Composition comprising a biochar and an aqueous extract of a seed legume

Abstract

Composition comprising a biochar and an aqueous extract of a seed legume. The present invention relates to a composition comprising a biochar and an aqueous extract of a seed legume, a method for preparing said composition and the use of the composition to promote seed germination, to improve the nutrient utilization efficiency of a seed, to promote seedling development and to improve seedling tolerance to abiotic stress.

Description

Title of the invention: Composition comprising a biochar and an aqueous extract of a seed legume technical field

[0001] The present invention relates to the field of agriculture. In particular, the invention relates to a composition comprising a biochar and an aqueous extract of a legume, a method for preparing said composition, and the use of the composition to stimulate seed germination in agriculture. Prior art

[0002] Biochar is a carbonaceous material produced by the controlled combustion of biomass such as wood waste, crop residues, garden waste, etc., in a low-oxygen environment. It is a porous and stable material commonly used in agriculture as a natural fertilizer for cultivated soils. Its effects include retaining moisture, reducing the risk of soil leaching, capturing CO2, and conserving nutrients. The use of biochar in agriculture therefore helps create a favorable ecosystem for plant growth [1].

[0003] The effect of biochar on increasing plant growth and yield is well documented, and biochars are commonly used in agriculture to promote plant growth and yield. However, few studies have investigated the influence of biochar on the early stages of plant growth, and in particular on seed germination.

[0004] The application of biochar to the soil impacts the mineralization of soil organic matter, which is linked to the release of nutrients such as nitrogen. This change in the soil's nutrient status can affect seed germination as well as seedling growth [2].

[0005] Seed germination is a complex phenomenon regulated by endogenous and exogenous factors such as hormones, seed maturity, dormancy, and also humidity and sunlight levels. Successful germination is key to the formation of a germinated plant that can develop into a healthy and productive plant.

[0006] Most studies concerning the effect of biochar on stimulating or inhibiting seed germination focus on forest plants [3, 4, 5, 6]. Regarding agricultural plants, some studies have demonstrated improved seed germination through the application of biochar, for example, for potato or wheat seeds [7, 8]. Other studies, however, have shown Studies have shown little to no effect of biochar application on the germination and early growth of seeds such as maize seeds [9]. For example, the study by Oh et al.

[10] investigated the effect of an aqueous extract of various biochars (orange peel, wood, wastewater sludge) on seedling germination and growth, finding little or no significant effect of these extracts on the germination and growth of lettuce seeds. Other studies have demonstrated a phytotoxic effect of certain biochars and biochar extracts, particularly on the germination and growth of seedlings of plants such as rice and maize, due to the presence of reactive oxygen species and / or conventional contaminants such as heavy metals within these biochars

[11] .

[0007] There is therefore a need to develop new biochar-based compositions that promote seed germination and plant seedling growth.

[0008] To this end, the Applicant has developed a composition comprising a biochar and an aqueous extract of a seed legume, the application of which has the effect of promoting seed germination, improving the efficiency of nutrient use in a seed, increasing enzymatic activity within a seed, promoting seedling development and finally improving seedling tolerance to abiotic stress.

[0009] The present invention derives from the advantages highlighted by the inventors of the association of a biochar and an aqueous extract of a seed legume, in particular the effects of a composition comprising a biochar and an aqueous extract of a seed legume on the germination of a seed, the increase of enzymatic activity within said seed, the development of a seedling and the tolerance of a seedling to abiotic stress. Summary of the invention

[0010] The present invention, which has applications in the field of agriculture, proposes a new composition comprising a biochar and an extract of a grain legume, a process for preparing said composition and the use of this composition to promote the germination of a seed, to improve the efficiency of use of nutrients of a seed, to increase enzymatic activity within a seed, to promote the development of a seedling and finally to improve the tolerance of a seedling to abiotic stress.

[0011] According to a first object, the invention relates to a composition comprising a biochar and an aqueous extract of a seed legume.

[0012] According to a second object, the invention relates to a method for preparing a composition according to the first object of the invention, comprising a step which consists of mixing a biochar with an aqueous extract of a seed legume in order to obtain a suspension.

[0013] According to a third object, the invention relates to the use of a composition according to the invention to promote the germination of a seed. Detailed description

[0014] Definitions

[0015] The term “biochar” refers to a carbonaceous material produced by the controlled combustion of biomass such as wood waste, crop residues, garden waste, etc., in a low-oxygen environment. The biochar production process, also known as pyrolysis, creates a porous and stable carbonaceous material that can be used in various applications. Biochar can be prepared by heating the biomass to a temperature of 300°C to 700°C for 1 to 2 hours in an atmosphere with an oxygen content of less than 1%, then cooling and grinding the mixture to obtain a particle size of less than 2 mm, for example, a particle size of 0.5 mm to 2 mm. The website www.european-biochar.org provides a summary table of biomasses that can be used to produce biochar according to the desired use (Table “Positive List of permissible biomasses for the production of biochar”: https: / / www.european-biochar.Org / media / doc / 2 / positive-list_en_vl0_3.pdf )• .

[0016] In the context of the present invention, the term "extract" refers to the product resulting from the extraction of compounds contained in a plant. Extraction methods are widely described in the literature and are easy for those skilled in the art to carry out. For example, an aqueous extract can be obtained by aqueous extraction in acidic, neutral, or alkaline media at various temperatures, or by using a solvent. In all cases, the extraction conditions are determined according to the characteristics of the compounds to be extracted and their location in the different organs of the plant.

[0017] The term "seed legume" or "Fabaceae" refers to a family of dicotyledonous plants in the order Fabales. This family comprises approximately 765 genera encompassing more than 19,500 species. Fabaceae, in a broad sense, are herbaceous plants, shrubs, trees, or vines. In the context of the invention, the legume of the Fabaceae family may be from the subfamily Faboideae. Preferably, the seed legume used in the invention belongs to the family of legumes, such as soybeans, beans, peas, chickpeas, broad beans, lentils or broad beans.

[0018] In this description, the terms "legume extract" and "seed legume extract" are interchangeable.

[0019] The term "permeate" refers to the liquid that has passed through the membrane in a physical separation process (reverse osmosis, ultrafiltration). For example, a soybean permeate refers to the liquid that has passed through the membrane in a physical separation process from a soybean extract (e.g., a soybean fiber extract or a soybean pulp extract). A soybean permeate can be obtained by ultrafiltration of soybean wash water as described in the 2011 Plant Science Review by David Henning.

[0020] The term "dry extract of seed legume" refers to the solid matter remaining after complete dehydration of an aqueous extract of seed legume, for example by heating, freeze-drying, or nebulization. A dry extract of seed legume has a moisture content of no more than 3% by weight of the total dry extract.

