When its windy and dry there will be a lot of dust in the air. This dust consists mostly of sand and other small particles.
This sand is literally top soil flying away, drifting in the wind.
If you are in an area like me, then all around you will be bare lands with exposed soil like a desert. Its especially in these desert like areas, the more sandy the wind becomes.
Any place where there is a lot of soil exposed, usually from plowing, combined with dry conditions and a good wind the air will become sandy because there is nothing to hold the soil particles fixed to the land, they simply blow away in the wind.
In lands where large areas are covered in green vegetation with either grasses or trees the vegetation will have the following 4 effects:
- The roots of the vegetation hold the soil together.
- The mulch created from leaf litter prevents soil from blowing away.
- The vegetation reduces wind speed, therefore reducing the force soil is blown away with.
- The combination of leaves, mulch, and roots catch dust in the wind and trap it.
It is the last point that is particularly interesting. Not only do we want to prevent soil erosion from wind and rain, we can also add fertility from the air by catching dust.
When a dusty wind sweeps trough the dust will stick to the leaves of the plants or be trapped in the mulch, especially if there are dense thickets of vegetation. In this way the vegetation acts as an air filter.
When the first rain comes the dust is washed off of the leaves and falls to the ground becoming part of the soil, adding new fertility.
Therefore it is important to always keep your land green and vegetated to not only prevent soil erosion, but to also add and retain more fertilizers without any extra costs.