We continually hear agronomists, researchers, farmers and natural resource management professionals (such as us!) talk about ‘soil health’ and ‘soil carbon’, but what does it actually mean? And why is it important?
Fundamentally soil health describes the capacity of the soil to function as a living system that can support and sustain the living organisms reliant on it. The foundation of good soil health is soil carbon, and an understanding of soil carbon levels is used by farmers in different ways for different decisions.
In this recent article featuring the Soil CRC, Dr Lukas Van Zwieten says that the more organic carbon in the soil, the better it is for the cycling of nutrients. This means that plants grow better and there is a reduced reliance on fertiliser application. Plus, healthier soil microbes lessen the chance of soil disease.
But there is also an economic value. According to the article, soils are estimated to contribute $63 billion annually to Australia’s economy through agriculture alone. The soils’ value increases exponentially when biodiversity and carbon storage are factored in as economic assets.
There are some interesting innovations coming out of the University of Newcastle when it comes to soil testing and soil resilience that can inform these decisions. Rapid, field-based tests are taking the form of chips that can measure dissolved organic carbon in the soil.
Landholders will be able to prepare a solution of their soil, mixed with water, that the chips can be applied to instantly measure carbon or nutrient concentration. This will help farmers make more educated assessments when it comes to cropping and fertiliser use.
Healthy soils are an asset. Understanding the relationship between soil carbon and soil health will become increasingly important as we deal with stressors such as drought, seasonal changes, soil acidity and compaction.