A FEW small plots of crops in Richmond could one day change the future of farming, as researchers test how crops respond to higher air temperatures and drought conditions.
Western Sydney University has set up an experiment at its Hawkesbury campus in Richmond called PACE – Pastures and Climate Extremes.
Researchers including professors and students began setting up the experiment last August and in April switched on their heat manipulation, effectively marking the start of the experiment.
The concept is a pretty simple one: how will specific crops grow when the air is three degrees hotter and with less watering.
Post-doctoral research assistant Amy Churchill, who studied her PhD in plant ecology at the University of Colorado, took the Gazette on a tour of the facility, to show how the experiment was being conducted.
The experiment
The researchers have set up a number of different plots of typical pasture crops – lucerne and native kangaroo grass for example, are some of the crops featured in the experiment.
The crops are growing underneath some shelters, which will allow the researchers to control how much water they receive.
Some of the crops are underneath heat lamps, which will keep the temperature around those crops at roughly three degrees above the surrounding air temperature.
“Three degrees is within the realm of what is expected in the not so distant future for this region and so that is important for the pasture folks and dairy folks,” Dr Churchill said.
The other crops are being deprived of rain. In winter and spring, the crops will receive only 60 per cent of the typical rain fall they would receive in this region, which overall is about a 20 per cent reduction from their yearly absorption.
The whole point of the experiment is to test how well the crops respond to these altered conditions.
The researchers currently have funding for a three year experiment.
What they’re looking at
Dr Churchill said over the three years, the researchers would take a number of different measurements as they assess how the crops perform under the altered conditions.
“I am interested in how the plants are changing in their relative greenness, how much production is happening, can we see that changing over time, are we seeing shifts in productivity above ground or below ground,” she said.
“We have some predictions about trade offs when it gets really hot and dry. Plants might invest more below ground so they can stay alive.”
Dr Churchill said cameras placed directly above the crops would take multiple images per day of the crops, so they could measure the greenness.
“We are expecting that warm and cool species will shift when they are green,” she said.
She said another measurement, quite an important one, was the yield.
“We do regular harvests following industry protocols so we know how much is coming off a plot, but we are also interested in above and below ground harvests, which you do with soil cores,” she said.
Along with yield, they want to see whether any crops lose nutritional value, or possibly even gain some.
“A cow can eat grass but not all grasses are the same, some are more nutritious than others,” she said.
Below the ground is important too. They have cameras inserted below the soil to take measurements as well.
“We are interested in the microbial plant interactions, the microbes and fungi living in the soil that can facilitate the plants doing really well,” she said.
“From an agricultural perspective, will those relationships allow the grasses to do better under drought conditions potentially?”
Why do the experiment?
“If we can find some species that are better and do better under drought and heating then that is very important for industry,” Dr Churchill said.
“The fortunate thing is no matter what results we find it is going to be interesting. Even if everything does great that is still a really, really important finding.”
Dr Churchill said after three years, she expected the experiment would continue, although possibly in a different form.
She said they may test the same crops, but look at why they went well, not simply that they did well under their altered conditions.
She said they may also opt to look at why crops did poorly, or even different ones altogether.
In any case, with predicted temperature rises and more drought like conditions in the future, she said the experiment could be incredibly important for the agricultural industry’s future.
