Growers have always cared about soil; however changing weather patterns are putting much more strain on our soils. Even more important though is a growing understanding of the damage to our soils through some current soil management practices and the need to modify them, where practicable, to better protect our soils.
Every time we use machinery on our soils we are reducing the life in it. Soil inversion destroys the habitats of the soil’s inhabitants, but minimum or no till does not necessarily solve all problems. Recent research is showing unintended consequences of some of the synthetic fertilisers, pesticides and herbicides in common use.
For example, fungicides do exactly what they are meant to, in soil as well as on the target plants, often leaving soils where such products are regularly applied bereft of the soil fungi so important for crops utilising mycorrhiza for growth.
The UK and Europe is losing precious fertile soil at an alarming rate. In the UK alone we lose 2.2 million tonnes of valuable top-soil every year and it takes 100 years to build 1cm of soil back. Leaving soils bare over winter leads to the greatest loss of soils, through erosion and run off.
Soil Organic Matter (SOM) plays a crucial role in mitigating the impacts of flooding and drought on our landscape as soils with higher levels of SOM are better able to hold water.
We also know that soils with higher levels of SOM are easier to work, with lower fuel costs and less wear and tear on machinery. However, retaining and building SOM is not easy, and a loss in SOM is likely where sources of crop waste, farmyard manure, green waste or decaying soil life are not available to growers.
The UK has moved away from mixed farming to more specialist, larger farms often with single enterprises. This has reduced the ability for many farmers to be able to access good sources of materials required to build soil organic matter.
Could bringing livestock back on to our farms be an option for improving soil organic matter? This will need a radical rethink of farm infrastructure, farm systems and the skills required.
Over the same period we have also moved away from long-term land stewardship, especially for soils where a rotation is required such as for vegetable growing. Short-term rental agreements make it more difficult for the land owner to ensure that soil health is respected. This is often at its most extreme for late harvested vegetable root crops.
The good news is that soil itself is very resilient and the organisms in it can respond very quickly to practices designed to support optimum populations of soil microbiota. This in turn can lead to improved soil structure and function as well as better yields.
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