Managing Vegetation in Salt Affected Soils

Transcription

1 Managing Vegetation in Salt Affected Soils Sharon A. Clay, CHERYL L. REESE, RACHEL OWEN, DAVID E. CLAY, TULSI KHAREL GIRMA BIRRU, * SOUTH DAKOTA STATE UNIVERSITY, BROOKINGS, SD BRUCE KUNZE, NRCS RETIRED JASON MILLER, NRCS SALINE AND SODIC WORKSHOP AND FIELD DAYS 8/12/2015 1

2 Why Salt Problems? Salts have always been deeper in soil profiles and indigenous to this area Late 1970s through 1980s, corn and soybeans introduced to this area and do not use as much water as perennial grass crops Increased rainfall, no till management and tiling have changed water use 8/12/2015 2

3 High Water Table and Salts Different Salts Different problems Saline = Calcium / Magnesium Salts Plants will not grow Sodic = Sodium Salts Plants will not grow and soil is dispersed. Commonality between saline and sodic problems is a high water table. 8/12/2015 3

4 What will grow in saline/sodic soils? 8/12/2015 4

5 8/12/2015 5

6 Crop Rotation 8/12/2015 6

7 White Lake: Sorghum/ Corn/Soybean Rotation Site Salts next to soil surface 8/12/2015 7

8 White Lake: Sorghum/Corn/Soybean Rotation Site Water in soil pit 8/12/2015 8

9 Seasonal water use of tall grass prairie can be greater than that of corn, soybeans, or wheat. Photo, Jim Millar 8/12/2015 9

10 White Lake Tall Wheatgrass Site: Salt Tolerant Field Site. Salts on the surface in that area, Sept /12/

11 White Lake Tall Wheatgrass Site: August 2014 No white salts on soil surface 4 inches Salts are moving down into the soil profile and were 4 inches from the surface 8/12/

12 White Lake Tall Wheatgrass Site: August 2014 No water at the bottom of the soil pit. Redox features Orange iron deposits. Appear when oxygen in soil atmosphere; no water! Tall wheat grass roots down to 4 5 feet. All these factors indicate water table is deeper in soil profile. 8/12/

13 Roots of big bluestem Corn roots 8/12/

14 Other species to revegetate sites 8/12/

15 SDSU NRCS CIG Study Site: Pierpont, SD July 2014 Species Barley / Alfalfa Strip Seeding Rates Seeding Cost per rate lb (lbs/a) $ / A Total Cost $/A Salinity Max Alfalfa $ $82.50 Barley $ $24.00 $ Alfalfa shown to lower water table even in very wet year 8/12/

16 Pierpont, SD July 2014 Salt Tolerant Grasses Seeding Rates Species Cost per lb Seeding rate (lbs/a) $ / A Western Wheatgrass, Arriba $ $50.00 Green Wheatgrass, Certified AC Saltlander $ $36.90 Thickspike Wheatgrass, Critania $ $42.00 This mix was planted at these seeding rates based on 33% for each variety in mix. 8/12/

17 Does applying a soil amendment help with cover crop establishment? 8/12/

18 Crops at Pierpont All cover crops seeded and amendments applied 2 inches of rainfall received within next 3 4 days. 8/12/

19 Pierpont: Soil Amendment / CC Elemental Sulfur: Barley germinated. Gypsum: Some barley germinated. CaCl2: None Untreated control Salt Treatment lb/ac tons /A Cost / lb for admendment Cost /A Gypsum $0.12 $ CaCl $0.37 $2, Elem S $0.37 $ /12/

20 Pierpont: Soil Amendment / CC No treatment: No Cover Crop Salts on soil surface Calcium chloride: Some Cover Crop Salts on soil surface Gypsum: More Cover Crop Fewer salts on soil surface Elemental S: Most Cover Crop Least salts on soil surface 8/12/

21 Summary Perennial grasses establishment (tall wheat grass) lowed the water table at White Lake. Elemental sulfur on Pierpont soils helped establish cover crops. What would be best for your situation? 8/12/

22 NRCS: Jeff Hemenway, Jason Miller Perennial grasses forage quality 8/12/

23 Salt tolerant grasses, full seed rate & cost Species (From Millborn Seed, Brookings, SD) Salt Tolerant Grasses Seeding Rates and Cost Cost per lb Full Seeding rate (lbs/a) $ / A DOM/CP Rating Green Wheatgrass, Certified AC Saltlander $ $ NA Shoshone Beardless Wildrye $ $ Tall Wheatgrass $ $ Slender Wheatgrass $ $ Garrison Creeping Foxtail $ $ Thickspike Wheatgrass, Critania $ $42.00 NA 8/12/

24 Funding Acknowledgements / Cooperators Natural Resources Conservation Service United States Department of Agriculture (NRCS USDA) Conservation Innovation Grant (CIG Grant) SD Corn Utilization Council South Dakota State University Cooperators Greg Tople, Pierpont, SD Roger Rix, Grant Rix, Andover, South Dakota Jim Millar, Kenny Sehlman, Jerry West, Redfield, SD David Gillen, White Lake, SD 8/12/

25 Thank you for attending! Questions? 8/12/

26 Amendment Rates: White Lake Soil amendments applied to change ratio of calcium / magnesium to sodium. Lower soil ph, add calcium or magnesium to soil solution. Force exchange of sodium White Lake Soil Amendment Rates Based on SAR of 12.7 Salt Treatment lb/ac tons /A Cost / lb for admendment Cost /A Gypsum $0.12 $ CaCl $0.37 $1, Elem S $0.37 $ No Salt $0.00 $0.00 8/12/

27 SDSU NRCS CIG Grant: Site Summary Salinity project Site Depth (inches) EC Ca (ppm) Saturated Paste Extract Mg (ppm) K (ppm) Na (ppm) SAR Pierpont, Average White Lake, Wheat Grass Soil Pit Site Near White Lake, Wheat Grass Soil Pit by Plots, White Lake 0-4 NA 58 NA Horizon Horizon Horizon /12/