Substrate for hydroponic or soilless cultivation

Abstract

This invention is related to a new substrate (6) for soilless cultivation consisting of a three-dimensional reticular structure which is elastically compressible, with empty cells bounded by threads made of polymer or any other material which are chemically inert, hydro-phobic or weakly hydrophilic. For example, the substrate which consists of a lattice made of threads in polyethylene (6) compressed into a container (4) equipped with an irrigation system (3) and with a support (2) where the plants have been inserted (5). The system is a closed cycle wherein the stored solution (1) is recirculated.

Claims

1. A system for soilless or for hydroponic cultivation, comprising a) a substrate comprising a three-dimensional reticular, elastically compressible, structure formed by empty cells bounded by threads made only of materials without porosity or low internal porosity, hydrophobic or weak hydrophilic and chemically inert, wherein the threads are made of thin threads of polyethylene having a diameter of 0.25 mm, and wherein the substrate is configured to retain water without absorption by adhesion of drops to a lattice of the threads due to the weak intermolecular forces and for entrapment into the cells of the lattice due to surface tension and further configured to not absorb almost any salinity; b) a container with holes in which the substrate is arranged; and c) a closed loop irrigation system.

2. The system according to claim 1, wherein the threads are made of polyethylene in which a porosity of said three-dimensional reticular structure is determined by interspaces among the threads of the lattice.

3. A system according to claim 1, wherein said polyethylene comprises compressed polyethylene.

4. A system according to claim 3, wherein said compressed polyethylene has an average density of 150 kg/m.sup.3.

5. A system according to claim 3, wherein said three-dimensional reticular structure has a porosity greater than 85%.

6. A system according to claim 1, wherein said container is supported by a support on a slope.

7. A system according to claim 6, wherein said closed loop irrigation system comprises a drip irrigation system configured to deliver water to said substrate.

8. A system according to claim 7, wherein said closed loop irrigation system further comprises a receiving tank, configured to receive water from said substrate.

9. A system according to claim 8, wherein said closed loop irrigation system further comprises a pump for recirculating water from said receiving tank back to said substrate.

10. A system according to claim 1, wherein said substrate is suitable for receiving seeds, seedlings, plants or combinations thereof.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The features of the present invention are shown in one form of practical realization illustrated by way of example, not limitative, in the annexed drawings.

(2) FIG. 1 shows the substrate (6) inserted in a container (4), suspended on a support (2), in which have been carried out some holes (5) to receive the plants irrigated by a dripper system (3) in closed cycle, wherein solution is collected in the container (1).

(3) FIG. 2 shows a particular of the plant's housing (5) and the substrate's threads (6).

(4) FIG. 3 a detail of the lattice structure of the substrate is enlarged (6).

(5) FIG. 4 a particular of the housing (5) and grown plant is zoomed.

REALIZATION OF THE INVENTION

(6) FIG. 1 shows an example of the invention: a lattice of threads made of polyethylene with a diameter of 0.25 mm was used (6) and compressed inside a pipe of 100 mm diameter (4), with a density of approximately 125 Kg/mc. A drip irrigation system, (3) with a dripper positioned close to each plant, had distributed a daytime fertigation of 400 ml, for each plant, every two hours and only once in the night with a quantity of 400 ml, for a total duration of operation of the circulation pump of 2 hours every 24 hours. The cultivation was, in the spring, outdoors under a shed. The temperatures were respectively 8° C. Min. and 22° C. Max. The pipe positioned on a support (2) was tilted to 2% to drain the recirculating solution collected in the container (1). The Gentilina salad was planted at the distance of 20 cm, each other, along the tube inside the holes of 10 cm diameter (5) after the cleaning the roots from the whole ground remained. The system was used in a closed cycle with a nutrient solution chosen according to the literature, that came periodically added and rebalanced in salinity and pH by adding nutrients. At the end of the cycle the salad was collected and the solution was stored and rebalanced for the next cycle.