Knowledge & tools to manage fertigation technologies in highly productive citrus orchards for minimal environmental footprint

High frequency fertigation is being adopted by Australian citrus producers as an alternative to traditional approaches to supplying water and mineral nutrients to trees. Information, guidelines and practical tools to assess performance are insufficient to support the economic & sustainable use of these technologies for citrus production on Australian soils.

Old fertiliser rates, and practices derived elsewhere, may inappropriate for Australian conditions; inappropriate practices may be associated with lower returns and undesirable on- and off-site effects. This project aims to develop and deliver to industry the knowledge and tools needed for sustainable and economic citrus production using the new technologies.

Aims

Develop guidelines, practical grower-friendly tools and information packages and provide training for irrigators and support industry for the sustainable and economical use of the new fertigation technologies in citrus production by:   

  • quantifying nutrient capture by roots of commercially relevant citrus rootstock genotypes in relation to supply
  • establishing commercial-scale demonstration sites of commercially relevant citrus scion varieties growing on commercially relevant rootstock genotypes by re-developing existing plantings to enable short- and long-term responses to nutrient supply to be quantified
  • developing framework to quantify water and nutrient escape below the rootzone of citrus trees growing in lysimeters
  • identifying the phenological stages when leaching is most likely to occur
  • evaluating and demonstrating to industry the efficacy of nutrient capture under different short- and long-term supply regimes using demonstration sites
    studying the effect of commonly practiced high intensity fertigation regimes on salt, water and nutrient movement within and below the root zone of the commercially relevant citrus enterprises
  • calibrating a 2D/3D solute transport model under lysimeters and validate under field conditions for predicting nutrient and water flux beyond the root zone

Outcomes

Adoption of practices associated with:

  • more efficient use of water
  • more efficient use of mineral fertilisers
  • reduced on- and off-site impacts of the use of modern irrigation/fertigation technologies
  • improved awareness and raised understanding of issues underpinning appropriate use of irrigation/fertigation technologies in other high value horticultural crops

Background

It is generally accepted that drip irrigation is the most efficient irrigation system, and the adoption of drip irrigation systems is generally accompanied by the adoption of technologies that allow nutrient application as frequently as water application. Sometimes these technologies are adopted along with a confidential service agreement, in which case management regimes (i.e. fertiliser recipes) are prescribed. More often, these technologies are being adopted without support, and nutrient supply regimes are based on experience and hearsay, and nutrient inputs often reflect the inefficiencies inherent in delivery technologies used in the past.

Either way, wider knowledge and higher skill levels are needed, and a lack of such skills and that knowledge are an impediment to adoption and to the most efficient use and management of drip irrigation/fertigation technologies by growers. Research and extension organisations have very little or no experience with the newer technologies, and are unable to properly service the skills and information needs of growers.  Thus, there is a strong need to demonstrate to industry the integration of modern efficient drip irrigation management with current “best bet” nutrient supply based on advanced understanding of citrus nutrient needs. There is also a strong need to widen the knowledge and skills base of growers and increase the availability of decision support tools. This will enable better decisions to be made in relation to irrigation and nutrient supply to reduce the potential environmental foot print associated with the mismanagement water and nutrient supply.


Metadata

Program

National Program for Sustainable Irrigation

Project ID:

DAN5027

Related Topics

id: 2644 / created: 10 September, 2008 / last updated: 09 March, 2010