FR3008577A1 - PROCESS FOR CULTIVATION OF COLZA ON A PLOT - Google Patents

Abstract

The present invention relates to a method of growing rapeseed on a plot. This process consists in implementing at least the following successive operations: - a planting operation of rape seed on said parcel, in association with a mixture of legume seeds consisting of seeds of common Vetch, seeds of purple Vetch and of clover seed of Alexandria, - following a phase of implantation of the rapeseed plants and the leguminous plants derived respectively from the said seeds of rapeseed and leguminous plants, and before a flowering phase of the said rapeseed plants, a determination operation the vegetative state of the leguminous plants within the said parcel, - in the case of the determination of a state not destroyed for the leguminous plants and before the said phase of flowering of the rape plants, a targeted destruction operation of the said plants legumes by keeping them on the said parcel.

Description

TECHNICAL FIELD TO WHICH THE INVENTION RELATES The present invention relates to techniques for the cultivation of rapeseed, in particular those using the plant association technique (also called "associated culture").

BACKGROUND OF THE INVENTION Rapeseed is conventionally grown in pure form, following a relatively precise cultivation route. The optimum yield is currently obtained by respecting certain cultural practices, mainly concerning: sowing, weeding, protection against bio-aggressors and fertilization. Still to ensure its productivity, but more economically and / or more environmentally friendly, another available route is based on the technique of growing rapeseed in association with other plants. These associated plants aim to: - generate a significant biomass, capable of stifling weeds, without, however, penalizing the development of rapeseed, - allowing an improvement of the soil structure at the time of implantation, and - ensuring a supply of nitrogen, to ultimately optimize the yield of rapeseed. For example, the known associations are based on legumes, including pea, lentil, fenugreek, etc., pure or associated.

But the known associations of the state of the art are not completely efficient. In addition, in practice, this technique is relatively complex, and a poor variety of associated plants can lead to serious consequences for the cultivation of rape, including competition type, yield loss, etc. It is therefore interesting, even indispensable, to propose new techniques of plant associations that are capable of improving the rapeseed crop yield, while preventing the occurrence of the aforementioned negative consequences. OBJECT OF THE INVENTION The present invention relates to a rapeseed cultivation process on a plot. This cultivation process consists in carrying out at least the following successive operations: a planting operation of rapeseed seeds on said parcel, in association with a mixture of legume seeds consisting of seeds of common Vetch, seeds of purple Vetch and clover seed of Alexandria, following a phase of implantation of rapeseed plants and legume plants derived respectively from said sown rapeseed and legume seeds, and before a flowering phase of said rape seedlings, an operation of determining the vegetative state of the leguminous plants within the said parcel, either in a destroyed state or in a non-destroyed state, - in the case of the determination of a state not destroyed for the leguminous plants and before that phase of rapeseed plants, a targeted destruction operation of said legume plants by keeping them on said plot.

According to other advantageous features of the invention, which can be taken in combination or independently: the operation of determining the state of the leguminous plants and the eventual operation of destroying said legume plants are carried out during winter or at the beginning of a spring vegetation recovery phase; - the operation of destroying the legume plants is carried out by applying a herbicide within the parcel, said herbicide being able to destroy the legume plants without destroying the rapeseed plants; - the legume seed mixture, sown in combination with the rape seed, contains Vetch seeds selected from the varieties SPIDO and VB19; - the legume seed ratios, expressed by weight of each component in the legume seed mixture, are as follows: - 45 to 50% Common Vetch seed, - 30 to 35% Purple Vetch seed, and - 18 to 22% clover Alexandria seeds; - during the sowing operation, the seeds are sown at the following densities on the plot, on the basis of an average seeding dose of between 20kg and 25 kg per hectare: - 15 to 25 Common Vetch seeds per m2, - 10 to 20 purple vetch seeds per m2, - 120 to 200 Alexandria clover seed per m2, and - 30 to 60 rapeseeds per m2; - The sowing operation consists of either simultaneous implantation of rapeseed and legume seeds, or successive implantation of legume seeds and rape seeds.

