During the major 2019 drought, the Gregg family decided to grow fodder for 120 Hereford breeders rather than the continuing expense of buying feed in. Leo Rheinberger from Think Water Mudgee suggested that sub-surface drip irrigation (SSDI) would be worth considering as water efficiency was a prime consideration.
Lomondo Olives is a mixed farming (mainly olive oil production) enterprise located between Mudgee and Wellington in Central NSW. The business began in 1998 with the planting of the first 13,000 olive trees by Frank Gregg and his family. Today, Lomondo is a well-known brand supplied through Harris Farm and other fine food outlets in Australia.
The SSDI system was developed in two stages. The first stage involved 12ha split into 2ha blocks. The second stage was an additional three 2ha blocks. Rivulis provided the design parameters.
Water for the system is supplied from the Cudgegong river, the new mainline connects with the existing olive irrigation system, which gives added water security should the olive water supply become unavailable.
The new system includes a Grundfos 15kW 77-4 submersible pump, which sits in a well, with water supplied from the river via a 20-meter-long Gabion rock-filled channel into a concrete lined pipe well. The system delivers seven litres a second to two 2 ha blocks at the same time.
Rivulis D5000 1.0 litre/hour drip tape was used for the project with a Rivulis 130 micron screen filter. The sub-surface drip irrigation system is controlled via a Hunter Pro C controller and Rivulis valves.
The blocks were initially planted with millet, which produced the first cut within 28 days. The systems ability to keep up with the high evapotranspiration of the crop in mid-summer meant production was greatly enhanced. 130 large square bales were cut from six blocks.
“We were spending up to $10,000 a month in feed,” said Paul “We got that to zero with the production we achieved from the millet”.
“We also needed to protect the millet from kangaroos and wild pigs, as it looked like an oasis!” said Paul. “so, we built an exclusion fence which kept them out”. The exclusion fence worked extremely well and saved the crop from being decimated.
Irrigation water for the olives is supplied via two bores. A new 25 kW solar-powered system has been installed on the hay shed roof to power the pumps and utilise daytime irrigation to further reduce the power bill. Subsurface drip is not subject to high wind evaporation rates, unlike overhead irrigation and can be used during daylight hours without loss.
“We use a third less water and weed control is much better”, said Paul. “Leo had plenty of good ideas which we put into practice, including using solar to power the pumps”.
Paul is sowing L56 lucerne for pasture production in the coming weeks, with the first cut likely to be due in November 2020.