Method for producing of fermented material comprising stalk particles of monocotyledonous flowering plants, and fermented particulate material obtained by this method

Abstract

The invention aims at providing a method for producing of a fermented particulate material comprising stalk particles of maize, and, possibly, at least one filler / additive, which can constitute a sustainable, ecofriendly & bio-sourced material. This aim is achieved by the invention which concerns a method for producing of fermented material comprising a clustered particulate material made of stalk particles of monocotyledonous flowering plants, preferably maize, and, preferably, at least one filler / additive, wherein said material having at least one of the following characteristics: (a) an average density Da as it is spread on the ground in a layer which height is 4-5 cm is between 750-900 (b) a specific density Ds of the material, in g dry matter per liter such as 100 ≤ Ds; (c) a specific water content Cw at saturation of the material is, in g / l such as 550 ≤ Cw ≤ 950; (d) a water holding capacity allowing a water extraction under a 75 mbar vacuum lower than or equal to – in % by mass – 6; (e) a Carbon / Nitrogen ratio C / N of the material is such as 60 ≤ C / N; and wherein at least some of the following steps are implemented, in this order or in a different order:.S1. harvesting the grains of maize, so as the stalks remain stand on the field;.S2. cutting and shredding, the remaining stalks standing on the field into a particulate material;.S3. possible transporting the material to a processing site;.S4. submitting the material, to an anaerobic fermentation; S5. water spraying on the grinded material from (S4);.S6. grinding the material up to a particle size given by their largest dimension Dld : 5 ≤ Dld ≤ 60;.S7. possible dewatering the grinded material, so as to get a dry matter content Cdm, in % by mass, 35 ≤ Cdm ≤ 60,.S8. loosening of the material;.S9. possible addition of at least one filler / additive,.S10. possible submitting the material, to a fermentation; S11. possible (steam) thermal treatment of the material;.S12. possible storing and / or conditioning the material from.S12.; S.13. possible transporting the material in a dry matter content Cdm, in % by mass, such as : 45 ≤ Cdm ≤ 65;.S14. possible addition / extraction of water to the material to adjust the dry matter content Cdm, in % by mass, such as : 10 ≤ Cdm ≤ 40; before using it. The fermented particulate material obtained in particular through this method is another object of the invention, as well as the use of this material as casing.

Description

Method for producing of fermented material comprising stalk particles of monocotyledonous flowering plants, and fermented particulate material obtained by this methodTechnical Field

[0001] The invention relates a method for producing of new bio-sourced materials, especially to a fermented particulate material comprising stalk particles of monocotyledonous flowering plants, preferably maize.

[0002] This fermented particulate material can be a culture medium and / or plant substrate component and / or a peat substitute, notably a casing material.

[0003] These new bio-sourced materials as obtained by this method and their implementation in numerous uses, are encompassed in the present invention.Background Art

[0004] US10,260, 169B2 describes a method for producing notably of superabsorbent pellets and / or of a fibrous material from crop residues of monocotyledonous flowering plants cultivation, comprising the following steps:(i) cutting the maize stalks planted in the ground of the field below the lowest cob of the stalks, so that leafy stalk segments stay on the field; each less leafy stalk segment including a spongy core, a stalk bark wrapping the core and a leafy matter wrapping the stalk bark or born by the stalk;(ii) cutting the less leafy stalk segments as close to the ground as possible;(iii) harvesting the less leafy stalk segments cut in step (ii);(iv) cutting the less leafy stalk segments harvested in step (iii) into stalk sections which largest dimension in mm is comprised between 5-50;(v) providing a mechanical impact to the stalk sections of step (iv) so as to separate spongy cores from stalk barks, as well as the leafy matter, to transform said stalk barks into elongated fiber pieces; and to obtain a mix containing: f1. said spongy cores forming a superabsorbent pellets fraction which water absorption capacity expressed in multiple of its own dry mass is greater than or equal to 15; f2. said elongated fiber pieces forming a fibrous matter fraction; f3. and said leaf matter forming a leafy fraction, the superabsorbent pellets fraction, the fibrous matter fraction, and the leafy fraction forming three fractions;(vi) separating the three fractions from each other;vii) recovering the three fractions f1 -f2-f3;(viii) optionally reducing the f1 superabsorbent pellets up to a smaller pellet size to have a largest dimension in mm between 0.1-20 mm.

[0005] The US10,260, 169B2 superabsorbent pellets f1 and fibrous material f2 are prime ingredients for the preparation of different compositions which are intending to be used in different fields: chemical treatments, depollution, purification, filtration, industrial processing aid, crop activation. In particular, fibrous matter f2 can be used as a plant substrate, plant substrate component and / or peat substitute.The US10,260, 169B2 fibrous material f2 are improvable as plant substrate, plant substrate component and / or peat substitute, especially regarding the growing efficiency and / or the growing selectivity of certain kind of plants or fungi.

[0006] Casing soil is currently produced almost exclusively from peat, which is a fossil resource. Thus, the production of mushrooms in its present way is not sustainable. Alternative raw materials for the production of casing soil have been tested for a long time (e.g. grass, wood fibers, waste paper, cocopeat), but they do not meet the very specific requirements of this application (structure formation, water holding capacity, biological stability) and are therefore not relevant in practice today.

