Soil Erosion - Dust Storms

On Saturday there were particularly strong winds (they caused a bit of damage with our polytunnels - but thankfully not too serious), and as we know these extreme weather events are a symptom of the changing climate (greater instability) - but the abnormality of this incident is not so much a direct result of the "unusual" winds, but rather can be traced back to poor farming practice. What is absolutely clear is that right across the world, the organic matter (and particularly humus content) of soils is falling - this is far more serious than most people appreciate. Soil organic matter (SOM) levels are dropping at a worrying rate, especially on arable agricultural soils. It is quite difficult to get good data, because soil types are so varied, but it is clear that on arable soils the trend is for organic matter and humus levels in soils to drop. Once SOM drops below 2% (and particularly below 1.5%), very negative cycles are set in train. Without enough organic matter, soils start to die. It is the microbial life in soils which drives the biology, and keeps soils healthy. Without a healthy soil life, gums and other substances cannot be produced which bind soil particles together into clusters, known as soil aggregates. Without binding into aggregates, soils become very prone to wind erosion - being blown around. This is blowing away of soils is often particularly bad when soils are cultivated in dry conditions, when they lack the necessary soil microbiology to say healthy. The result is dust storms - which are obviously dangerous in themselves, but by far the most serious effect is that soils lose their fertility, their ability to grow nutritious food crops and to support life in the soils which ensure a long term future for food production.

We plan in the next couple of newsletters to do a mini-series on the soil-food-web, which provides the essential explainations for soil biology and soil life. As consumers, we all need to appreciate the links between environmental and human health and farming practice.

Own photo, dust storm on the fields behind our farm on the 11th March 2023. You can see the soil of the organic garden does not blow away because of its better soil structure, high organic matter content and biodiversity.