By Wayne Parrott, PhD
The wealth of nations springs from the fertility of soils. Take a leisurely drive through the countryside. It will be easy to tell if the soils are good or not just by looking at the size and quality of the buildings and the cars their owners drive.
A fertile soil is a microbial wonderland, holding organic matter and forming a tiny ecosystem too small to see with our eyes. Yet, the soil ecosystem retains and recycles the nutrients that fertilize the plants that nourish animal life, including ourselves. Life as we know it would not be possible without soils.
However, what is good for crops is good for weeds, and that is where problems start. Weeds rob crops of their nutrients. In any given year, weeds rob enough nutrients around the world to have fed one billion people. Clearly, farmers have to get rid of weeds. But, getting rid of weeds is easier said than done.
Over the years, nothing has been better to get rid of weeds than plowing the soil. But plowed soil easily washes away. Its organic matter burns away, and its ability to hold nutrients is destroyed. Until recently, controlling weeds took a Devil’s bargain — farmers frequently had to choose between their crop and their soil. In fact, the World Wildlife Fund says that half of the world’s soil has already been lost in the past 150 years. In other words, we have been living on borrowed time unless food can be grown differently. Then, 20 years ago, the combination of GM crops and herbicides came along and made conservation agriculture that protects the soil much easier to do.
The premise is simple. Soil is no longer plowed to control weeds. Instead, a machine punches a small hole in the ground, and a seed gets dropped in. The crop will start growing among the weeds. However, the crop has been engineered to resist certain types of weed killers. Thus, the farmer can come along, add the weed killer over the top, and kill the weeds without killing the crop. As a bonus, the dead weeds are left behind, and act as a blanket that protects the soil from washing away in the rain.
This new combination has had a profound effect on agriculture. Farmers do not have to buy fossil fuel for tractors that plow soil, and the soil does not wash away. Furthermore, today’s chemicals are far less toxic than the ones used last century, and are frequently used in smaller amounts. It is a win-win for farmers and the environment. But more challenges lie ahead in the quest to protect the soil. There will need to be far greater use of GM crops engineered for conservation agriculture before we can truly say our soil is safe and our future secured.
Dr. Wayne Parrott received a degree in agronomy from the University of Kentucky, and MS and PhD degrees in Plant Breeding and Plant Genetics from the University of Wisconsin-Madison. He joined the faculty at the University of Georgia, where he has been conducting research on the development, use and safety of transgenic (i.e., GM) and edited crop plants, using grant monies from USDA-NIFA, NSF, DOE and the United Soybean Board.