[0007] WO2012066511A1 discloses a method for preparing casing material (pH of 7.5) for button mushroom production includes the steps of:- providing a body of plant parenchyma tissue or pith extracted from a plant source in the form of sugarcane bagasse;- mixing the body with water to provide a starting mixture;- adding a decomposition enhancer (cattle rumen content), to the starting mixture for stimulating microbial activity;- allowing the starting mixture to compost; and- allowing excess nutrients to leach from the mixture.Watering of the fermented material is carried out on days 1 2, 7, 12, 17, 22, 27, 32, 37, 42, 47, 52, 57, 62, 67, 72 and 77 of composting, with the aim of maintaining the moisture content of the composting casing material at 65%, throughout the composting period. During the composting stage, care should be taken not to allow the composting casing material to dry out, as it will inhibit microorganism growth and composting. The ratio of carbon to nitrogen (C:N) of the casing material is maintained at 40 - 50:1 .The casing material has a water holding capacity in excess of 350 ml water / 100g dry mass. The casing is used in a method of producing button mushrooms {Agaricus bisporus).The casing material according to WO2012066511A1 has the following drawbacks : the low C:N ratio results in poor biological stability and the cattle rumen content adds undesirable salts.In this context, the design of new bio-sourced materials that takes into account the environmental concern, especially, but not only, with respect to the spoiling of to-day preserved peat bogs, is a necessity of public order. These new bio-sourced materials must not only be environment friendly but must also perform well in terms of productivity (culture yield for growing media), crop quality, and crop selectivity. These qualities are notably production method dependent. It is notably true for the use of these materials in casing material as peat substitute. Actually, it is suitable these new biosourced materials, as culture media, have an high water holding capacity and / or biological stability and / or a low content of nitrogen and / or phosphorous and / or sulfate.As far as high water holding capacity ( / .e. increased matric / matrix potential / water) is concerned, mushrooms need indeed a lot of water to form the fruit bodies: for a yield of 25 kg of mushroom per m2 growth surface, the tiny mushroom must pump 23 kg of water from the casing material into the fruit bodies (the dry matter content of the mushroom is around 9%), within a few days! Therefore, high mushroom yields can only be achieved when there is a maximum of water in the casing material.

[0008] It exists also a need to have the fields rapidly cleared from the stalks / stems, after grains harvest, especially for maize. Said need is linked to the necessity of having crop rotation and of preventing the decomposition of the remaining vegetal material after grains harvest, which can be a source of pollution of groundwater, as well as controlling crop infestations, notably the corn stem borer.

[0009] Another concern in the crop field is the biological stability and storage safety of the remaining vegetal material, after grains harvest. The stalks / stems below the cob attachment are significantly wetter than the grains and have a dry matter content of only 25-30%, depending on weather conditions. At this moisture content, rapid development of microorganisms associated with material degradation and heat generation can be observed on a central raw material store. The material degradation leads to an undesired material loss and the heat development results in a fire risk. This situation makes the storage of wet corn stalks for subsequent utilisation impossible.Objectives of the invention

[0010] In this context, the invention aims to satisfy at least one of the following objectives.

[0011] An objective of the invention is to provide a method for producing fermented particulate material comprising stalk particles of monocotyledonous flowering plants, preferably maize, which can constitute a sustainable, ecofriendly & bio-sourced material, said method being simple and industrial.

[0012] An objective of the invention is to provide a simple and industrial method for producing a fermented particulate material comprising stalk particles of monocotyledonous flowering plants, preferably maize, which can constitute a sustainable, ecofriendly & bio-sourced material, useful as high-performance and / or selective culture medium and / or plant substrate component and / or fertilizer and / or a peat substitute, notably for casing.

[0013] An objective of the invention is to provide a simple and industrial method for producing fermented particulate material comprising stalk particles of monocotyledonous flowering plants, preferably maize, which can constitute a sustainable, ecofriendly & bio-sourced material, useful as culture medium and / or plant substrate component and / or fertilizer and / or a peat substitute, notably for casing, and having a high-water holding capacity, and / or a biological stability and / or a low content of nitrogen and / or phosphorous and / or sulfate.

[0014] An objective of the invention is to provide a simple and industrial method for producing fermented particulate material comprising stalk particles of monocotyledonous flowering plants, preferably maize, which can constitute a sustainable, ecofriendly & bio-sourced material, said method being economical and swift.

[0015] An objective of the invention is to provide a simple and industrial method for producing fermented particulate material comprising stalk particles of monocotyledonous flowering plants, preferably maize, which can constitute a sustainable, ecofriendly & bio-sourced material, useful as culture medium and / or plant substrate component and / or fertilizer and / or a peat substitute, notably for casing, said method making possible the removal from the fields, of the remaining vegetal material after harvest.

[0016] An objective of the invention is to provide a simple and industrial method for producing fermented particulate material comprising stalk particles of monocotyledonous flowering plants, preferably maize, which can constitute a sustainable, ecofriendly & bio-sourced material, said method addressing the problem of the moisture content (70-75% depending on weather conditions) of the remaining vegetal material (stalks) after grains harvest, and of the subsequent difficulty of biological stability and storage of said remaining vegetal material.

[0017] An objective of the invention is to provide a fermented particulate material obtained by the method according to the above objectives, this material being a sustainable, ecofriendly & biosourced material, useful as high-performance and / or selective culture medium and / or plant substrate component and / or fertilizer and / or a peat substitute, notably for casing.

[0018] An objective of the invention is to provide a fermented particulate material obtained by the method according to the above objectives, this material being an advantageous peat substitute, notably for casing, having, in particular, high water holding capacity.Summary of the invention