[0021] The term "plant seed" or "plant seed" refers to the dormant plant organ that results from the fertilization and development of the ovule in a flowering plant, and which is capable, after germination, of producing a plant.

[0022] The "germination of a seed" is a complex process involving a series of biochemical reactions that transform a dormant seed into an embryonic plant and then into an adult plant. The first organ to develop is the radicle, followed by the stem, which may bear embryonic leaves called cotyledons. Multiple internal and external factors influence germination, such as the type of seed, the age and dormancy status of the seed, as well as soil temperature, humidity, light, and oxygen levels. Germination begins with the imbibition of water in the seed, causing it to swell and activating hydrolytic enzymes. The food reserves stored in the seed are broken down by these enzymes, thus releasing the nutrients necessary for the growth of the embryo.

[0023] Enzymatic activity within the seed is a fundamental element for germination because enzymes break down the energy reserves within the seed, thus making nutrients available and assimilable by the seedling. In particular, we can refer to phytases, which degrade phytic acids to produce phosphate, proteases, which degrade proteins, and also amylase and lipases, which respectively degrade carbohydrates and lipids to produce carbon compounds. During this phase of germination, the seedling is said to be heterotrophic because it uses the nutrients present in the seed; this is followed by an autotrophic phase where the young plant will to be able to produce its own organic matter from nutrients present in the environment, in particular mineral salts.

[0024] The terms "nutrients of a seed" correspond to the nutrient reserves present in the seed such as phytates, carbohydrates, lipids, proteins.

[0025] The terms "improve the efficiency of nutrient use of a seed" mean increasing the assimilation of products generated by the activity of hydrolytic enzymes in the seed such as phosphorus, carbon, nitrogen, proteins, amino acids, lipids, macro-elements and micro-elements by the seedling.This utilization efficiency can be monitored, for example, by measuring i) the quantity of products generated by hydrolytic enzymes, namely the quantity of phosphorus, particularly in the form of phosphate, carbon and / or nitrogen, proteins, amino acids, lipids, macro-elements and micro-elements, and / or ii) the rate of emergence of the radicle, hypocotyl and / or stem bearing the cotyledons, and / or iii) the rate at which the plant transitions from heterotrophy to autotrophy, for example, by monitoring the emergence of the first leaves, and / or iv) the acceleration and / or increase in seedling development, for example, the acceleration of emergence and / or the increase in the volume of root and / or leaf biomass of the seedling.

[0026] In the context of the invention, the terms "promote the germination of a seed" mean i) increasing the activity of one or more of the hydrolytic enzymes present in the seed, namely phytase, amylase, lipase and / or proteinase; and / or ii) increasing the amount of products of said hydrolytic enzymes, namely the amount of phosphorus, carbon and / or nitrogen, proteins, amino acids, lipids, macro-elements and micro-elements; and / or iii) accelerating the appearance of the hypocotyl, the stem bearing the cotyledons and / or the seedling; and / or iv) accelerating the rate at which the plant transitions from heterotrophy to autotrophy, for example by following the appearance of the first leaves; and / or v) accelerating the appearance and / or increasing the volume of the root and / or aerial biomass of the plant.

[0027] The term "soil" refers to the substrate explored by the roots of cultivated plants. The term "soil" includes any type of substrate on which a plant can grow, such as, for example, artificial soil, cultivated agricultural soil, uncultivated agricultural soil, peat, potting soil, rockwool, or coconut fiber. The term "soil" therefore also covers growing media, which can be used, in particular, for so-called "soilless" cultivation, for example, in pots.

[0028] In the context of the invention, "phytase activity" refers to the enzymatic activity of phytases. Phytases, which are hydrolytic enzymes present in the seed, hydrolyze the phytates present in the seed to produce phosphorus in the form of phosphates. Thus, the increase in phytase activity can be measured (i) by an increase in the amount of phosphates, particularly in the root and / or aerial parts of the plant, and / or (ii) by a decrease in the amount of phytates in the seed. Methods for measuring the amount of phosphate and / or phytates are detailed in the experimental section.

[0029] “Promoting seedling development” refers to the ability i) to increase the volume of the seedling's root biomass and / or aboveground biomass, and / or ii) to accelerate the emergence of the seedling's hypocotyl and / or the stem bearing the seedling's cotyledons and / or the seedling's leaves, and / or iii) to accelerate the seedling's transition from heterotrophy to autotrophy, for example, by following the emergence of the seedling's first leaves. "Seedling water use efficiency" refers to a seedling's ability to efficiently use the water available in the air and / or in the growing medium for its growth. This water use efficiency can be monitored by measuring the seedling's actual evapotranspiration, which is the sum of the seedling's transpiration and the direct evaporation of water from the soil. This water use efficiency can be measured by the amount of biomass produced per unit of water consumed.

[0030] “Abiotic stress” refers to suboptimal growth conditions for a plant caused, for example, by water stress (drought or excess water), salt stress, or extreme temperatures. In particular, within the scope of the invention, the abiotic stress considered is water stress, and preferably low soil moisture content.

[0031] The composition according to the invention can be considered as a "biostimulating composition", that is to say a composition which stimulates the nutrition processes of plants independently of the nutrients they contain, for the sole purpose of improving one or more of the following characteristics of plants or their rhizosphere: a) the efficiency of nutrient use; b) tolerance to abiotic stress; c) qualitative characteristics; d) the availability of nutrients confined in the soil or rhizosphere.

[0032] In the context of the invention, the composition is said to be "biostimulating" in the sense that it allows, for example, to promote the germination of a seed and / or to improve the efficiency of use of nutrients of a seed and / or to increase the enzymatic activity within a seed and / or to promote the development of a seedling and / or to improve the tolerance of a seedling to abiotic stress.

[0033] Composition according to the invention

[0034] The first object of the invention relates to a composition comprising a biochar and an aqueous extract of a seed legume.

[0035] The Applicant has observed that mixing a biochar with an aqueous extract of a legume with seeds promotes seed germination, increases the activity of hydrolytic enzymes within a seed, improves the efficiency of nutrient use in a seed, promotes the development of root and / or aerial biomass in a seedling, and improves the tolerance of a seedling to abiotic stress, in particular water stress.

[0036] All of these effects are illustrated in the experimental part of this patent application.

[0037] In a particular embodiment, the composition is in liquid form.

[0038] In a particular embodiment, the composition comprises between 1% and 10% in dry weight of biochar relative to the total weight of the composition and / or between 90% and 99% by volume of seed legume extract relative to the total volume of the composition.

[0039] In a particularly preferred embodiment, the composition according to the invention comprises 5% by dry weight of biochar relative to the total weight of the composition and 95% by volume of seed legume extract relative to the total volume of the composition.

