WO1991011410A1

WO1991011410A1 - Products for the cultivation of plants on all types of soil, and processes for their manufacture

Info

Publication number: WO1991011410A1
Application number: PCT/FR1990/000079
Authority: WO
Inventors: Salah Barbary
Original assignee: Salah Barbary
Priority date: 1990-02-01
Filing date: 1990-02-01
Publication date: 1991-08-08
Also published as: AU5047490A

Abstract

Product enabling cultivation in infertile conditions, either separately or mixed with a soil, comprising a polymeric hydrogel capable of absorbing and fixing water in a quantity which is at least one order of magnitude greater than the weight of the polymer, characterized in that it comprises, as starting material, a limited quantity of water combined with the polymer and, in solution with this limited quantity of water, a balanced fertilizer containing potassium, phosphorus and nitrogen, and a substantial quantity of oligo-elements.

Description

Products allowing the cultivation of plants on all types of soil and methods of manufacturing such products

The present invention relates to a product intended to make it possible to cultivate plants in all types of soil, even totally arid.

The invention relates more particularly to a product based on hydrophilic material capable of reversibly absorbing water in relatively large quantities. We know in particular by patents

US 4,076,663, US 4,090,013 and EU 87,301,047 such materials in the form of a resin-based gel, in particular of the poly (acrylic acid) type and corresponding crosslinked salts.

Consideration has already been given to agricultural applications of these materials as agents facilitating the germination of seeds and means of retaining water in the soil.

The present invention is based on the discovery of the possibility of combining the water retention function with that of nutrient reserve located precisely and advantageously within the immediate reach of the root system of the plants to be cultivated.

To this end, the invention provides a product in the form of a granule comprising a polymer hydrogel capable of absorbing and fixing water in an amount of at least one order of magnitude greater than the weight of polymer, characterized in that it comprises d 'Origin a limited amount of water bound to the polymer and, in solution in this limited amount of water, a balanced fertilizer and a significant amount of trace elements.

The granules according to the invention thus contain all the nutrients of good arable land while remaining capable of absorbing and retaining water in an amount which can be of the order of 1,000 times the initial volume.

This allows a considerable saving in irrigation water while the nutrients incorporated in the product are released practically without loss as and when the plants' own needs arise.

Further analysis of the technical improvement provided by the invention reveals an impressive list of advantages offered in combination:

- The very great capacity of the granules to absorb and retain water wherever it comes from: irrigation, rain, dew or natural soil moisture deeply absorbed by capillarity, the water thus collected being put, without wasting, at the arrangement of plants according to their strict needs.

- The granules, swollen with water, resembling crystals, buried in the ground, form a network with tight meshes which limits the effects of percolation, or those of evaporation.

- The effects of percolation or evaporation being made very limited, the roots of the plants are the bénéficiairesonly beneficiaries of the regular and permanent humidity brought by the granules thus creating constant conditions useful for their development. They are no longer affected by drought or lack of irrigation.

- The granules, saturated with water, keep their reserves whatever the pressures exerted on them (passage of an agricultural tractor, for example). Only the roots have the power to penetrate these "food chambers" and benefit from their water reserves.

- The granules retain a permanent elasticity, they swell by absorbing water, retract by feeding the plants, swell up on contact with the slightest humidity ... and so on for years. Regenerated, the material retains its nutritive properties, thus remaining a constant reserve of food for plants regardless of the nature of the soils exploited.

- This effect of "accordion" resulting from the alternation of expansions and contractions ensures aeration of the grounds and an oxygenation of the roots which develop without mold. Crops become possible in compact soils (clay) which see their hydro-dynamics changed.

- The regular availability of water and nutrients in the granules have, as a consequence, a more vigorous development of the plants with a larger volume of root masses and leaf masses.

- The incorporated reserve of nourishing material favors the germination of seeds, the taking of seedlings and the transport of young plants. It facilitates their integration into their new environments during subcultures (thanks to the crystals in which their roots plunge). These seedlings have, moreover, a greater robustness than that of seedlings from common lands.

- We can estimate an average of 80% savings in irrigation water compared to the needs of conventional crops.

- The saving in irrigation equipment (in the case of new installations) can be estimated at 50%, allowing a doubling of the Irrigated areas with existing installations.

