Grains of sand are mysterious particles and worth contemplating as we lounge on the beach. Each one is millions of years old and could have traveled thou- sands of miles to reach its current location. A grain of sand is the ultimate gypsy on its unique voyage through time and space, land and water.
The forces of erosion by wind and water (how sand grains are formed) are powerful and patient. These forces whittle away at the earth’s surface 24/7. Usually, they are invisible forces, but sometimes they are sudden and violent.
With great regularity – every rainy season – they impact the terrain here on coastal Jalisco and Nayarit. Landscapes and beachscapes yield to wind and water naturally but often how humans manipulate land accelerates the action of the forces dramatically. In fact, in the last 150 years, half of the world’s topsoil has been washed into its oceans due to human agriculture and development practices. It’s not a topic conversed about at cocktail parties nor does it have the sexiness of climate change, but topsoil loss is one of the planet’s most critical challenges as far as us successfully living on it goes.
The issue is that it takes nature 1000 years to gradually build topsoil on most of the planet. This is the soil zone where we grow food – below this humus layer is a pure gritty mineral matrix that does not sustain most life. Because topsoil is such a precious layer built over time, nature guards it militantly with a green mantle of plant life – in many cases what we consider weeds or aggressive plant species. These plants create a protective layer – roots to hold soil in place and shoots to buffer the soil against direct rain, wind, and sun.
The fact that “nature abhors a vacuum” was a huge epiphany for me as a horticulturist as it is the basic law of logic behind mulching and not leaving gaps in garden plantings. Because by doing so, and not mulching, we wage a perpetual war against nature in which she defends her precious topsoil with every weed she can come up with. This is a war that is only over with either topsoil destroyed or the gardener changing her ways.
This might sound quaint in a gardening context, but takes on a new significance when we consider that the vast majority of human agri- culture – especially grain produc- tion – relies on maintaining naked soil around the crops and never mulching. We are talking millions of hectares here, around the globe and, quite literally, chemical warfare. The solution entails overhauling how we grow food.
Here in Nayarit and Jalisco, we as homeowners can take charge of our erosion in several ways. One is to buy as much food as possible from small farmers who treasure their soil. The other is to utilize a plant called Vetiver, which can grow its roots 2 meters down without expanding laterally or being invasive in any way. Vetiver, which is a type of tall grass, stabilizes slopes, protects house foundations and is espe- cially effective at bioengineering the sandy soil most of us have here. Two local landscaping companies who can install vetiver are Tropical America and La Costera. Lastly, please mulch, utilize good erosion prevention design with any new roads you require and use gutters to prevent unmitigated roof runoff.
As you suntan on the beach, staring at all those grains of sand, I’m sure you can think up other ways to protect our precious soil as well.