[0040] In a particular embodiment of the invention, the composition is in solid form.

[0041] In a particular embodiment, the seed legume extract is a dry extract having a moisture content of a maximum of 3%, preferably 2% and even more preferably 1% relative to the total weight of the dry extract.

[0042] In a particular embodiment of the invention, the composition in solid form comprises between 40% and 50% by weight of biochar relative to the total weight of the composition and between 50% and 60% by weight of dry extract of grain legume relative to the total weight of the composition.

[0043] In particular embodiments, the biochar is in solid form.

[0044] In particular embodiments, the aqueous extract of seeded legume is in solid form. In particular embodiments, the aqueous extract of the seed legume is in liquid form.

[0045] When the aqueous extract of seed legume is in solid form, an aqueous solution, preferably water, is added to the mixture in order to obtain a suspension.

[0046] When the aqueous extract of a seed legume is in liquid form, it is generally not necessary to add an aqueous solution to the mixture to obtain a suspension. However, an aqueous solution, preferably water, may be added to the mixture depending on the desired concentration of seed legume extract in the composition.

[0047] In a particular embodiment, the composition may be in liquid or solid form, for example as a suspension, solution, powder, or granules. According to a particularly preferred embodiment, the composition implemented in the invention is in the form of granules. In this particular embodiment, the composition is subjected to a dehydration step until a dry composition is obtained.

[0048] In a particular embodiment, the biochar used in the invention is produced from biomass originating from: - from agricultural operations, including residues and biomass deliberately cultivated for biochar production, or - forestry and wood processing methods, for example from natural, untreated or mechanically treated bark and wood from logging operations, sawmills or similar operations, or - in the field of landscape management, for example, waste generated by municipalities, landowners, landscape contractors, NGOs active in nature conservation, or - from the field of the recycling economy, for example biomass from organic residues and waste from industrial processes or from collection / separation by specific recycling companies, or - from the food industry sector, for example the plant-based food industry, wholesale food, supermarkets, food stores, or - from the marine domain, for example marine plant biomass such as aquatic plants and algae, or - in the field of wastewater treatment, for example sludge from municipal wastewater treatment or other water treatment.

[0049] In a particular embodiment, the biochar is chosen from: i. wood biochar, manure biochar, ii. straw biochar, iii. Bamboo biochar, iv. cocoa bean shell biochar, or v. a mixture of several biochars selected from (i) to (iv).

[0050] In a particular embodiment, the composition is in the form of a suspension of a biochar in an aqueous extract of a seed legume.

[0051] In a particular embodiment, the biochar has a moisture content of between 10 and 50%, preferably between 20 and 40%, preferably between 20 and 30%, preferably still between 20 and 25% relative to the total weight of the biochar.

[0052] In a particular embodiment, the biochar has an ash content of between 10 and 50%, preferably between 20 and 40%, preferably still between 20 and 30% relative to the total weight of the biochar.

[0053] The ash content of biochar corresponds to the content of inorganic matter or total solid mineral residue remaining when a biomass sample is burned in the presence of excess air.

[0054] In a particular embodiment, the biochar has an organic carbon content of between 50 and 90%, preferably between 60 and 85%, preferably between 65 and 80%, preferably still between 65 and 75% relative to the total weight of the biochar.

[0055] In a particular embodiment, the biochar has an H / Corg ratio ranging from 0.1 to 0.7, preferably an H / Corg ratio of 0.1.

[0056] In a particular embodiment, the biochar has an electrical conductivity (capacity to carry electricity) ranging from 10000 pS / cm to 15000 pS / cm.

[0057] In a particular embodiment, the biochar has a density ranging from 150 kg / m3 to 200 kg / m3, preferably ranging from 155 kg / m3 to 180 kg / m3, preferably ranging from 160 kg / m3 to 175 kg / m3, preferably ranging from 165 kg / m3 to 170 kg / m3, preferably again from 165 kg / m3.

[0058] In a particular embodiment, at least 50% by dry weight of the biochar has a particle size between 0.1 and 5 mm, preferably between 0.5 and 2 mm.

[0059] In a particular embodiment, at least 70%, preferably at least 80% and preferably still at least 90% by dry weight of the biochar has a particle size between 0.1 and 5 mm, preferably between 0.5 and 2 mm.

[0060] In a particular embodiment, at least 50%, preferably at least 70% by weight of the biochar has a particle size between 2 and 5 mm and at least 50%, preferably at least 30% by weight of the biochar has a particle size between 1 and 2 mm.

[0061] In a particular embodiment, the biochar is a biochar having the technical characteristics described in Table 1 below:

[0062] [Tables 1] Technical characteristics: Particle size 0.1-5 mm (80% of particles), 0.5-2 mm (20% of particles); pH 10-12.2; Organic carbon (OC) content 60-85%; H / OC ratio 0.5; Density 150 kg / m³ Electrical conductivity 13000 pS / cm

[0063] In a particular embodiment, the biochar is a biochar having the technical characteristics described in Table 2 below:

[0064] [Tables2] Technical characteristics: Particle size 2-5 mm (60% of particles), 1-2 mm (40% of particles); pH 10-12.2; Organic carbon (OC) content 65-80%; H / OC ratio 0.3; Density 160 kg / m³; Electrical conductivity 10,000-15,000 pS / cm

[0065] In a particular embodiment, the biochar is a biochar made from cocoa bean shells.

[0066] In a particular embodiment, the biochar is a cocoa bean shell biochar having the technical characteristics described in Table 3 below:

[0067] [Tables3] Technical characteristics: Particle size 2-5 mm (75% of particles), 1-2 mm (25% of particles); pH 10-12.2; Organic carbon (OC) content 65-70%; H / OC ratio 0.1; Density 165 kg / m³; Electrical conductivity 10,000-15,000 pS / cm

[0068] According to a particular embodiment, the biochar is a cocoa bean shell biochar whose chemical composition is described in Table 4 below: [Tables4] Chemical elements: Proportion by weight relative to the total dry weight of biochar C 10-50% N 1-5% by weight relative to the total weight of the biochar as is; P2O 1-5%; K2O 5-10%; Mg 1-5%; Ca 1-2%; S 0.1-1%; Si 1-5%

[0069] According to a particular embodiment, the biochar is a biochar made from cocoa bean shells whose chemical composition is described in Table 5 below: [Tables5] Chemical elements: Proportion by weight relative to the total dry weight of biochar: C 20-30%, N 1.69% by weight relative to the total weight of the biochar as is; P2O 1.1%, K2O 8.4%, Mg 1.3%, Ca 0.8%, S 0.2%, Si 2.5%

[0070] Within the scope of the invention, biochar can be obtained by any suitable pyrolysis technique. Pyrolysis processes for the production of biochar are widely described in the prior art, and those skilled in the art will encounter no difficulty in implementing them.

