Solar Augmented Capillary Wick Based Self Irrigating Container For Pots
In combining the best features of solar irrigation with capillary wick watering this innovation provides yield (growth) optimisation with reliable self watering capability.
Advances to date
Capillary wick irrigation is far from novel. It is in best prescribed by US patent No. 4344251 August 17th 1982.
Further refinements such as US4741125 and US6418664 2002 followed but the essence is the same.
Although widely used in commercial horticulture to self water flat beds upon which immature plants are raised (often in pots) there are few examples of proprietary capillary wick pot systems employed in raising large mature or high yielding plants. One example of a currently available ubit is the “Pyramid Pot”. Other examples are limited to house plant cultivation and “holiday watering” when the expectations are more towards sustaining a living plant rather than optimising yield. The consensus is that wicks are unable to deliver water to plant roots to satisfy demand from fast growing plants in high water usage environments such as in a greenhouse during fine days in the summer. In these situations plants react very severely to water starvation with drastic effect on the overall yield.
The solar power operation of a pump is common and not surprisingly the arrangement has been adapted to self waer plants. Although large pumps powered by large collector arrays are a common feature of dry area irrigation from subterranean water sources our concern is not with these bu is with solar power usage in self watering container grown plants especially of high growth high yielding crop plants such as tomatoes and cucumbers. In this field there are few working examples but these include “Wand” solar-irrigation, “Irrigatia” solar irrigation and “Solar hydro” (by Greenhouse Sensation).
The limitations of solar power in this field are clear. On the one hand unless a reliable battery backup is provided, irrigation is reduced or absent when the sun does not sufficiently power the unit. On the other hand if the sun is continually shinning the unit delivers to much water resulting in saturated compost. In either of these scenarios the outcome is much reduced plant growth and yield. Engineering measures may be introduced to mitigate these influences but they add unnecessary cost and complexity to what should be a simple operating system.
The current innovation
- The container for the plants is mounted above a reservoir of water with soluble fertiliser added.
- Several containers may be mounted above a single reservoir.
- Each container is fitted with a capillary wick such that the wick extends into the reservoir of water and up into the upper reaches of the container.
- A free draining (hydro) compost such as “HydroCoco 60/40” is used to fill the containers.
- A solar powered submersible pump is loacted in the reservoir.
- A suitable sized solar collector is directly coupled to the the pump such that in high periods of high illumination the pump operates.
- A suitable water distribution arrangement connects between each container and the pump such that upon the pump operating water is delivered to each container at a rate far above the water usage capacity of the plant. Excess water rapidly drains through the hydro compost and back into the reservoir.
- An auto top up device maybe be fitted to the reservoir to vastly decrease or remove altogether the regularity of manual topping up of the reservoir.
- In periods of low light intensity the plant is adequately sustained by water supplied by the capillary wick.
- In periods of high illumination the planter is immediately converted to a high yielding hydro cultivation unit by the onset of the solar powered pump.
- Ordinarily there is no need to control the pump running time and frequency but if for cultivation reasons control is desired simply tilting or partially rotating the collector from due south will provide control.
Plants grown using this method of cultivation regularly produce exceptionally high yield with very low manual input.