Organic Water-Soluble Fertilizer with Humic Properties

Abstract

The invention relates to an organic water-soluble fertilizer, in solid form, with humic properties, comprising carbon and nitrogen with a carbon-to-nitrogen ratio of between 4 to 14, wherein more than 0% and up to 30% of the total nitrogen content is chemically bound as ammonium nitrogen, more than 0% and up to 20% of the total nitrogen content is chemically bound as easy-to-hydrolyse amide nitrogen and at least 50% of the total nitrogen content is chemically bound as difficult-to-hydrolyse amide nitrogen. The invention further relates to a method for producing an organic water-soluble fertilizer provided in solid form and the use of such a water-soluble fertilizer.

Claims

1. An organic water-soluble fertilizer, in the form of a solid, with humic substance properties comprising carbon and nitrogen in a carbon-to-nitrogen ratio of 4 to 14, wherein more than 0% and up to 30% of the total nitrogen content is chemically bound as ammonium nitrogen, more than 0% and up to 20% of the total nitrogen content is chemically bound as easy-to-hydrolyse amide nitrogen and/or easy-to-hydrolyse amide-like bound nitrogen; and at least 50% of the total nitrogen content is chemically bound as difficult-to-hydrolyse amide nitrogen and/or difficult-to-hydrolyse amide-like bound nitrogen.

2. The organic water-soluble fertilizer, in the form of a solid, according to claim 1, wherein the easy-to-hydrolyse amide nitrogen and/or easy-to-hydrolyse amide-like bound nitrogen is easy-to-hydrolyse amide nitrogen, and wherein the difficult-to-hydrolyse amide nitrogen and/or difficult-to-hydrolyse amide-like bound nitrogen is difficult-to-hydrolyse amide nitrogen.

3. The organic water-soluble fertilizer, in the form of a solid, according to claim 1, which has a total nitrogen content of 3 to 11 wt. %, with respect to the dry weight of the fertilizer.

4. The organic water-soluble fertilizer, in the form of a solid, according to claim 1, which is obtained in by subjecting lignite to an oxidizing and ammoniating treatment.

5. The organic water-soluble fertilizer, in the form of a solid, according to claim 1, wherein the solid is present in powder form, as granules or as pellets.

6. The organic water-soluble fertilizer, in the form of a solid, according to claim 1, which has a residual moisture content of at most 30 wt. %, with respect to the total weight of the organic water-soluble fertilizer, in the form of a solid.

7. A method for the preparation of an organic water-soluble fertilizer, in the form of a solid, with humic substance properties according to claim 1, wherein the method is performed as a continuous method and comprises the following steps: a) feeding lignite particles and/or lignin particles and an aqueous ammonia solution as well as optionally recovered product of step b) as starting materials into a dispersing circuit having a dispersing device, a recirculation container, and a circulation pump; dispersing the starting materials while simultaneously reducing the lignite particles in size until a suspension of the lignite particles and/or the lignin particles and the aqueous ammonia solution is formed; taking the suspension out of the dispersing circuit and transferring it to step b); b) oxidizing the suspension obtained in step a) in an oxidation reactor with an oxygen-containing oxidizing agent at a temperature of <100° C., thereby forming a product suspension; c) separating a liquid phase from the product suspension; and d) drying the liquid phase obtained in step c) to generate the organic water-soluble fertilizer with humic substance properties as a solid.

8. The method according to claim 7, wherein the lignite particles and/or the lignin particles and the aqueous ammonia solution are lignite particles.

9. The method according to claim 7, wherein step c) and/or step d) comprises removing free ammonia and after step d), step e) takes place: e) cooling the solid organic water-soluble fertilizer obtained in step d).

10. The method according to claim 7, wherein the liquid phase separated in step c) is a colloidal suspension.

11. The method according to claim 7, wherein the separation in step c) is by centrifugation.

12. A method comprising applying the liquid phase obtained in step c) of the method according to claim 7 as a fertilizer to soil.

13. The method according to claim 12, which comprises applying the liquid phase obtained in step c) to the soil of already existing plant stands for subsequent soil conditioning and/or as a biostimulant for reducing plant stress.

