethanol amine with boric trihydrogen acid - H3BO3. The liquid boron concentrate thus prepared contained approximately 11 wt. % boron (as B), i. j. 150 g of boron per liter.

After thoroughly mixing the tank contents, 2000 kg of NPK-S + B liquid fertilizer solution was prepared as described above, containing:

more than 7.0 wt. % nitrogen (as N) in amide form,

6.3 wt. % phosphorus (as P2O5),

18.6 wt. % potassium (as K 2 O), more than 7.6 wt. % of total sulfur (as S), predominantly in the silane form and more than 0.5 wt. % boron (as B) in the form of a boroethanolamine complex. The prepared product had a practically neutral chemical reaction (pH: 7.6), was clear and practically odorless.

The product diluted with water in a volume ratio of approx. 1: 150 - 200 was applied by foliar to oilseed rape.

Industrial usability

The liquid NPK solution fertilizers of the present invention are prepared based on potassium hydrogen phosphate and dihydrogen phosphate, also containing significant amounts of sulfur and boron. It is characteristic of these liquid fertilizers that the source of the sulfur contained therein is a silane (thiosulfate) anion, the boron being bound in the form of an alkanolamine complex. One of the ammonium and / or potassium sulfates may be used in their preparation, and ammonium sulfate (NI 14) 2.82 () 3 has proven to be particularly suitable. Boronone ethanolamine concentrate of boron has proven to be the most suitable alkanolamine complex in practice. The preparation of liquid fertilizers in terms of solution is undemanding and does not require the use of special equipment.

Claims (5)

Solution liquid NPK fertilizers containing potassium hydrogen phosphate and potassium phosphate dihydrogen, as well as sulfur and boron, characterized in that 100 parts by weight are at least 8 parts by weight of sulfur bound in the form of a silane anion and at least 0.5 parts by weight of boron bound in the form alkanolamine complex. Solution liquid NPK fertilizer according to claim 1, characterized in that the source of silane anion is ammonium and / or potassium silane. 3. Solution liquid NPK fertilizer according to claim 1, characterized in ZEV 100 parts preferably comprise from 17.8 to 33.5 parts by weight Simatai ammonium (NH _{4) 2} S ₂ O 3. Solution liquid NPK fertilizers according to claim 1, characterized in that they contain ethanolamine boron complex. Use of liquid liquid NPK fertilizers according to claims 1 to 4 for off-root plant nutrition.