- There is a very significant saving in fertilizers: the application of 10 to 30 grs / m ² of product according to the invention transforms a poor, sandy or rocky soil, into a soil which will have the same fertility and water holding capacity as the best cropland.

- We save on the preliminary work required to improve the soils of desert areas.

- We can expect savings of more than 50% on the labor required for most stages of cultivation (plowing, irrigation, etc.).

- The invention allows fixing of sandy soils (dunes) or sloping (embankments, mountains) by the development of root masses whose power and volume are much greater than those encountered in conventional crops in universal soils.

- This large root mass makes it possible, after a period of the order of 7 years and according to the natural process of biological decomposition, the transformation of a poor, sandy or rocky land into a rich arable land.

- It becomes possible to carry out the development, fixation and regeneration of trees in difficult, shallow or sloping soils.

- The plants, cultivated with the product, present a robustness, a force, a resistance to the diseases - optimal - with as a consequence a saving in insecticides and in products of disinfection of grounds.

- The use of the product is very easy: it is within the reach of farmers around the world; it does not require any high agricultural technology and allows natural cultures in all seasons, except greenhouses, and without fear of the periods of drought ... even in arid zones.

- Seedlings (flowers, vegetables requiring transplanting), food for animals, can be grown on any surface (in plastic, for example) with only granules according to the invention.

- Certain plants (rice, barley, certain varieties of clover, etc ...), certain trees (olive tree, orange tree, jojoba, etc ...), will be able to receive an irrigation in sea water - or in brined water -; in this case, the granules according to the invention will selectively absorb water alone (pH 4 to 9): they will create "food chambers" in which the roots will be immersed, which will thus be protected from the ravages of salt.

- All plants cultivated with the product according to the invention retain a natural biological composition.

The product according to the invention as defined above in accordance with claim 1 lends itself to various embodiments set out in claims 2 to 10.

In accordance with claims 2 and 3, use may be made, within the scope of the invention, of one or other of the polymers already known in the prior art for their ability to absorb and retain water in relatively large quantities. important, whether of the sodium acrylate type or of the acrylamide type. An important criterion of orientation of the choice will therefore be the swelling capacity of the product.

However, according to a development of the invention set out in claim 4, it is advantageous to mix with the polymer hydrogel itself a certain amount of cellulose starch, the presence of which in the hydrogel mass has the effect of modifying the structure physics of this mass, in particular giving it a more favorable behavior at low temperatures. This appears to be due to the ability of the starch grains to split the gel mass into areas between which air circulation passages remain. Claim 5 places the amount of water linked to the product according to the invention between 2.5 and 10% by weight relative to the polymer: experience justifies these limits by showing that below the lower limit of 2.5% , the manufacturing cost can become prohibitive while beyond the upper limit of 10%, there appears a tendency to agglomeration of the hydrogel grains.

Claims 6 and 7 respectively set out preferred compositions for the balanced fertilizer on the one hand, and for all the trace elements on the other hand.

The dose of fertilizer to be provided at the time of manufacture of the product according to the invention may vary depending on the nature of the applications envisaged: it may typically be of the order of 25% of the initial composition in the case of a current product. This proportion could be increased, for example to 40% or even 50% in the case of products suitable for certain types of soil or crops.

A particular type of composition is set out in claim 8 for a product intended for use in desert areas.

The performance of such a product can be further improved to a surprising extent by the arrangements set out in claims 9 and 10, especially in the case of desert soils with high sunshine.

The subject of the invention is also a new industrial product constituted by a coated seed as defined in claim 11. These products are intended to face the problems of crops based on rare seeds with the advantages of avoiding practically any loss of rare seeds, improved germination conditions and better plant development. An additional source of progress may be constituted by protection against parasites according to the improvement set out in claim 12.

The invention finally also encompasses the processes for preparing the various products previously considered.

Such a process is generally stated in claim 13 with the two options recalled in claims 14 to 16 for the choice of the hydrogel.

According to claim 17, the drying of the final product is carried out at a drying current temperature below 100ºC.

However, and this is the subject of claim 18, the drying can also be carried out with a stream of hot air of temperature significantly above 100 ° C; this possibility which can lead to faster and more economical manufacturing conditions results from the discovery of the surprising fact that the hydrogel impregnated with liquid fertilizer according to the process of the invention is capable of withstanding temperatures without altering its properties. very much higher than 100 ° C; thus it was possible to locate at 564 ° C the melting temperature of an example of a polymer hydrogel impregnated with liquid fertilizer according to the process of claim 19.

