No-Till's ability to hold on to soil carbon ranks right at the top among farming systems for slowing greenhouse gas concerns.

A recently completed research trial by Michigan State University (MSU) crop and soil scientists demonstrates that no-till adds more heat-trapping power to the atmosphere than it removes, offering still another key reason for expanding the no-till acreage.

Conducted at the MSU Kellogg Biological Station in Hickory Corners, Mich., the 10-year study offers the most comprehensive data ever gathered on how field crops affect the atmosphere’s global warming potential.

The study included four corn and soybean rotations managed with:

• Conventional tillage and conventional chemical inputs.

• No-tillage and conventional inputs.

• Reduced chemical inputs.

• Organically with no chemical inputs.

Perennial alfalfa, poplar trees, cover crops and several fields of unmanaged vegetation that would be similar to Conservation Reserve Program (CRP) ground were also included in the study.

While no-till accumulated the most carbon, Robertson says each of the cropping systems accumulated varying amounts of soil carbon over the 10-year period. With the organic cropping system, the study suggested most of the carbon accumulation is due to the use of winter cover crops rather than using organic farming practices.

The study indicated that farmland that had been taken out of crop production (such as CRP) and allowed to grow wild removed significant amounts of greenhouse gases from the atmosphere, especially during the first few years.

How It Works

When soil is turned over, organisms such as bacteria and fungi break down the carbon…