Much of the talk around soils is currently focused on their ability to provide Public Goods such as carbon storage and flood alleviation. Agriculturally soils perform several more important roles including water retention and drought prevention but also provide a reservoir for plant nutrients and an environment in which a host of microorganisms can convert the plants simple sugars into plant available nutrients.
For a soil to do these things it has to be cared for as a complex living organism which needs to be fed and looked after. Soils like other living organisms want a consistent environment in which they are regularly fed and not disturbed. In return they will provide the above ground plants with an environment in which their roots can grow and build diverse communities that transfer nutrients back to the plant in exchange for some of the sugars that the plant produces by photosynthesis.
With these few requirements in mind, it becomes easier to see how to look after the soils and build a fully functioning soil. A key component is ensuring that there is a diverse below ground community. This will come from having a wide range of plants. Ideally across the rotation but also at any one time. Diverse above ground cropping leads to strong community below ground who can exchange chemicals and help the plant grow above and below ground. Diverse crops have differing root architecture feeding different fungal and bacterial colonies that form relationships with roots building organic matter.
Feeding the below ground community with manures and composts is an obvious way to help, but the volume of biomass below ground far outweighs most applications of FYM or manures and these sources when piled on in larger amount become a burden. Applying a little and often is a much better way.
Perhaps one of the most overlooked issues with crops is the use of fungicidal seed dressings which are placed right at the point where seedlings need to build the fungal associations that allow the plant to move nutrients from the soil to the plant.
Reducing cultivation is often seen as the starting point for producers seeking reduced costs. Whilst reducing cultivation especially deep cultivation is important, the soil has to be in a condition where it can look after its structure without the help of cultivation. Cultivation to the below community is a bit like an earthquake to a city, so trying to keep the cultivation as shallow as possible is important.
If you want to know more on all matters soil, contact William at email@example.com in the Andover Office or your local FCG Office.