[0019] The inventors have had the merit to invest a lot of time and money in R&D to eventually find out a method for producing new crop bio-sourced material, complying with at least one of the above objectives. This is how the invention concerns a method for producing fermented material comprising a lumpy particulate material made of stalk particles of monocotyledonous flowering plants, preferably maize, and, preferably, at least one filler / additive, wherein said material can have different dry matter contents Cdmand at least one of the following characteristics:(a) an average density Daas it is spread on the ground in a layer which height is 4-5 cm is between 750-900, preferably 800-880 g / l;(b) a specific density Ds, in g dry matter per liter and in an increasing order of preference, such as :100 < Ds< 250 ; 120 < Ds< 220 ; 130 < Ds< 200 ; 140 < Ds< 200 ;(c) a specific water content Cwat saturation, in g / l and in an increasing order of preference, such as :550 < Cw< 950 ; 600 < Cw< 900 ; 650 < Cw< 900 ; 800 < Cw< 850(d) a water holding capacity (WHC) allowing a water extraction under a - 75 mbar vacuum, which is lower than or equal to - in % by mass and in an increased order of preference-: 6 ; 5 ; 4 ; 3 ; 2;(e) a Carbon / Nitrogen ratio C / N, in an increasing order of preference, such as : 60 < C / N ; 70 < C / N ; 80 < C / N ; 90 < C / N ; 95 < C / N < 120; and wherein at least some of the following steps are implemented, in this order or in a different order:,S1 . harvesting the grains of monocotyledonous flowering plants, preferably from the subfamily Panicoideae, and more preferably maize, so as the stalks remain stand on the field;,S2. chopping and, preferably shredding, the remaining stalks standing on the field into a particulate material;.S3, possible transporting the particulate material to a processing site;,S4. submitting the particulate material, to an anaerobic fermentation;,S5. water spraying on the fermented particulate material;,S6. grinding the watered fermented particulate material so the largest dimension Dldof the particles, in mm and in an increasing order of preference, be such as :Dld< 15 ; D2ld< 12 ; D2ld< 9 ; D2ld< 6 ; D2ld< 3,S7. possible dewatering the grinded fermented particulate material, so as to get a dry matter content Cdm, in % by mass, such as : 35 < Cdm< 60 ; preferably 40 < Cdm< 55;,S8. loosening of the grinded fermented particulate material;,S9. possible addition of at least one filler / additive to the loosened fermented particulate material, preferably consisting of at least one clay;.S10. possible submitting the fermented particulate material, to at least another fermentation (preferably aerobic) during a time sufficient, so that the temperature of the material reaches a value Tp(°C) greater than or equal to, in an increasing order of preference; 30 ; 40 ; 50 ; 65 ;,S1 1 . possible thermal treatment of the fermented particulate material, preferably steam treatment;.S12. possible addition of water to the fermented particulate material and storing;.S13. possible storing and / or conditioning and / or transporting the fermented particulate material, in a dry matter content Cdm, in % by mass, such as : 45 < Cdm< 65 ; preferably 50 < Cdm< 60;.S14. addition of water to the fermented particulate material to adjust the dry matter content Cdm, in % by mass, such as : 10 < Cdm< 40 ; preferably 15 < Cdm< 30; to get so a lumpy fermented particulate material ready to be used.

[0020] This efficient, industrial, and reliable method leads notably to the advantageous fermented particulate material according to the invention, by recovering rapidly, less than 2-3 weeks, after the grains harvesting, the stalks of the plant, and by transforming them into a technical and functional fermented growing raw material.

[0021] This method respects all requirements of authorities and raw material suppliers, and especially regulations supporting groundwater protection and the control of the corn stem borer, which migrates in the corn stalks to the soil after harvest, overwinters there and causes crop damage in the following year.

[0022] This method does not allow rapid development of microorganisms associated with the so produced material degradation and heat generation, during storage of the recovered crop material. It means undesired material loss does not occur, as well as the control of heat development according to this method significantly limits the fire risk during bulk storage.

[0023] According to a variant of this method for producing fermented material, the starting products are not the stalks are not directly extracted from crop fields and shredded in situ, but cut stalks stored in suitable conditions in this state.

[0024] This variant corresponds to the method according to claim 1 , wherein the steps ,S1. , ,S2.& .S3, are replaced by the following steps :.S01 . implementing cut stalks of monocotyledonous flowering plants, preferably from the subfamily Panicoideae, and more preferably maize;.S02. shredding the cut stalks from (S01) into a particulate material;.S03. possible storing of the particulate material.

[0025] The method according to the invention has also at least one of the following features:(-f.1-) : Step (S2) is implemented by means of forage harvester.(-f.2-) : Step (S2) takes place within 20 days, preferably within 14 days after the grain harvest.(-f.3-) : Step (S02) is implemented by means of a forage harvester.(-f.4-) : Step (S2) or (S02) leads to chopped stalk particles having a particle size given by their largest dimension D2ld, in mm and in an increasing order of preference, such as :D2ld< 30 ; D2ld< 15 ; D2ld< 9 ; D2ld< 6 ; D2ld< 3;(-f.5-) : Possible step (S7) is a mechanical dewatering implemented by means of a screw press.(-f.6-) : The chopped particulate material from S2, -possibly dewatered according to step S7 (press cake)- is pressed into round bales and wrapped in foil to ensure anaerobic storage.(-f.7-) : Step (S6) is a grinding implemented by means of at least one mill chosen in the group comprising -preferably composed of- impact mill, grinding mill, disk mill, combinations thereof, disk mill being preferable.In the case where the mill is an impact mill, this latter can have a tip speed of the rotating working tools, which is greater than or equal to, in m / s and in an increasing order of preference; 60 ; 65 ; 70 ; 75 ; and more preferably comprised between 80 and 100.(-f.8-) : In step (S5), the addition of water is comprised between 100 and 200 L / m3, preferably between 130 and 170 L / m3, and more preferably between 145 and 155 L / m3.(-f.9-) : In step (S5), water is added in order to achieve a dry matter content Cdmof 15-30%, and preferably 18-25% Cdm(-f.10-) : In step (S9), the addition of filler / additive is comprised between 5 and 150 kg / m3, preferably between 20 and 100 kg / m3, and more preferably between 30 and 80 kg / m3.(-f.11-) : In step (S9), the filler is chosen in the group comprising -ideally consisting of - clay , peat and mixtures thereof.

[0026] Among advantages of the method according to the invention, one can mentioned that the step (S4) of anaerobic fermentation ( / .e during storage) involves the use of standard agricultural technology for anaerobic storage, and also no volume losses, no heating, less colonization with foreign microorganisms or fungi, less contamination of the storage material in anaerobic conditions, and no external influence of weather factors during storage in anaerobic conditions.

[0027] According to the method of the invention, there is a spontaneous formation of stable lumps from the particulate material, notably during at least one of the steps ,S4. ; ,S5. ; S6. ; ,S8. ; S9. ; .S10. ; .S14..

