‘A farmer’s greatest resource is his or her soil’ – Nuffield Scholar, Simon Mattsson, in his report Making the Most of Your Soil’s Biological Potential, 2016.
Soil quality, as any farmer knows, is critical to the success of their crop. The humble farmer wears several hats; that of business owner, caretaker, provider and scientist. While all roles are complex and integral to his or her success, the responsibility of Chief Scientist is for many, the most challenging.
The kind of expertise involved in monitoring soil quality, and implementing strategies to correct or enhance it, is not only complex but expensive and time-consuming. As if farmers were not busy enough!
Thanks to the likes of Simon Mattsson, and fellow soil-biology enthusiasts like David Wolfenden, the hard yards in research and trial-and-error have been taken care of, and the results are available for all to enjoy.
David, a farmer from the Rand area in NSW, has trialled soil improvement strategies on his land which have resulted in better yields and higher profits. After hosting a NSW Department of Primary Industries (DPI) trial investigating minimal soil tillage back in 1978, he became keenly interested in soil health and its benefits for production and profit. David went on, along with other growers interested in testing new farming innovations, to help found the Southern Farm Management Group.
“A key lesson was that good yields are a result of getting many factors right, with soil health a major contributor to most of these factors,” David says.
His initial efforts to reduce tillage and retain stubble within his fields took a decade to produce any measurable results. When the returns for his efforts were revealed, however, it was clear that the practices he’d adopted had been more than worthwhile. In 2011 a study was conducted into the benefits of adjusting the water-holding capacity (WHC) of soil.
According to GRDC (Grains Research and Development Group) article ‘Soil Health Checks Keep Profit Potential Alive’:
“A gross margin analysis showed the added net income from applying 10kg/ha of phosphorus was $37/ha, resulting in a $2.63 return for every $1 spent.”
Those kinds of figures would keep any bookkeeper happy, although an initial investment in the trialling of different additives was necessary. Fortunately, David’s research, and that of many others have resulted in some tried-and-tested methods available to any farmer.
Simple tips that any farmer can trial
Manage soil pH
Optimal soil conditions require a near-neutral pH level. Lime can be added to raise the pH of alkaline soils. Furthermore, CSIRO’s Dr Clive Kirkby suggests ‘feeding the bugs’ in soil with sulphur, phosphorous and nitrogen to encourage breakdown of stubble by bugs into nutrients in the soil. Happy bugs = happy plants.
WHC (water-holding capacity)
Variations within fields of water-holding capacity can affect yields, as David Wolfenden discovered in his trial. Managing the capacity of soil to hold water, with phosphorous, can result in increased yields. Drone technology can help farmers to monitor their soil health, water retention, temperatures and even detect disease. (Check out our article: Drones: The Future of Farming? for more information).
Alternating species/Crop rotations
Mixing, alternating and rotating crops can help soil’s biodiversity by adding nutrients naturally, and increasing organic carbon (OC) levels. In Simon Mattsson’s paper, he recommends co-planting of sugar cane with sunflowers in order to increase OC levels, and also provide an extra cash crop to farming for the season.
Rotating of crops can also manage disease, such as crown rot in wheat, for example. Alternating fields with a ‘break crop’ can reduce inoculum levels in soil while avoiding over-tilling which can result in removal of nutrients and can affect water retention. (Read more in our article: How to Treat Crown Rot, Septoria and other Pesky Wheat Diseases for more information about combating diseases in wheat crops.)
Minimum tillage and stubble retention
Over-tilling of soil, while providing some short-term benefits for disease control, can result in disturbance of water supply, soil quality and destruction of stubble. Applying minimal or even zero-till practices can preserve cooler, more moist and nutrient-rich soils which are ideal for planting.
Using organic fertilisers
Organic fertilisers increase OC levels in soil, and increase biological activity as a result. Furthermore, according to reports, organic fertilisers are a more sustainable long-term solution for farmers.
Minimising use of pesticides
Pesticides such as fungicides and insecticides can result in higher levels of harmful chemicals in soil, and therefore affect soil quality. Fungicides can also affect beneficial fungi which are present, and necessary within soil. By spraying strategically, farmers can reduce the need for use of pesticides.
There are a number of new technologies available to help farmers to manage their crops and livestock, along with their soil—farming smarter and reducing costs. By fostering healthy soil, farmers can exponentially improve their yield and ultimately their profits.