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The Missouri Approach to Soil Health Dr. David Hammer 1 Mark Abney 2 Dr. Randy Miles * 1. * Presenter 1 Soil Scientist, University of Missouri 2 Soil Scientist, Natural Resources Conservation Service. Objectives.
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The Missouri Approach to Soil Health Dr. David Hammer 1 Mark Abney 2 Dr. Randy Miles * 1 • * Presenter • 1 Soil Scientist, University of Missouri • 2 Soil Scientist, Natural Resources Conservation Service
Objectives • Discuss soil health with emphasis on “Missouri perspective” and scientific underpinnings. • Put soil health into soil systems framework with role of water. • Discuss the Missouri Soil Health Laboratory.
NRCS and the University of Missouri are Partners in the Soil Health Initiative Fred Jorge JR David Russ Donna 1. Holistic approach with science-based goals. 2. Laboratory renovation to address key soil health variables and integrate soil health into existing data base.
Soil Health Soil health, also referred to as soil quality, is defined as how well soil does what we want it to do. Healthy soil gives us clean air and water, bountiful crops and forests, productive grazing lands, diverse wildlife, and beautiful landscapes. As defined on NRCS web site This implies the importance of key SOIL FUNCTIONS
What is soil? Soils are natural bodies formed from the effects of the active factors of living organisms and climate working upon parent materials, over time, as modified locally by topography. Three phase systems (solid, liquid, gas). Mineral and organic. Biological. Complex in space and time. Intimately intertwined with water. Slow to form, but quickly eroded/altered. Different things to different people. Marshall Soil
Contains life A complex mixture
Surface water runoff seldom occurs under diverse native vegetation in humid environments.
Four species of native prairie plants, each with different rooting, flowering and seeding habits. Competition ensures that “someone always is thriving” in most native ecosystems, all resources are being used but conserved (competition) and the systems are in a dynamic equilibrium with their environment.
Climate: The Missouri Challenge Annual temperature and precipitation distributions; Frequency, intensity and duration of extreme events. Effects on vegetation.
More than 24,000 soil series in the U.S. and nearly 500 in Missouri.
Dennis Doniphan Gerald Bolivar Twomile Menfro Creldon Keene Thank you Dr. Scrivner
The most important interface In the biosphere? From The soil profile . . . To the hillslope . . . To the watershed.
Soil Health Soil health, also referred to as soil quality, is defined as how well soil does what we want it to do. Healthy soil gives us clean air and water, bountiful crops and forests, productive grazing lands, diverse wildlife, and beautiful landscapes. As defined on NRCS web site This implies the importance of key SOIL FUNCTIONS
Specific Agricultural SOIL FUNCTIONS include, but are not limited to: • Water infiltration, percolation, filtering, and delivery to aquifers and plants in “clean” condition; • Decomposition of biological detritus; • Carbon sequestration; • A source of support, nutrients and water for plant communities; • Home for immeasurable species of soil fauna. • Energy transformation and distribution. • Sustainable interactions among soil, soil fauna, vegetation and water. The MOSOHEAL (Missouri soil health) idea is that healthy soil functions are sustainable interactions among soils and the biotic and abiotic components of the geosphere and biosphere.
Measureable Components of Soil Health by Broad Categories Soil biology Soil physical properties Soil chemical properties Soil-water interactions Soil organic carbon (SOC)
Sanborn Field:Residues removed before 1949; returned after 1950
Summary of Long-Term SOC Levels on Sanborn Field: Monocultures and Crop Rotations • With removal on residues up to 1949, SOM levels decreased throughout soil profile through 1963 analysis. • In some instances, SOC levels increased from the 1963 analysis to the 1988 soil profile analysis. • After initiation of residue return in 1950, the manure treatments nearly returned to 1915 SOC levels. • Loss of SOC in subsoil from residue removal does not always return to 1915 levels with return of residues.
Gains and Losses of SOM in Sanborn Field Plots • Soils samples from 1915 were earliest samples; therefore, they were the reference. What was the original SOM as Sanborn Field was initiated? • Once residues were returned to plots there was a time lag for reaction. • Gains and losses of SOM from the depths lower than 8 inches are much more slight and possess greater lag in time than upper 8 inches. • It takes 30-40 years after application of residues to obtain SOM nearing the “original” SOM of 1915.
Attributes of a Healthy Soil • Stable soil surface with good soil structure; • SOC in dynamic equilibrium with its management and the environment; • Robust, diverse microbial population that efficiently decomposes detritus and cycles nutrients; • Effectively infiltrates, percolates and transmits precipitation; • P, N, herbicides and pesticides not in sufficient quantities to cause water quality problems in the event of an unexpected erosionalevent or normal hydrology; • Rooting volume sufficient in quantity and quality to sustain a permanent vegetative cover; • Sustainable under its land use or management system.
Soil Structure Cannot Be Over Emphasized Soil surface structure allows water infiltration, aeration, root penetration, larger surface area for roots and microbes . . . Subsurface structure important for water movement, root penetration . . . “the quantity and quality of the rooting environment.”
Permeable soil surface. Strongly structured surface. High O.M. content. Minimal erosion. Strong subsoil structure. Rapid water percolation. High available water-holding capacity. Favorable soil texture throughout. Excellent quality and quantity of rooting volume. Water infiltration, percolation and storage are excellent in this soil. Quantity and quality of rooting volume are excellent! Marshall Soil
How does cultivation alter the complex soil system?
Cover Cropping – Simulate Nature Continuous cover. Return biomass to system. Diversity of microbial populations and rooting. Increased SOM – aggregates, nutrients, infiltration. Optimize water infiltration and retention.
Soil Health Laboratory Analyses(Specific to “A” horizons) “Active fraction” of soil organic matter. Total soil organic matter. Phospholipid fatty acid analyses– PFLA. Aggregate stability (can water infiltrate throughout rainfall event?). Bray 1 and Bray 2 phosphorus. Texture by pipette. pH. Total N Mineralizable N. On selected sites and reference areas – infiltration and Ksat. Over time . . . relationships among these. Rates of response to cover cropping systems.
Dennis Doniphan Gerald Bolivar Different soils will have different “health” values. Not all soil health attributes will improve at the same rates. Interactions among soil health attributes are largely unknown, particularly among soils and with respect to various cover cropping practices. We don’t have a soil health baseline, so . . . We will have difficulty making recommendations for a while.
Projects to Develop Interpretations • Build a data base – • Key representative soils • Natural areas • Best cropping/tillage practices • Develop a soil health index. • Tracking soil health improvementsunder specific cover cropping systems over time. • Analyzing interactions among soil health parameters across a range of soils and management practices. • Obtaining sufficient infiltration and Ksat data to understand and predict water behavior – drought mitigation.
We think our approach is logical, cost-effective, and maximizes current resources while building upon previous investments. We’re looking forward to serving and working with you.