How can we make sure everyone on Earth has enough to eat? It’s a question scientists have been pondering since the world population topped seven billion in 2011. It’s expected to reach 9.6 billion by 2050.
While many researchers focus on how to increase crop yields, Mike Klug - a retired microbial ecologist from Michigan State University - says we should be looking at the ground. Klug says we’re losing soil at a rapid rate.
According to the Food and Agriculture Organization of the United Nations, the world has already lost one third of its usable soil. Klug will give a talk on Vanishing Soil Communities Thursday at Pierce Cedar Creek Institute.
That's "Soil" Not "Dirt"
Klug says dirt is what you sweep out of the corners of your kitchen floor. It has no structure and very little life. Klug says soil has structure to it.
If you grab a hand full of soil, it doesn't slip through your fingers quite like dirt or sand. It's like a community - with minerals, organic matter, microbes, and invertebrates.
Klug says some scientists think that at the beginning of the Earth's formation, most of the ground was dirt.
"Now the major question is, are we returning more towards dirt because we're losing the structure. We're losing components within the food web," says Klug.
Klug says food grown in good soil has been shown to have health benefits because of these microbial relationships. He says studies show that children living in rural areas are also healthier because they get expose to a diversity of organisms in the soil.
Why We Need More And More Fertilizer
Klug says as humans started to farm, we began taking more good stuff out of the soil than what we were putting back in.
A plant's roots can feed nutrients to the soil and create that soil community, but those roots have to have time to grow. Because most farmers plant annual crops - crops that only last one season - the roots can't grow deep enough to help the soil.
Farmers also often leave the soil bare in order to grow annual crops. That leads to wind and water erosion, which erodes away the top layer of soil or - topsoil - which contains the majority of the soil's nutrients.
So, how do we get plants to grow in a less habitable soil? Fertilizer.
"If you do not have the biological community transforming the organic matter [decaying plants] back into nutrients, we have to supply more and more fertilizer and in many cases water in order to maintain the productivity that we need to feed the population that we have today," says Klug.
Erosion Is Serious Business
Remember the dust bowl of the 1930's? Klug says that's probably the best example of wind erosion.
Klug says erosion may seem like something that happens all the time, but we need to start taking it more seriously.
"Wind erosion sort of nickels and dimes you to death, in that it's continuously occurring but it occurs at such a slow rate that people do not take notice of it," says Klug.
Water erosion is a little more obvious, says Klug. Water can wash away large portions of soil, which often pollutes rivers, lakes, and streams with excess sediment. That can be expensive too. Klug says there are entire industries built on dredging sediment out of waterways.
The Hardy Native Plant
Klug says one way to stop the degradation of soils is to plant native plants. He says native plants are hardier because they have developed survival methods over time - like a large roots system.
"So the root systems go down many meters into the soil. As a result of it, they're scavenging nutrients and they're scavenging water from great distances in the soil and therefore they require very little maintenance after they've been established," says Klug.
Native plants don't need as much water or fertilizer. Because native plants survive longer seasons, they provide more food for bees and other insects. Those insects in turn support birds and other wildlife.
"There's such an array of native plants that from your very early spring flowering plants - some of which are flowering almost while the snow is still on the ground - to things like asters which are present even after frosts. So there's a continuous supply of nectar and pollen throughout the entire season if you provide a high diversity of native plants," says Klug.
What Can We Do To Help The Soil?
Here are Mike Klug's tips:
- Do crop rotations in your vegetable gardens. This will make sure the soil gets a variety of nutrients.
- Plant some cover crops in your yard or on your garden after your annual crop is gone. Things like clover, sudangrass, winter rye, oats, and field peas. Klug says this feeds the soil nutrients and reduces erosion.
- Increase organic matter. You can do this through adding compost or by letting plants die where they are instead of ripping them out of the ground and putting them in a pile.
- Try to reduce the amount of fertilizer you use.
- Never leave your soil bare. Bare soils encourage erosion.
- Reduce the use of herbicides and pesticides. They kill pollinators that plants need.
- Buy produce from local farmers that use good farming practices instead of big companies where you don't know how your food is grown.
- Plant native plants to feed the soil and pollinating insects.