14. A method comprising applying the organic water-soluble fertilizer, in the form of a solid, with humic substance properties according to claim 1 to the soil of already existing plant stands for subsequent soil conditioning and/or as a biostimulant for reducing plant stress.

15. An organic water-soluble fertilizer, in the form of a solid, with humic substance properties which is obtained in accordance with the method according to claim 7.

16. The organic water-soluble fertilizer, in the form of a solid, according to claim 1, wherein more than 0% and up to 20% of the total nitrogen content is chemically bound as easy-to-hydrolyse amide nitrogen.

17. The organic water-soluble fertilizer, in the form of a solid, according to claim 1, wherein at least 50% of the total nitrogen content is chemically bound as difficult-to-hydrolyse amide nitrogen.

18. The organic water-soluble fertilizer, in the form of a solid, according to claim 2, which has a total nitrogen content of 3 to 11 wt. %, with respect to the dry weight of the fertilizer.

19. The method according to claim 8, wherein the liquid phase separated in step c) is a colloidal suspension.

20. The method according to claim 9, wherein the liquid phase separated in step c) is a colloidal suspension.

Description

EXAMPLE

[0122] 100 kg/hr of lignite dust are continuously taken out of a receiving vessel and supplied to a dispersing device (model Ytron ZC).

[0123] An aqueous 5% ammonia solution is continuously fed into the circulation system via the recirculation vessel, so that a mixture of 20 wt. % of lignite dust and 80 wt. % of ammonia solution, with respect to the total weight of the mixture, is formed. The mixture is pumped through the circulation system for a mean retention time of 180 min, whereby the lignite particles are intensively blended and reduced in size.

[0124] The resulting lignite suspension is continuously fed out from the recirculation vessel and supplied to the oxidation reactor.

[0125] The oxidation reactor has a vessel of a suitable volume. In this assembly, the lignite suspension is gassed with compressed air under stirring for a mean retention time of 120 min at 0.3 MPa (3 bar) and a temperature of 70° C. The oxidized product suspension is continuously fed out from the reactor via a receiving vessel, with the receiving vessel being under standard pressure.

[0126] The product suspension is continuously transferred from the receiving vessel into a centrifuge. The product suspension comprising a liquid and a solid phase is centrifugated at 4000 rpm. This way, the liquid phase is separated from the product suspension.

[0127] Subsequently, the separated liquid phase of the product suspension is continuously transferred into a thin layer evaporator at a rate of e.g., 300 L/hr and dried to a residual moisture of 25 wt. %, with respect to the total weight of the dried product, at an average temperature of 115° C. for a mean retention time of 0.5 hrs. This results in the organic water-soluble fertilizer with humic substance properties as a solid with 15 kg/h.

[0128] After drying the fertilizer is cooled and, if required, further agglomerated with agglomerating agent. In an additional step the solid organic water-soluble fertilizer can be packed and prepared for shipment.

[0129] The thus obtained water-soluble fertilizer was analyzed by means of elemental analysis:

[0130] C: 54%,

[0131] N: 8%,

[0132] H: 5%,

[0133] S: 0.3%.

[0134] Bonding forms of the nitrogen have been determined as follows:

[0135] Ammonium nitrogen: about 150 mg of test material are laced with 2 g of MgO and connected to a distillation plant according to Kjeldahl, e.g., by the firm Gerhard, model Vapodest. The apparatus automatically adds water and automatically distils NH.sub.3 released into a receiver of boric acid. The content of NH.sub.4.sup.+ of the sample is calculated from the consumption of boric acid determined by titration with NaOH solution.

[0136] Easy-to-hydrolyse amide nitrogen: in analogy to ammonium nitrogen, but 8% NaOH solution is added instead of MgO. The content of amide-N of the sample is calculated from the consumption of boric acid determined by titration with NaOH solution and considering the ammonium content of the sample.

[0137] Difficult-to-hydrolyse amide nitrogen: Calculation from the difference between the total content of N of the sample and the sum of ammonium and easy-to-hydrolyse amide nitrogen.

[0138] With respect to the total product the following values have been obtained:

[0139] ammonium nitrogen: 1.4%,

[0140] amide nitrogen, easy to hydrolyse: 0.8%,

[0141] amide nitrogen, difficult to hydrolyse: 5.8%.

