A NEW manual and DVD aim to debunk the myths and give commercial horticultural growers a step-by-step analysis of the pros and cons of converting to hydroponics.
Backed by five years of in-depth research, the Converting to Hydroponics manual gives growers options to upgrade their existing structures, rather than spend tens of thousands of dollars on new high-tech greenhouses.
Its other practical advice includes: Comparisons between the growth rates, yields and returns from greenhouses converted to hydroponics and crops still grown in soil; Examples of existing structure conversions; Conversion costs, general management and daily maintenance and monitoring; Nutrition and irrigation information; Further benefits and limitations, such as disease control and the boundaries of the growing environment in low-medium technology greenhouses.
The manual gives the minimum equipment needed to do simple hydroponics in low-medium technology greenhouses and the options available for fertigation equipment, irrigation controllers, growing media, fertiliser tanks, gutter systems and irrigation and monitoring equipment.
Funded by the vegetable levy through Horticulture Australia Limited, the South Australian Research and Development Institute (SARDI) and NSW Department of Primary Industries used demonstration sites and worked extensively with consultants and growers.
SARDI senior research scientist Kaye Ferguson said hydroponics should not be seen as the “magic fix” for all problems associated with growing in soil.
“Growers need to have a good, hard look at a number of things before converting to hydroponics,” Dr Ferguson says.
“There are still advantages to growing in soil if it is managed properly, has good structure and little disease.”
“Soil is an excellent natural buffer against extremes in the temperature, water and nutrients in the root zone. In hydroponics you don’t have that natural buffer.”
Some of the good reasons to convert to hydroponics are poor soil health, soil-borne diseases and nematodes, increased water use and fertiliser controls within a closed system, better yields and, potentially, better return on investment.
“Converting to hydroponics in low-medium technology greenhouses doesn’t automatically mean you’ll be getting 50kg/m2 - but 15-20kg/m2 is achievable,” Dr Ferguson warns.
The not-so-good reasons include converting to hydroponics to manage poor-quality water, to get complete control of production and climate (it only gives more control over the temperatures of the root zone of the crop) or because a neighbour has made lots of money from converting.
“Learn what you can from the people around you who are growing successfully in hydroponics and adapt principles and practices to your own situation,” Dr Ferguson advises.
The 170-page hard copy manual costs $56.70 ($49 plus $7.70 for postage and handling) and includes demonstration videos. Alternatively, the videos and a PDF of the manual are available on DVD for $20.50 (includes postage and handling).
Copies of Converting to hydroponics can be obtained from SARDI, Waite Campus, Urrbrae. Contact Barb Hall on 08 8303 9562 or email email@example.com