Plan B Defense - Jim Cave - 12/15/15

Date: December 15, 2015
Time: 11:15 a.m.
Location: NR 130

Are Soil Health Tests Useful for Tree Fruit Production in Michigan? 

Linking Grower Perceptions of Orchard Performance to Soil Health Indicators

Master of Science Plan B Defense 

Jim Cave

Department of Community Sustainability

Tuesday, December 15, 11:15 a.m., Room 130 Natural Resources Building


Soil degradation is a major threat globally.  Traditional soil tests focus on helping farmers manage inorganic nutrients using fertilizer.  Soil health tests, by contrast, provide a more holistic view of soil by adding physical and biological indicators to the traditional chemical indicators.  Farmer understanding of soil health concepts, however, is poor.  In addition, the usefulness of soil health tests for farmers is limited as the tests have not been validated for specific agricultural systems, such as orchards.    

The purpose of this study is to examine the usefulness of soil health indicators to commercial tree fruit producers in Michigan.  The work is exploratory and compares the performance of soil health indicators against farmers’ perceptions of orchard performance.  A case study approach is taken.  Four commercial fruit growers from a single geographic area were chosen based on their interest in exploring the use of soil health indicators on their farms.  A battery of soil health tests, including 10 physical, chemical, and biological indicators, was performed on soil samples collected from four orchards from each farm.  In-depth, open-ended qualitative interviews identified farmers’ experiences with orchard performance.  Farmers’ perceptions of orchard performance were compared to measures of soil health.  Promising indicators were identified based on their ability to 1) differentiate high- and low-producing orchards and 2) provide management recommendations.    

The results suggest that soil health indicators are useful to commercial fruit growers who are interested in soil quality.  Three indicators, potentially mineralizable nitrogen, active carbon and aggregate stability were able to 1) differentiate between good and bad orchard sites and 2) provide suggestions for how to increase or maintain soil health.  The results suggest that system-specific recommendations are needed for soil health tests to be a useful tool for extension educators and growers.  

Committee members:

Kimberly Chung, chair

John Kerr

George Bird