Open Hydroponics - the gateway to organic certification?

[GaryD]

Hi,

Jobney posted some information on Open Hydroponics following a visit to a citrus field day recently.

That sparked my curiosity about open hydroponics to the point where I started to do a little desk research.

While Open Hydroponics seems to have its focus around fruit trees, I see no reason why it couldn't be extended to other trees, fodder shrubs and vegetables.

Along the way, I came across an article by Dr Mike Nicholls (a retired NZ researcher) in which he said:

The International Federation of Organic Agricultural Movements (IFOAM) not only require the production system to be soil based, but also make it very clear that ‘hydroponics’ is not permitted, but there is no clear definition of hydroponics given by IFOAM.

So, what if you use open organic hydroponics?

Since open hydroponics has the plants growing in soil.....using hydroponic nutrient delivery systems.....there should be no barrier to organic certification.

Of course, this fertigation process should avoid the use of the term hydroponics because it appears (according to Dr Nicholls) that the word "hydroponics" (rather than the process) is the greater evil to some certifying agencies.

Gary

[weldnfab]

Sounds to me like some more of them need to retire.... assisting natural growth with natural nutrients is still organically sound.

[Pugo]

This is just to weird sounds like some kind of an oxymoron, soil and hydroponics together? Some of my favorite ones are, Microsoft Works, unbiased opinion, criminal justice. LOL

[Earthan Group]

This is just to weird sounds like some kind of an oxymoron, soil and hydroponics together?

I have seen them using soil in hydro. Sounds odd though I know.

[jet]

There was a system called "Openfield Hydroponics System" all licensed and run by Martinez from Spain. Included big $$ consultancy too.
Basically involved very intensive irrigation and fertigation of fruit trees, only irrigated in daylight hours, constant proportional fertigation and usable soil volume was greatly reduced.Good results and efficiencies are achieved.
As with many highly tuned systems it was prone to failures from controllers and mechanical breakdowns so full backup systems required and the cost was very high. Trees could only last hours without irrigation before crop impacts seen.
It allowed very accurate tuning of fertiliser and water attempting to remove much of the variability seen in "normal" soil systems. It is an extension of soil less media concepts so does share some ideas from true Hydro.
There are still citrus growers using this but never took off. Mainly very high value export fruit.

A few steps backwards from this high intensity setup is what is used on modern sucessfull orchards today. Still irrigate a few times per day, fert whenever water running.

A difficulty with organics is much of the nutrient used is not suitable for being water run and as the used soil volume is reduced dramatically soil applied products dont impact as they normally could. Additionally I doubt the premium from organics could justify this type of technology and management input.

I did do some work where gravel filled trenches or bags were used alongside trees and fertiliser applied by drip on top. Water provided on the other side of the tree as normal. This provided better nutrient uptake, particularly Fe as soil pH and other impacts were avoided. Again didnt take off due to costs. This was also labelled a type of Hydro but really was just an adjusted soil system.

Using Grodan rockwool on hanging gutters is essentially hydro with media, it pretty much the standard system in greenhouse tomatos now. Still called Hydroponics?

The term hydroponics is often used where all nutrients supplied through water as the way the plant is held upright isnt that important and highly varied.

[jobney]

Link to my original post with links to the event I attended. The pdf is nice.
http://www.aquaponicshq.com/forums/s...f-Citrus-in-FL

[GaryD]

Hi,

I imagine that there are simple variations on the open hydroponics theme.....more toward drip feeding soil-based plants....that would also be able to exploit nutrient-rich water from an AP system.

Gary

[jobney]

One issue in the system that I saw was that we normally use microjets for supplemental water and freeze protection. The drip fertigation used in open hydroponics keeps the trees watered but you still need the microjets set up freeze protection. You need two runs of water lines down each row and you will only use the jets a few times a year. I'm not sure if they clog just sitting there not running. In conventional growing the jets clog over time and need checked periodically.