The present invention also relates to a seed mixture for the cultivation of rapeseed, consisting of a mixture of legume seeds consisting of Common Vetch seeds, Purple Vetch seed and Alexandria clover seed. The invention also relates to a seed mixture for the cultivation of rapeseed, comprising rapeseeds in association with a mixture of legume seeds as defined above. The legume seed ratios, expressed as the weight of each component in the legume seed mixture, are preferably as follows: 45 to 50% common vetch seeds, 30 to 35% purple vetch seeds, and - 18 to 22% clover Alexandria seeds. DESCRIPTION OF THE INVENTION The applicant proposes a process for the cultivation of rapeseed on a plot. By "rapeseed" is still meant the plant known scientifically Brassica napus or more precisely Brassica napus var. napus. This plant is an annual plant with yellow flowers of the family Brassicaceae. It is widely grown for the production of edible oil and agro-fuel, the solid residues obtained after extraction of the oil (called cakes) being used in animal feed. By "rapeseed" is meant in particular a winter rapeseed, sown in full summer (from August 15 to September 15); it may be for example a rapeseed variety DK exstorm or DK explicit.

In general, after sowing in late summer, the rapeseed crop cycle can be divided into two major periods and six growth stages. In autumn: vegetative development - Stage A: development of cotyledons (emergence) - Stage B: formation of the leaf rosette In spring: reproductive phase - Stage C: stem rise - Stages D and E: formation of flower buds - Stage F: flowering - Stage G: formation of siliques and grains. In the present case, the applicant proposes a new technique or process for growing rapeseed, based on the plant association technique.

This technique, also called "associated culture", is a technique sometimes used in gardening to associate different plant species within the same plot, these plants can be exchanged various services if their choice is judicious (nutrition, repellent action or toxic to specific insects and / or weeds ...).

The cultivation process according to the invention essentially consists in carrying out at least the following successive operations: - a planting operation of rapeseed seeds on a plot, in association with a specific mixture of legume seeds, this preferably in end of summer (between the 15th of August and the 15th of September), with the aim of associating rapeseed with a vegetable cover of leguminous plants, - an operation of determination of the vegetative state of the leguminous plants within this parcel, this preferably at the end of winter, so as to check the destroyed or not state of the vegetal cover of legumes, - a possible operation of targeted destruction of the leguminous plants (in the case where they have not been destroyed in a natural way by the cold, especially by the winter frost), keeping them on the plot. These various operations are presented in more detail below in the context of the invention.

Firstly, during the seeding operation (in one or more passages), the legume seed mixture, sown in association with the rapeseeds, is constituted by a combination of three specific species, namely: Common Vetch seeds, Purple Vetch seeds, and Alexandria clover seeds. The varieties of these three legume species are chosen according to the following criteria: ability to cover the soil quickly, frost sensitivity, rapid mineralization after destruction with a low C / N ratio. For example, common Vetch seeds are of the variety SPIDO (code GNIS 073 0136) or NACRE (code GNIS 073 0132), registered in the French Catalogs which can be consulted on the database of the GNIS (National Group of Interprofessional Seeds and Plants) , FR); Purple Vetch seeds are of the variety BINGO or VB19 or TITANIUM (the latter is described in particular in a plant variety certificate 20162); and the clover seed of Alexandria is of the TABOR variety, listed in European Catalogs and German Catalogs. These legume seeds are advantageously mixed in particular proportions. In this respect, for example, the ratio of each species is hereinafter expressed as a percentage by weight of each component in the mixture: - 48% Common Vetch seed, - 32% Purple Vetch seed, and - 20% of clover seed from Alexandria. These seeds are preferably sown at the following densities on the plot, on the basis of an average seeding dose of between 20kg and 25kg per hectare, namely: - 15 to 25 Common Vetch seeds per m2, - 10 to 20 Purple Vetch seed per m2, - 120 to 200 Alexandria clover seed per m2, and - 30 to 60 rapeseeds per m2. In general, these proportions of leguminous seeds are advantageously provided to obtain the following desired stand on the plot: - 25 to 40 vetch plants per m2, - 60 to 100 Alexandria clover plants per m2, and - 25 to 35 plants of rapeseed per m2. The interest of the composition according to the invention is as follows: - a rapid soil cover, limiting the soiling, - a secure implantation of the associated plant (three species of legumes), - an improved soil structure, thanks to to the complementary root work of the three leguminous plants, - an excellent nitrogen restitution to the rapeseed crop, - a reinforced soil fertility (effect of legumes), - the use of varieties susceptible to frost destruction (to seek a natural destruction of legumes and limit the use of chemical destruction by the farmer). This sowing operation is advantageously adapted to promote the growth of rapeseed and associated legume plants, and to increase the susceptibility to freezing of legume plants by the most advanced stage of development possible and by the early maturity of the varieties used. This possible destruction by frost during the winter allows a mineralization of the canopy improving the supply of nitrogen to the rapeseed at the end of winter. The sowing operation can be carried out in two ways: - a simultaneous implantation of rapeseed and legume seeds (mixed in the seeder or in two separate seed boxes), or - a successive implantation of the seeds of legumes then rapeseed (also called "two-stage sowing"). Simultaneous seeding in a single pass is preferred. For this, one uses either a drill equipped with a double hopper, or a direct rapeseed / leguminous mixture in the drill used for cereals.

