FR2510351A1 - Underground irrigator for vegetable culture - uses network of flexible pipes in horizontal plane below roots to feed porous pipes at regular intervals - Google Patents

Abstract

The irrigator feeds water into the structure of the soil in metered quantities sufficient to achieve the required humidity of the bed under cultivation. The water is distributed at a depth corresponding approximately to the plant root length and is dispersed in regularly spaced zones. The system may comprise a network of flexible pipes (11,13,16) distributing water to regularly spaced points on a horizontal plane beneath the plant roots, dispersal being effected by porous pipe lengths (18) with closed ends. The main (11) may be fed from a tank of which the floor is at the same level and the feed may be controlled by a valve activated by humidity sensors.

Description

Irrigation method and installation for implementing this method
The subject of the invention is an irrigation method and an installation for implementing this method.

Up to now, the irrigation of a soil is obtained either by a controlled submersion and this by means of hydromechanical equipment ensuring practically constant levels, or else by means of rotating alternating spray devices. carried by vertical mobile columns, or by spraying vehicles moving on the ground.

All known methods have drawbacks if the water distribution is irregular and / or the penetration into the soil is insufficient. In addition, certain areas of the land are privileged and others disadvantaged.

On the other hand and mainly, they entered an enormous consumption of water, for the greater part due to the surface losses by evaporation.

The method according to the invention eliminates these drawbacks. It is characterized by the fact that the irrigation of the so is obtained by diffusion of water in the aous-ssolt
The invention provides for diffusion at points distributed in the subsoil and applies the capillarity of the soil to ensure a regular distribution of water and a substantially uniform humidification.

The invention also relates to an installation for implementing the method, characterized in that it comprises pipes buried in the ground, forming a grid or network and which are fitted, from place to place, with porous sleeves ensuring the diffusion.

The dimensions of the meshes that form the grid depend on the nature of the ground to be humidified, climatological conditions and also on the type of plants that one wishes to cultivate.

The depth of burial of the pipes depends on the length of the roots of the crops
The pipes are advantageously flexible.

The assembly of the porous sleeves on the pipes can be done in the factory.

Transport is done by section of pipes and assembly is carried out on site.

By the method according to the invention, the irrigation is permanent.

 It only requires fixed installations, which can be executed inexpensively. The water present at the roots practically does not evaporate.

It is no longer necessary to have a high water supply pressure. The pressure of the city network or that of an intermediate basin is more than sufficient.

The supply can also be made by a free-flowing source at the highest point of the land to be irrigated, or by a tank whose base is substantially at the same level as the distribution pipes.

The invention provides for conducting irrigation while holding. takes into account eminently variable temperature conditions between day and night, mainly in countries with high sunshine. During the day, the high temperature of the soil surface contributes to the ascent of water from the underlying sleeves. During the night, on the contrary, part of the water present in the surface layer is recovered following an advance in the opposite direction.

In the following description, given by way of example, reference is made to the appended drawing in which the single figure is a perspective view of an installation part according to the invention, the floor being assumed to be transparent.

A pipe 11 of relatively large section is connected by one of its ends 12 to a source of supply of reservoir water, city network, etc., the water intake being controlled by a valve, not shown. Pipe 11 come from perpendicular pipes, such as pipe 13, of smaller cross section and assembled with pipe II by fittings 14. A pipe 13 has, regularly distributed over its length, fittings 15 from which come from other pipes 16, of even smaller section, and alternately directed in one direction and the other, pipes 161, 163, 165, etc.

being directed in one direction and the pipes 162, 164, 166, etc., being directed in. the opposite direction.

Regularly distributed along a pipe 16 are fittings 17 on which depend porous hollow sleeves 18 iron més at their end opposite to the fitting 17. Said sleeves are perpendicular to the pipes 16 on which they depend. They can be between horizontal or directed upwards, as shown in 18ê and 18b3 They are assembled by Screwing or gluing on the fittings 17.

The various fittings are preferably mounted on a swivel joint.

