Water and fertiliser are the two biggest input costs in vegetable production in Western Australia. Rising costs of fertiliser and significant reductions in water allocations have the capacity to severely impact the profitability of WA’s vegetable producers. VegNET Regional Development Officer Truyen Vo reports on some of the latest findings from Vegetable business benchmarking (VG17000), a strategic levy investment under the Hort Innovation Vegetable Fund.

A financial and production benchmark report, produced by vegetablesWA in partnership with PlanFarm, shows the Western Australian grower’s average fertiliser, irrigation and power costs are $3,999, $218 and $1,530 respectively; with a large portion being used for irrigation pumping. A 10 per cent reduction of fertiliser and irrigation costs would result in a benefit of $570/ha/crop. This is a significant improvement to grower profits, since the average profit before tax of the WA vegetables industry is $6,200/ha/year.

While the initial investment of upgrading your irrigation system’s hardware or technology may be seen as a barrier for innovation adoption, an inefficient irrigation/fertigation system presents its own suite of productivity limitations.

In 2019, vegetablesWA assisted the Department of Primary Industries and Regional Development (DPIRD) with a North Wanneroo irrigation efficiency assessment. The assessment demonstrated that with a proactive water management strategy, acceptable levels of efficiency were achievable. It stands to reason that the improvement of irrigation and fertiliser application practices and technology could bring significantly positive outcomes to growers.

Planning ahead

Environmental resource sustainability is a priority issue throughout horticulture. With a drying climate, growing population and increased demands on horticultural production, a proactive approach is recommended. As growers in North Wanneroo are facing a 10 per cent water allocation cut by 2028, the WA Regional Development Officers (RDOs) have identified this issue as a central industry objective.

In establishing a Regional Strategic Plan, as part of phase two of the VegNET project (VG19016), an enhanced focus on productivity improvement, environmental sustainability and business profitability through the productive use of water and fertiliser was identified. A water use efficiency project outline was further developed as part of the Regional Strategic Plan.

A collaborative field day – supported by DPIRD, the Department of Water and Environmental Regulation, Irrigation Australia and vegetablesWA – was held on 1 October 2020 (see breakout box).

Gaining soil knowledge

The water use efficiency project aims to enhance growers’ understanding of soil characteristics; the regional soil map; how water filters through the soil profile; the nutritional demands of different crop types and growth stages; and irrigation techniques.

The goal of the Western Australian RDOs is to support the grower in taking the necessary steps to initiate practice change. A result of a 10 per cent reduction in net fertiliser costs and a 10 to 25 per cent reduction in irrigation volumes would be considered a key indicator of success and adoption.

Whether through written literature, assessment of trial site data or holding on-farm demonstrations, the ultimate intention is for wider adoption of on-farm best practice.

Field day wrap-up

With a solid mix of growers and industry, the Water Use Efficiency Field Day was a success. There were multiple company displays showcasing the latest in irrigation technologies and an address by the Hon. Alannah MacTiernan MLC, Minister for Agriculture and Food, assuring continued support for the adoption of water use efficiency best practice.

The field day activities included:

• Drip irrigation dye demonstration (in field).
• Overhead irrigation distribution uniformity demonstrations (in field).
• Presentation on the benefits of incorporating soil moisture sensors to assist with water management.
• A regional irrigation system assessment overview.

The event ended as all good grower events should, with a chance to network while enjoying a barbecued sausage in a bun.

Find out more

For more information on the water use efficiency project, please contact Regional Development Officer Truyen Vo on truyen.vo@vegetableswa.com.au.

VegNET – Western Australia is a strategic levy investment under the Hort Innovation Vegetable Fund.

This project has been funded by Hort Innovation using the vegetable research and development levy and contributions from the Australian Government.

Project Number: VG19016

This article first appeared in Vegetables Australia – Summer 2020/21. To read the full publication, please click here.