[0028] Without being bound to the theory, this trend of the fermented material to spontaneously form lumps could be closely related to its fineness and the presence of small pores. As the small pores are filled with water, the material shrinks in volume, evacuates air from the pores and forms lumps. These lumps are stable at a very high water loading and do not release water, even if a vacuum of e.g.-75 mbar, is applied to the material. Actually, a vacuum of e.g. -75mbar makes it possible to extract the capillary water from the material and leaves only the matrical water (water which is bonded in the material against the force of gravitation) in it.

[0029] For this reason, the water holding capacity WHC under vacuum of the clustered particulate material according to the invention [characteristic (d)] does not only describe the water loading available for the growth of mushrooms, as far as the use of peat substitute for casings is concerned, but also its capacity to form stable lumps.

[0030] The lumps are formed spontaneously, after addition of minerals and after watering of the particulate matter to its saturation point, e.g. during handling, spreading and dosing of the material onto the mushroom production shelves.

[0031] Furthermore, it is worthfully according to the invention to press the storage material in anaerobic conditions during at least a part of step (S4), in order to need less storage space.

[0032] The implementation of grinding step (S6) by means of disk mill, provide a better defibration and therefore finer fibres, smaller pores and higher as well as stronger WHC, and also less susceptibility to faults because disk mills are ideally suited to wet raw materials, better nutrient leaching due to better defibering, and higher milling capacity.

[0033] Surprisingly, lumpy structure of the fermented lumpy particulate material according to the invention, is especially interesting in its use as casing material, wherein it promotes the formation of strands of Mycelia on the surface of the lumps and such thick strands of Mycelia generate a desired high mushroom yield in commercial production.

[0034] The possible thermal treatment (S11) of the fermented particulate material, preferably steam treatment, affords a remarkable hygienization. Steam treatment can be made by injection of steam into a screw conveyor, thereby allowing continuous steaming of the material. Such a steam technology is already in use. It makes it possible online hygienization in the method according to the invention (instead of batch). Steam technology requires less space and less time. Temperature and time can be set precisely.

[0035] The simple, industrial and economical method according to the invention leads to an eco- friendly and crop-sourced material which is a noteworthy new raw material.

[0036] This new raw material per se is another object of the invention, whatever be the method to produce it.

[0037] This new raw material is fermented material comprising a clustered particulate material made of stalk particles of monocotyledonous flowering plants, preferably maize, and, preferably, at least one filler / additive, wherein said material having at least one of the following characteristics:(a) an average density Daas it is spread on the ground in a layer which height is 4-5 cm is between 750-900, preferably 800-880 g / l;(b) a specific density Dsof the material, in g dry matter per liter and in an increasing order of preference, such as :100 < Ds< 250 ; 120 < Ds< 220 ; 130 < Ds< 200 ; 140 < Ds< 200(c) a specific water content Cwat saturation of the material is, in g / l and in an increasing order of preference, such as :550 < Cw< 950 ; 600 < Cw< 900 ; 650 < Cw< 900 ; 800 < Cw< 850(d) a water holding capacity (WHC) allowing a water extraction under a - 75 mbar vacuum, which is lower than or equal to - in % by weight and in an increased order of preference- 6 ; 5 ; 4 ; 3 ; 2;(e) a Carbon / Nitrogen ratio C / N of the material is, in an increasing order of preference, such as : 60 < C / N ; 70 < C / N ; 80 < C / N ; 90 < C / N ; 95 < C / N < 120.

[0038] This new raw material, which is for instance produced through the method according to the invention, is notably useful as culture medium and / or plant substrate component and / or fertilizer and / or a peat substitute, notably for casing, especially for mushrooms production, such as button mushrooms. This fermented material obtained by the method according to the invention, has a peculiar lumpy, fibrous and porous structure. It has an extraordinarily high-WHC. This is achieved by not only utilizing the water binding capacity of the fibers (i.e. the ability of the cellulose fibers to absorb and retain water using hydrogen bonds), but also by developing a capillary binding capacity (the formation of fine pores filled with water). Through its porosity, the material shrinks to a smaller volume with the addition of water and develops capillary binding forces and form water-filled lumps (agglomerates), exactly as it is suitable, notably in the production of casing soil.

[0039] In order to be a culture substrate of choice, notably as casing soil for the mushrooms production, the fermented material obtained by the method according to the invention, has to comply with a key specification, which is pretty antinomic with its high-water retention capacity, namely a biological activity at the lowest possible level to prevent the unwanted propagation of foreign organisms.

[0040] Moreover, the fermented material obtained by the method according to the invention, is advantageous thanks to its capacity to be agglomerated and so to be shapable in various 3D forms, having a certain mechanical strength.

[0041] Preferably, the particulate fermented material obtained after step S6 of the method according to the invention is characterized in that at least a part of the particles are fibers particles, the average length Laof the fibers particles being preferably, in mm and in an increasing order of preference, such as :La< 15 ; La< 12 ; La< 9 ; La< 6 ; La< 3Lais measured as follows: a 0.5 liter sample of the particulate fermented material is fractionated by sieve, using (a) a sieve with a mesh of 3mm and (b) a sieve with a mesh of 1 mm. If the fraction between 1-3mm in length was >0.25 liter, Lais specified as <3mm.

[0042] Advantageously, the fermented material obtained by the method according to the invention has a biological stability corresponding to an oxygen consumption Oclower than or equal, in g per day per g of material, and in an increasing order of preference: 3; 2.8 ; 2.7 ; 2.6 ; 2.5 ; 2.4 ; 2.3 ; 2.2 ; 2.1 ; 2.

[0043] In preferred embodiments, the fermented material obtained by the method according to the invention is a culture medium and / or plant substrate component and / or fertilizer and / or a peat substitute, like a casing soil for instance.

[0044] The fermented material obtained by the method according to the invention can be mixed with standard casings in a proportion preferably of up to 70% v / v, preferably 0, even 5, -40% v / v.Definitions

[0045] According to the terminology of this text, the following non limitative definitions have to be taken into consideration:

[0046] any singular is equivalent to a plural.

[0047] “matrical water3’ is the water bonded in the material against gravity.

[0048] “capillary water3’ is the water extracted under a - 75 mbar vacuum, to measure the water holding capacity (WHC), with the test TWHChereinafter described.