The set of pipes 16 constitutes a network or grid with rectangular meshes buried in the ground, in principle at constant level, at a depth which is slightly greater than the length of the roots of the plants to be cultivated.

The pipes are advantageously flexible made of polyvinyl chloride, polyethylene, etc.

The hollow sleeves are made of porous material, like porous porcelain.

The distribution of the porous sleeves is such that the volume zone that each of them is suitable for humidifying is substantially tangent to the other zones humidified by the adjacent porous sleeves, as mentioned in dotted lines in the figure.

The installation of the installation depends on the nature of the land to be irrigated, the plants to be cultivated and the operating equipment,
A spacing of 5 m between the adjacent pipes 16 and a spacing of 3 m between the porous sleeves 18 of the same pipe have given good results.

During the day, during the period of sunshine, mainly in tropical or equatorial countries, the water injected deep is requested by thermal effect towards the surface of the ground: during its ascent, it moistens the earth.

During the night, as the surface of the ground cools, the water migrates towards the porous sleeves which act as drains.

The excess water is returned to a tank, the contents of which, during the day, are transferred by pump, advantageously electro-solar, to a main storage tank.

The need for water decreases very quickly during the first days of irrigation to stabilize at a low value.

The control of the irrigation according to the humidity of the soil can be obtained by probes, driven from place to place, the circulation of the water being then controlled by solenoid valves.

A plant treatment can be obtained simply by adding a suitable product to the irrigation water,
It has been observed that the consumption of water is incomparably lower than by using conventional humidification devices by spraying, of the order of 1 to 20 and even 30.

 It becomes possible, in Mediterranean or tropical countries, where most of the water supplied is currently lost by evaporation, to cultivate mane outside the rainy season and this with minimal consumption of water withdrawn on surface or underground reserves.

The absence of an aerial spraying system allows the building to be unhindered by climatic greenhouses.

Claims (12)

Claims 1. Irrigation method for growing plants, characterized in that the water is brought into the soil itself in a quantity dosed according to the desired humidification in the cultivated layer. 2. Method according to claim 1, characterized in that the water is distributed at a depth substantially equal to the length of the roots of the cultivated plants. 3. Method according to claim 1, characterized in that the water is distributed in the soil in quasi-punctual zones regularly distributed. 4. Method according to claim 1, characterized in that the water is diffuse. 5. Irrigation installation for growing plants, for implementing the method according to any one of claims 1 to 4, characterized in that it comprises a distribution network or grid (11,13,16) of water in points of the basement regularly distributed on a horizontal plane sensiblenient to a depth slightly greater than that which corresponds to the length of the roots of the plants to cultivate. 6. Irrigation installation for growing plants according to claim 5, characterized in that the network consists of pipes (11.13,16) made of flexible material. 7. Irrigation installation for the cultivation of plants according to claim 5, characterized in that a pipe (11) of water inlet come from the parallel branches (13) perpendicular to the inlet pipe and where depend pipes (16) perpendicular to the branches with, from place to place of said last pipes, water distributors (18).  & Irrigation installation for growing plants according to claim 7, characterized in that a distributor (18) is constituted by a porous sleeve, 9. Irrigation installation for growing plants according to claim 8, characterized in that the sleeve (18) is closed at its end opposite to that linked to the pipe (16). 10. Irrigation installation for growing plants according to claim 5, characterized in that a main supply pipe (11) is connected to a tank. 11. Irrigation installation for growing plants according to claim 10, characterized in that the base of the tank is substantially at the level of the main supply pipe (11). 12. Irrigation installation for growing plants according to claim 10, characterized in that the circulation of water in an inlet pipe (11) is controlled by a valve. 13. Irrigation installation for growing plants according to claim 5, characterized in that probes immersed in the ground control one or more valves as a function of the soil moisture. 14. Pipe section forming part of an installation according to one of claims 5 to 13 and comprising a porous sleeve (18).  15, MWn porous plug for the distribution of water and associated with a pipe section (16) according to claim 14.