Testing for Soil Health and Soil Wellness Soil s role in storing and releasing carbon By William F Brinton Ph.D. Founder, Director: Woods End Farm Laboratories, inc Faculty Associate, University of Maine
A vibrant, healthy soil takes a long time (years) to achieve (and lesser time to destroy) Open crumb structure; aggregate stability Clod integrity Rich in biological activity 2
Soil Composition Soils of geo-mineral origin; Soil organic content (usually < 5%) due to accumulated residues (plants/roots/microbes). Farming harvest residues contribute 1 ton/a yr* 1-5% of soil C lost yearly from CO2-respiration. *source: Rothamsted Long Term Plot Studies, UK as reported at ASA.SSSA Mtgs Nov 2009 Pittsburgh 3
Complex Soil-Plant Carbon-Oxygen Cycle 1. Natural microbial soil respiration will consume O 2 and produce CO 2 2. Plant root metabolism requires O 2 and releases CO 2 3. Photosynthesis by plant surfaces absorbs CO 2 and produces O 2 10/4/2013 4
Soils as Carbon Reservoir Soils considered a carbon-reservoir since they can accumulate organic matter humus At 3% OM, a 6 deep acre slice* contains 30,000 pounds of carbon/ acre much more in deep soils 6 12 Kansas Soil Profile, USDA-NRCS *6 layer 1,000 tons soil at 1.3g/cc Bulk Density; 50-54% of OM is carbon 5
USA Soil Carbon Stocks* * In 2010 the USDA-NRCS Rapid Assessment of U.S. Soil Carbon (RaCA) program collected 144,833 samples of soil from the top 1 meter of 32,084 soil profiles at 6,017 randomly selected locations for measurement of organic and inorganic carbon 6
Turnover of Soil Carbon vs Total Carbon Storage RESPIRATION: the natural turnover of stored organic matter converting it to CO 2 CO 2 rate is tied to the mass of stored carbon Factors that influence respiration will also affect amount that is pushed to atmosphere 7
SOIL: Largest active reservoir of C BIOGENIC RESPIRATION: Aside from insects soil microbes represent the largest global biological respiration of carbon FOCUS: Soils traditionally under-appreciated for their C role.
Solvita: Two Applications CO2-Burst and Basal
Solvita: Two Applications CO2-Burst and Basal 1) LAB CO2-Burst TEST 2) BASAL FIELD TEST
Solvita: Basal Field Test LAB CORE BASAL TEST SOIL CORER FOR UNDISTURBED SAMPLE
Solvita: CO2-Burst test intended as lab only procedure Approved in the ALP soils program since 2010 and recently added to NAPT (ASA-SSSA) Soil Test Proficiency 1. Used by more than 30 commercial soil labs (see map) 2. Helps standardize testing respiration Mimics drying-rewetting pulse of CO2 and nutrients 3. 4.
