![Stuart McDonald has his July/August 2018 drop Merino wethers grazing on a paddock of Clearfield 9070 canola originally sown with a mic of sorghum last October then spread with 70 wet tonnes a hectare of biosolids. The caanola was resown after March rain this year at 2.5kg/ha. Stuart McDonald has his July/August 2018 drop Merino wethers grazing on a paddock of Clearfield 9070 canola originally sown with a mic of sorghum last October then spread with 70 wet tonnes a hectare of biosolids. The caanola was resown after March rain this year at 2.5kg/ha.](/images/transform/v1/crop/frm/DqX4VhD5F8i25ENbyJmL9R/7eb611ef-bd04-4e2b-a6f8-39adb11cb7f9.JPG/r0_74_3055_1955_w1200_h678_fmax.jpg)
NOT directly utilising summer moisture from November to the end of April is seen as an inefficient way to extract value out of high-value Canowindra farming country.
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Stuart McDonald is trialling harvesting that moisture with cover crops over a period when his paddocks are getting more than a quarter of the annual rainfall, and probably only retaining half of that moisture for the following main cash crop.
Annual rainfall at Belmont is non-seasonal at 600 to 650 millimetres and generally on average 50mm can fall in any month of the year.
Supported by the Grains Research and Development Corporation (GRDC), Mr McDonald gained a Nuffield Scholarship in 2018 to research how continuous grain cropping with integration of livestock can be sustained in a high rainfall environment.
He and wife, Dr Ellen Downes, run 35 Australian Illawarra breeders and a 1000 ewe Merino flock of Winyar blood growing 19 micron wool with their continuous cropping enterprise of 1100 hectares.
In the past seven years they have built a benchmarking system where results identified their cropping paddocks to be the most profitable.
"So we have increased our intensity and made those paddocks continuous cropping," Mr McDonald said.
Rotations before paddock's pasture phase may have lasted five to 10 years, but are now continuously winter cropped with wheat, wheat, canola across 75 per cent of Belmont with the other quarter dedicated to pasture in a mix of natural and improved.
After touring continuous cropping farming systems in Europe and the United States, Mr McDonald believes additional income can be extracted and soil health benefits would come from integrating livestock to continual cropping.
"We aim to extract more value from our cropping program without compromising it, and improve our soil resource by using a grain and graze option of wheat and canola which plays its part for tup to three months generally in a portion of the cropping phase.
"But what is interesting is the potential to grow a crop of either a grain or forage or both through the summer phase."
The aim of having 14 species growing in a paddock over the course of two years was a target he was exploring.
"Ideally a mix of summer grasses and legumes in summer, and winter grasses and legumes, giving the option of being harvested with livestock to generate income and quickly add diversity into a two crop rotation.
Multi-species cover crop build soil diversity
SUMMER cover crop experiments on two paddocks at Belmont, Canowindra, are adding to the diversity of rotations for Stuart McDonald.
From his studies in the United States and Europe, Mr McDonald saw producers growing multi-species cover crops with legumes and grasses in the mix.
"The different root systems host different microorganisms, fungi and soil life that improve the dynamic properties of soil leading to healthier soil that can infiltrate more moisture and retain it," he said. "Fertility increases with more organic matter. The higher water absorption potential leads to more moisture being retained in the root zone where we can use it for crops."
He said while building soil properties he must generate income, and the easiest way would be from harvesting forage with livestock.
"A cover crop can be seen as the way to fill the gap between cash crops when no plants are growing. I am looking to identify ways to do this profitably. Traditionally harvesting moisture with zero plant growth over summer has seen a lift in winter crop production, but this idea turns that concept on its head.
"We are inefficiently using our non-seasonal rainfall over summer and I want to use every drop of rain in our paddocks. I also want to use that moisture to grow something that can earn money, and improve my soil resource."
Currently, Mr McDonald is grazing July/August 2018 drop Merino lambs on a CL970 canola crop resown in March after first sowing it with CL970 canola and sorghum last October.
Biosolids at 70 wet tonnes per hectare were incorporated at sowing. Both cover crops have helped capture rainfall moisture without losing topsoil in the more erratic and intense rain events.