NRCS s Soil Health Initiative and its Relationship to Water Quality Kip Potter, NRCS, Vermont United States Department of Agriculture is an equal opportunity provider and employer.
The NRCS Soil Health Initiative Formally announced in August 2012 Focus on public relations and education Expanding agency technical capacity and assistance to producers Includes development of regional Soil Health Management Systems
Increase soil carbon and reduce CO 2 emissions Save energy and input costs Save water and increase drought tolerance Reduce disease and pests Improve water quality Soil Health Benefits
What is Soil Health More than just fertile soils with adequate nutrient levels soil quality Physical structure good aggregate stability, pore space, and bulk density Biology soil microorganisms provide natural living system, nutrient mineralization, organic glues, etc. Vegetative cover perennial vegetative cover, preferably living plant systems, provide source of carbon, lower soil temperature, etc. Increase in organic matter soil tillage burns organic matter Systems that mimic mother nature
Soil Organic Matter Loss Recent research U of Minn
Relative Amount of Microbes and other Organisms in Handful of Soil Bacteria up to 50 billion Actinomycetes up to 2 billion Fungus Protozoa up to 100 million up to 50 million Nematodes 10,000 Arthropodes 1000 Earthworm 0 to 2
Sticky substance, glomalin from fungus, surrounding soil aggregates, water insoluble. Soil Glue!
How is Soil Health Measured Cornell Soil Health Assessment basic test is $45 ARS Soil Health Test free for now Both tests include physical parameters such as aggregate stability, bulk density, water holding capacity and particle size distribution Both include percent OM, and nutrient levels ARS Test includes soil slaking, respiration rate, # earthworms and other factors.
Soil Health and Water Quality Improving Soil Health has the Potential to: Increase water infiltration rates Increase soil s water holding capacity Decrease overland flow to surface waters Decrease soil erosion Decrease needed nutrient amendments Increase nutrient retention in soil Lack of studies that look at long-term impacts of improving soil health and implementing associated management systems on water quality
Soil Infiltration and Water Holding Capacity Healthy non compacted soils can infiltrate and hold 2 to 3 times the amount of water as tilled soils
Infiltration Demonstration http://www.youtube.com/watch?v=rpl09xp_fw&feature=player_detailpage
Soil Health and Soil Erosion Reductions resulting from a combination of factors including: living cover, less surface runoff and greater soil stability Conservation tillage studies have shown a typical range in reductions in sediment loss of 45 to 65 percent, with some as high as 99 percent Largest reductions in sediment loss often occur in the larger storm events
Soil Slaking Demonstration http://www.youtube.com/watch?v=9_itehcrlo Q&feature=player_detailpage
Conservation Tillage Study in Vermont Reduced tillage paired watershed study in Starksboro, VT looking at pesticide loss Storm runoff was decreased by an estimated 50 to 63% on the treated watershed The largest reductions in storm runoff were associated with the larger storm events Overall sediment loss was reduced by 99 percent Overall pesticide loss in surface runoff was reduced by a total of 90 percent Reductions in sediment and pesticide loss were largely attributed to reductions in storm runoff (Claussen and Potter, 1990)
Soil Health and Nutrients Nutrients are assimilated and recycled in soil by microbes Nutrients are also assimilated and recycled in living plants Nitrogen is fixed in the soils using legumes Increased soil organic matter increases soil adsorption of nutrients Less need for chemical nutrient amendments
Conventional-tilled field No-tilled field Sediment runoff from conventional-tilled field Clear runoff from no-tilled field Impact of disturbed Aggregates
Soil Health Management Systems (SHMS) Criteria Used by NRCS Diversify soil biota with crop diversity Manage more by disturbing the soil less Grow a living root year-round Keep the soil covered as much as possible Will be templates available for each region of the country. Will include a system of several practices. VT Example for Annual Cropland: Mulch Tillage with manure injection and multispecies cover crop
NRCS Practices Used in Soil Health Management Systems Primary 328 Conservation Cropping Rotation 329 No-till, Mulch Till or Strip-till 340 Cover Crops 590 Nutrient Management 595 Pest Management (Integrated) Secondary, As Applicable 512 Forage and Biomass Planting 345 Mulch 633 Manure Utilization and Management 393,332 Conservation Buffers, Filter Strip Secondary, As Applicable (Con t.) 449 Irrigation Conservation 311 Alley Cropping 317 Composting Facility 610 Salinity Management Deep Tillage? Others, Recommended Precision Application of Nutrients Controlled Traffic no Tillage Flotation Tires no Tillage Strip Cropping Most of these practices are approved for NRCS payments through existing programs!
Some Practices to be Included in Soil Health Management Systems Cover Crops Permanent Hay Manure Injection Reduced Tillage
Special Issues for Vermont Systems for colder climates issues with short growing season and cover crop establishment Systems for use on heavy, clay soils assumptions that reduced tillage will not work on clay soils and that they have to be fall plowed Practices to incorporate manure as part of a reduced tillage system do not leave nutrients on the surface Soluble phosphorus loss associated with systems over tile drainage, reduced tillage can increase these losses
Tracking Hydrologic Pathways of Phosphorus, Ewing Watershed, Qc Water yields and TP exports from Ewing catchment according to groundwater, subsurface drainage and surface runoff pathways. Fall 2008 Spring 2009 Sept. 21 Dec. 8 Mar. 25 Jun. 21 Water yields Groundwater / mm (%) Subsurface drains / mm (%) Surface Runoff / mm (%) Total / mm Phosphorus yields TP groundwater / g ha -1 (%) TP subsurface drains / g ha -1 (%) TP surface runoff / g ha -1 (%) TP other sources / g ha -1 (%) TP total / g ha - 28 (40) 34 (48) 8 (12) 70 24 (9) 82 (30) 139 (50) 31 (11) 276 58 (49) 47 (40) 12 (10) 117 13 (4) 82 (28) 121 (41) 77 (26) 293 Seasonal percentage Poirier, Michaud, Whalen, 2012
Soluble Phosphorus Losses in Tile Drainage Tile drains can transport significant loads of phosphorus Phosphorus in tile drainage is primary soluble phosphorus which is ready available for plant uptake Reduced tillage can increase soluble phosphorus losses in tile May need to consider practices to treat phosphorus and nitrogen in tile discharges, such as constructed wetlands, bioreactors and other treatment systems
NRCS Current, Ongoing Efforts National and State Soil Health Initiative focusing on education and outreach (past and future workshops) New National Soil Health Division that will provide additional technical assistance to States (training courses) State Soil Health Committee (including partners) focused on promoting soil health in Vermont Development of state specific guidance and templates for soil health, including multispecies cover crops and soil health management systems Priority: development of a demonstration farm(s) to highlight benefits of soil health (State CIG grant)
NRCS Current, Ongoing Efforts (cont.) Implementation of EOF monitoring projects to evaluate water quality benefits of soil health management systems Adjusting existing NRCS conservation programs to prioritize practices that promote soil health, especially soil health management systems
Summary Soil health provides both environmental and economic benefits, as well as longterm agricultural sustainability Soil health has become an area of focus for NRCS and farmers throughout the country The potential water quality benefits of improved soil health have been largely ignored Improving soil health in the Lake Champlain Basin would decrease overall sediment and nutrient loading to the Lake and to other waters in the state Additional research and practices are needed to minimize soluble P losses from reduced tillage cropping systems with tile drainage
Summary