[0071] In a particular embodiment, the biochar is obtained by pyrolysis at a temperature ranging from 200°C to 700°C, preferably at a temperature ranging from 500°C to 700°C, for example at a temperature of 650°C. The pyrolysis time generally ranges from 1h to 2h.

[0072] In a particular embodiment, the aqueous extract of the seed legume is a seed legume permeate, preferably a soybean permeate. The permeate soy can be obtained by ultrafiltration of soybean wash water or a soy extract (e.g., a soy fiber extract or a soy pulp extract).

[0073] In a particular embodiment, the grain legume is chosen from: i. soybean, ii. the broad bean, iii. the lens, iv. the bean, v. the bean, vi. the pea, vii. the chickpea, or viii. a mixture of several leguminous seeds selected from (i) to (vii).

[0074] In a particular embodiment, the aqueous extract of seed legume is an aqueous extract of seed legume of the Fabaceae family, such as a soybean extract, a bean extract, a pea extract, a chickpea extract, a lentil extract and / or a broad bean extract.

[0075] Processes for preparing aqueous extracts of leguminous seeds are widely described in the literature. The processes classically used are applicable for the preparation of aqueous extracts of leguminous seeds, for example, aqueous extraction in acidic, neutral, or alkaline media.

[0076] Preferably, the aqueous extract of the grain legume is an aqueous soybean extract. For example, a soybean extract may be a soybean fiber extract, a soybean pulp extract, or a soybean permeate. In one particular embodiment, the aqueous extract of the legume from the Fabaceae family is a soybean extract, for example, an aqueous soybean extract, such as an aqueous soybean pulp extract. The aqueous soybean pulp extract may, for example, be obtained by mixing soybean pulp with water under stirring at a temperature between 20°C and 25°C and then removing the solid residues, for example, by membrane filtration.

[0077] The aqueous extract of a legume can be more or less concentrated by adding a solvent (e.g., water) or by dehydration. Complete dehydration of this extract, to obtain a dry extract, can, for example, be carried out using a drum dryer or by spray drying. The dehydrated extract can then be rehydrated to obtain a liquid extract.

[0078] In a particular embodiment, the composition is in the form of a suspension of a cocoa bean shell biochar in an aqueous soy extract, preferably a soy permeate.

[0079] Preparation process

[0080] A second object of the invention relates to a method for preparing a composition according to the first object comprising a step which consists of mixing a biochar with an aqueous extract of a seed legume in order to obtain a suspension.

[0081] In a particular embodiment, the aqueous extract of seed legume used can be processed at a temperature ranging from 50 to 80°C, preferably at a temperature ranging from 55 to 65°C, more preferably at a temperature ranging from 60 to 65°C.

[0082] This temperature makes it easier to mix the aqueous extract of the legume with the biochar and thus to make it easier to obtain a suspension.

[0083] In a particular embodiment, the mixing is carried out under agitation.

[0084] In a particular embodiment, the mixing is carried out at a temperature ranging from 50 to 80°C, preferably at a temperature ranging from 55 to 75°C, preferably even more at a temperature ranging from 60 to 65°C.

[0085] In a particular embodiment, the mixing is carried out until complete homogenization of the suspension.

[0086] In a particular embodiment, the mixing is carried out for at least 1h, preferably at least 2h.

[0087] In a particular embodiment, the invention relates to a method for preparing a composition according to the first object in which: i. the mixing is carried out under agitation, and / or ii. The mixture is prepared at a temperature ranging from 50 to 80°C, preferably at a temperature ranging from 55 to 75°C, and even more preferably at a temperature ranging from 60 to 65°C, and / or iii. The mixing is carried out for at least 1h, preferably at least 2h.

[0088] In a particular embodiment, the process includes a step of dehydrating the suspension obtained after mixing to obtain a composition in solid form.

[0089] The present invention also relates to a composition according to the first object of the invention which can be obtained by implementing the process according to the second object of the invention.

[0090] Use of the composition according to the invention

[0091] A third object of the invention relates to the use of a composition according to the invention to promote the germination of a seed.

[0092] In a particular embodiment, the germination of a seed located in a growing medium to which the composition according to the invention has been applied is increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, advantageously at least 30%, at least 35%, at least 40%, at least 45%, advantageously at least 50%, at least 55% compared to a seed that is in a culture soil on which the composition according to the invention has not been applied.

[0093] The present invention applies to any variety of plants. Examples include: - major crops such as cereals (wheat, corn, barley), - protein crops (peas), - oilseeds (soybeans, sunflowers), - Solanaceae crops (potatoes), - Amaranthaceae (beetroot) crops, - specialized crops such as in particular market gardening (lettuce, spinach, onion, shallot, tomato, melon), vines, arboriculture (pear, apple, nectarine), or horticulture.

[0094] In particular, the plant may belong to the order Monocotyledons, preferably to the family Poaceae. Poaceae, commonly known as grasses, include most of the species commonly called "grasses" and "cereals." Cereals are widely cultivated, primarily for their grains, and are used for human and animal consumption. Advantageously, the plant is a Poaceae, preferably selected from wheat, rice, barley, oats, rye, sugarcane, prairie grass, or maize, preferably maize.

[0095] The present invention also relates to the use of a composition according to the invention to improve the efficiency of nutrient use of a seed, preferably to improve the efficiency of phosphorus use.

[0096] More specifically, the phosphorus use efficiency of a seed is improved when i) the amount of phosphorus in the form of phosphate present within the seedling is increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, or at least 55% compared to a seed not treated with the composition according to the invention and / or ii) the rate of emergence of the radicle, hypocotyl, and / or stem bearing the cotyledons is increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, or at least 55% compared to an untreated seed with the composition according to the invention and / or iii) the rate at which the seedling transitions from heterotrophy to autotrophy is increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%,at least 45%, at least 50%, or at least 55% compared to an untreated seed with the composition according to the invention and / or iv) the rate of emergence and / or the volume of the root and / or aerial biomass of the seedling is increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least , 35%, at least 40%, at least 45%, at least 50%, or at least 55% compared to an untreated seed with the composition according to the invention.

[0097] In a particular embodiment, the use according to the invention makes it possible to: i. stimulate the hydrolysis of phytates in the seed, and / or ii. stimulate the transformation of phytates into phosphate, and / or iii. stimulate the enzymatic activity in the seed of one or more enzymes chosen from among a phytase, an amylase, a lipase and / or a protease, preferably a phytase.

