Executive summary

Almond Irrigation Benchmarking 2002 - 2011

The DPI Almond Irrigation Benchmarking Project was initiated during the season 2002/03. It was established primarily as a tool for identifying "best irrigation management practices" with the goal of improving irrigators' performance and efficiency.

This annual report contains nine years of growers' data from Victoria, covering seasons 2002/03 to 2010/11. Examples of the main information gathered were the amount of water used per site and crop variety, the irrigation systems and scheduling methods used, the pumping and water costs, and the crop yields and gross returns per site.

Eighteen new sites (336 ha) were included in the study in 2011. This brought the number of participating sites to 53 for a total area of 512 hectares. It should be noted that the data presented in this report does not necessarily reflect the performances of other growers in the industry and care must be adopted when attempting to extrapolate the results to the broader irrigation community.

The almond varieties planted at the different sites were Carmel, Fritz, Mission, Monterey, Ne Plus, Nonpareil, Peerless and Price. In terms of irrigation systems, the growers were using either low level sprinkler or drip irrigation.

The above normal rainfall events during summer 2010/11 affected many almond orchards resulting in water-logging and loss of trees in some patches. The yields results also showed a decline in the median yield value in 2011 (2.29 t/ha) compared to the previous two seasons, i. e. 2009 (2.96 t/ha) and 2010 (3.10 t/ha).

In terms of volume of water applied to the participant sites, the 2011 season had the lowest median of all of the years benchmarked, i. e. 9.7 ML/ha compared to 12.8 ML/ha in 2009 and 13.2 ML/ha in 2010.

A comparison by irrigation system showed the nine-year average yield of drip irrigated sites (2.6 t/ha) was 0.2 t/ha higher than that of low level irrigated sites.

Over the last four years, the seasonal average water applied by drip irrigated sites has been 1.5 ML/ha higher than that of low level irrigated sites. This contrasted with seasons 2004/05 and 2005/06, when drip irrigated sites were using on average 5.5 ML/ha less water than low level irrigated sites.

In the most recent season, a high percentage of sites (85.7% in 2010 and 83% in 2011) had application efficiencies below the 85-90% recommended range and hence were deemed over-irrigating. Over the nine-year period, the application efficiency for drip irrigation systems was on average 8% higher than for low level irrigation systems.

Drip irrigation produced a higher nine-year average crop production per volume of water applied than that for low level sprinkler irrigation. However in 2011, the results for low level irrigated sites (0.38 t/ML) were 0.14 t/ML higher than for drip irrigated sites.

In 2011, except nonpareil all varieties had a crop production per megalitre above their respective nine-year average. Over the nine-year period, varieties Nonpareil and Carmel achieved the highest average results with drip or low level irrigation system type.

In terms of gross return per dollar water input, the median value for gross return per dollar water input for 2011 (18.90), was similar to the pre-drought results, i. e. post 2007. The low results for many participants between 2008 and 2010 were attributed to the combined effect of the reduced price of almonds and the increased cost of additional water purchased in recent years.

The gross return and cost performance indicators should be treated only as technical information, as they were determined using a partial system approach. A sound economic analysis was beyond the scope of the study, since it would have involved a whole system approach and more complex analysis, e. g. marginal analysis.

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