[0049] "around" means for instance more or less 10%.

[0050] "stalk" stands for "stem" and reciprocally.

[0051] "peat" refers to organic material extracted from peat bogs.

[0052] "casing" refers to the top layer of mushrooms growing substrate, especially Agaricus bisporus growing substrate.

[0053] "compost" refers to the lower layer and nutrient source for mushrooms, especially for Agaricus bisporus.Detailed descriptionMethod for producing notably of the fermented material according to the invention

[0054] Main, mode of implementation.:. Steps S1 to S14

[0055] Step. SI : Harvest of the grains using a standard corn thresher, with an elevated cutting bar, leaving stalks with a height of e.g. 50-100cm standing on the field. Grain harvesting is accomplished for instance using a John Deere type corn thresher with a raised cutter bar. A reduced-width caterpillar drive is used on the thresher to prevent harvest losses.

[0056] Step S2: Chopping and, preferably shredding, of the remaining stems / stalks in the field, using a forage harvester, with a chopping length [largest dimension D2ld< 30 mm] of e.g. 2-8 mm to get a chopped particulate material. S2 is implemented for instance less than 10 days after step S2, complying so with the requirements of authorities and raw material suppliers. In particular, it is performed within 2 hours after grain harvesting using a chopper, type Claas Jaguar, with a theoretical chop length of 6mm.

[0057] Step .S3: Possible transportation of the chopped particulate material from S2 by any conventional means.

[0058] Step S4: The chopped particulate material from S2, -possibly dewatered according to step S7 (press cake)- is pressed into round bales and wrapped in foil to ensure anaerobic storage.

[0059] Step S5: Water spraying of particulate material from S6 is implemented by any conventional spraying means.

[0060] Step _S6 : Grinding or milling, in particular to defibrate the stalks particles of the watered particulate material from S5. It is for instance carried out with a disc mill which refines the particles of material to its largest dimension Dld< 15 mm, e.g. 5-10 mm.

[0061] Step S7 : Possible dewatering of the grinded or milled particulate material from S6, so as to get a dry matter content Cdm, in % by mass, such as : 30 < Cdm< 60; e.g. 40-50 % by mass.

[0062] Step S8 : Loosening of the dewatered particulate material from S7 in hammer mill, e.g. type Agerskov AM1 10.

[0063] Step S9 : Possible addition of at least one filler, preferably of clay, type montmorillonite, in an amount comprised between e.g. 10% and 30% by dry mass of the clustered particulate material.Standard casings, notably all peat based casings, can be also incorporated as fillers / additives.

[0064] Step S1.0 : possible fermentation, preferably an aerobic fermentation, for instance during a storage, is implemented preferably during a time sufficient so that the temperature Tpof the (stored) particulate material may increase initially and becomes stable (around 50°C) or decreasing after depletion of nutrients and / or water. The total dry matter of the (stored particulate) material has a variation percentage per 24H, equal to or lower than, in an increasing order of preference, 20% ; 15% ; 10% ; 5 %; 1 % .

[0065] Step S.1.1 : Possible thermal treatment of the fermented lumpy particulate material, preferably steam treatment.

[0066] Step S 1.2 : possible addition of water to the fermented particulate material and storing. For instance, it could be packed in big bags.

[0067] Step SI 3 : Possible storing and transporting the fermented particulate material in a dry matter content Cdm, in % by mass, such as : 45 < Cdm< 65.

[0068] Step S14 : Addition of water to the fermented particulate material to adjust the dry matter content Cdm, in % by mass, such as : 10 < Cdm< 40, to transform it into a lumpy fermented particulate material ready to be used, for instance as casing for mushrooms production.

[0069] Microbiological analysis of this material showed no presence of human pathogens (Enterobacteriaceae, E.coli, Campylobacter ssp., Listeria monocytogenes, Salmonella ssp and / or potential diseases of Agaricus (Mycogone sp, Lecanicilium fungicola, Cladobotryum ssp). In addition, the material has no detectable levels of pesticides or plant growth regulators. This means that the material is safe for commercial utilization. However, the material may contain spores of Coprinus andPeziza, which may develop under industrial Agaricus production conditions, depending on the blend used, wet storage time, irrigation procedure, and more.This makes it possible to obtain a fermented material used as casing, which does not contain relevant levels of unwanted fungal spores

[0070] Moreover, the addition of clay in mixtures (without standard casing -i.e. peat-) significantly improves the strength and, thus, ensures the industrial suitability of the casing.

[0071] Variant. of i plemenJation _: Steps S01 to S03

[0072] Step ..SOI.: Implementing cut stalks of monocotyledonous flowering plants, preferably maize.

[0073] Step. S02: Chopping, preferably shredding, the cut stalks from (S01) of the remaining stems / stalks in the field, using a forage harvester, with a chopping length [largest dimension D2ld< 30 mm] of e.g. 2-8 mm to get a chopped particulate material., with a cutting length of e.g. 2-8 mm to get a chopped particulate material.

[0074] The following steps are identical to steps 4-12 of the main mode of implementation.Fermented particulate material

[0075] The crop-sourced material obtained by the method according to the invention comprises particles made of lumps monocotyledonous flowering plants, preferably maize. These particles result from the cutting, the shredding and the grinding of stalks, preferably maize stalks.