[0098] In a particular embodiment, the enzymatic activity of one or more enzymes selected from among phytases, amylases, lipases, and / or proteases within the seed is increased by at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or 55% compared to a seed untreated with the composition according to the invention. The enzymatic activity can be measured, for example, by measuring the quantity of products generated by an enzyme, such as the amount of phosphate produced by phytases within the seed, or the amount of carbon compounds produced by amylase, lipases, and / or proteases. A suitable measurement method is described in the experimental section.

[0099] In a particular embodiment, the composition according to the invention stimulates the activity of phytases within a seed.

[0100] Preferably, the enzymatic activity of phytases within the seed is increased by at least 10%, preferably by at least 15%, at least 20%, or at least 25% compared to a seed untreated with the composition according to the invention. The increase in the enzymatic activity of phytases within the seed has the effect of stimulating the hydrolysis of phytates within the seed and / or stimulating the transformation of phytates into phosphate within the seed.

[0101] In a particular embodiment, the invention relates to the use of a composition according to the invention to stimulate the efficiency of use of phytates present in the seed.

[0102] Preferably, the quantity of phytates within the seed is reduced by at least 10%, preferably by at least 15%, by at least 20%, or by at least 25% compared to a seed not treated with the composition according to the invention.

[0103] According to one aspect of the invention, the reduction in the amount of phytates is observed within the seed. According to another aspect of the invention, the reduction in the amount of phytates is observed within the roots and / or the aerial parts of the plant.

[0104] In a particular embodiment, the composition according to the invention increases the amount of phosphate within a seedling compared to a seedling not treated with the composition according to the invention. Preferably, the amount of phosphate in the seedling's breast is increased by at least 10%, at least 15%, at least 20%, or at least 25% compared to a seedling not treated with the composition according to the invention.

[0105] According to one aspect of the invention, the increase in the amount of phosphate is observed within the roots and / or aerial parts of the seedling. According to another aspect of the invention, the increase in the amount of phosphate is observed within the seed.

[0106] In a particular embodiment, the composition according to the invention stimulates the activity of amylases (i.e. amylase activity) within a seed.

[0107] Preferably, the enzymatic activity of the amylases within the seed is increased by at least 10%, at least 15%, at least 20%, or at least 25% compared to a seed untreated with the composition according to the invention. The increase in the enzymatic activity of the amylases within the seed has the effect of stimulating the hydrolysis of starch within the seed and / or stimulating the transformation of starch into carbon compounds such as glucose within the seed.

[0108] In a particular embodiment, the composition according to the invention reduces the amount of starch within the seed compared to a seed not treated with the composition according to the invention.

[0109] Preferably, the amount of starch within the seed is reduced by at least 10%, at least 15%, at least 20%, or at least 25% compared to a seed not treated with the composition according to the invention.

[0110] According to one aspect of the invention, the decrease in the amount of starch is observed within the seed. According to another aspect of the invention, the decrease in the amount of starch can be observed within the roots and / or the aerial parts of the plant.

[0111] In a particular embodiment, the composition according to the invention increases the amount of carbon compounds within a seedling compared to a seedling not treated with the composition according to the invention. Preferably, the amount of carbon compounds within a seedling is increased by at least 10%, at least 15%, at least 20%, or at least 25% compared to a seedling not treated with the composition according to the invention.

[0112] According to one aspect of the invention, an increase in the quantity of carbon compounds such as glucose can be observed within the roots and / or aerial parts of the plant. According to another aspect of the invention, an increase in the quantity of carbon compounds such as glucose can be observed within the seed.

[0113] In a particular embodiment, the invention also relates to the use of a composition according to the invention to promote the development of a seedling, preferably in which the composition stimulates the development of the root and / or aerial biomass of the seedling.

[0114] In particular, the use of the composition according to the invention advantageously makes it possible to increase the volume of the root and / or aerial biomass of the seedling by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, or at least 55% compared to a seedling not treated with the composition according to the invention.

[0115] In a particular embodiment, the composition according to the invention makes it possible to increase the volume of the root biomass of a seedling by at least 25%, at least 30%, at least 40%, at least 50%, at least 60%, or at least 70% compared to a seedling not treated with the composition according to the invention.

[0116] In a particular embodiment, the composition according to the invention makes it possible to increase the volume of the aerial biomass of a seedling by at least 25%, at least 30%, at least 40%, or at least 50% compared to a seedling not treated with the composition according to the invention.

[0117] In a particular embodiment, the composition according to the invention makes it possible to accelerate the rate of seedling development. In particular, the composition according to the invention makes it possible i) to accelerate the appearance of the hypocotyl and / or the stem bearing the cotyledons and / or the leaves of the seedling, and / or ii) to accelerate the transition of the seedling from heterotrophy to autotrophy, for example by following the appearance of the first leaves.

[0118] The invention also relates to the use of a composition according to the invention to improve the water use efficiency of a seedling.

[0119] The invention also relates to the use of a composition according to the invention to improve the tolerance of a seedling to abiotic stress, preferably the abiotic stress being water stress or osmotic stress. Water stress can be drought or excess water.

[0120] The use of the composition according to the invention advantageously makes it possible to increase the tolerance of a seedling to water stress by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, or at least 55% compared to a seedling not treated with the composition.

[0121] The resistance of a plant to water stress can be assessed by measuring the root and / or aerial biomass of a plant and / or by quantifying the transpiration of a plant and / or by measuring the amount of aquaporins expressed at the level of the cell membranes of the plant.

[0122] The invention also relates to the use of the composition according to the invention to improve the resistance of a seedling to osmotic stress.

[0123] Osmotic stress, also known as "salt stress" in agriculture, corresponds to an increase in the concentration of salts in the soil. Salt stress reduces water absorption by the plant and generates water stress in the plant.

[0124] The resistance of a plant to osmotic stress can be assessed by measuring the root and / or aerial biomass of a plant and / or by quantifying the transpiration of a plant and / or by measuring the amount of aquaporins expressed at the membranes of the plant cells.

[0125] The experimental part of this application describes suitable measurement methods.

[0126] According to a particular embodiment, the composition according to the invention is applied to the soil at the time of sowing.

[0127] In another particular embodiment, the seed is brought into contact, for example by impregnation, with the composition according to the invention before sowing said seed. In this embodiment, the seed can be immersed in the composition according to the invention, for example for at least 2 hours, at least 4 hours, or at least 6 hours. A person skilled in the art will be able to adapt the duration of contact between the seed and the composition according to the invention according to the nature and condition of the seed.

[0128] In a particular embodiment of the use according to the invention, the composition according to the invention is applied to the soil in a quantity ranging from 1 to 100 kg / ha, preferably ranging from 5 to 20 kg / ha, preferably about 10 kg / ha.