Commercial USA Labs Offering Solvita CO2-Burst Test PA: Skyview Labs Boswell PA 814.629.5441 NJ: Rutgers Soil Lab New Brunswick NJ 848.932.9295 OH Brookside Labs, New Bremen OH 419.977.2766 VA A&L Eastern Lab, Richmond VA 804.743.9401 NY, VT, NH, ME: University of Maine Soil Lab OTHERS: see http://solvita.com/soil/map
Solvita CO2 Detection: An exponential response
CO2-Burst LAB TEST - An Agronomic Tool for Nitrogen and Yield Management
Early USDA-ARS Work: In-situ CO 2 Tests CO 2 evolution viewed per unit area (acre, hectare, m 2 ) helpful for real-world glimpse of actual soil and atmospheric carbon balance USDA SQI recognized two protocols: Dräger and Solvita Refs: USDA-ARS (1999) Soil Quality Test Kit Guide, NRCS-Soil Quality Institute (on-line) Doran J., M Tsivou (1997) Field and Laboratory Solvita Soil Test Evaluation. USDA-ARS, University of Nebraska, Lincoln
Semi in-situ BASAL (field) Respiration Test with Fresh Soil In situ or Ex situ - CO2 Output per acre SEE: www.soils.usda.gov/sqi/asses sment/educators.html
Basal Respiration Interpretation
Basal Respiration in-situ and ex-situ Soil air captured in head-space of cylinder represents ~3 of soil depth Solvita Probes compare closely to other analysis methods (GC, Dräger). Allows estimating field CO2 output (e.g. as lbs/acre per day)
Cover Cropping/No-Till Effects Greensboro NC Piedmont* soil after 30 years no-till; soils normally depleted (<1%OM) under tobacco cultivation * Clifford sandy clay loam 0-4 sample R. Archuleta photo
SOIL RESPIRATION RESULTS
ACCUMULATED SOIL ORGANIC-N
Factors that influence rate and efficiency of Soil CO2 Diurnal temperature (min, max) Moisture flux Age of SOM (OM additions, cropping) USDA NRCS Soil monitoring stations provide helpful views Drying-rewetting bursts Source: USDA SCAN (Soil Climate Analysis Network)
What most likely happens. Under temperate climate conditions most of the soil carbon is released during the growing season in accordance with temperature cycle and assuming moisture is adequate. Modified after SCAN data for central PA
Long Term Studies in Soil Health Focus on field effects of manure, composts, vs intensification of inorganic fertilizers Ex situ respiration testing principle focus in observing biological effects Reports: Brinton, Pettersson, Wistinghausen (1979) Sweden Long Term Effects of Organic and Inorganic Fertilizers. Nordisk Forskningsring Report Nr. 30. Järna, Sweden
mg/100g CO 2 * 2.7 = ppm CO 2 -C 17 yr effects of soil treatments * CO 2 respiration in soil reflected a nexus of biological effects of fertilization. * Reduced Tillage with 4 yr Crop Rotation Reports: Compost BD Cert. Compost #2 ORG Raw manure Manure + NPK Control no amendment Chemical NPK 1X 2X 4x rates - Pettersson, Wistinghausen Brinton (1978) Long Term Effects of Organic and Inorganic Fertilizers. Nordisk Forskningsring Meddelande Nr. 30. Järna - Dlouhy, J. 1981. Alternativa odlingsformer - växtprodukters kvalitet vid konventionell och biodynamisk odling (Alternative forms of agriculture with English summary). Swedish Univ. Ag Sci. Report 91. Uppsala -Granstedt, A & Lkjellenberg. 1997 Long-Term Field Experiment in Sweden. In Proceedings, Tufts University, Agricultural Production and Nutrition, Mass. March 1997.
Source: Brinton et al. (1981-1997) Swedish Field Plot Studies
Concluding remarks NEW TOOLS are available to assess soil health factors. RESPIRATION: the aggregate metabolism of carbon due to humus, litter, roots and soil organisms SLAN: the evaluation of stored organic-n representing cover crop and humus effects Soil Basal Respiration is an overall indicator of current soil processes and helps understand field behavior; CO2-Burst represents potential biological performance and can be performed by several labs. SOIL HEALTH TOOL is an integrated model that incorporates nutrient and health factors into one test.
Soil Health Tool Testing: condition of soil and nutrient supplying power interpreted
Soil Health Tool Tests Starting in Jan 2014 Take soil samples at 2 depths: 0-3 (remove surface litter carefully) 3-6 (remove obvious roots and stones) Note: take 3-4 grabs at different locations and mix and combine in order to send about 1 pound each; do not pre-dry sample; mark bag outside with a Sharpie marker that does not wash off List current management and last 3 years Provide soil type info if known; Give address of farm and lat/long if possible (this will be used to match to USDA soil maps) SEND SAMPLES to: Woods End Laboratory 290 Belgrade Road, Mt Vernon Maine 04352 LAB@WOODSEND.ORG OTHER LABS SOON OFFERING COMPREHENSIVE SOIL HEALTH TOOL: WARD LABS, BROOKSIDE LABS