How Human Activity Affects Erosion

What happens to life on earth if soil all over the globe erodes away faster than nature can replace it? Disaster is perhaps too mild a word, since food production allows human life, and all non-human life depends also upon soil.  Preventing erosion and using sustainable methods protects not just species, but natural systems and non-organic elements. 

In the 1930s, the United States saw hundreds of acres of degraded soil turn to dust and blow hundreds of miles away.  This Dust Bowl was a cautionary tale.  Dr. Bruce Wilkinson at University of Michigan presented a paper at the National Geologic Society of America in 2004 addressing precisely this concern.  His findings, along with those of other researchers, include that human activity erodes soils ten times faster than natural geologic processes.

The alarming news is that human activity is what strips away most soils, causing not just reduced food production, but vulnerable areas where people impact soils by unsustainable crop processes; deforestation, which makes the ground quite vulnerable; mining and human development; and human activities, such as off-road and cross-country vehicle recreation, and even hiking.

Climate change is accelerated as more forests fall to food production.  Human development, both agricultural and in resource extraction, cause a great deal of damage to soil.  Plants and their root systems are the highly evolved method nature uses to retain and enrich soil.  Any practice that removes the all-important plant vegetation anchoring will result in eroded soils.

And any process such as paving results in more water damage.  This is because impermeable barriers such as  concrete or asphalt  concentrate where rain drains, wind blows and gravity pulls, carrying valuable soils and nutrients with them.  A taxing burden to all food production is overpopulation. People require housing, fuel, food, water, roads and industry, all of which gobble up the living soil along with the ecosystems it sustains.

Therefore, it is not just agricultural practice that is of concern.  Over-grazing by livestock results in grazing animals eating new shoots, and digging into soils to find food. And confining them on feedlots, known as CAFOs (concentrated animal feeding operation) also produces contaminated, loose and flooded soils that accelerate erosion in those areas near concentrated industrial feed lots.

Poverty is perhaps the biggest indirect threat to soil.  In places where people do not have the resources to practice sustainable mining, farming, ranching or even careful development, soils are more vulnerable. Slash and burn agriculture quickly removes soils, as does destroying ecosystems for “dirty” (extraction of fossil fuels) mining and drilling.  

But it is good news that family planning, education and simple-to-learn techniques can dramatically improve the human relationship to soil and conservation.  Farm techniques that keep cover crops as field cover, use efficient and not flooding irrigation, use safe fertilizers and non-toxic pesticides protect the ground and its nutrients.  For over-grazing and CAFO sites there is a simple solution, which is just to move grazing animals frequently and reduce concentrations of them.  Thus, herbivores become a benefit to retaining soils, which they fertilize as they graze. There is strong evidence that grazing cows, for example,  can greatly help degraded regions.

For reducing development, urban and suburban areas can benefit by keeping as much green space, rooftop gardens, protected waterways and community farmer’s market programs as possible.  And education about human dependence upon soil results in people being more willing to protect, defend and appreciate that which makes life not just possible but pleasant.  A less crowded, hungry and degraded planet is the ultimate goal involved in soil conservation.  It is one well worth pursuing.