Editor’s note: This is the third part of a five-part series exploring the topic of sustainability. The next part will be about the social element of sustainability.

As the world continues to become more and more connected and worldwide concerns such as climate change become more pressing, one of the basic systems of life – agriculture – faces a challenge: How will it become sustainable?

Several people at Iowa State work toward ways to answer that question – including students taking courses related to sustainable agriculture, Ph.D. students enrolled in the graduate program in sustainable agriculture and those working at the Leopold Center for Sustainable Agriculture.

The issue of sustainable agriculture is as deep as it is broad, and as Frederick Kirschenmann, distinguished fellow for the Leopold Center, pointed out, it is more of a journey than anything else.

Soil management is one of the more important issues to those studying sustainable agriculture. Kirschenmann said he learned from his father that taking care of the land was more important than money.

Kirschenmann said researchers need to focus more on how soil management is related to nutrition. He said organic agriculture was initially about managing soils correctly by returning organic matter to the soil to increase its biological activity.

Now, Kirschenmann said, organic agriculture has more to do with certification, which farmers can gain by using natural rather than synthetic fertilizers, and it is not necessarily focused on correct soil management.

People who wonder if organically grown food is more healthful, he said, should study the relationship between soil management and nutrition.

The distance food travels is also a concern of sustainability. Rich Pirog, program manager for the Leopold Center, said the average produce item travels approximately 1,500 miles before being sold or consumed.

Pirog said that, as fossil fuel supplies continue to dwindle, a question to ask is whether this kind of system can continue.

Individual consumers can make personal choices that impact the amount of energy used in the food system. He said 31 percent of energy used in the food system is actually used by consumers.

Therefore, Pirog said, simple actions such as combining shopping trips, purchasing food from farmers’ markets and even owning energy-efficient appliances can all positively affect the food system.

Pirog said people will soon see “carbon labels” on their food indicating the greenhouse gas emissions generated from the processes used to make and ship the products they purchase.

One company has just put out a carbon calculator, found at www.eatlowcarbon.org. One thing to keep in mind, however, is that carbon is only one measure of environmental impact. Nutrients used to grow the food also make an impact on the environment.

Pirog said the current agricultural system needs to account more for external costs of production. He said if farmers cause soil erosion or contaminate the water, they should be held accountable.

“There needs to be clear incentives for farmers and businesses to be able to deliver on all three facets of sustainability – [social, economic and environmental],” Pirog said.