In the case of a double hopper, a first hopper receives the seeds of rapeseed; a second hopper receives the legume seed mixture. For a direct rapeseed / legume mixture, the combination of different seed types contributes to a good homogeneity and fluidity of the mixture The weight of a thousand grains (PMG) and the texture of the seed coat limit the separation of the components of the mixture. The operator thus sows a preconstituted seed mixture for rapeseed, including rapeseed and legume seeds. For two-stage implantation, the mixture of leguminous seeds (without rapeseeds) is advantageously sown at reduced spacing with a cereal-type seed drill (17 to 20 cm between the rows); the rapeseeds are then sown with a precision seeder or Striptill, with a spread of 35 to 45 cm depending on the equipment. The term "Striptill", known in the agronomic field, means work in bands (lines). The technique of "Striptill" allows to work only the seeding band.

Before the sowing operation, the application of a herbicide can be considered (situations with high pressure weeds); but post-emergence weeding is preferred. The operation of determining the vegetative state of the leguminous plants, within the plot, consisting of a visual observation of the state of the canopy, is useful during the winter to judge the desirability of a destruction by weeding. This determination operation is carried out following an implantation phase of the rapeseed plants and legume plants respectively from said seeded seeds of rapeseed and legumes, and before a flowering phase of said rapeseed plants. By "vegetative state of leguminous plants" is meant in particular the vegetative state of these plants either in a destroyed state (or dead) or in a non-destroyed state (living or vegetative growth). In fact, the selected legume plants are frosty (sensitive to frost). These plants are thus normally intended to be destroyed naturally, by a winter period of freezing. In the case where the leguminous plants are destroyed (in the abovementioned destroyed state), no further operation is necessary against these plants.

On the other hand, in the case where the same legume plants are not destroyed (in the aforementioned non-destroyed state) (in particular in case of non-freezing during the winter period) and before the flowering phase of the rape plants, it is planned to implement a targeted destruction operation of legume plants (preferably a chemical destruction) by keeping them on said plot. Here again, this targeted and in situ destruction operation is advantageously carried out during the winter or at the beginning of a spring vegetation recovery phase.

The destruction of this canopy is in particular achieved by the application of a selective herbicide within the plot, to destroy these legume plants without destroying rape plants. For this purpose, it is possible, for example, to apply a Lontrel type herbicide (registered trademark - Syngenta), at a reduced dose of 0.5 to 0.7 liter starting February 15th (stage C1 to D1). Legume plants, destroyed on site (naturally during the winter by frost, or following the application of the specific herbicide), break down on site to participate in an additional supply of nitrogen to rapeseed during its development especially during the recovery and flowering phase. This contribution is mainly due to the mineralization of the aboveground and root biomass of the associated cover. Rapeseed nutrition is also optimized by: - improved rapeseed rooting through the root system of legume plants, and - overall improvement in soil functioning. Rape benefits from the benefits of destroyed legumes, until flowering, to reduce the supply of nitrogen fertilizer. For example, experiments have been carried out to compare the agricultural yield, expressed in terms of quintal per hectare or q / ha, between - a single rapeseed control and - a rapeseed in combination with a mixture of legume seeds consisting of common vetch seeds, of purple vetch and clover seed of Alexandria. The yield of the rapeseed control alone is 33.88 q / ha, compared to a yield for the rapeseed in the associated crop of 36.28 q / ha.

