Downloaded 15 times
Uploaded bySoil and Water Conservation Society
Restoring Depleted Soils - Kitchen
- Extensive plowing and grain production in the U.S. Midwest around 100 years ago led to severe soil erosion and declining crop yields between 1926-1936. More recently, a heavy rainfall event caused gullying that consumed 2 cm of topsoil, an amount that could take 300-400 years for grasslands to replace. - No-till and cover crop practices implemented over the past decade at a research station have led to a 32% reduction in sediment loss from the field compared to the watershed and 350% more soil formation at the field level. These practices also reduced nutrient loss from the field. - Soil health, as measured by factors like organic carbon, aggregation, and microbial activity, was significantly
More Related Content
Similar to Restoring Depleted Soils - Kitchen
More from Soil and Water Conservation Society
Restoring Depleted Soils - Kitchen
- 1. Restoring Depleted Soils: CoverCrops and Soil Health Newell Kitchen USDA-ARS Cropping Systems and Water Quality Research Unit Columbia, MO February 18, 2015 Cover Crops Iowa Conference, West Des Moines, IA
- 2.
- 3. “…. did notso much collapse as consume itself.” How do we get away from treating soil as a consumable?
- 4. Recent Times U.S.Piedmont used to be a major agricultural region Cultivation brought immediate and devastating soil erosion
- 5. • In theU.S. Midwest, extensive flat grasslands were plowed and put into grain production about 100 years ago. • Multiple and damaging large flood events caused severe soil erosion and property damage between 1926-1936. Grain crop yields for many fields actually declined when compared to the previous century (Bennett, 1939). More Recently
- 6. • A 10-cmrainfall event created gullies that followed the planter rows (channeled by the planter furrow) • About 5-cm deep x 30-cm wide, of a 76 cm-row spacing corn crop • Erosion “consumed” 2 cm of topsoil • Could be replaced by growing grass for 300-400 years Few Years Ago
- 7.
- 8. What is theimpact of past erosion on productivity? • Average 7” topsoil lost since farming started ~120 yrs ago • Impact on production today? • Soybean: 7” x 0.7 bu/in/a/yr x $13/bu = $64/a/yr • Corn: 7” x 2.9 bu/in/a/yr x $5/bu = $102/a/yr • C-S rotation: average loss $83/a/yr
- 9. “… the slowerthe emergency, the less motivated we are to do anything about it.” Dirt, David R. Montgomery
- 10. What do weknow about soil health and cover crops today that we didn’t already know 30 years ago?
- 11.
- 12.
- 13.
- 14. What has beenthe impact of a decade of no-till and cover crops?
- 15. Long-Term Research Field 1991-2003 Corn-SoybeanMulch-Till 2004-present Soybean-Wheat (N) Soybean-Corn (S) No-Till + Cover Crop
- 16. Average Annual SedimentLoss 32% of Watershed Rate of Soil Formation 350% more @ Field than Watershed
- 17. 1991-2003 Mulch-Till 2004-present No-Till + CoverCrop Impact of CC and No-till on Nutrient Loss 1991-2003 2004-present
- 18. Downside of CoverCrops Female meadow voles have a gestation period of three weeks, have an average litter size of five, and produce four to five litters per year. They reach sexual maturity at 40 days and have a reproductive life span of 1 to 2 years
- 19. Soil Health Soil ManagementAssessment Framework (SMAF) Physical Score • bulk density • water-filled pore space • water-stable aggregates Biological Score • organic C • B-glucosidase • microbial C • mineralizable N Chemical Score • pH • electrical conductivity Nutrient Score • extractable P • extractable K
- 20. SMAF Total Score(0-5 cm) G+CC Grass/Pasture NT G MT G a ab bc c c d
- 21. Long-Term Research Field 1991-2003 Corn-SoybeanMulch-Till 2004-present Soybean-Wheat (N) Soybean-Corn (S) No-Till + Cover Crop ~76 ~88
- 22. “How might werethink the conventional wisdom of conventional agriculture to find a way to work with nature?” Stop “trying to make soil adapt to our technology.” Use technology and innovation to give us the tools to adapt to how we manage soils. Premise: Future agricultural will require innovation and technologies to achieve a sustainable framework for managing soils.
- 23.
- 24. Physical Score • bulkdensity • water-filled pore space • water-stable aggregates Biological Score • organic C • B-glucosidase • microbial C • mineralizable N Chemical Score • pH • electrical conductivity Nutrient Score • extractable P • extractable K SMAF Total Score (0-5 cm)
Editor's Notes
- #3 a commodity that is intended to be used up relatively quickly
- #12 As humans, we are a whole lot better at seeing things that we do wrong than we are at seeing things that we do right Engineer solutions, now we are seeing cover crops as a way to restore function
- #13 As humans, we are a whole lot better at seeing things that we do wrong than we are at seeing things that we do right Engineer solutions, now we are seeing cover crops as a way to restore function
- #20 The Soil Management Assessment Framework (SMAF) provides site-specific interpretations for soil quality indicator results. Because the definition of soil quality for your site depends on your management goals, climate, crops, and soil type, a framework approach to soil quality indexing is used. This allows for the necessary differences in site- and goal-specific interpretations of indicator results. The index framework involves three main steps: Indicator selection to efficiently and effectively monitor the critical soil functions Interpreting indicators in terms of soil function (using expected ranges determined by the soil's inherent capability) Combining indicator scores into an integrated index of soil quality (optional). The result is a relative measure of the soil's ability to perform the functions necessary for its intended use. Andrews et al., 2001