Organic farmers discuss reduced-tillage techniques

Reduced-tillage organic vegetable production systems may help make it easier for new farmers to get into the business by reducing the need to invest in expensive equipment.

This can be an important advantage, because equipment and land costs are the major barriers that prevent people outside of farming families from starting farm businesses.

"We had increased yield and less weed pressure, and we also had less overhead," said Michael Whamond, who grows vegetables on his Hillview Farm outside Auburn.

Whamond made his remarks during the 40th Annual Ecological Farming Association Conference in Pacific Grove, as farmers shared their experiences with reduced tillage to cut costs and build soil.

Though weed control can be a challenge in organic reduced-tillage systems, some relatively small farmers say they have found ways to make this system work by steadily reducing the seed bank during a period of years.

"More biologically active soil leads to healthy plants, which mean higher profits," Whamond said. "Keep living plants in the soil, because without plants there is no soil; keep a diversity of plants in the soil because it feeds the soil ecosystem; and disturb the soil as little as possible."

He called the approach he uses the "Living Soil Method," and said it gives him more biologically active ground, better soil structure, increased water-holding capacity and, over time, reduced weed pressure.

"Managing the beds is one of the most difficult parts," Whamond said. "If you're not tilling the soil, you have to manage the residue much better. We flail mow the residue and tarp it. In soil we've had in the program, we can just tarp the ground to decompose residue and get rid of weeds. We've seen broccoli residue decompose in a week and a half or two in the winter."

Eventually, the weed seed bank is depleted in reduced- or no-tillage systems, because new seeds are not brought up to the top—but farmers said there is no specific way to handle the difficult transition.

"There is no one way to do no-till," said Andrew Mefferd, who farms in Maine and wrote The Organic No Till Farming Revolution, a compilation of methods developed by 17 family farmers around the country.

Working under a Virginia Tech professor, Mefferd learned about the roller-crimper method, in which an attachment both crushes weeds or cover crops and cuts them off, but found it not suited to smaller, diversified farms.

"Some people say we need more big farms, and some say we need more small farms," Mefferd said. "We just need more farms, and no-till can lower the barriers because you don't have to invest as much in equipment."

Some of the farmers at the conference moved toward reduced tillage because they found their more conventional approach was making their ground steadily more difficult to work.

"When I started farming in 1974, I had no idea what I was doing and by 1985, I saw that my ground was getting harder and my equipment kept getting larger," said Scott Park, who grows 1,700 acres of vegetables and field crops. "I gave up the model of chemicals plus heavy equipment to beat soil into submission."

The heart of Park's new program is to put enough crop residue, compost and cover crops in the soil to add 15 tons of biomass an acre every year, so the ground never goes to sleep.

"The three 'C' s are cover crops, crop rotation and conservation tillage," he said. "I have 26 fields, and every one of them gets better every year. Water retention is unbelievable, and the quality of the crops is the biggest difference."

More than 30 years after his decision to convert to organic systems that include reduced tillage, Park is still conducting trials to make the approach work better.

"We probably have 15 trials going on now," he said. "Observation is my most important tool."

When he implements a no-till program in a field, Whamond said he first evaluates the problem weeds and develops a strategy to manage them during the transition until the time when pressure has been diminished.

"The living soil program shifts the ecology away from weeds over time, but I had never dealt with perennial weeds with rhizomes until I started in Auburn," he said. "We had lots of bindweed. It's hard to do no-till with bindweed, Johnson grass and Bermuda grass. We had to adapt. We had to use a transplanter that does not disturb the very top of the soil."

Before implementing no-till, he speeds the process by ripping compressed soil once, adding compost and tilling the ground again to get it farther down into the soil.

"This is a way to get these nutrients down into the soil right away to begin," Whamond said. "You need a system that works for you and your farm."

After the ground is ready for tarps and mowing to replace ripping, the job of regularly loosening the soil is turned over to cover crops and crops.

"We're using plants to do tilling for us," Whamond said. "Think of cover crops in terms of how the roots break up the soil at depth and add organic matter."

Reduced equipment costs are a major incentive to adopt no-till, but Whamond found his greatest reward when PG&E began periodically turning off the power on him and other farmers.

"I started farming in a drought, so some of these principals were instilled in me," he said.

(Bob Johnson is a reporter in Sacramento. He may be contacted at bjohn11135@gmail.com.)