[0076] This fermented particulate material has preferably at least one of the following characteristics :* (a) an average density Daas it is spread on the ground in a layer which height is 4-5 cm is preferably 800-880 g / l. The average density Dais measured as follows: A bucket is filled with of fermented lumpy particulate material to a level of 5cm in height. The weight of the bucket is measured before and after the addition of the fermented lumpy particulate material, and the density is calculated by division of the net weight of the fermented lumpy particulate material by the volume of the layer covered to 5cm thickness.* (b) a specific density 100 < Ds< 180 g dry matter / L per liter and advantageously 120 < Ds< 160 g dry matter / L. Dsis preferably around 140 g dry matter / L and can be determined as described in detail hereinafter : A big bag of WOOL volume is filled with fermented material and weighed. Five samples of around 0.5 L each are taken and blended for creation of one representative sample. 100g of this sample are dried to constant mass at 110°C. The dry matter content is the dry mass in % of the wet sample mass (100g). Specific density Dsis calculated by multiplication of the fresh mass in the big bag by dry matter content.* (c) Specific water content Cwat saturation, i.e at the saturation point, which is the maximum water content a given material volume can hold without allowing any leakage of liquid. The saturation point is measured using a sieve test using a fine sieve with an open mesh of 0.5 mm, filling it with 100g of material, draining it with water, and waiting until no more leakage occurred, respectively no more water was passing through the sieve.Cwcan be determined as described in detail hereinafter : First, the dry matter content of a defined quantity (in grams) of crop-sourced & fermented material according to the invention is determined according to the procedure defined above. Second, the saturation point of that material was measured according to the procedure defined above. The specific water content Cwin g / l is calculated as(total mass at saturation point in g / l) - (dry mass in g / l).According to the invention Cwis so defined:700 g / l < Cw< 900 g / l by mass and advantageously 750 g / l < Cw< 850 g / l by mass. The specific water content at saturation Cwis preferably around 800 g / l by mass and*(d) the clustered particulate material having a water holding capacity allowing a water extraction under a - 75 mbar vacuum, which is preferably lower than or equal to - in % by weight - 2.The water holding capacity WHC (d) of the fibrous fermented clustered particulate material is determined by means of a test Twc, wherein an 2500 ml Erlenmeyer is connected to a vacuum pump RG GmbH PM19629 - 035 via a suction hose. On the Erlenmeyer is set up a Buchner funnel apparatus with a vacuum suction filter. 200 g of material to be tested is watered to its saturation point and put into the funnel apparatus, forming a homogenous layer. A vacuum of -75 mbar is applied to the material for a duration of 5 minutes. Under such conditions, the capillary water is extracted from the material and the matric water which is bonded stronger, resists to the vacuum and remains in the particulate matter: <6%, preferably < 2% and for instance < 1 % of its mass. The material from which the water has been extracted is weighed to measure its weight Waand calculate the % of remaining matric water : (200 - Wa) / 200*100.This confirms two key aspects of the invention: The extraordinarily high WHC of the fermented material and its suitability to form stable 3-dimensional lumps.* (e) 95 < C / N < 120 . ("C" for carbon atom and "N" for nitrogen atom). C / N is determined using the following standard procedure https: / / en.wikipedia.orq / wiki / Carbon-to-nitroqen ratio. The fermented material is burned to ash at 950°C for release of the CO2 and N2 contained therein, detection of C and N in the gas stream and expression as total mg C per g of material and total mg N per g of material, and calculation of the ratio C / N.

[0077] The maximum water content at the saturation point of the fermented particulate material according to the invention, includes some capillary bonded water, which runs off the material at a minor pressure, mechanical impact or impacts related to the rewatering of the material, such as occurring under the conditions prevalent in professional practice. In the application of the fermented particulate material according to the invention as casing for mushrooms culture, run-off of water from the casing material shall be preferably avoided or limited, because it destabilizes the lumbs of the fermented lumpy particulate material according to the invention and favors the development of unwanted diseases of the mushrooms. The WHC is one of the parameters of the fermented particulate material according to the invention, which contributes to the stabilization even under such practical stress.

[0078] The particles of the fermented particulate material according to the invention, are at least partly fibers particles, especially cellulosic fibers particles which form a porous network included in a matrix made of fermented crop material and possibly containing at least one filler: clay for instance. Other fillers like peat can be contemplated.

[0079] The fiber fineness, i.e. the average fiber length and fiber length distribution, after step S6, are important features of the fermented particulate material according to the invention. Indeed, the fiber length distribution is expected, on the one hand, to favour the formation of very fine pores and, on the other hand, to contain sufficiently long fibers which favor the coherence of the lumps / agglomerates which can be formed with the material, and thus the strength of these lumps / agglomerates. According to a best embodiment of the invention, the average length La< 3mm after step S6, give good results.

[0080] The biological stability is another way to define the fermented particulate material obtained by the method according to the invention. So, said material has a biological stability corresponding to an oxygen consumption Oclower than or equal, in g per day per g of material, and in an increasing order of preference: 3 ; 2.8 ; 2.7 ; 2.6 ; 2.5 ; 2.4 ; 2.3 ; 2.2 ; 2.1 ; 2.The oxygen consumption Occan be determined as described in detail hereinafter : For every atom of carbon (C) one molecule of oxygen (O2) is consumed in the oxidation reaction. Dry matter loss during composting in the container is directly linked to oxygen consumption. Total fresh mass and their respective dry matter contents are measured (see §

[0041] ) before and after the composting process. The difference in total dry matter multiplied by 1.14 yields the oxygen consumption for the entire container. Cellulose which is the main organic component in maize straw has a molar carbon to oxygen ratio of 1 :1 . During biological degradation, one oxygen atom from air and one O atom from cellulose are required to remove one C. Biological degradation is limited by the availability of nutrients and water. If they are consumed, the oxygen consumption goes down and the degradation comes to a halt.

[0081] The fermented particulate material obtained by the method according to the invention can be mixed with standard casings like dark milled peat, dry peat or semi-dry peat. The proportion of standard casing to fermented material in such mixture can be up to 70% v / v, preferably 0, even 5- 40% v / v, 20% v / v for instance. Such a standard casing incorporation can be useful to buffer the fermented material according to the invention and / or to reduce the electrical conductivity and pH of the mixture to e.g. < 1 .2 mS / dm and < 7.5, respectively, which may also favour fungal growth.Examples

[0082] Example 1 :

[0083] Step SI..: The grains of the raw material corn (Zea mays) are harvested using a Claas Lexion®, a standard combine harvester. The varieties used were Pioneer® 0725, Pioneer® 0312, Dekalb® 4598 and Dekalb® 5141. The harvest of the stems is conducted using a Claas Jaguar® forage harvester. This harvest is executed 2 days after the grain harvest, at an average dry matter content of the material of 27%.

