NBC Leads Research on Agroforestry and Soil Health

By Blake Jackson

Agriculture plays a vital role in the U.S. economy, generating more than $1 trillion annually and supporting millions of jobs. It also occupies a significant portion of the nation’s land, with roughly 17% dedicated to farming, according to the U.S.D.A.

However, conventional farming practices such as monocropping, synthetic fertilizers, pesticides, and intensive tillage can harm the environment. Poorly managed croplands often contribute to soil erosion and nutrient runoff, affecting waterways.

In Pennsylvania, for instance, the Environmental Protection Agency has flagged over 8,000 miles of streams impaired by agricultural activities.

Agroforestry offers a promising alternative by integrating trees with crops or pastures. At Penn’s New Bolton Center (NBC), researchers from the School of Veterinary Medicine and the Weitzman School of Design are exploring how this approach can support both animal agriculture and environmental health.

“Agroforestry requires ‘a longer view,’” says Elliot Bullen, a research associate and project manager at PennPraxis. The multiyear initiative focuses on riparian buffers and silvopasture combining trees and shrubs with grazing livestock. In January 2024, the team planted 250 trees along White Clay Creek to establish a riparian buffer.

“Planting trees along waterways offers several advantages: their roots shore up the soil along the edge of the stream and prevent erosion,” says Penn Vet’s Thomas Parsons. “But you can also imagine a scenario, particularly around farmland, where there are excess nutrients, such as phosphorus and nitrogen, that might run off into the stream; these additional plants then act as a buffer to help absorb them.”

The project includes “working” buffers, where vegetation like blackberry or mulberry bushes provides economic value while protecting the stream. “We are putting in fodder blocks trees and shrubs that the animals can eat,” adds Parsons. Silvopasture is also being established on hillier pastures to create a savannah-like landscape, providing shade and food for livestock.

This summer, cows began rotational grazing within the agroforestry system. Parsons plans to use GPS and GoPro devices to track their pasture preferences, while the team studies biodiversity, water quality, and soil health.

“We’re trying to promote NBC as a living laboratory to study the interface of animal agriculture and the natural world,” he says, highlighting the site’s potential for research, teaching, and practical demonstration for farmers.

This project exemplifies NBC’s role as a hub for interdisciplinary collaboration, aiming to advance sustainable agriculture while balancing productivity and environmental stewardship.

Photo Credit: pexels-binyaminmellish