Example of Use

[0142] It was investigated in a test what influence the fertilizer according to the invention has on the vitality of tomato plants.

[0143] In particular, it was investigated how many resources the plant has to spend on its stress management during drought stress and consequently, is no longer available for biomass production (i.e., in the end exploitation rate).

[0144] Tomato plants have membranous oxidases (for example, respiratory burst oxidase homolog D (RbohD)) forming extracellular ROS (reactive oxygen species). Said oxidases are activated by signalling molecules of pathogens (so-called elicitors) and suddenly produce high concentrations of ROS (defense reaction) which have cytophathogenic effect on the pathogen and also on the own cells. For this reason, low concentrations of ROS entering the surrounding tissue (with respect to the site of attack) and thereupon are passed forward into the plant by RbohD, act as a signal and there, prepare a set of protective measures against oxidative stress by ROS (both, intra and extracellular). ROS signals are also activated in plants exposed to thermal stress (doi: 10.1080/14620316.2004.11511805). Moreover, however there is also prepared the ROS defense reaction against pathogens, so that when detecting a further elicitor the ROS defense reaction is stronger and more rapid (thus, there is an increased formation of ROS). Said preparation process is called priming (doi: 10.1016/j.jplph.2014.11.008).

[0145] It could be shown that treating the plant with the fertilizer according to the invention reduces the abiotic stress and the strength of the ROS defense reaction that was triggered by an elicitor.

[0146] Therefore, a reduced defense reaction to a biotic elicitor in the early growth phase is an indicator for a growth-promoting effect. In this sense, the fertilizer according to the invention (Novihum Liquid) was tested together with the conventional product (N25) as well as a product available on the market (competitor) against an untreated control.

[0147] The organic water-soluble fertilizer in form of a solid according to the invention (Novihum Liquid) which was used in the test was prepared in accordance with the method described in the application and had an ammonium nitrogen content of 2.0%, a content of easy-to-hydrolyse amide nitrogen of 0.8% and a content of difficult-to-hydrolyse amide nitrogen of 5.2%, with respect to the total amount of the fertilizer in the form of a solid according to the invention. The carbon-to-nitrogen ratio was 7.6.

[0148] For the treatment of the plants an aqueous solution of Novihum Liquid was prepared at a concentration of 0.01% and poured onto the substrate in an amount of 200 mL. Said treatment was carried out twice within 4 weeks.

[0149] The conventional product used in the test was prepared in accordance with the method of WO 2017/186852 and had an ammonium nitrogen content of 1.6%, a content of easy-to-hydrolyse amide nitrogen of 0.4% and a content of difficult-to-hydrolyse amide nitrogen of 2.4%, with respect to the total amount of the product. The carbon-to-nitrogen ratio was 13.

[0150] It was used as follows: 240 g were homogeneously mixed with 60 L of propagation substrate (Floraton 3 by Floragard).

[0151] The competitive product had an ammonium nitrogen content of 0.2%. No easy-to-hydrolyse nitrogen was found. The content of difficult-to-hydrolyse nitrogen was 0.7%. The carbon-to-nitrogen ratio was 43. The competitive product was used as follows.

[0152] The competitive product was present in a solid form. The competitive product was mixed to an aqueous solution at a concentration of 0.01%. The plant was watered twice with 200 mL of the aqueous solution each within 4 weeks.

[0153] The tomato plants used in the test had the same age and were cultivated in 3 L pots under otherwise the same conditions, so that the cultivation conditions differed only in the addition of different fertilizers. The test was done with 12 repetitions each.

[0154] The stress test was carried out 4 weeks after seeding. Carrying out such stress tests is described for example in WO 2019/179656 and is commercially offered and carried out by several service providers. In the present case, the stress test was carried out by Bex-Biotec GmbH & Co. KG in Munster.

[0155] In FIG. 1, the ROS production is illustrated as a standardized defense reaction of the differently treated plants (tomato). The plants treated with the fertilizer according to the invention and the classical, water-insoluble product spend significantly less resources on the stress reaction than the control or a competitive product, respectively.