Open Hydroponics: Risks and opportunities

An open hydroponic system (OHS) is a continuous method of supplying a crop’s water and nutrient needs in a very precise way. Unlike traditional soiless media hydroponic systems, in the open field hydroponic system the soil is used as the medium in which the plant grows and its primary function is to provide the support structure to anchor the plant and accommodate its root system.

The system allows for the supply of a complete and balanced nutrient system on an ‘as required’ basis as determined by careful and detailed monitoring of the plant and climate. The nutrients are not recycled in an open hydroponics system.

Aims

Stage one of the project is a desktop study to:

• Review the current knowledge and status of OHS including grey and published literature
• Evaluate the impact of OHS on water supply infrastructure
• Examine the potential impact of OHS on the environment

Stage two of the project will work with industry to:

• Validate water use, nutrient leakage and salt accumulation of OHS
• Determine the potential return on investment from OHS through examination of yield and quality dividends
• Develop Best Management Practice guidelines for industry to optimise productivity and minimise environmental impact

Outcomes

Stage 1:

An understanding of OHS principles and practices and the availability of relevant information for irrigators, policy makers and industry.  This opportunity for understanding will lead to better defined OHS design techniques.

An understanding of the feasibility of the system for various locations in Australia and this will build upon other existing tools for crop/climate/soils selection. 

An initial assessment of the barriers, environment, social (skills) and economic (capital costs) that will be required to be overcome for successful adoption.

Better understanding of the impacts of adoption on water service providers and environmental agencies that may change the design parameters for infrastructure refurbishment and environmental monitoring.

Stage 2:

An improvement in the sustainability of irrigation by:

• better informed investment decisions by industries, producers and lending providers, and
• improved understanding of  the risks and benefits of broadscale adoption of the technology.

Facilitation of the adoption of more efficient and effective water use and nutrition practices if the technology is proved to be sustainable. Specific improvements will occur through:

• the adoption of wide-spread objective management systems for  drip irrigation (that includes fertigation),
• matching irrigation to crop water use (quantity applied),
• understanding the varying nutrient requirements of the plant,

Potential for increased economic viability through improved production (quality and quantity).

Understanding of the social implications that may result from wide-spread adoption of this technology. Also an understanding of the likely rate of adoption of the technology will be an outcome.

Potential for gains for the supply and support industries (eg. manufacturers, designers and consultants)

Background

This system is relatively new to Australia and there are a number of commercial citrus operations currently in place using the principles of OHS. Yandilla Park in South Australia is a large commercial operation currently using and marketing a technology imported from Spain(Martínez Open Hydroponics Technology). Other commercial orchards are using their own interpretations and variations of OHS. There is potential that OHS is suitable for a range of other crops (peaches, almonds, grapes, citrus, avocados and several vegetables) with suitable irrigation systems.

Publications and Resources