The characteristics and advantages of the invention will become more apparent from the following description of certain embodiments and applications to be considered as non-limiting examples.

Example 1. Preparation of a product according to the invention

7.5 kg of a crosslinked sodium acrylate gel in granules, having a water-absorbing capacity of at least 500 times by weight of the dry polymer, are taken at pH between 6 and 8. Such an acrylate gel is manufactured by LEON BECK under the commercial designation "GRAIN D'EAU". This gel is spread in a relatively thin layer, and 2.5 liters of a 4-5 / 5-6 NKP fertilizer containing 160 g of solids is sprayed on this thin layer with a regular surface density.

Potassium oxide 60 g (37.5% solids by weight)

Phosphoric anhydride 50 g (31.5% solids by weight)

Combined nitrogen 40 g (25% solids by weight)

Trace elements about 10 g (6%) QSP water 1 liter

The trace elements being in the following weight proportions:

Mn 20% Mg 20%

Zn 5% B 8%

Mo 5% Cu 17%%

Fe 25%

The acrylate, after complete absorption of the liquid fertilizer, is dried in a hot air blow dryer, at 70ºC, until the quantity of water retained has decreased to 5% by weight of the dry gel, this which corresponds, for the present example, to a moisture loss of 1,725 g. 8.2 kg of granules are thus obtained which are packaged.

Example 2. Usage tests

Tests were carried out on two plant species, namely:

- a grass, Ray-Grass Westerwald, and

- a legume, clover from Alexandria or Bersim.

We used pots of about 24 liters, simulating 0.1 m ² of cultivated soil worked at

25 cm deep approximately. These pots were filled with two types of soil, deliberately not very fertile or infertile, in this case, a first type consisting of equal parts, poor, gravelly soil, normally provided with humus, and neutral silica sand (Fontainebleau sand); and a second type consisting solely of Fontainebleau sand, with no organic matter contained. This Fontainebleau sand had a particle size of 52% fine sand and 48% medium sand, fine and medium sands corresponding to the usual definitions in agronomy.

In a first series of pots, 4 g of product was added according to Example 1, intimately mixed with the part of the soil which occupies the upper half of the height of the pot. In a second series, 2 g of product were added according to Example 1. A third series, forming a control, did not receive any product.

The plant species were transplanted, at the seedling stage with 4 true leaves, at the rate of 4 plants of the same species, per pot.

Watering was carried out every seven days, at an average of 1 liter per pot. The trial lasted 63 days. However, for the first series, watering stopped after the 7th day, and on the other series, after the 49th day.

At the end of the test, the qualitative color examinations of the plants and their turgidity showed a clear advantage of the first series over the second, the control series being frankly less good than the second series. The type of soil made up of a mixture of poor soil and sand proves to be superior to pure Fontainebleau sand. However, the incorporation of the product according to Example 1 into Fontainebleau sand brings a spectacular improvement in color and turgor. The qualitative observation of the average growth of plants corroborates the previous results:

The tillering of the plants gives on average, for the first series, 7 to 9 tillers per plant at the start, for the second series of 5 to 7 tillers and the control series of 3 to 5 tillers.

Measurements of the aerial parts of the plants showed that, in the first series of pots, the aerial parts of the plants at the end of the tests were practically equal for the two types of soil, than for the second series of pots, the aerial parts of the plants with Fontainebleau sand alone were slightly inferior to plants in the mixture of poor soil and sand, while in the control series, the growth retardation was considerable for Fontainebleau sand.

In addition, for grasses, the first series showed an average height of 380 mm, a leaf width of 9 mm and a sheath height of

60 mm, the second series a height of 340 mm, a sheet width of 7 mm and a sheath height of 55 mm. The third comparison series shows an average height of 255 mm, a sheet width of 6 mm and a sheath height of 50 mm.

When we consider the root masses, we find an increase in mass for the first series of pots compared to the control series, which goes from 2 to 9. This result is particularly interesting, because the formation of humus is related direct with the previously developed root mass.

Example 3. Preparation of a product of the invention

The procedure is as in Example 1, replacing the sodium acrylate with a polyacrylamide with a water absorption capacity of approximately 600 times and sold by SONY under the name "STOCK 2000".

