FR2823502A1 - Organo-mineral soil amendment comprising synergistic mixture of lime-treated household rubbish and plant compost, having e.g. structuring, clay-humus complex formation and aeration promoting effects - Google Patents

Abstract

An organo-mineral amendment (I) for structuring soil comprises a mixture of (a) lime-treated household rubbish and (b) plant compost. An Independent claim is included for the production of (I), by: (i) milling household rubbish (optionally after preliminary sorting); (ii) removing any ferrous metals; (iii) treating the rubbish with lime; (iv) screening then storing the product; and (v) mixing the product with plant compost.

Description

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  Organo-mineral amendment for soil structuring The field of the invention is that of agriculture. More specifically, the invention relates to amendments to improve the structural stability of

soils, especially agricultural.

  In this area, it is currently observed that most of the soils have been destroyed, in particular due to the intensive use of mineral fertilizers and deep plowing. These practices helped to generate a structure of

  soil is waterproof and suffocating.

  The agronomic potential of the soil is therefore impaired and we observe in particular: - an accelerated reduction in the organic matter contained in the soil; - a reduced capacity of the soil with respect to the retention of water and mineral salts;

  - soil erosion and compaction.

  It is known that organic matter constitutes, with the clay complex

  humic, an essential element for food and plant growth.

  Organic matter is also a determining element for maintenance

  soils and maintaining their fertility.

  In the soil, organic matter undergoes a transformation cycle, which results in the formation of humus, and which is broken down into two phases: - a mineralization phase leading to the formation of simple mineral elements; - a humidification phase which causes the reorganization of the elements

into stable humic compounds.

  To improve the quality of agricultural land, we know in particular the structuring power on the soil of green waste composts (grass clippings, hedge trimming, leaves, pruning branches ...) which constitute a contribution

important organic matter.

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  However, the production of green waste is seasonal and requires storage facilities which can be costly. In addition, the effectiveness of such composts used alone, is however limited and these do not provide a

solution stable over time.

  The use of these composts has therefore been proposed by combining them with other elements such as slurry, and in particular poultry droppings. The product obtained then falls into the fertilizer category and does not provide soil

than a reduced structuring effect.

  The invention aims to overcome these disadvantages of the prior art.

  More specifically, the invention aims to provide an amendment which has a structuring effect on the soil more effectively and more durably than

the solutions of the prior art.

  Another object of the invention is to provide such an amendment which

  increases the pH of acid soils.

  The invention also aims to provide such an amendment which promotes the retention of water and mineral salts in the soil while limiting the

  erosion and compaction phenomena.

  Another objective of the invention is to provide such an amendment which meets the logistical and regulatory requirements linked to agronomic efficiency, safety and consistency of the composition (homogeneity,

invariability and stability).

  The invention also aims to provide such an amendment which improves, or at least preserves, the porosity, permeability and aeration of the soil. Another object of the invention is to provide such an amendment which increases the capacity for exchange of nutrients in the soil and improves the storage regulation and the supply by the soil of ions and organic compounds.

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  These various objectives are achieved with the help of an organo-mineral amendment for soil structuring, comprising a mixture of garbage

  whitewashed housewives and vegetable compost.

  According to a preferred solution, the amendment comprises a mixture of the fermentible fraction of said limed household waste and vegetable compost. A particularly favorable mixture is thus obtained for structuring the soils. Household waste represents a considerable resource of organic matter, containing a fermentable fraction which is particularly favorable for the formation of stable humus when the organic matter of the waste,

  likely to evolve quickly, is mixed with vegetable compost.

  In other words, the calcium in the lime allows the association of the humus micelles of the green waste compost with those of the soil clays to lead to the formation of clay-humic complexes, while the organic matter is fresh from the garbage housework rather evolves towards stable humus in

presence of calcium.

  This allows an advantageous synergy between calcium and humus from

  the amendment which promotes the formation of clay-humic complexes.

  The amendment according to the invention allows the formation of additional clay-humic complexes, providing a structure which is most favorable to the improvement of physical fertility. This structure effectively provides excellent aeration of the soil, improves cation exchange and promotes

  penetration of plant roots.

  The amendment obtained is not a simple compost because all its organic matter is not stabilized, nor a fertilizer because it does not contain enough

  mineral nutrients to enter this classification.

  The invention further provides a way of recovering the organic matter contained in household waste produced in increasingly large quantities and thus provides an alternative to their elimination by

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  incineration which pose many economic problems,

environmental, even technical.

  According to an advantageous solution, said mixture comprises, by weight, approximately two thirds of limed, screened household waste for approximately one third of vegetable compost. With these proportions, a structuring effect for the mixture is effectively achieved, while taking into account the quantities of resources available. It is in fact economically interesting to recover significant quantities of

  organic matter contained in household waste.

  According to a preferred solution, said mixture comprises by weight at least

% of organic matter.

  Advantageously, the amendment includes a lower nitrogen content

  at 2% of the weight of the dry matter of said mixture.

  Preferably, the amendment comprises, by weight, less than 3% of one of the following: - nitrogen; - phosphorus;

- potassium.

  With such characteristics, the amendment obtained meets the current normative specifications concerning the characteristics required for

organic amendments.

