BE1019754A3 - PROCESS FOR THE PREPARATION OF A FERTILIZER ENRICHED IN MICROORGANISMS BY "BLENDING" AND FERTILIZING THUS OBTAINED - Google Patents

Description

PROCESS FOR THE PREPARATION OF A FERTILIZER ENRICHED IN MICROORGANISMS BY "BLENDING" AND FERTILIZER THUS OBTAINED

Technical area

The present invention relates to the field of agriculture, and more particularly to fertilizers containing microorganisms.

According to the invention, the abiotic ingredients and the biotic elements commonly used in agriculture are combined in a bulk blending mixer. The result is a fertilizer enriched with microorganisms to improve plant production through fertilization of soil and plants.

State of the prior art

For many decades, the agricultural world has been seeking solutions to improve soil quality and to stimulate plant growth.

For this purpose, many fertilizers have been developed. Fertilizers are any organic or mineral substance intended for soil fertilization. The mixing of these substances with the soil makes it possible to introduce chemical principles that can be used and assimilated by plants. Thus, the fertilizer application stimulates the nutrition and therefore the growth of the cultivated plants.

At the same time, amendments can be added to the fertilizer or even used alone. An amendment is a mixture of substances capable of improving the physicochemical properties of the soil, making it more suitable for crop production. Particularly useful amendments are those containing calcium and magnesium, in the form of oxides, whose main action is to raise the pH of the soil, made more favorable to the growth of plants.

Mineral fertilizers, as well as fertilizer amendments, are generally in solid, compacted or granular form. There are also liquid formulations.

It is also known to mix different fertilizers in the form of granules or powder, so as to obtain compound fertilizers also known as "bulk blending".

The addition of these substances, mainly of chemical origin, to soils is however not neutral for the environment and can cause pollution, especially water tables.

This is why, in the perspective of sustainable, integrated and sustainable agriculture, fertilizers incorporating biotic elements, more specifically microorganisms and mainly bacteria or fungi, have been developed.

These new fertilizers or fertilizer amendments are certainly more effective and thus allow their use with smaller amounts of leachables.

According to the document FR 2 901 787, the two components -biotic and abiotic respectively- are mixed and then compacted so as to form granules. More generally, such granules can be homogeneous or multilayer. In any case, the granules currently available are physical entities of well-defined composition, incorporating the microorganisms in an intimate manner. These granules, called "coated", allow a slow release of active ingredients in the presence. However, the manufacturing process of such granules remains constraining and delicate.

Thus, there is a clear need to develop new fertilizers, amendments or amendments fertilizers containing microorganisms, effective but easier preparation.

Presentation of the invention

The present invention is based on the demonstration by the Applicant that the technique known as "bulk blending", conventionally used for mixing chemical fertilizers in the form of granules of millimeter size so as to obtain compound fertilizers, could be used to enrich these granules microorganisms and allowed to obtain fertilizers of higher efficiency.

Thus, according to a first aspect, the present invention relates to the use of a "bulkeuse" type mixer for producing a fertilizer enriched with microorganisms in the form of granules.

More specifically, the present invention relates to a process for preparing or manufacturing a fertilizer enriched with microorganisms which comprises the following steps: - introduction of at least one fertilizer in the form of granules and at least one microorganism in a mixer ; - mechanical mixing of the fertilizer and the microorganism by means of the mixer; - recovery of fertilizer enriched with microorganisms.

According to an advantageous embodiment, the method according to the invention is limited to these steps.

In the context of the invention and in the following description, the term "mixer" means a receptacle or a tank for mixing or mechanical mixing of the ingredients in the tank. Such a tank may in particular be provided with a screw system, in particular an endless screw, making it possible to stir the contents of the tank. It can also be rotatable: the tank then rotates as a whole. This type of mixer is known in the field of fertilizers under the term "bulkeuse" and allows mixtures to be made in batch or in bulk, and not continuously.

While, as already said, such a system is already used for the mixing of chemical fertilizers in the form of granules of millimeter size, it is proposed here to use it to mix the granules of chemical fertilizers with microorganisms.

Unexpectedly, the method proposed in the context of the present invention makes it possible to obtain a fertilizer of improved effectiveness, thus demonstrating that it makes it possible to fix the microorganisms in a homogeneous and viable manner on the surface of the granules, although these microorganisms are generally in the form of a micrometric powder, introduced in an extremely small amount relative to the granules of fertilizer (of the order of 0.1%).

