Blog reposted from the Columbia – SIPA website.

Against the backdrop of the rolling hills of Pennsylvania, Professor Glenn Denning’s class in  Global Food Systems took a break from classwork to visit the Rodale Institute, an agricultural research organization specializing in organic farming.

Having studied food systems and farming methods from around the world all semester, the students welcomed the opportunity to explore agricultural practices in person. “It’s rare that we actually have the opportunity to be on a farm,” said Olivia Snarski MPA-DP ’14. “Our academic brains were buzzing because we were able to visualize the application of our agricultural development knowledge.”

Welcoming the students to the farm, the associate research scientist Dr. Gladis Zinati gave a review of the research being conducted by the Institute. While organic matter only accounts for 5 percent of the soil, it is critical for maintaining overall soil health, she explained. In order to maintain healthy soils the biological components must be kept in balance. Particularly, one can predict the health of the soil by the types of protozoa present – too many ciliates could mean trouble.

After an organic lunch of oven-baked pizza, the students got their hands dirty. Pitchforks in hand, the students helped to aerate compost — decayed plant material used as organic fertilizer. Many of the students were shocked to see steam rising from the center of the musty dark-brown pile. Well-maintained compost, Zinati and her colleagues explained, has a high internal temperature and, if aerated properly, produces an entire world of beneficial fungus and bacteria that can be used to improve farm soil quality.

Rodale is at the forefront of research into farming best practices. Rodale’s Farming Systems Trial is America’s longest-running study comparing the effects of organic versus conventional farming practices. “It was very interesting that organic farming methods were shown to have equal yield as conventional agriculture,” said Marissa Strniste MPA-DP ’14.

The trial also found that conventional farming has a negative impact on soil health – reducing the carbon content of the soil. Denning argued that this finding does not hold true in all situations, especially in a resource-poor setting with highly degraded soils. “The idea that chemical fertilizers are universally bad for soil health is simply not correct,” Denning said.

“Used incorrectly, chemical fertilizers can be bad for soil health and the wider environment,” he continued. “Used correctly, they can help restore degraded soils, achieve higher yields, improve food security, and save lives.”

Among the agricultural innovations that the Rodale Institute demonstrated to the SIPA students were the use of compost tea and zero tillage. Compost tea is made by steeping a bag of compost in water. The solution is then sprayed on farmland as fertilizer and to improve the biological content of the soil. Zero tillage avoids the disruptive use of tills and plows, which can lead to soil erosion. Instead of plowing, a leguminous cover crop is rolled with a metal barrel leaving an organic mat that suppresses weeds and fertilizes the soil. Both innovations could be used in resource-poor settings to extend the impact of limited available compost and reduce the cost of agricultural inputs such as fertilizer, herbicide and labor.