Linking Soil Testing with Farmer Decision Making – An Interdisciplinary Approach

View the project final report

Commodities

• Agronomic: corn, rye, soybeans, wheat, grass (misc. perennial), hay

Practices

• Animal Production: feed/forage
• Crop Production: application rate management, cover crops, nutrient cycling
• Education and Training: extension, focus group, networking, participatory research
• Natural Resources/Environment: carbon sequestration, indicators
• Production Systems: agroecosystems
• Soil Management: nutrient mineralization, organic matter, soil analysis, soil chemistry, soil quality/health

Row crop growers traditionally use soil tests as part of their soil management strategy, particularly to know what inputs to add – such as specific nutrients and lime. A new emphasis on soil health has led to novel approaches at soil testing and management recommendations based on these test results. It is unclear how growers used to traditional soil test might alter management based on testing for soil health. At the Kellogg Biological Station, we have begun to use soil health approaches to gauge soil health tests sensitivity to different cropping systems. We will complete soil health tests on a series of management gradients as a means of calibrating sensitivity to different row crop managements. Then with Michigan State University (MSU) Extension educators we will work with 10-12 row-crop growers and with their guidance, sample soils reflecting a range of productivity and managements on their fields. A portion of sampled soils will be submitted to MSU soil testing lab for a traditional soil test. In our own lab we will run a series of established soil health assays measuring soil physical, chemical and biological characteristics. The biological attributes will include nitrogen availability as assessed by nitrification – a key biological process that reflects turnover of plant available nitrogen. With traditional soil and soil health tests output in hand, we will discuss specific results with each grower and interview them about test interpretation and recommendations stemming from results. We will use these responses to aid in structuring soil health workshops to discuss interpretation of soil health parameters, results from their farms, and from KBS gradients, and how test results influence their own management decisions. The goal of the interviews and workshops is to use grower input to better translate soil health test results to management, and with their input ‘co-create’ an extension bulletin and outreach materials based on soil health. This work will adapt novel soil testing to on-farm management decisions that ultimately control the fate of soil fertility.

The goal of this work is to translate soil analyses developed to measure soil ecosystem processes to practical soil health tests that guide grower decisions toward improved soil management. We will evaluate the sensitivity of different soil testing approaches to variability on management gradients at experimental field stations and on Michigan farms. In addition, we will incorporate a measure of nitrification - a critical variable controlling plant available nitrogen (N) – with other soil health parameters. We will work with extension staff to test soil health on farmer fields and ask growers to help select soils of interest on their fields. Through individual interviews and workshops we will learn from growers how they understand and value different soil test results, and their effectiveness at capturing soil health on soils they help select. We will use workshops as a forum to invite other growers in the county to discuss soil health, testing and relevance of tests to their management. In the process we will generate a Michigan soil health lab manual available for future researchers and extension staff. Through grower input we will co-create the content of an extension bulletin that describes different soil health assays, how to describe their parameters and their relevance to management decisions.