[0084] Step S2: Chopping is executed using a direct disc mower, for a cutting length of around 5mm.

[0085] Step S3: The harvested material is delivered to a processing site.

[0086] Step S7: It is possibly subjected to a mechanical dewatering of the residual moisture and dissolved nutrients. Dewatering is executed using a Trumag® EX40 screw press. The dry matter content Cdmof the material in the resulting press cake is 43%. The press juice is collected and redistributed to the agricultural fields.

[0087] Step S4: In the case where dewatering S7 is implemented, the press cake, or without S7 the harvested material, is pressed into round bales and wrapped in foil to ensure anaerobic storage. A Case IH round baler, model RB456, can be used for this purpose. This baler achieves an hourly output of 30 tons of fresh material per hour. The film wrapping is carried out with a Gbweil G2020. The dry matter content is 43% and there is no loss of volume or heating during anaerobic storage.

[0088] Step S5: The stored material is used immediately and throughout the whole year for further processing. The material is sprayed with water. The water addition is around 150 L per m3of material throughput.

[0089] Step S6: The material is mechanically disintegrated using a disc mill Model High Consistency Refiner, Xuridong ZDPH 600 55kw This machine is set to maximize the fragmentation of fibers and disintegration efficiency:the largest dimension Dldis 15 mm.

[0090] Step S7: It is possibly subjected to a mechanical dewatering of the residual moisture and dissolved nutrients. Dewatering is executed using a Trumag® EX40 screw press. The dry matter content Cdmof the material in the resulting press cake is 46%. The press juice is collected and redistributed to the agricultural fields.

[0091] Step S8: The press cake is loosened in structure using a rotating mill AGERSKOV KM110.

[0092] Step S?.: Bentonite is used as a filler, at a rate of 50 g per liter of fermented particulate material.

[0093] Step .10: The material is stored for 3 days (aerobic fermentation) and shows a temperature increase to 45°C, the related mass loss is <2%.

[0094] Step .12: After addition of water, the material is stored for another 20 hours, allowing for the full development of the matrical bonding capacity.

[0095] Step.S1.4: 310 g of water are added to the material to get the lumpy fermented particulate material ready to be used notably as casing for mushrooms culture.

[0096] Measurements > average density Da= 845 g / l > density Ds= 122 g / l_ specific water content Cwat saturation = 650 g / l_ water holding capacity (WHC) = 645 g / l_ Carbon / Nitrogen ratio C / N = 106_

[0097] The density Dsof the final material is measured by filling a 20L cylinder for density determination according to EN12580.

[0098] The dimensions of the particles of the final material are measured using the method explained above.

[0099] Dry matter contents Cdmwas measured as dry mass as determined according to the method described above.

[0100] The stability of the lumps / agglomerates is determined by the so-called “snow ball test”, which is a well introduced test in the industry. The material at water saturation is used to form a snow ball manually and this snow ball is thrown against a wall. If the entire snow ball sticks to the wall and no parts fall to the ground, the material is sticky and the agglomerates of good stability.

[0101] Assessment of the. so ..obtained fermented, material

[0102] Results

[0103] The fermented, peat-free fermented clustered particulate material is tested as follows (after addition of minerals and water): A sample is prepared using of 150 g of milled fibers at a dry weight of 48.7% corresponding to 73.05g dry weight and 47g of minerals was blended and 310 g of water were added to reach the saturation point. At that point, the total weight of the material is 507g and the total dry matter including minerals is 120g , corresponding to 23.7% dry matter. After 1 day, the pH is 8.2 and the EC is 1 .2. Clusters were formed by simple movement of the material and the density Daof the lumpy particulate material is 845 g / l. 200 g of this material are distributed evently in the Buchner funnel for determination of the water holding capacity using the above-described vacuum test Twhc: A -75mbar vacuum for 5minutes resulted in 2g water extraction, corresponding to 1 % of the test material.

[0104] Example 2In a specific implementation of the invention, the storage and transportation of the fermented particulate matter is executed at semi-dry state, thereby largely reducing the water load during transport. This option is possible because of the initially rather high dry matter content of the particulate matter and its capacity to absorb and hold large volumes of water directly before the intended use of the material for casing of the mushroom beds.The material is produced according to example 1 . It is stored and transported at semi-dry state, with a water content of 121 kg / m3 and a density of 280 kg per m3. This allows to load 90 m3 or a total of 25.2 t of fermented particulate material in one full truck load, thereby using the practical limits of the truck (maximum loading volume 90m3, maximum loading weight 26 t) almost to its theoretical maximum. On the growers site, 310 g of water are added per 197 g of semi-dry fermented particulate material, thereby increasing the total weight per delivery to 64.8 t. As a result, one truckload of thecasing material according to the present invention can cover a mushroom production area of around 1535 m2 with a layer of 5cm.At this point it is important to know, that standard black peat based is extracted and transported at a density around 850 kg / m3, and a truck is at its weight limit at only around 30.6 m3 of casing material. As a result, one truckload of a black peat based casing material can only cover a mushroom production area of around 611 m2 with a layer of 5cm thickness.The fermented particulate material produced by the method according to the invention, or the fermented particulate material according to the invention as such, increases the transport efficiency by a factor of 2.5, meaning that one truckload of the claimed material can serve 2.5x more production area than a truckload of standard black peat.The watering of the new casing made of the material produced according to the invention or defined according to the invention, can e.g. be done on the site of a mushroom grower, using a screw conveyor equipped with a set of water spray nozzles, allowing the addition of 310 liters of water per 197 g of semi-dry material. However, the growers should respect that development of the full water holding capacity of the watered material and the optimum formation of lumbs requires 1-2 days of resting time.