In the context of the invention and in the remainder of the description, the term "fertilizer" is understood to mean: fertilizers, namely any organic or mineral substance intended for the fertilization of the soil; - the amendments, namely a mixture of substances capable of improving the physicochemical properties of the soil, in particular a basic calcium and / or magnesium mineral amendment; fertilizer amendments, namely fertilizers in which are added amendments, more specifically substances containing calcium and / or magnesium, generally in the form of oxides, hydroxides or carbonates.

Conventional mineral fertilizers are those based on nitrogen (N), potassium (K) and / or phosphate (P), optionally in combination. In the case of a mineral fertilizer, it advantageously contains at least 15% of nutrient carrier, including sugars, favorable to the growth of microorganisms. This is for example an NK fertilizer containing 3% N and 16% K20 on gross weight, derived from beet vinasse and containing 20% of carrier rich in sugars.

Essentially according to the invention, the fertilizer is in solid form, more specifically granules or powder particles. In the remainder of the description and for reasons of simplicity, the term "granules" is used. The size of these granules can range from 0.1 to 5 mm, advantageously from 1 to 5 mm. It may especially be compacted or spherical granules. The particle size chosen may also depend on the type of spreading envisaged, typically: from 1.4 to 1.8 mm for a localized fertilizer; from 2 to 4.5 mm for a fertilizer with conventional spreading in full.

The second essential component of a fertilizer according to the invention is one or more species of microorganisms, advantageously viable. In the context of the present invention are selected microorganisms of agronomic interest, that is to say having a beneficial effect in particular on the quality of soil, plant nutrition and / or the health status of plants ( for example repellent effect vis-à-vis pathogens). The presence of these microorganisms results in a stimulation of plant growth, a synergy being observed between the mineral nutrients and live microorganisms capable of colonizing the cultures after treatment with a fertilizer according to the invention.

The preferred microorganisms are bacteria and fungi.

Bacteria, for example of the genus Pseudomonas such as the species P. putida or P. fluorescens, are able to mobilize the nutrients of the soil: nitrogen, phosphorus, potassium hydroxide, trace elements such as iron, manganese, etc.

Fungi, especially of the genus Trichoderma such as the species T. harzianum, colonize and "hygienize" the organic matter of the soil and the ihizosphere.

A particularly suitable cocktail in the context of the invention is a mixture of P. putida, P. fluorescens and T. harzianum.

In a preferred manner according to the invention, the microorganisms are in the form of a dehydrated inoculum and therefore in the form of a powder with a micron particle size, advantageously between 10 and 100 μm.

The first step of the process according to the invention therefore consists in introducing the two essential components, granules of chemical fertilizers on the one hand and microorganisms on the other hand, into the mixer. This introduction must be carried out so as to obtain as homogeneous a distribution of the two components as possible.

The proportion of the two ingredients is adjusted. Advantageously, the chemical fertilizer, in the form of granules, is introduced in a quantity of the order of one tonne, for example 5 tons. In practice, the quantity of microorganisms introduced is between 0.5 and 20 kg of inoculum per tonne of product, which corresponds to a mass proportion of microorganisms / fertilizer of between 0.05% and 2%, advantageously equal to 0, 1%. This proportion is adjusted in particular according to the concentration of CFU (colony-forming units) / kg of the inoculum. Advantageously, the final fertilizer contains an amount greater than or equal to 107 CFU (colony forming units) per ton.

In a second step, a mixing or mechanical stirring is performed by implementation of the mixer. This mixing must be carried out under appropriate conditions so as to: - not deteriorate the physical integrity of the fertilizer granules; - not to affect the viability of microorganisms; - allow a homogeneous distribution of microorganisms on the surface of the granules; - allow the attachment and maintenance of microorganisms on the surface of the granules.

As already said, this stirring can be performed in a mixer type "bulkeuse", in which one or more rotating screws provides the stirring.

In practice, the important parameters of operation of the mixer are: the time of the order of several minutes, for example 4 minutes for 5 tons of product; the speed of rotation which must be moderate, of the order of a few hundred revolutions per minute; - the temperature which must avoid heating. Thus, it is possible to work cold or at room temperature.

