Ava McCune

Evaluating the Soil Health Effects of Long-Term Cover Cropping in High Tunnels

High tunnels are an important agricultural technology in organic vegetable production. However, maintaining soil health while minimizing negative environmental impacts has proven to be a challenge within these systems. Intensified production and increased crop nutrient uptake result in concerns over organic matter content and nutrient quality of soils within high tunnels. Manure is a commend amendment to these systems, and while rich in organic matter, its high phosphorous content can create environmental concerns. One strategy to mitigate these negative effects in organic high tunnels may be the introduction of cool season nitrogen-fixing cover crops, in rotation with a summer cash crop. Research within the Grossman Lab has begun to investigate the use of leguminous cover crops within organic high tunnel systems, and their short-term effects on soil health and plant available nutrients. The objective of my research was to expand upon this knowledge through an evaluation of the effects of long-term cover cropping in high tunnels on soil health. Soil health was evaluated along metrics outlined in the Comprehensive Soil Health Manual produced by Cornell University, specifically through an analysis of: 1) wet aggregate stability, 2) total soil organic matter content through loss on ignition, and 3) soil microbial respiration. There was no significant difference in aggregate stability between cover cropped and non-cover cropped plots, however, cover-cropped plots had a slightly higher percent organic matter than non-cover cropped plots, indicating some organic matter accumulation in these cover-cropped plots.