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Digging deeper into soil health: Research on the horizon

Elise Brown Published on 05 March 2014

There’s something magical about turning a shovelful of soil in a pasture or an alfalfa field – the sound of the shovel slicing smoothly into ground, the rich smell of soil and the sight of wriggling earthworms.

We recognize all of these as signs of healthy soil, and they’re particularly familiar to many forage growers, whose rotations often favor great soil-building conditions.

But when it comes to quantifying soil health – putting numbers and dollar signs to it or even figuring out the best way to explore it – healthy soil remains somewhat mysterious.

But stay tuned. Over the next couple of years, an exciting program in Indiana promises to shed light on many of the hidden aspects of healthy soil. Data from 17 demonstration sites across the state are currently being analyzed for insight into what makes soil great.

Results from the current round of tests and further samples taken over the next two years will provide valuable insight to farmers around the country and to the people who serve the agriculture industry.

The Conservation Cropping Systems for Soil Health and Productivity program is driving science-based conservation to new heights, funded by a three-year conservation innovation grant from the USDA-NRCS and a grant from the National Fish and Wildlife Foundation.

Through the program, the Indiana Association of Soil and Water Conservation Districts’ Conservation Cropping Systems Initiative (CCSI) is digging deep into the science of soil health, learning how to best quantify and analyze healthy soil, and connect its development with a variety of conservation practices in large-scale, real-world conditions.

Streams of data
The study protocol for the Conservation Cropping Systems for Soil Health and Productivity program will provide a thorough comparison of 12 host farmers’ existing conservation tactics and programs that introduce new practices.

No-till, strip-till, cover crops and various crop rotation systems are being assessed for their impacts on the chemical, physical and biological properties of the soil.

Researchers and grad students measure soil moisture, soil temperature, soil penetration resistance (a good indicator of the density of the root environment), soil nitrate at three different times of the growing season, stalk nitrate levels in corn, chlorophyll, cover crop biomass and cash crop yields.

They also analyze soil aggregation to check on the health of each field’s soil structure, and they’re currently reviewing streams of data from a new generation of biological assessments.

The biological assessments (conducted in years one and three of the study) are particularly exciting because they’ll provide insight into the microbial diversity of soils under different conservation programs.

They’ll also provide an index of some of the countless soil microbes at work in the vast underground ecosystem that nurtures crops by cycling nutrients.

Finally, these assessments will allow us to compare the new tests with older assessment methods, so we’ll learn how to best use and interpret the results of this technology.

Members of the program team also will be testing a nitrogen calculator developed at Oregon State University to see whether it is able to accurately predict how much nitrogen is available to cash crops from cover crop residues in Indiana conditions.

Economic angle
To add to the science-based conservation perspective, the Conservation Technology Information Center is conducting an economic analysis of the study plots, using host farmers’ real-world figures – another vital set of numbers.

The goal is to provide producers with an idea of the value of different conservation practices from both agronomic and economic angles – and, we hope, to start understanding what soil health is really worth. Taking that information, along with your conservation plan, to a landlord or banker could be valuable.

Hub system
The scope of this project also is fairly unique. The Conservation Cropping Systems Initiative has been built around four regional hubs. These hubs represent the diverse topography, soil types, cropping systems and climate around the state.

Within each hub, non-farm hub hosts – including Purdue University’s Crop Diagnostic and Training Center, the Northeastern Purdue Agriculture Research Center, the Southeast Purdue Agriculture Center, Wabash Farm and Vincennes University’s Jasper Campus – provide deep wells of expertise for the program.

Public-private partnerships
Agricultural conservation practices are the common ground where the interests of the public and private sectors, business and academia, and on-farm and off-farm stakeholders meet.

To assemble the brainpower, funds and facilities that bring a three-year, four-hub, 17-site project to life, support from each sector was needed.

Under the CCSI banner, partners in this program include the Indiana Association of Soil and Water Conservation Districts, Indiana’s 92 local soil and water conservation districts, NRCS, Purdue University Extension Service, the Indiana State Department of Agriculture, the State Soil Conservation Board, the Indiana Soybean Alliance, the Indiana Corn Marketing Council, the Conservation Technology Information Center (a clearinghouse for information on conservation farming), Vincennes University, the National Fish and Wildlife Foundation and the CCSI farmers.

Stay tuned
Forage producers enjoy some great advantages as we explore some of today’s most exciting conservation farming practices.

Improved pastures and multi-year hay crops such as alfalfa provide year-round cover and soil-building benefits like cover crops do. They also provide diversity in growers’ crop rotations, which is increasingly being recognized for its value in enhancing microbial diversity in soils.

Also, forage crops like clover or alfalfa can easily be interseeded into standing crops like wheat, corn or soybeans to establish protective cover for the following winter.

Green-chopping silage also gives growers valuable extra weeks to establish a robust cover crop before autumn frosts. Forage growers are uniquely positioned to put cover crop biomass to work through grazing or harvest.

Ultimately, what we learn through Cropping Systems for Soil Health and Productivity could provide forage growers with facts and figures that help build even better relationships with landlords and lenders.

Information will be flowing in from the program for the next three years, from data to workshops on how, when and why to collect field samples.

Check out Conservation Cropping Systems Initiative periodically for details or look for CCSI on Facebook and Twitter. We’ll keep you posted on what we’re learning.  FG

Elsie Brown
Elise Brown
Conservation Technology Information Center