[0129] A person skilled in the art will be able to adapt the formulation of the composition, the frequency of application and the quantity of composition to be applied to the soil according to the nature of the soil and / or the plant cultivated in the soil, so as to benefit from the advantageous effects of the composition.

[0130] The composition is preferably applied to the soil at the same time and in the same place as the plant seed. Thus, the seed and the composition, preferably in granular form, are applied close together in the soil, for example in the same well created in the soil. This embodiment is particularly advantageous because the granular material is in the immediate vicinity of the seed, which can thus benefit more easily and effectively from the beneficial effects provided by the seed.

[0131] In certain embodiments, several successive soil treatments may be carried out. A person skilled in the art will be able to adapt the number of treatments according to the needs and according to the nature of the soil and / or the plant cultivated in the soil.

[0132] The application of the composition to the ground, in liquid or granular form, can be carried out by automated or semi-automated techniques allowing to apply the mixture to the soil at the time of sowing, for example using a localized fertilizer spreader. A professional is familiar with these techniques and will know how to choose the most appropriate one.

[0133] In other particular embodiments, when the composition is in liquid form, the composition can be spread homogeneously on the ground over a field or crop of plants.

[0134] In a particular embodiment, the composition is applied to the soil in combination with one or more fertilizers, for example, a soil amendment, and / or a fertilizer. The soil amendment may be chosen from mineral and organic amendments. The fertilizer may be chosen from urea, ammonium sulfate, ammonium nitrate, phosphate, potassium chloride, ammonium sulfate, magnesium nitrate, manganese nitrate, zinc nitrate, copper nitrate, phosphoric acid, potassium nitrate, and boric acid.

[0135] The application of the composition alone or in association with one or more biostimulating substances can be in liquid form or in granule form, for example in the form of a granule as described below.

[0136] Granulated formulation, commonly used in agriculture, facilitates the use and preservation of the composition. Granulation methods are widely described in the literature. In most cases, the process used to obtain granules involves an agglomeration operation without compression, known as wet granulation. This granulation technique aims to transform materials that are generally powdery into small granules. Agglomeration is achieved by introducing the powdery material (or a mixture of solids) and a small quantity of liquid, usually water, into an agitator (such as a drum or plate granulator). It is also possible to add additives, such as fertilizers, during the granule preparation process.

[0137] For example, the fertilizer can be selected from (i) an amendment, for example selected from mineral amendments and organic amendments, and / or (ii) a fertilizer, for example selected from urea, ammonium sulfate, ammonium nitrate, phosphate, potassium chloride, ammonium sulfate, magnesium nitrate, manganese nitrate, zinc nitrate, copper nitrate, phosphoric acid, potassium nitrate and boric acid.

[0138] In a particular embodiment, the fertilizer provides nitrogen. For example, the fertilizer contains ammonium, ammonia, and / or urea. Examples of fertilizers containing ammonium are calcium ammonium nitrate, calcium ammonium nitrate, ammonium sulfate nitrate, ammonium sulfate, and Ammonium phosphate. An example of a fertilizer containing ammonia is ammonium nitrate.

[0139] The fertilizer may also supply potassium (K) and / or phosphorus (P). It may be an inorganic and / or an organic fertilizer. Examples of fertilizers supplying N, as well as P or K, include so-called "NP" or "NK" fertilizers, such as monoammonium phosphate or diammonium phosphate. Examples of fertilizers supplying N, P, and K include so-called "NPK" fertilizers.

[0140] The amendment may be an organic amendment or a mineral amendment, such as calcium carbonate.

[0141] The granule composition may also include micronutrients such as molybdenum, zinc, boron, and copper. These elements are typically supplied as water-soluble salts.

[0142] This description also describes a method for manufacturing granules of a composition comprising biochar and an aqueous extract of seed legume, in which a mixture comprising biochar and an aqueous extract of seed legume is wet-granulated.

[0143] In a particular embodiment, all or part of the mixture is prepared beforehand in dry form, that is to say that all the powders are mixed dry before granulation.

[0144] The present invention will now be illustrated by the following non-limiting examples.

[0145] Legend of the figures

[0146] [Fig-1]: [Fig.1] is a graph that represents the root biomass of a maize plants with or without the application of a biochar extract (Biochar) or a composition comprising a biochar and an aqueous legume extract (Composition). The maize plants were grown on vermiculite with (i) a treatment that includes the application of a composition according to the invention comprising a biochar and an aqueous legume extract (i.e. histogram "Composition"), or (ii) a treatment that includes the application of a biochar extract (i.e. histogram "Biochar"), or (iii) with a treatment that includes no application (i.e. histogram "Control").

[0147] [Fig.2]: [Fig.2] is a graph that represents the aboveground biomass of a maize plants with or without the application of a biochar extract (Biochar) or a composition comprising a biochar and an aqueous legume extract (Composition). The maize plants were grown on vermiculite with (i) a treatment that includes the application of a composition according to the invention comprising a biochar and an aqueous legume extract (i.e., histogram "Composition"), or (ii) a treatment that includes the application of a biochar extract (i.e., histogram (Biochar)), or (iii) with a treatment that does not include any application (i.e., histogram “Control”).

[0148] [Fig.3]: [Fig.3] is a graph that represents the quantities of phosphate of a maize plant with or without application of a biochar extract (Biochar) or of a composition comprising a biochar and an aqueous legume extract (Composition). The maize plants were grown on vermiculite with (i) a treatment that includes the application of a composition according to the invention comprising a biochar and an aqueous legume extract (i.e. histogram "Composition"), or (ii) a treatment that includes the application of a biochar extract (i.e. histogram "Biochar"), or (iii) with a treatment that includes no application (i.e. histogram "Control").

[0149] [Fig.4]: [Fig.4] is a graph that represents the quantities of phytate of a maize seed with or without application of a biochar extract (Biochar) or of a composition comprising a biochar and an aqueous legume extract (Composition). The maize plants were grown on vermiculite with (i) a treatment that includes the application of a composition according to the invention comprising a biochar and an aqueous legume extract (i.e. histogram "Composition"), or (ii) a treatment that includes the application of a biochar extract (i.e. histogram "Biochar"), or (iii) with a treatment that includes no application (i.e. histogram "Control").

[0150] [Fig.5]: [Fig.5] is a graph that represents the root biomass of 12 Maize plants with or without application of a composition including biochar and an aqueous legume extract (Composition) during the application of water stress (Stress). The maize plants were grown in soil with (i) a treatment that includes the application of water stress after the application of a composition including biochar and an aqueous legume extract (i.e. histogram "Stress + Composition"), or (ii) a treatment that includes only the application of water stress (i.e. histogram "Stressed Control"), or (iii) with a treatment that includes no application and no stress (i.e. histogram "Control").

