Lessons from Scotland
Cultivated agriculture in Scotland might appear to be at low risk from soil erosion. Soils that support crops and managed grass are usually well structured, containing adequate organic matter left by the plants that have previously grown on them, and rarely collapsing into erosion gulleys as seen in many parts of the world. Yet soils are at risk here from long-term or chronic loss.
Looking back at the hard times, those of agricultural deficit and famine, the soil itself is rarely blamed directly. During the Ill Years of the 1690s, a run of atrocious weather and poor land management were the culprits. The Improvements of the 1700s brought in much better husbandry and much hope, but that was still not enough to prevent famine at times in the 1800s, and then the realisation that the country could not feed itself at 1814, the start of WWI. But all through these times, the soil was an important factor limiting production. The cultivation depth was shallow and nutrients essential for crops were exhausted by previous cropping.
It was not until the mid-1900s that tractors began to replace draught animals with the result that plough depth increased, making more of the soil accessible by crops and grass, and then nutrients such as nitrogen (N) and phosphorus (P) became widely available through industrial process and mining. Yields of crops and grass increased.
The shifts to repeated, deep soil cultivation in many fields and heavier machinery causing compression and slaking of soil, led to an increase in the risk of erosion. It’s not on the scale of the dust bowl but it is widespread, gradual and often intermittent. Loss of soil quality and subsequent erosion is arguably the greatest threat to food security here.