At the end of this mixing, a fertilizer enriched with microorganisms is obtained in the form of granules of a size similar to that of the introduced granules, namely of size conventionally comprised between 0.1 and 5 mm and advantageously millimetric, even more advantageously between 1 and 5 mm. At the end of the process, the fertilizer is recovered and can be packaged in bags of variable size (for example from 20 kg to 1 t).

On the surface of these granules are fixed microorganisms, hence the term "fertilizer support" which can be used to designate the fertilizer (fertilizer) initially introduced.

In order to improve the fixation of the microorganisms on the granules of fertilizer and to "freeze" the mixture, it may be envisaged to add a sticky material to the mixer. This can be in liquid or powder form. Such materials, already used for this purpose in the preparation of conventional compound fertilizers, are of the clay type, vegetable oil or seaweed extracts. They are advantageously added at a height of 5 kg / ton.

Remarkably, the fertilizer obtained at the end of this process is a fertilizer enriched with microorganisms but which differs from those already available. In fact, the fertilizers of the prior art, obtained by coating, are in the form of granules in which the microorganisms are intimately integrated either homogeneously or in the form of layers, hence their slow release. On the contrary, in the context of the present invention, the microorganisms are present on the surface of the granules, which allows their rapid release especially under the action of rain or soil moisture.

It is very clear that the method implemented according to the invention is much easier and more flexible than those of the prior art, while allowing to obtain a fertilizer of increased efficiency.

Such a fertilizer can also be used in the context of the spreading in full, that is to say with a homogeneous distribution on all the soil, or in localized, that is to say in line according to the rank of plantation . The homogeneity and the viability of the fertilizer according to the invention can be verified in situ thanks to the determination of the microorganisms introduced.

According to another aspect, the invention relates to a device adapted to the implementation of the method which has just been described. A central element of such a device is the mixer whose sizing and operating characteristics have been described above.

Such a device is also characterized by means for introducing granules of fertilizer, possibly present in the conventional "bulkeuses", but also by means allowing the homogeneous introduction of microorganisms.

Such a device may further comprise other elements arranged upstream or downstream of the mixer, such as: a loading hopper; - a sieve; - elevators; - a bagger; - Feeding and routing means;

The invention and the advantages which result therefrom will emerge from the following example of embodiment, with the aid of the appended figures.

As already stated, the invention is further illustrated in connection with a fertilizer but it also covers amendments and fertilizer amendments.

Legend of figures

Figure 1 is a block diagram of a production line of a fertilizer according to the invention.

Figure 2 illustrates the dry matter harvest of the first cut of a mixed grassland, depending on the fertilizer used.

1 / Preparation of a fertilizer according to the invention

Figure 1 illustrates a production line of a fertilizer according to the invention, allowing the implementation of the method of the invention.

In the loading hopper 1 is loaded the fertilizer in the form of granules. In the case of a mixture, the different fertilizers can be loaded successively in the hopper or mixed directly in the hopper. A supply system can be provided at the level of the hopper.

The fertilizer is for example a fertilizer NK equilibrium 3 0 16 (3% N 0% P205 and 16% K20 on gross weight), derived from beet vinasse and containing 20% carrier rich in sugars.

The fertilizer or the mixture of fertilizers is then taken care of by means of risers with straps 2, which make it possible to drop by gravity the fertilizer or the mixture in a two-stage screen 3. This screen allows possible to sort the granules according to their size, thanks to a grid system. Typically, granules having a size of between 1 and 5 mm are selected.

The granules are then introduced into a mixer 4 of the "bulkeuse" type. This type of mixer, for example marketed by the company SN DEBOFFLE under the name DBF, is well known to those skilled in the art since it is already used to manufacture compound fertilizers. It is a tank equipped with a screw system that allows bulk and batch brewing of the ingredients present in the tank. Such a mixer can receive several tons of products. Typically, about 5 tons of granular fertilizer is introduced into the mixer.

It is at the level of this mixer 4 that the microorganism is introduced, advantageously in the form of an inoculum, preferably dehydrated in the form of a micrometric powder (10 to 100 μm). In practice, the mass proportion of microorganisms / fertilizer is from 0.5 kg to 20 kg of inoculum per ton of fertilizer, typically of the order of 0.1%. This proportion is chosen so that the final fertilizer contains an amount greater than or equal to 107 CFU (colony-forming units) per tonne of fertilizer.

