Leave the Tilling to Mother Nature
Published on April 26, 2017
COLUMBUS, Ohio — Whether talking to farmers in France, Ghana or southern Ohio, Rafiq Islam’s message is consistent: Tilling the land does more long-term damage than good.
As an Ohio State University soil scientist, Islam is among the disciples in the movement to convince farmers that plowing their fields before they plant or after they harvest harms the health of the soil and its ability to spur growth and resist erosion.
Soil plowed repeatedly can lose key ingredients that enrich it, including carbon, which can evaporate as carbon dioxide gas into the air. Left undisturbed, soil can maintain that carbon, and the dry decaying stalks in an untilled field add to the organic materials in the dirt.
After crops such as soybeans or corn are picked, a farmer can plant a cover crop in a field instead of plowing it. The cover crop isn’t harvested for food but instead keeps the soil covered and porous and contributes carbon to it, Islam said. Land left bare is more susceptible to erosion and cannot absorb water from rain or snow as efficiently as when cover crops are planted on it.
Last month, Islam was part of a team of soil specialists who traveled to France to host four workshops on climate change, soil health, cover crops and no-till farming, events sponsored by two farm organizations in France. More workshops are planned for the summer in Ukraine and China, in the fall, in Uzbekistan and in the winter, in Ghana.
In most parts of the world, the majority of farmers regularly plow. So it’s not easy to convince long-time conventional farmers or even younger farmers not to plow their land, said Islam, who is the soil, water and bioenergy program leader at Ohio State’s South Centers in Piketon. The centers are part of the university’s College of Food, Agricultural and Environmental Sciences.
“You try to open their eyes by showing them the actual field results and demonstrating the user-friendly field tests and tools,” Islam said. “It’s tough. Farmers are businessmen. Some don’t want to take risks.”
To many, tilling makes sense. Running a disk or plow through the land breaks up the soil and helps mix in fertilizer to ready the field for new seeds.
But, say Islam and other proponents of no-till and cover crop farming, plowing the land can kill some of the crucial beneficial microorganisms in the soil. Even on fields crowded with the dry remains of last season’s crop, new seeds can be sown using drill attachments to planters. And the root system of cover crops helps break up the soil to make room for the roots of newly planted seeds. In other words, Mother Nature can take care of the plowing.
And when Mother Nature performs the work, farmers can save on the fuel and time it would have taken them to do the job.
Protecting the health of soil is critical given the expected worldwide population doubling by 2050 and the challenge of feeding everyone, especially those in developing countries, Islam said.
“The health of soil is important to human health,” he said. “We have to do some proactive measures to improve our soil health, control air pollution, minimize water pollution and feed the growing population in the world.”
No-till farming does come with tradeoffs. Farmers can’t just leave their plows in the barn and expect the same results as when they used them. If farmers choose to leave fields untilled, they likely will need to purchase attachments to their planters, such as a drill, that will assist them in sowing seeds.
Initially, fields left untilled may not yield as many bushels until the earthworms and other organisms in the soil have had the time to build up, increasing the biological diversity and efficiency of the soil, said Alan Sundermeier, director and agriculture and natural resources educator in OSU Extension’s Wood County office. Sundermeier was on the team of OSU soil specialists who traveled to France to lead the workshops there.
Cover crops planted on unplowed fields can help improve the performance of the fields within a few years.
No-till farming “takes more management, understanding and patience,” Sundermeier said.
But, he pointed out, over time the productivity of a field left untilled will equal, if not surpass, that of a plowed field.