  According to another preferred characteristic of the invention, said mixture comprises a fraction of cellulose and lignin greater than 39% by weight of the

dry matter of said mixture.

  Although having a limited organic matter content, such a fraction of cellulose and lignin ensures the product a more humic potential.

  important that the limed household waste crushed and screened alone.

  According to an advantageous solution, said vegetable compost comprises, in

  weight, between 35 and 40% organic matter.

  Such a vegetable compost will thus contribute to the fact that the amendment obtained:

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  - provides stable humus; - increases the biological activity of the soil; improves the water retention capacity of soils:

  - promotes the assimilation of mineral elements.

  The invention also relates to a method for obtaining an amendment as defined above, comprising the following steps: - grinding said household waste; - removal of ferrous metals contained in said household waste; - liming said household waste; screening of said limed household waste; - storage of the product obtained;

  - mixing of said product obtained with said vegetable compost.

  Such a process helps to achieve regulatory and legislative requirements in terms of safety. The metallic micropollutants are largely eliminated at the end of the iron removal operation, while the pathogenic microorganisms are destroyed by lime (the destruction of the most resistant microorganisms is effective after approximately

hundred days).

  The screening process is carried out to allow sufficient removal of unwanted material. The screening is carried out with a sieve having a mesh of dimension appropriate to the technique and the regulations. Thanks to this characteristic, almost all inert materials are eliminated

  contained in household waste.

  Preferably, the method comprises a preliminary sorting step

  recycling of said household waste.

  Especially at the level of the undesirable, better results are thus obtained.

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  Other characteristics and advantages of the invention will appear more

  clearly on reading the following description of an embodiment

  preferred of the invention, given by way of illustrative and nonlimiting example, and of the drawings among which: FIG. 1 represents in the form of a flowchart the steps of a

  process for obtaining a structuring amendment according to the invention.

  According to the preferred embodiment of the process for obtaining a structuring amendment according to the invention, the household waste used is said to be gray and contains, after sorting, less wood, paper, cardboard,

  glass, metals and plastics as unsorted household waste (step 1).

  The gray household waste is then crushed (step 2) so as to empty the bags of their contents and to reduce the heterogeneity of the particles, while still allowing the elimination of undesirable materials as will be

indicated below.

  We then proceed to a de-ironing operation (step 3) in a conventional manner in itself in order to extract ferrous and non-ferrous metals from

household waste.

  At the end of the cleaning, the household waste is limed (step 4) at the rate of an addition of lime equivalent to approximately 35% by weight of the

  dry matter of crushed garbage.

  After liming, the product is left to stand for an appropriate time to

  allow the lime to produce its hygienic effect.

  The limed household waste is then screened (step 5)

  suitable for eliminating unwanted.

  The product obtained is then stored (step 6).

  After storage, a green waste compost is introduced into the product from steps 1 to 6 of the process to obtain an organic amendment.

mineral (step 7).

  The quantity of plant compost introduced corresponds, by weight, to the

  half of the product obtained after the screening step.

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  After analysis of batches of product obtained with the process according to the invention, it is verified that the amendment has a low nitrogen content (0.557% according to a test carried out) and stable, compared with the usual value of the composts which are

is around 2%.

  The levels recorded for the fertilizing minerals, in particular for phosphorus and potassium are relatively low, being respectively

  2.88% o and 2.08% o on certain lots analyzed.

  The biochemical characterization of the organic matter of the amendment according to the invention, which makes it possible to estimate the humic potential and to express the percentage of organic matter which turns into stable humus, shows that the product is rich in mineral matter. and that the addition of cellulose and lignin (greater than 39% by weight of the amendment) generates a structuring effect

verifiable on soils.

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Claims (10)

REVENDIC AT IONS   1. Organo-mineral amendment for soil structuring, characterized in that it comprises a mixture of limed household waste and plant compost. 2. Amendment according to claim 1, characterized in that it comprises a mixture of the fermentible fraction of said household waste limed and vegetable compost.   3. Amendment according to any one of claims 1 and 2, characterized   in that said mixture comprises, by weight, about two thirds of garbage   limed housewives screened for about a third of vegetable compost.   4. Amendment according to any one of claims 1 to 3, characterized   in that said mixture comprises by weight at least 20% of organic matter.   5. Amendment according to any one of claims 1 to 3, characterized   in that it comprises a nitrogen content of less than 2% of the weight of the dry matter of said mixture.   6. Amendment according to any one of claims 1 to 3, characterized   in that it comprises by weight, less than 3% of one of the following elements nitrogen; - phosphorus; - potassium.   7. Amendment according to any one of claims 1 to 6, characterized   in that said mixture comprises a fraction of cellulose and lignin   greater than 39% of the weight of the dry matter of said mixture.   8. Amendment according to any one of claims 1 to 7, characterized   in that said vegetable compost comprises, by weight, between 35 and 40% of organic materials. 9 2823502   9. Procedure for obtaining an amendment according to any one of   Claims 1 to 8, characterized in that it comprises the steps   following: - grinding of said household waste; - removal of ferrous metals contained in said household waste; - liming said household waste; - screening of said limed household waste; storage of the product obtained;   - mixing of said product obtained with said vegetable compost.   10. Method according to claim 9, characterized in that it comprises a