Stories: On the Farm
Scott McCalman - Mullaley, New South Wales, Australia
Cotton farmer builds special machinery to improve soil health and nutrients
Like most cotton farmers Scott is a problem solver. He had to come up with a way to improve soil health and reduce the impact of drought on his 1150-hectare dryland and irrigated farm in Mullaley, New South Wales.
The fifth-generation mixed-cropping farmer had been using cover cropping since 2002, but it was when he implemented crimp rolling in 2012 that he saw a major difference in soil health and input costs.
Cover cropping involves growing crops and leaving the stubble in the field to prevent soil erosion, improve water use efficiency and decrease the need for synthetic fertilisers.
Scott’s method of cover cropping isn’t harvested – it’s grown solely for soil health.
“Most farmers love solving problems, and with cover cropping you can see the system working in front of you and how the different pieces of the puzzle fit together,” Scott said.
“For me, it feels like I’m on a winning football team where everything is clicking. It’s put the enjoyment back into cropping.”
In late summer/autumn, Scott plants a mix of cereal rye, field peas and radish across 15-20% of his winter cropping area to target specific soil health functions.
The cereal rye provides biomass and root penetration, the field peas add nitrogen to the soil while radish is used to improve soil structure and pull up nutrient pools deep in the soil.
The crop is terminated at 12 weeks as the plants end the vegetative life cycle, using his homemade crimp roller – a special machine that knocks the crops over and crimps the stems in several locations so they cannot continue growing.
“I built my own chevron pattern roller crimper to terminate the cover crop after a lot of research of what works in the United States,” Scott said.
“The crimper leaves a mat of green matter on the ground to plant into and it works perfectly in dryland or overhead irrigation systems.”
Since introducing crimp rolling into his program, Scott has seen a significant reduction in soil moisture evaporation, increased nitrogen in the soil through cover crop production and he has halved his herbicide use – all benefits to his sustainable cropping operation.
“We adopted cover cropping to reduce the impact of drought, but we weren’t expecting the spectacular nitrogen boost we get from the big release of nitrogen that comes from cover crop biomass breaking down from the crop,” Scott said.
“We saw dryland yields of around two bales per hectare (behind cover crops) in the worst drought on record. Pre-cover cropping drought affected cotton yields would sometimes be as low as .8 bales per hectare.
“But the last couple of very good wet seasons, we have been achieving seven to ten bale dryland cotton crop yields, following terminated cover crop fallows and lint quality has vastly improved.
“So, it stacks in all seasonal conditions in our farming system, it provides resilience and an extremely robust risk management strategy.”
Check out Scott’s YouTube channel here for more info on his homemade crimp roller and cover cropping program.