Perennial pastures are built for the South Coast

This short film features Bremer Bay farmers discussing the many benefits of cropping into kikuyu pastures.

Built for this Country was produced by South Coast NRM’s Climate Action on Farms project to promote the findings of a series of Australian Government funded soil carbon trials conducted on a Bremer Bay farm owned and managed by the Reddington family.

South Coast NRM carbon farming project officer Charlotte Powis said pasture cropping into kikuyu is a fairly recent activity and its success has varied greatly in WA.

“Built for this Country is a local example of farmers giving it a go and seeing some great results that could be of real benefit to other farmers,” Charlotte said.

“Kikuyu has been widely adopted across the South Coast sandplains over the past 20 years to largely help prevent wind and water erosion, but even when well-managed, the pastures gradually decline in productivity. This observation was true of the Reddington’s property,” she said.

Ken Reddington said the family had looked at different options to stabilise their top soil and chose kikuyu because it appeared indestructible.

“Kikuyu stabilised the soil and responded to summer rain events, we got good quality green feed off it and ended the problem of paddock blow,” Ken said.

“However, we noticed after 20 years the kikuyu had become less productive and started to choke out some the annual species,” he said.
The Reddingtons, who are primarily livestock producers, noticed that anywhere they had worked or “tickled up” the kikuyu it really responded well.

“Canola has a large tap root, so by cropping it we could use the root as a soil aerator as well as using the crop to knock the kikuyu back. It also allowed us to get a cash flow off it at the same time as controlling the kikuyu,” Paul Reddington said.

The Reddington’s became involved in the South Coast NRM soil carbon trials as they were interested to discover whether the kikuyu paddocks produced higher soil carbon levels than annual paddocks and whether cropping into kikuyu affected soil carbon stores.

South Coast NRM worked closely with University of Western Australia Phd Student Kanako Tomita to find the answers to these questions.
“We generally expect soil carbon stores to be greater in perennial pastures as opposed to annual pastures due to their well-developed root system which persists all year round,” Kanako said.

“However it was surprising to find that soil carbon stores were not affected after two years of cropping into the kikuyu pasture,” she said.

“Soil carbon plays a pivotal role in contributing to the physical, chemical and biological processes of soils and is essential for having a healthy soil, so the Reddington’s were pleasantly surprised with the results of the soil carbon trials.”

“Since cropping into the kikuyu we have noticed it comes back looking healthier, more invigorated and with increased production. Ken Reddington said.

By growing kikuyu, the Reddingtons now have a reliable source of feed for their livestock, are able to utilise out of season rainfall, have the ability to be opportunistic and grow a cash crop if the conditions are favourable and most importantly, have confidence their paddocks will remain stable throughout the year.

“Cropping into kikuyu allows farmers to take advantage of unseasonal rainfall events, making their farming systems more robust against future climate variability without affecting soil carbon stores and having the added bonus of rejuvenating old kikuyu pastures,” Charlotte said.

A case study regarding this work will be released in the coming months.