Compost the right ingredient

WA farmers have dug up a way to improve harsh sandy soils.

The introduction of organic matter by way of application of compost has given Gingin olive grower Marek Kwiecien-Fisher the capacity to expand his farm.

Mulching, as well as pulse irrigating, have allowed the Regans Ridge Olives owner to halve water consumption on the farm.

“We were losing 15 per cent moisture content in the soils in summer, and now we have been able to expand our property on the one water licence, ” Marek said.

Marek said using moisture sensors was a smart system, and mulching with compost was the icing on the cake.

Marek and his father, former geologist turned olive grower Derek Fisher, use an innovative technique involving a machine that buries compost in the root zone and as a mulch layer on top.

“The nutrient and water holding capacity of the harsh aeolian sand was very low, and during summer the ground would heat up to 50 to 60C, ” Marek said.

“We had two options; hay or compost. Hay mulch blows around and is hard to spread, but the compost was very easy to use and provided nutrients for the plants, while supporting the biology of the soil.”

In the 14 months since Marek trialled Custom Compost’s mulch, he has found a huge difference in the amount of water needed.

They have reduced water use on their farm by up to 50 per cent, a feat that led to them being inaugural winners of the Rural Industries Research and Development Corporation Olive Innovation Award in 2009.

“I just want to put it everywhere now, ” Marek said.

“Within three weeks of putting it on, the roots started to grow upwards towards the compost.

“The compost keeps the water in and helps with weed control.”

Marek said the olive trees grew stronger and produced fruit in third year of growth, which usually occured at a later stage.

“We had 15 per cent more fruit on the composted trees than on the control block, ” he said.

“I’m going to get eight to nine tonnes per hectare on three-year-old olive trees.”

The compost is recycled household organic waste and is the ideal solution for a large-scale operation looking for a low-cost soil enhancer.

Regans Ridge’s olive grove comprises 87,000 trees planted in both a high-density planting and a super-high-density planting.

The application of the compost was done to allow for research to be conducted over the next year with several methods incorporated on different blocks, including control blocks for comparison.

In addition to the direct application of compost into the sands, the application of humic acid and polyacrylamides is being undertaken via the micro pulse irrigation system.

This allows the water and nutrients to remain in the top soil for substantially longer than normal, retaining the nitrates in the upper layers.