The product obtained, used as in Example 2, showed comparable results. Example 4.

A product is prepared as in Example 1, however replacing 1.5 kg of sodium acrylate with 750 g of a cellulose copolymer with an acrylic monomer and 750 g of a starch copolymer and a acrylic monomer. After impregnating a liquid fertilizer and drying, a product with a higher water absorption capacity is obtained.

Example 5. Preparation of a Product for Use in a Desert Zone

In a solid material mixer, successively:

5 kg of a cellulose copolymer and an acrylic monomer;

5 kg of a starch copolymer and an acrylic monomer;

5 kg of a copolymer of sodium acrylate and acrylamide;

45 kg of sodium acrylate as in Example 1. After careful mixing of the preceding components, the mixture is spread out in a thin layer on which 15 liters of 4-5 / 5-6 liquid fertilizer are sprayed, such as 'in Example 1; after which the whole is passed through a mixer for complete homogenization.

After the liquid fertilizer has been completely absorbed by the mixture of the preceding hydrogels, the mixture is brought to an air dryer at approximately 50 ° C, until the mass consists of separate, non-clumping grains.

The mixture thus dried is poured onto a conveyor belt to regularly add:

10 kg of a granulated delayed action fertilizer, comprising substantially by weight: P ₂ O ₅ 10%

Total nitrogen compounds 17% (of which NH ₄ 6.5%,

NO ₃ 5.5%, urea 5%)

K ₂ O 12.3%

0.24% trace elements (with a

relative composition as in Example 1)

Mineral binder the rest

Then 5 kg of a granular supplement fertilizer comprising:

P ₂ O ₅ 8%

K ₂ O 10%

Total nitrogen compounds 15% (of which NH ₄ 9%, urea 4%, NO ₃ 2%)

Trace elements (Mn, Mg) 0.1%

Then 7 kg of granulated organic fertilizer;

Then 1 kg of blue algae (nitrogen fixator), 1 kg of yeast of nitrifying bacteria with 2% silver nitrate, 1 kg of sulfur in flower and 1 kg of quicklime.

After intimate mixing of the components, in a mixer the product is dried in a hot air dryer between 50 ° and 80 °, until the water content by weight of the hydrogels is between 2.5 and 10%.

The product thus prepared has proven to be very effective in desert type soils, without any humus. In particular, in tests similar to those mentioned in Example 2, the product according to the present example in the second type of soil (pure Fontainebleau sand) gives results which are practically superior to those of the product according to Example 1 or Example 3 in the first type of soil (mixture 50% poor soil, 50% silica sand).

Example 6. Other preparation of a product for use in a desert area

The same products are used as in Example 5, but the sequence of operations is different. In a solid material mixer, 5 kg of each of the copolymers and 45 kg of sodium acrylate are mixed.

In another mixer, the previously ground materials are placed: 10 kg of granulated delayed-effect fertilizer, 5 kg of additional granulated fertilizer, 7 kg of organic fertilizer, 1 kg of blue-green algae, 1 kg of yeast nitrifying bacteria, 1 kg of sulfur in flower and 1 kg of quicklime; the mixture being in action, 45 liters of liquid fertilizer 7-8 / 8-9 are added, and the mixing is continued until a liquid of uniform consistency is obtained.

The hydrogel mixture is spread out in a thin layer, on which the fertilizer liquid is spread uniformly, and the whole is passed through a mixer until homogeneity is optimized.

After that, the homogenized mass is dried in a current of hot air between 60 ° and 80ºC.

The product thus prepared gave results superior to those of the product according to Example 5.

However, in the event of excess irrigation water, or heavy thunderstorm precipitation shortly after sowing, the product according to the present example gave results very close to those obtained without excess water in the first time, while the product according to the example

5 showed slightly lower results in the presence of excess water at the start of sowing. The result thus obtained by the product according to the present example is explained by the reduction of the percolation of the nutritive matters in the soil with the drainage water thanks to the incorporation of the fertilizer in the hydrogel.

