Enhancing soil health and promoting biodiversity

In a pasture system, grazing animals account for only about 25% of the living organisms in the system. The rest is accounted for by tiny living organisms that exist in the soil, and litter (decomposing plant material lying on the soil surface).  

The activity of microorganisms and earthworms that feed on soil organic matter and recycle nutrients helps to improve soil structure and water holding capacity. Healthy biodiversity in soil organisms is also important for suppressing undesirable pathogens. 

The top 10 centimetres of most soils is a precious, non-renewable resource. This surface layer contains most of a soil’s nutrients, plant roots and living organisms (biota) including bacteria, fungi, protozoa, nematodes, earthworms and other soil animals. Soil biota represents a large portion of the Earth’s biodiversity. 

The living organisms in soil require a food source, air, water, shelter and a stable environment. Ground cover and litter supports soil biota by maintaining a more stable temperature environment (lessening temperature fluctuations) and provides shelter. Ground cover levels can also help to control weeds and reduce the impact of root-feeding grubs, such as cockchafers and scarabs. 

The biological activity in the soil relies on providing food together with suitable temperature and moisture conditions. By far the most critical management action producers can take to protect their soils and keep them healthy is to maintain high levels of ground cover.