By Karen Hopper Usher
Heavy farm machinery is squishing the life out of soil, the president of the International Union of Soil Scientists said recently.
“Pay attention. We need our soils forever,” Rainer Horn told participants at an environmental symposium at Michigan State University.
Soils are a non-renewable resource and are vital to food production, air quality and water quality, he said.
And not all soils are created equal, Horn said at the “Fate of the Earth” symposium. He gave a talk titled “The Effects of Land Use Management Systems on Coupled Hydraulic Mechanical Soil Processes Defining the Climate-Food-Energy-Water Nexus.”
It’s important to know how strong soil is. Some soils are too weak for heavy machinery, he said.
If farmers drive heavy farm machinery on soil that isn’t tough enough to handle it, the fields might produce less food, Horn said.
That’s bad news because the planet loses 186 square miles of soil every day and is going to need that soil badly in 2050, when the world population is expected to hit 9 billion, Horn said.
Or important chemical processes that take place in the dirt beneath your feet can go wrong—ultimately resulting in more methane gas being released into the atmosphere. Methane is a greenhouse gas that can contribute to global warming.
Heavy machines can also hurt the root system in weak soils. That makes it harder for groundwater to be recharged, Horn said. And it can lead to more run-off, where dirty water just slides across the ground and into surface water instead of sinking down into the soil.
“The soil doesn’t need to be adjusted to the machine. It’s vice versa,” Horn said. “Tell the government.”
It’s not that Horn thinks farmers should go back to using horses to farm massive fields. Lightweight machines that can be operated remotely already exist and are being used in Australia, Finland and Germany, he said.
But as long as it’s cheaper to build big tractors out of steel, that’s what industry will do, Horn said. Governments should use regulations to make using the smaller, lightweight machines more attractive.
Farmers should use whatever machines they want as long as it doesn’t exceed the internal strength of the soil, Horn said.
Taking care of the planet’s soils should be a top concern, he said.
“Everybody likes to eat something, have water and fresh air,” Horn said.