Example 7. Preparation of a product for desert soils with high insolation

A product is prepared as in Example 5 or 6, but the copolymer and sodium acrylate solids are poured before mixing in the mixer solid matter, 200 ml of an elixir, capable of promoting the rise of the sap in plants, and the reduction of water evaporation by the leaves. This elixir is prepared in the following way:

7 liters of demineralized water, 300 g of powdered absinthe, 100 g of ginseng root, 160 g of thyme, 3 g are introduced into a ceramic fire-resistant container of about ten liters. of chamomile, 7 g of mint, 2 g of aloe powder, 1 g of myrrh, 3 g of camphor, 0.4 g of saffron, 3 g of senna leaf, 3 g of rhubarb root, 3 g of manna, 3 g of zedoaire root, 3 g of venetian theriac, 1 g of carline root and 3 g of angelica root, bring to the boil and keep at a gentle boil for about 40 minutes, transfer the warm decoction in a clear glass container with a narrow neck, 2.4 liters of 50% by volume ethanol are added, the glass container is hermetically sealed, and this container is placed in a location exposed to solar radiation for approximately 90 days , or about 1,000 hours of daylight.

Example 8 Preparation of coated seeds A hydrogel-fertilizer product analogous to the product according to Example 1 is prepared with a liquid fertilizer comprising, in active substances 3 parts of nitrogen compounds, 2 parts of potassium oxide and 2 parts of phosphoric anhydride, these active substances representing 7% by weight of the final product, the hydrogel of which is sodium acrylate.

Capsules are used in two interlocking parts, a receptacle and a cover, made of water-absorbent and water-soluble gelatin, of the type of capsules used in the pharmaceutical industry.

In the receptacle part, a quantity of the hydrogel-fertilizer product is first placed in an amount corresponding to a volume of between 25 and 45% of the interior volume of the capsule, then a mature seed of a selected seed of a hybrid but, we add a new quantity of hydrogel-fertilizer substantially equal to the first, and finally we close the capsule.

When the capsules are sown, humidity causes the capsule to disintegrate, followed by swelling of the hydrogel. The seed is thus placed in an environment favorable to its germination.

Corn seeds can be replaced by other cereal seeds, or other plants.

In addition, it will often be advantageous to add to the hydrogel-fertilizer, during its preparation, a pesticide suitable for specific pests of the plant of which the seed is coated. We will quote for example the

"Deltamethrin" and the "Toxaphen".

Of course, the preceding examples cannot be exhaustive, and are subject to variations; thus Example 8 was repeated with the different types of products mentioned above.

From this point of view, the drying rate of the base hydrogel, or of the hydrogels, can vary between 2.5% and 10% of residual water; below 2.5%, the energy expenditure for the evaporation of the absorbed water becomes excessive, and there is a risk of making part of the hydrogel incapable of reabsorbing water. At more than 10% water, the hydrogel grains may clot, especially if the packaging is not strictly tight against water vapor, while the mass of the product increases with the same mass of active product, this which can increase the transport costs without advantages in return.

From another point of view, drying air temperatures were given. Now it must be understood that it is essentially the temperature of the air at the end of drying, where the saturated vapor content is substantially in equilibrium with the hydrogel at the desired dryness rate. At the start of drying, the drying air may be, at the inlet of the dryer, at a temperature much higher than 100 ° C., the loss of water from the hydrogels causing cooling of the air in contact with these hydrogels so that they are not damaged.

Claims

1. Product intended to allow cultures under infertile conditions, alone or mixed with a soil, comprising a polymer hydrogel capable of absorbing and fixing water in an amount at least an order of magnitude greater than the weight of the polymer, characterized in that it comprises, of origin, a limited amount of water bound to the polymer, and, in solution in this limited amount of water, a balanced fertilizer comprising potash, phosphorus and nitrogen, and a significant amount of trace elements.

2. Product according to claim 1, characterized in that the polymer constituting the hydrogel is a crosslinked sodium acrylate per se known.

3. Product according to claim 1, characterized in that the polymer constituting the hydrogel is an acrylamide per se known.

4. Product according to claim 1, 2 or 3, characterized in that the hydrogel is supplemented by an addition of cellulose starch.

5. Product according to any one of the preceding claims, characterized in that the said quantity of water bound to the polymer is between 2.5 and 10% by weight relative to the polymer.

