Summer rain a ‘major blessing’ for region’s farmers

The summer storms that finally brought rain to most places in the Mid West always bring varied results for farmers.

Very heavy rain causes flash flooding bedsides other things.

The summer was a mixed bag of heatwaves and cooler periods.

The rain that just came with thunder and lightning was the first substantial rain in Geraldton for six months.

I contacted Belinda Eastough, a farmer and agronomist at Yuna, and asked her how farmers used and managed summer rainfall.

“The summer rain of approximately 25mm-60mm around the region that was generated by thunderstorm activity has been a major blessing, particularly for grain growers, as it means stored subsoil moisture ready for the 2020 crop,” she said.

“The Yuna farm improvement group has installed 16 soil moisture probes throughout the Yuna area and prior to the rain there was no subsoil moisture down to 80cm at all sites, except for the site on fallow. This is a reflection of the rainfall and high temperatures experienced in 2019.”

With moisture storage, a general rule of thumb is one third of summer rainfall will be available for the following winter crop to use.

I was told the amount of rain from this fall has enabled some moisture storage for the next crop, and nitrogen will begin to mineralise and become plant-available during the early development stages of the crop which aids in providing a more consistent supply of nitrogen.

“To conserve moisture it is important that summer weeds are sprayed in a timely manner after summer rain,” Belinda said.

“Stubble retention aids in retaining moisture as it reduces evaporation from the soil surface and minimises run-off. Amelioration of soils using tillage techniques such as spading, Plozza ploughing and deep ripping in previous seasons also aid in the infiltration of soil moisture by removing the compaction layer, especially in our sandier soils.”

The Yuna group practices include engineering controls such as grade banks which were installed in the 1980s and 90s, but due to techniques such as furrow sowing, reduced tillage, wider row spacing and stubble retention, combined with lower rainfall water, erosion has not been a prevalent issue in the area.

“In relation to stock feed, the rain may have assisted many sheep and cattle producers, as the stubble value from 2019 was low due to lack of biomass and poor yields,” Belinda said.

“So many producers were beginning to run out of good grazing stubble, as at least 30 per cent ground cover is required to prevent wind erosion. The rain has germinated the volunteer cereals and lupins, providing a green pick for sheep, and many cattle producers have perennial grasses that need summer rain to grow foliage.”

She said her farming business ran sheep and cattle, and due to the rain received, her stock enterprise now had some green feed.

“However, the feed value of the standing stubble has been reduced,” she said. “Lupinosis used to be a prevalent issue in the 70s-90s after summer rain. Now the newer lupin varieties are more resistant to Phomopsis sp. infection but all lupin stubbles should be treated with caution when grazing after summer rain.”

Summer spraying is expensive and Belinda said summer weeds were emerging, which sometimes required different chemical spikes.

“The increased use of canola in the rotation has also made summer spraying more complex due to plant back issues with some herbicides,” she said.

“The best return on investment you can hope for is a decent summer rainfall event, ie 25mm-plus, which will encourage a more thorough weed germination and enable at least 10mm plant-available moisture storage.”

Many farmers have told me they are hoping for a good season.

Generally, this rain has introduced some positivity back into farming as the last five seasons in this area have been a rollercoaster for everyone in broadacre agriculture. Belinda’s story shows how different farming is from my days at Mingenew in the 1960s and 70s.