Fresh Science

A soil cover that’s sprayed onto soil around crops has been found to reduce water loss from evaporation by up to 76 per cent in the lab.

“I hope to help farmers increase their crop yield. The soil cover can be sprayed directly onto soil, forming a barrier to reduce the amount of water lost through evaporation,” says lead researcher Dr Priscilla Johnston, a postdoctoral fellow at CSIRO.

“But the material allows any water applied from above to pass through into the soil, also preserving water from rainfall and irrigation.

“Irrigated agriculture is worth more than $15 billion to Australia, but water scarcity threatens the industry’s long-term viability—farmers have to make the most of every drop. And since the soil cover safely degrades in soil after two months, they don’t need to remove and dispose of it at the end of the growing season like they do for plastic covers,” Priscilla says.

Priscilla has recently scaled up the laboratory experiments and tested the performance of the soil cover in a glasshouse with cotton, where she measured how much water it could save in different soils and irrigation scenarios.

She found that when the soil cover is used, cotton plants grew up to 30% taller per unit of water applied.

The next phase of testing will investigate how the soil cover behaves out on a farm in real-life growing conditions.

The Department of Agriculture and Water Resources and the Cotton Research and Development Corporation supported the research.

Priscilla and her team want to help farmers save water while also increasing their crop yields.
Credit: Lachlan Ciddor