6. Product according to any one of claims 1 to 5, characterized in that the fertilizer comprises, in a quantity by weight based on the total weight of the active constituents:

K ₂ O 37.5%

P ₂ O ₅ 31.5%

Nitrogen compounds 25.0%

Trace elements 6%

7. Product according to claim 6, characterized in that the trace elements comprise, by weight relative to the total weight of the elements, approximately Mn 20% Mg 20%

Zn 5% B 8%

Mo 5% Cu 17%

Fe 25%

8. Product according to claims 1 to 3 taken together, intended for use in desert areas, characterized in that it comprises, in weight shares:

45 of crosslinked sodium acrylate;

A polymer blend comprising in equal parts, a cellulosic polymer, a starchy polymer, and a copolymer of potassium acrylate and acrylamide;

7 organic fertilizers;

15 balanced solid fertilizers comprising potassium, phosphorus and nitrogen, with trace elements;

1 blue algae;

1 bacteria yeast 2% silver nitrate;

1 of sulfur in bloom;

1 quicklime.

9. Product according to claim 8, characterized in that it contains an effective amount of an elixir obtained by maceration in a mixture of water and alcohol at 1-3% by volume of ethanol, per liter, of 30 g of wormwood powder, 10 g of ginseng root, and 16 g of thyme.

10. Product according to claim 9, characterized in that it was further macerated in the mixture of water and alcohol, per liter, 0.3 g of chamomile, 0.7 g of mint, 0 , 2 g aloe powder, 0.1 g myrrh,

0.3 g of camphor, 0.04 g of saffron, 0.3 g of senna leaf, 0.3 g of rhubarb root, 0.3 g of manna, 0.3 g of zedoaire root, 0, 3 g of Venetian theriac, 0.1 g of carline root and 0.3 g of angelica root.

11. Seed coated in application of a product according to any one of claims 1 to 10, characterized in that it comprises:

- a capsule in two nested parts, consisting of water-absorbent and water-soluble gelatin;

- at least one mature seed of a chosen plant species;

- An amount of said product sufficient to fill at least 50% by volume of the capsule, the seed being maintained substantially in the center of the capsule.

12. coated seed according to claim 11, characterized in that the capsule also contains an effective amount of a toxic product suitable for specific parasites of the chosen plant species.

13. Process for the preparation of a product intended to allow cultures under infertile conditions, alone or in mixture with a soil and comprising, for the most part, a hydrogel capable of absorbing and fixing water in a quantity greater than at least minus an order of magnitude by weight of polymer, process characterized in that one to four parts of hydrogel are mixed with one part of a balanced liquid fertilizer comprising potassium, phosphorus and nitrogen with trace element metals, then dry the mixture in a stream of hot air.

14. The method of claim 13, characterized in that the hydrogel is a crosslinked sodium acrylate.

15. The method of claim 13, characterized in that the hydrogel is an acrylamide.

16. Method according to claim 13, characterized in that the hydrogel is composed of copolymer of cellulose and of an acrylic monomer, copolymer of starch and of an acrylic monomer, copolymer of sodium acrylate and of acrylamide, cellulose starch.

17. The method of claim 13, 14, 15 or 16, characterized in that the temperature of the drying air stream is between 50 ° and 80 ° C.

18. The method of claim 13, 14, 15 or 16, characterized in that the temperature of the hot air stream is greater than 100ºC.

19. Method according to any one of claims 13 to 18, characterized in that the liquid fertilizer contains, in weight percentages:

K ₂ O 1.5%

P ₂ O ₅ 1.25%

1% nitrogen compounds

0.05% Mg

Mn 0.05%

Zn 0.01%

B 0.02%

Mo 0.01%

Cu 0.04%

Fe 0.06%

20. Process for the preparation of an elixir intended for a product according to one of claims 9 and 10, characterized in that the components to be macerated corresponding to 10 liters of elixir are introduced into a ceramic receptacle going to the fire with 7 liters of water, the mixture is heated to boiling and the boiling is maintained for approximately 40 minutes, the contents are transferred to a glass container, 2.4 liters of 50% ethanol by volume are added , the glass container is sealed and placed in a location exposed to solar radiation for approximately 90 days.

21. The method of claim 13 for the preparation of a product according to any one of claims 8, 9 and 10, characterized in that all of the additives comprising organic fertilizers, balanced solid, blue algae, yeast of bacteria, sulfur, lime, is mixed with the part of equilibrated liquid fertilizer ibré before the operation of mixing with the hydrogels.