[0151] [Fig.6]: [Fig.6] is a graph that represents the aboveground biomass of 12 maize plants with or without application of a composition including biochar and an aqueous extract of a grain legume (Composition) during the application of water stress (Stress). The maize plants were grown in soil with (i) a treatment that includes the application of water stress after the application of a composition including biochar and an aqueous extract of a legume (i.e., histogram "Stress + Composition"), or (ii) a treatment that includes only the application of water stress (i.e., histogram "Stressed Control"). or (üi) with a treatment that includes no application and no stress (i.e., histogram "Control").

[0152] [Fig.7]: [Fig.7] is a graph that represents the transpiration of a plant maize plants were grown in water with or without the application of a composition comprising a biochar and an aqueous extract of a grain legume (Composition) before the application of osmotic stress (Stress). The maize plants were grown in water with (i) a treatment that included the application of osmotic stress after the application of a composition comprising a biochar and an aqueous extract of a legume (i.e., histogram "Stress + Composition"), or (ii) a treatment that included only the application of osmotic stress (i.e., histogram "Stressed Control"), or (iii) with a treatment that included neither application nor stress (i.e., histogram "Control"). EXAMPLES

[0153] Example 1: Measurement of the effect of the composition according to the invention on the germination of a seed and the efficiency of nutrient use in a seed

[0154] a) Materials and methods

[0155] i) Preparation of plant material

[0156] Maize seeds (Zea Mays cv. MAS 20S) were surface sterilized with 2.6% sodium hypochlorite for 5 minutes, then rinsed 6 times with demineralized water before being sown on vermiculite soaked to 80% of its water-holding capacity with i) demineralized water (Control) or ii) demineralized water supplemented with biochar extract (Biochar) or iii) demineralized water supplemented with biochar extracted in an aqueous extract of a grain legume (Composition). The seeds were placed in the dark for 3 days for germination, then placed under natural light. After 12 and 16 days of growth, the seedlings were harvested and dissected into 3 fractions using a scalpel (aerial part, root part and residual grain), weighed to determine the fresh biomass, and immediately placed in liquid nitrogen before being stored at -80°C for analysis.

[0157] ii) Determination of aboveground and root biomass

[0158] For each of the treatments (Control, Biochar, Composition), four batches of plants harvested according to point i) were prepared (1 batch = 1 biological replicate). After 16 days of growth, the aboveground (leaves and stems) and root biomass of each plant were separated, weighed (fresh biomass) and then finely ground in liquid nitrogen.

[0159] iii) Determination of the amount of phosphate in the plant

[0160] For each of the treatments (Control, Biochar, Composition), four batches of plants harvested according to point i) were prepared (1 batch = 1 biological replicate). After 16 days of growth, the aboveground (leaves and stems) and root biomass of each plant were separated, weighed (fresh biomass), and then finely ground in liquid nitrogen. The phosphate content in the plant was determined using the malachite green colorimetric technique adapted from PP Van Veldhoven et al.

[12] .

[0161] iv) Determination of the quantity of phytate in the seed

[0162] For each of the treatments (Control, Biochar, Composition), four batches of plants harvested according to point i) were created (1 batch = 1 biological replicate). After 12 days of growth, the residual seeds were separated and then finely ground in liquid nitrogen. The total phosphorus content was determined by inductively coupled plasma optical emission spectrometry (ICP-OES, 5110 VDV, Agilent, CA, USA) after acid etching of the samples (Multiwave Pro, Anton Paar, Les Ulis, France), thus allowing the determination of the residual phytate content of the seed, representing 80% of the total P according to Raboy et al

[13] .

[0163] b) Results and conclusions

[0164] i) Determination of aboveground and root biomass

[0165] We observe in [Fig. 1] an increase in root biomass in the presence of the composition comprising a biochar and an aqueous extract of legume (i.e. histogram “Composition”), of +70% compared to the “Control” treatment and of +31% compared to the “Biochar” treatment.

[0166] We observe in [Fig.2] an increase in aerial biomass in the presence of the composition comprising a biochar and an aqueous extract of legume (i.e. histogram “Composition”), of +46% compared to the “Control” treatment and of +15% compared to the “Biochar” treatment.

[0167] ii) Determination of the amount of phosphate in the plant

[0168] We observe in [Fig.3] an increase in the quantity of phosphate in the plant in the presence of the composition comprising a biochar and an aqueous extract of legume (i.e. histogram “Composition”), of +24% compared to the “Control” treatment and of +14% compared to the “Biochar” treatment, reflecting a stimulation of phytase activity in the seed.

[0169] iii) Determination of the quantity of phytates in the seed

[0170] We observe in [Fig.4] a decrease in the quantity of phytate in the seed in the presence of the composition comprising a biochar and an aqueous extract of legume (i.e. histogram “Composition”), of -22% compared to the “Control” treatment, reflecting a stimulation of phytase activity in the seed.

[0171] c) Conclusion

[0172] The results obtained highlight the ability of the composition according to the invention to increase enzymatic activity within a seed, in particular phytase activity, as well as the efficiency of use of nutrients in a seed to promote its germination and ultimately increase the leaf and root biomass of the plant.

[0173] Example 2: Measurement of the effect of the composition according to the invention on the tolerance of a seedling to abiotic stress

[0174] a) Materials and methods

[0175] i) Evaluation of the response to water stress

[0176] Maize (Zea mays cv. Antonello) seeds were sown in seed furrows in acidic soil saturated with 80% water. Demineralized water (Control) or demineralized water supplemented with a composition comprising biochar and an aqueous extract of a grain legume (Composition) was applied to this soil. After 3 days (seedling emergence), some plants were maintained at 80% soil moisture (Control), while the other plants were maintained at 40% soil moisture until harvest 7 days later (Stress Control and Stress + Composition). The fresh root and shoot biomass of the plants after 7 days of stress is shown in Figures 5 and 6.

[0177] ii) Evaluation of transpiration in response to osmotic stress

[0178] Maize (Zea mays cv. Antonello) seeds were sown on water-saturated vermiculite for germination for 11 days. The seedlings were then transferred to 180 mL pillboxes containing 150 mL of tap water. The pillboxes were sealed to prevent any loss of water from the culture medium. Transpiration was measured by successive weighings of the pillboxes to monitor the evolution of water loss. On day 12, the seedlings were returned to water (Control) or to water supplemented with a composition comprising biochar and an aqueous extract of a grain legume (Composition) for 24 hours. On day 13, some untreated plants were kept in water (Control) while the other plants were subjected to osmotic stress in 15% polyethylene glycol 6000 for 8 hours (Control Stress and Stress + Composition). The addition of this compound reduces the plant's osmotic potential and creates water stress.Transpiration of the seedlings was measured by weighing every hour during stress. The percentage of transpiration compared to the control is shown in [Fig. 7].