In this mixer 4 can also be added a tacky material in liquid or powder form. Such materials, already used for this purpose in the preparation of conventional compound fertilizers, are of the clay type, vegetable oil or seaweed extracts. They are advantageously added at a height of 5 kg / ton. They make it possible to strengthen the fixation of the microorganisms on the surface of the fertilizer granules and in particular to prevent their subsequent segregation in the bags after packaging in the bagger 6.

The mixer 4 operates under conditions allowing a homogeneous distribution of the microorganisms, without deterioration of the viability of the inoculum or the qualities of the fertilizer. In practice, the brewing is carried out for a few minutes (of the order of 4 minutes for 5 tons), without heating (for example at room temperature) and in mild conditions (a few hundred revolutions per minute).

The mixture is then taken over by another elevator 5 which makes it possible to introduce the mixture by gravity into a bagger 6. The bagger 6 is intended for the appropriate packaging of the fertilizer according to the invention, consisting of a fertilizer under form of granules on the surface of which are fixed microorganisms. Typically, the fertilizer is packaged in the form of bags of 20 kg to 1 t intended for agriculture.

2 / Demonstration of the effectiveness of a fertilizer according to the invention:

In order to demonstrate the effectiveness of the fertilizer according to the invention, three distinct manures were tested: - Supply of a control fertilizer, called "ammonitrate control", nitrogenous fertilizer (Ammonitrate: 33.5 N units per 100 kg) of 120kg / ha; - Supply of an NK fertilizer, called "NK support only fertilizer", consisting of 300 kg / ha of NK 3/0/16 fertilizer alone (without microorganisms) + nitrogen fertilizer supply (Ammonitrate: 33s5 N units) 100 kg) of 120kg / ha; - Supply of fertilizer enriched with microorganisms according to the invention, called "NK fertilizer with microorganisms", consisting of 300 kg / ha of fertilizer NK 3/0/16 with microorganisms (Pseudomonas fluoric esc ens, Pseudomonas putida and TricJioderma harzanium ), prepared according to the protocol described above and called Myco'Sol® + nitrogen fertilizer supply (Ammonitrate: 33.5 N units per 100 kg) of I20kg / ha.

Each of these fertilizers was sprayed on a mixed grass prairie consisting of English Grass Rye and white clover.

At the first cut (end of the first cycle), the quantity of dry matter harvested, expressed in kg / ha, was weighed. The results are shown in Figure 2.

It turns out that the fertilizer according to the invention enriched with microorganisms allows an increase of 12% compared to the non-enriched fertilizer, and 73% compared to the ammonitrate control. The effectiveness of the fertilizer according to the invention is therefore demonstrated and validates the feasibility and validity of the preparation process proposed in the context of the present application.

Claims (1)

CLAIMS Use of a mixer, advantageously of the "bulkeuse" type, for the preparation of a fertilizer in the form of granules enriched with bacteria and fungi. A method for preparing a fertilizer enriched in bacteria and fungi comprising the following steps: - introduction of at least one fertilizer in the form of granules and bacteria and fungi in a mixer, preferably of the "bulkeuse" type; - mechanical mixing of the fertilizer, bacteria and fungi using the mixer; - recovery of fertilizer enriched with bacteria and fungi. Process for the preparation of an enriched fertilizer according to claim 2, characterized in that the bacteria and fungi are in the form of a powder, advantageously of micrometric size. Process for the preparation of an enriched fertilizer according to one of Claims 2 to 3, characterized in that a sticky material is introduced into the mixer. Process for the preparation of an enriched fertilizer according to one of Claims 2 to 4, characterized in that the bacteria and fungi and the fertilizer are introduced in a mass proportion of between 0.05% and 2%, advantageously equal to 0.1 %. Fertilizer enriched in bacteria and fungi obtainable by means of the method according to one of claims 2 to 5, in the form of granules of fertilizer on the surface of which are fixed bacteria and fungi. An enriched fertilizer according to claim 6 in the form of granules of millimeter size. Device adapted to the implementation of the method according to one of claims 2 to 5 comprising: - a mixer, preferably of the "bulkeuse" type; means for introducing at least one fertilizer in the form of granules and bacteria and fungi. Use of a fertilizer according to claim 6 or 7 for spreading in full or in spot.