22/5/13

Weather:
SW winds 28kph
rain - 29.6mm
high 11C low 9C

This morning we were given a presentation on hydroponic growing by Shaun Shale(second year hort student?). He is enthusiastic and offered a lot of information.
 Here is what I recall...

Hydroponics will be/is the future of horticultural sustainability.
Water, an Anchor, Nutrient and, of course, Light is all you need.
An anchor is for the roots to hold onto, water to carry nutrient and oxygen and light for photosynthesis.

The idea of hydroponics is as old or older than known human history, the Hanging Gardens of Babylon being one example. There is evidence that these ancients also used "raft" gardens and their descendants still do to this day in some places.

In 1920 a man named Dennis Hoagland worked out exactly the type and ratios of macro and micro nutrients that plants need for optimum growth and his calculations and solutions are still used today.

In the 1940's hydroponics were used to grow massive amounts of food at an accelerated pace to feed the troops in the pacific with enough fresh vegetables.
Even today I believe The Navy(her royal whatsit) uses hydroponics and controlled environment growing to produce fresh food whilst on long voyages.

Some media you commonly used to anchor your plant(s) are:

• Hydroton, expanded clay balls covered in macropores(big little holes). They provide good moisture retension and surface area to hold oxygen and root structure.
• Vermiculite, expanded silica. It's light, tough and lets light in somewhat. Soft light is actually beneficial to roots.
• Coco coir, stripped coconut husks. It expands, it's organic, low carbon footprint. Discarded coir can be used to enliven clay soils.
• Rock wool, volcanic rock particles spun like candy-floss. It never breaks down.

Hydroponic systems are a good way of recycling plastic, either for containers or for shelter.

They are also a great way to conserve fresh water as there is no run-off to ground and the only water lost is through evaporation.

For a passive solar-sink to keep night time temperatures up you can use large water containers to absorb energy from the sun which is then gradually released throughout the night.

Controlled environment growing can extend the growing season year round. With this type of growing pest and disease can be a real problem. 

There are companies whom produce beneficial predator insects and parasitic insects that can help reduce infestations in a controlled environment situation.

Growing indoors with lights and hydroponics and shelves in a 20ft shipping container one can produce as much as an acre of earth outside!

This afternoon in Plant ID class we discussed the parts of a leaf and then learned about different ways to describe a leaf.

Leaf Parts: 

• Lamina(leaf blade, including apex, margin, midrib and lateral veins.
• Apex(tip)
• Margin(edge)
• Midrib(central vein)
• Lateral Vein(veins from Midrib outwards)
• Petiole(leaf stalk)
• Leaf base(where Lamina joins Petiole)

Leaf Set relates how the leaves are arranged on the stem/branch. Some kinds of Leaf Set are, opposite, alternate, whorled and spiral.

I tried to describe a leaf given to me in class and this is how it turned out.....
An oppositely set simple leaf, deep emerald green in colour, shiny and waxy in texture, eliptic and obovate in shape with rounded AND apiculate tips, reticulate veining and an attenuate base.
I think it was a type of Coprosma.