[0179] b) Results and conclusions

[0180] i) Evaluation of the response to water stress

[0181] We observe in [Fig.5] an increase in root biomass in the presence of the composition according to the invention (i.e. histogram “Stress + Composition”), of 32% compared to the “Stressed Control” treatment.

[0182] Figure 6 shows an increase in aboveground biomass in the presence of the composition comprising a biochar and an aqueous legume extract (i.e., the "Stress + Composition" histogram), of 41% compared to the "Stressed Control" treatment. The asterisk indicates a significant difference between the two treatments.

[0183] These results highlight the ability of the composition according to the invention to increase the resistance of a plant subjected to water stress compared to a plant subjected to water stress but whose seed was not grown in soil to which the composition according to the invention was applied. Indeed, it is observed that the root and shoot growth of the plant subjected to water stress in the presence of the composition according to the invention is increased compared to the plant subjected to water stress but whose seed was not grown in soil to which the composition according to the invention was applied.

[0184] ii) Evaluation of transpiration in response to osmotic stress

[0185] Figure 7 shows an 11% increase in transpiration in plants subjected to water stress in the presence of the composition according to the invention (i.e., histogram "Stress + Composition") compared to the "Stressed Control" treatment. The asterisk indicates a significant difference between the two treatments.

[0186] These results highlight the ability of the composition according to the invention to increase the resistance of a plant subjected to water stress compared to a plant subjected to water stress but whose seed was not grown in soil to which the composition according to the invention was applied. This increase in transpiration in the plant subjected to water stress could contribute to better plant growth under water stress conditions compared to a plant subjected to water stress but whose seed was not grown in soil to which the composition according to the invention was applied. References

[0187] [1] Pramod Jha, 2010, Biochar in agriculture - prospects and related implications. CURRENT SCIENCE, VOL. 99, NO. 9.

[0188] [2] Solaimen et al, 2011, Biochars influence seed germination and early growth of seedlings, Plant and Soil. 353(1-2).

[0189] [3] Choi D et al, 2009, Seed germination and seedling physiology of Larix kaempferi and Pinus densiflora in seedbeds with charcoal and elevated CO2. Landsc Ecol Eng, 5:107-113.

[0190] [4] Pierce SM et al, 1994, Germination ecology of 6 shrubs in fire-prone cape fynbos. Végétation, 110:25-41.

[0191] [5] Reyes O et al, 2006, Seed germination of Quercus robur, Q-pyrenacia and Q-ilex and the effects of smoke, heat, ash and charcoal. Ann Forest Sci 63:205-212.

[0192] [6] Tian YH et al, 2007, Addition of activated charcoal to soil after clearing Ageratina Adenophora stimulâtes growth of forbs and grasses in China. Tropical Grasslands 41:285-291.

[0193] [7] Bamberg JB et al, 1986, Use of activated charcoal to enhance the germination of botanical seeds of potato. Am Potato J 63:181-189.

[0194] [8] Van Zwieten L et al, 2010, Effects of biochar from slow pyrolysis of papermill waste on agronomie performance and soil fertility. Plant Soil 27:235-246.

[0195] [9] Free HF et al, 2010, The effect of biochars on maize (Zea mays) germination. New Zeal J Agr Res 53:1-4.

[0196]

[10] Oh et al, 2012, Effect of Aqueous Extract of Biochar on Germination and Seedling Growth of Lettuce (Lactuca sativa L.). Journal of the Faculty of Agriculture Kyushu University 57(1):55-60.

[0197]

[11] X. Bai et al, 2022, Exploring the négative effects of biochars on the germination, growth, and antioxidant System of rice and corn. Journal of Environmental Chemical Engineering, Volume 10, Issue 3, 107398.

Claims

Demands

1. Composition comprising a biochar and an aqueous extract of a seed legume.

2. Composition according to claim 1, comprising 1% to 10% by dry weight of biochar relative to the total weight of the composition and / or 90% to 99% by volume of seed legume extract relative to the total volume of the composition.

3. Composition according to any one of claims 1 to 2 wherein the biochar is selected from: i. a wood biochar, manure biochar, ii. a straw biochar, iii. a bamboo biochar, iv. a cocoa bean shell biochar, or v. a mixture of several biochars selected from (i) to (iv).

4. Composition according to any one of the preceding claims, wherein at least 50% by dry weight of the biochar has a particle size between 0.1 mm and 5 mm, preferably between 0.5 and 2 mm.

5. Composition according to any one of the preceding claims, wherein the aqueous extract of seed legumes is a seed legume permeate.

6. Composition according to any one of the preceding claims, wherein the legume seed is selected from: i. soybean, ii. broad bean, iii. lentil, iv. broad bean, v. bean, vi. pea, vii. chickpea, or viii. a mixture of several legume seeds selected from (i) to (vii).

7. A method for preparing a composition according to any one of claims 1 to 6, comprising a step of mixing a biochar with an aqueous extract of a seed legume to obtain a suspension.

8. A process according to claim 7, wherein: i. the mixing is carried out under agitation, and / or ii. the mixing is carried out at a temperature of 50 to 80°C, preferably at a temperature of 55 to 75°C, preferably further at a temperature of 60 to 65°C, and / or iii. the mixing is carried out for at least 1h, preferably at least 2h.

9. Use of a composition according to any one of claims 1 to 6, to promote the germination of a seed.

10. Use of a composition according to any one of claims 1 to 6, to improve the nutrient use efficiency of a seed, preferably the nutrient is phosphorus.

11. Use according to claim 9 or 10, wherein the composition: i. stimulates the hydrolysis of phytates from the seed, and / or ii. stimulates the transformation of phytates into phosphate, and / or iii. stimulates the enzymatic activity in the seed of one or more enzyme(s) selected from a phytase, an amylase, a lipase and / or a protease, preferably a phytase.

12. Use of a composition according to any one of claims 1 to 6, to promote the development of a seedling, preferably wherein the composition stimulates the development of the root and / or aerial biomass of the seedling.

13. Use of a composition according to any one of claims 1 to 6, to improve the tolerance of a seedling to abiotic stress, preferably the abiotic stress is water or osmotic stress.

14. Use according to any one of claims 9 to 13, wherein the composition is applied to the soil at the time of sowing.

15. Use according to any one of claims 9 to 14, wherein the composition is applied to the soil in an amount from 1 to 100 kg / ha, preferably from 5 to 20 kg / ha, for example about 10 kg / ha.

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