In the present example, the implementation of the method according to the invention thus provides an agricultural yield gain of 2.4 q / ha. In general, the process according to the invention has the following advantages: - rapid installation and development of the associated canopy plants, - high soil cover capacity, without penalizing the installation of rapeseed, - ease of destruction by frost, - a high capacity of mineralization at the end of winter and a spread of the return of the nitrogen to the rapeseed, and - a low PMG (weight of 1000 grains) for the species considered, for a greater ease of sowing in association.15

Claims (10)

1. A rapeseed cultivation method on a parcel, characterized in that it consists in implementing at least the following successive operations: - a planting operation of rapeseeds on said parcel, in association with a mixture legume seeds consisting of common vetch seed, purple vetch seed and clover seed of Alexandria, following a phase of implantation of the rape seedlings and legume plants derived respectively from the said rapeseed and leguminous plants, and before a flowering phase of the said rape seedlings, an operation for determining the vegetative state of the leguminous plants within the said parcel, either in a destroyed state or in a non-destroyed state, - in the case of determining a non-destroyed state for leguminous plants and before said flowering phase of rapeseed plants, a targeted killing operation of said seedlings legumes retaining them on the said parcel. 2. A method of cultivating rapeseed on a plot according to claim 1, characterized in that the operation of determining the state of the leguminous plants and the eventual operation of destruction of said legume plants are carried out during the period. winter or at the beginning of a spring vegetation recovery phase. 3.- rapeseed cultivation method on a parcel according to any one of claims 1 or 2, characterized in that the operation of destruction of legume plants is carried out by applying a herbicide within the parcel, said herbicide capable of destroying legume plants without destroying rape plants. 4. A method of cultivating rapeseed on a plot according to any one of claims 1 to 3, characterized in that the mixture of legume seeds, sown in association with the rapeseed, comprises Vetch seeds selected from SPIDO and VB19 varieties. 5. A rapeseed method on a parcel according to any one of claims 1 to 4, characterized in that the fat ratios of legumes, expressed by weight of each component in the mixture, are the following: - 45 to 50 % of Common Vetch seeds, - 30 to 35% of purple Vetch seed, and - 18 to 22% of Alexandria clover seed. 6. A rapeseed cultivation method on a plot according to any one of claims 1 to 5, characterized in that, during the sowing operation, the seeds are sown at the following densities on the plot, on the basis of an average planting dose of between 20 kg and 25 kg per hectare: - 15 to 25 Common Vetch seeds per m2, - 10 to 20 purple vetch seeds per m2, - 120 to 200 seeds of Alexandria clover seed per m2, and - 30 to 60 rapeseeds per m2. 7. A method of cultivating rapeseed on a plot according to any one of claims 1 to 6, characterized in that the sowing operation consists of either a simultaneous implantation of rapeseed and legume seeds, or in a Successive implantation of legume seeds and then rapeseeds. 8.- Mixture of seeds for the cultivation of rapeseed, characterized in that it consists of a mixture of legume seeds consisting of seeds of common Vetch, seeds of purple Vetch and clover seeds of Alexandria. 9. Seed mixture for the cultivation of rapeseed, characterized in that it comprises rapeseeds in combination with a mixture of leguminous seeds according to claim 8. 10. Seed mixture for rape cultivation according to claim 8, wherein the legume seed ratios, expressed by weight of each component in the mixture, are as follows: 50% common vetch seeds, - 30 to 35% purple vetch seed, and - 18 to 22% Alexandria clover seed.