Claims

Claims

1. A method for producing of fermented material comprising a clustered particulate material made of stalk particles of monocotyledonous flowering plants, preferably maize, and, preferably, at least one filler / additive, wherein said material can have different dry matter contents Cdmand at least one of the following characteristics:(a) an average density Daas it is spread on the ground in a layer which height is 4-5 cm is between 750-900, preferably 800-880 g / l;(b) a specific density Ds, in g dry matter per liter and in an increasing order of preference, such as :100 < Ds< 250 ; 120 < Ds< 220 ; 130 < Ds< 200 ; 140 < Ds< 200 ;(c) a specific water content Cwat saturation of the clustered particulate material is, in g / l and in an increasing order of preference, such as :550 < Cw< 950 ; 600 < Cw< 900 ; 650 < Cw< 900 ; 800 < Cw< 850(d) a water holding capacity (WHC) allowing a water extraction under a - 75 mbar vacuum, which is lower than or equal to - in % by mass and in an increased order of preference-: 6 ; 5 ; 4 ; 3 ; 2;(e) a Carbon / Nitrogen ratio C / N, in an increasing order of preference, such as : 60 < C / N ; 70 < C / N ; 80 < C / N ; 90 < C / N ; 95 < C / N < 120; and wherein at least some of the following steps are implemented, in this order or in a different order:S.1 .harvesting the grains of monocotyledonous flowering plants, preferably from the subfamily Panicoideae, and more preferably maize, so as the stalks remain stand on the field;5.

2. chopping and, preferably shredding, the remaining stalks standing on the field into a particulate material;5.

3. possible transporting the particulate material to a processing site;5.

4. submitting the particulate material, to an anaerobic fermentation;5.5.water spraying on the fermented particulate material;5.

6. grinding the watered fermented particulate material to its largest dimension Dld, in mm, and in an increasing order of preference, is such as :D2ld< 15 ; D2ld< 12 ; D2ld< 9 ; D2ld< 6 ; D2ld< 35.

7. possible dewatering the grinded fermented particulate material, so as to get a dry matter content Cdm, in % by mass, such as : 35 < Cdm< 60 ; preferably 40 < Cdm< 55;S.

8. loosening of the grinded fermented particulate material;S.

9. possible addition to the loosened fermented particulate material of at least one filler / additive, preferably consisting in at least one clay;5.

10. possible submitting the fermented particulate material, to at least another fermentation during a time sufficient, so that the temperature of the particulate material reaches a value Tp(°C) greater than or equal to, in an increasing order of preference; 50 ; 55 ; 60 ; 65 ;5.1 1. possible thermal treatment of the fermented particulate material, preferably steam treatment;5.

12. possible addition of water to the fermented particulate material and storing;5.

13. possible storing and / or conditioning and / or transporting the fermented particulate material, in a dry matter content Cdm, in % by mass, such as : 45 < Cdm< 65 ; preferably 50 < Cdm< 60;5.

14. addition of water to the fermented particulate material to adjust the dry matter content Cdm, in % by mass, such as : 10 < Cdm< 40 ; preferably 15 < Cdm< 30; to get so a lumpy fermented particulate material ready to be used.

2. A method according to claim 1 wherein the steps ,S1 . ; ,S2. & .S3, are replaced by the following steps :.S01 . implementing cut stalks of monocotyledonous flowering plants, preferably from the subfamily Panicoideae, and more preferably maize;.S02. shredding the cut stalks from (S01) into a particulate material;.S03. possible storing of the particulate material.

3. A method according to claim 1 or 2, wherein step (S2) or step (S02) is implemented by means of forage harvester.

4. A method according to any of claims 1 to 3, wherein step (S2) or (S02) leads to stalk particles having a particle size given by their largest dimension D2ld, in mm and in an increasing order of preference, such as :D2ld< 15 ; D2ld< 12 ; D2ld< 9 ; D2ld< 6 ; D2ld< 3

5. A method according to any of claims 1 to 4 wherein step (S6) is a grinding implemented by means of at least one mill chosen in the group comprising -preferably composed of- impact mill, grinding mill, disk mill, combinations thereof, disk mill being preferable.

6. A method according to any of claims 1 to 5 wherein in step (S5), water is added in order to achieve a dry matter content Cdmof 15-30%, and preferably 18-25%.

7. A method according to any of claims 1 to 6 wherein in step (S10), the addition of filler is comprised between 5 and 150 kg / m3, preferably between 20 and 100 kg / m3, and more preferably between 30 and 80 kg / m3.

8. Fermented material, produced in particular by the method according any of the claims 1 to claim 7, said fermented material comprising a clustered particulate material made of stalk particles of monocotyledonous flowering plants, preferably maize, and, preferably, at least one filler / additive, wherein:(a) an average density Daas it is spread on the ground in a layer which height is 4-5 cm is between 750-900, preferably 800-880 g / l;(b) a specific density Dsof the material, in g dry matter per liter and in an increasing order of preference, such as :100 < Ds< 250 ; 120 < Ds< 220 ; 130 < Ds< 200 ; 140 < Ds< 200(c) a specific water content Cwat saturation of the material is, in g / l and in an increasing order of preference, such as :550 < Cw< 950 ; 600 < Cw< 900 ; 650 < Cw< 900 ; 800 < Cw< 850(d) a water holding capacity (WHC) allowing a water extraction under a - 75 mbar vacuum, which is lower than or equal to - in % by weight and in an increased order of preference- 6 ; 5 ; 4 ; 3 ; 2;(e) a Carbon / Nitrogen ratio C / N of the material is, in an increasing order of preference, such as : 60 < C / N ; 70 < C / N ; 80 < C / N ; 90 < C / N ; 95 < C / N < 120.

9. Fermented material according to claim 8 having a biological stability corresponding to an oxygen consumption Oclower than or equal, in g per day and g of material and in an increasing order of preference: 3; 2.8 ; 2.7 ; 2.6 ; 2.5 ; 2.4 ; 2.3 ; 2.2 ; 2.1 ; 2.

10. Fermented material according to claim 8 or 9 characterized in that it is a culture medium and / or plant substrate component and / or a peat substitute.

11. Fermented material according to any of claims 8-10, characterized in that it is mixed with standard casings in a proportion preferably of up to 70% v / v, preferably 0, even 5-40% v / v.