Organic Vs. Conventional: The Long Term Study

Share this post

FB-organic-farm-transBy Judith Redmond of Full Belly Farm, courtesy of  Capay Valley Farm Shop

I participate in a national group that for the past few years has worked to develop policy and action recommendations for food and agriculture.   The group includes people from various parts of the food chain, and it has been clear from the start that while there are many interesting discussions taking place, most of the participants view the practices of organic agriculture as a “niche” or “boutique” part of farming, rather than potentially game-changing solutions to the many challenges faced by the world’s increasing population.   When it comes to addressing the converging and increasingly pressing challenges of hunger, poor water quality and climate change, the proponents of chemicals, monoculture and an industrialized-type approach to farming are well represented.

In part because of my participation in these discussions, I was especially interested in a recently published report about an experiment that was started all the way back in 1998, called the “Long Term Agroecological Research Experiment,” one of the longest running comparisons of organic and conventional agriculture in the U.S. In a nutshell, the   study concludes that producers making the switch to organic crops not only fetch premium prices, they also build healthy soil and sequester carbon, making organic agriculture a useful strategy for dealing with climate change.

“Farmers interested in transitioning to organic production will be happy to see that, with good management, yields can be the same, with potentially higher returns and better soil quality,” said Kathleen Delate, agronomy and horticulture professor at Iowa State University, who leads the project.

The experiment is located on 17 acres at the Iowa State University Research and Demonstration Farm near Greenfield. The project compared four crop rotations using identical varieties that are repeated four times in 44 plots. The conventional rotation received synthetic nitrogen, herbicides and insecticides at recommended rates. The organic corn plots received composted manure from a local chicken operation. Weeds were managed by timely tillage, longer crop rotations and cover crops.

The study found that soils in the organic plots (three- and four-year rotations of corn, soybean, oats and alfalfa) had significantly higher quality compared to the plots using a conventional two-year rotation of corn and soybeans. The organic plots had up to 40 percent more biologically-active soil organic matter, which is important for fertility and nutrient availability. Organic soils also had lower acidity and higher amounts of carbon, nitrogen, potassium, phosphorous and calcium.

Healthy soils hold more water and improve water infiltration, increasing a farm’s resiliency to drought, heavy rainfall and extreme weather events. Farming practices that build soil health also increase carbon storage in soil, called carbon sequestration, which buffers climate change and contributes to better water quality.

Project investigators gathered data on yields and economic viability: Corn and soybean yields were statistically equivalent in the organic and conventional systems during both the transitional phase (1998-2001) and established phase (2002-2010) of the experiment. Yields for organic oats and alfalfa exceeded county averages.

Based on plot-level data, the economic analysis showed that the organic crops fetched roughly $200 more per acre over the 13 years of the study because of premium market prices and reduced input costs. In 2010, for example, an acre of land planted with the four-year organic rotation returned $510, while an acre planted with conventional corn-soybean returned $351.

On average, labor requirements doubled for the organic systems. There was no significant difference in the number of crop pests. The results suggest that skilled management practices can overcome the need for synthetic inputs.

 

Subscribe to the WEEKLY BITE

* indicates required

 

Recent The FruitLife articles:

Beehives, swales, and vermicomposting, oh my!
April 29, 2019
Spring fruit varieties and how to enjoy them
April 16, 2019
A tribute to the “Lemon Lady” of Redwood City
March 11, 2019
The FruitGuys New Year’s poem
January 8, 2019
Sowing the seeds of entrepreneurship
October 31, 2018
Give the delicious gift of farm-fresh fruit and healthy snacks
October 4, 2018
Summer to fall transition brings new fruit into the rotation
October 2, 2018
Bring some fruitful fun to your workplace on Tuesday, October 2
September 27, 2018
Farmer suicide is a public health threat and could hurt our food supply
August 14, 2018
How to keep your favorite fruit fresh through the summer heat
July 19, 2018

More recent articles:

Best onboarding practices
May 21, 2019
Quick, easy steps to spruce up your office space
May 14, 2019
Grilled portobello recipe
May 9, 2019
How to prepare physically and mentally for race day
May 9, 2019
Three simple ways to enjoy watermelon radishes
May 2, 2019
Easy spring salad recipe
April 25, 2019
Reduce plastic use with these earth-friendly alternatives
April 22, 2019
Food:
History of the tomato
April 18, 2019
How to make sure you’re getting enough iron in your diet
April 11, 2019
How fostering psychological safety increases performance
April 8, 2019

About Us

Our online magazine offers a taste of workplace culture, trends, and healthy living. It features recipes for easy, delicious work meals and tips on quick office workouts. It's also an opportunity to learn about our GoodWorks program, which helps those in need in our communities and supports small, sustainable farms.