Researchers at Iowa State University are targeting an answer to one of the most deliberated topics in agriculture — which is better, conventional or organic farming methods?
A 16-year study at the Neely-Kinyon research farm south of Greenfield has shown little to no difference in the yields of the two growing methods in corn and soybeans.
Kathleen Delate, a professor of agronomy and horticulture at ISU, presented their findings to more than 60 visitors Tuesday on soil quality and pest management while comparing yields in conventional and organic growing methods.
“(Conventional farming) is something farmers have grown up with and are hesitant or resistant to change,” Delate said. “It becomes an issue of time or interest.”
The long term agroecological research (LTAR) plot at Neely-Kinyon has shown conventional and organic corn yields were equivalent, provided 120-145lbs per acre of synthetic nitrogen. Researchers found similar results with soybeans.
The conventional nine-year corn yield average has produced 180 bushels per acre compared to 178 bu/acre by organic methods. Soybeans averaged 49bu/acre for conventional and 51 bu/acre for organic.
Considered the traditional method of growing, conventional practices can use chemical fertilizers to promote plant growth.
Wayde Ross, the district conservationist for Union and Ringgold County with the Natural Resources Conservation Service, has grown up using conventional practices.
“With conventional growing, you have the ability to use a lot of the technology and hybrids they have developed,” Ross said.
During the growing period, synthetic insecticides and herbicides can be used to control pests, disease and weeds.
Ross said the advancements made in conventional practices make it possible for farmers to cover more land to produce more food to help feed the world.
Organic growing practices use natural fertilizers, such as manure from cattle, swine and chickens. Compost can also be used to help feed the soil and plants.
Dale Raasch, an organic farmer at Bridgewater Farm, started the transition to organic farming practices in 2006.
“Our farm is up on a ridge, so we can control what we put on our soil and what goes into our ground water,” Raasch said. “I didn’t want the chemicals on our farm.”
To control pests and diseases, organic farmers use natural pesticides and sophisticated crop rotations.
“Farmers, especially Iowa farmers, have a low tolerance for weeds,” Delate said. “With organic farming, there will be more weeds.”
According to U.S. Department of Agriculture, 50 years of research is still inconclusive if conventional or organic crops are more nutritious for the consumer.
However, organic food shoppers will typically get hit with a higher cost.
“We can be quite a bit higher,” Raasch said. “It is best to figure out the things you can grow and do well on your farm.”
Raasch added some buyers shy away from buying organic because the produce does not always escape minor damage from pests or weeds.
“If it doesn’t look like what you would buy in the store, people think something is wrong with it,” Raasch said.
Farmers wanting to switch from conventional farming to organic can’t make the transition over night.
“I usually suggest a farmer starts with 50 acres to see if it is manageable,” Delate said. “It is best to go slow when converting.”
Organic farms require more maintenance and time due to the lack of chemical fertilizers, insecticides and herbicides.
“Organic farming can be very restrictive and very labor intensive,” Ross said.
It also takes time to establish the best crop rotations. Cover crops are becoming a critical part of successful organic farms. They can be used with conventional growing methods.
Cover crops help prevent erosion, suppressing weeds and improving soil health. They also help control nitrate and phosphorus levels in the soil.
“All plants need nitrate to grow, but too much can be polluting,” Delate said. “The idea is to have little to no nitrate in the ground water.”
Ross agreed that cover crops, even in conventional practices, are becoming a critical part of helping to improve crops.
The largest organic farm Delate knows about in Iowa is more than 1,200 acres and is managed by several farmers with years of experience on the land.
While researchers debate on which method is healthier or better yielding, organic farmers are willing to trade convenience for peace of mind.
“We need to know exactly what we are eating and what is going into our food,” Rassch said.