SOIL AMENDMENT APPLICATIONS DURING DROUGHT PERIODS

Transcription

1 SOIL AMENDMENT APPLICATIONS DURING DROUGHT PERIODS 5 th Annual PAW Reclamation Conference Casper, WY December 6, 2012 Brenda K. Schladweiler

2 What do plants require? Sunlight Nutrients Air CO 2 above ground O 2 below ground Water In an arid/semi-arid landscape, plenty of the first four needs.generally limiting on the fifth need

3 Water Usually limiting in an arid/semi-arid environment Is needed to activate many of the applied soil amendments Can be thought of as a treatment in itself to get plants to grow

4 Drought

5 Definition of Drought Short Term vs. Long Term Six weeks away from drought at any given time What a difference a year makes

6 National 2012 Drought

7 Historical National Drought

8 Challenges to Reclamation

9 Soil Challenges Physical - Texture Excess Sand Excess Clay Excess Silt

10 General issues with too much sand Inherently droughty, low water holding capacity Infiltration generally good High percolation Depending on size of sand grain, can physically be moved by wind, e.g., saltation

11 General Issues with too much clay High water holding capacity Can hold onto hygroscopic water too tightly Infiltration can be an issue Complicated if high sodium

12 General issues with too much silt Highly erosive High volume, short duration precipitation events problematic

13 Soil Challenges (cont.) Chemistry High salinity (as measured by EC) Seedling generally has ½ the tolerance of established plants High sodicity (as measured by SAR or ESP) physiological-drought Generally high ph Generally high lime Low organic matter

14 Sources of salts Parent materials Dissolved salts in the water Manure applications Fertilizer applications Salts from amendments Salts from materials added during disturbance activities

15

16 Organic matter benefits Provides a number of benefits Increase infiltration Increase percolation and drainage Increase water holding capacity Ameliorates the effects of salinity

17 During drought All inherent soil issues are magnified The problem soil children grow while the grass doesn t

18 How to mitigate

19 General Provide natural water gathering systems Pitting Surface roughness Directing water Increase water infiltration Textural Chemical - sodium Increase water holding capacity Reduce negative impacts of salinity Osmotic potential for the plant Importance of proper topsoil salvage is enhanced

20 Sand Increase inherently low organic matter contents Man-made products Nurse/cover crop systems Prevent saltation Installation of man-made structure Wind-rows of soil

21 Clay Increase infiltration Incorporation of organic matter at or near surface Apply gypsum to mitigate accompany sodicity, if present Maintain long-term percolation Avoid compaction

22 Silt Prevent erosion Incorporation of energy reducing organic material Blankets if steep slopes Monitor after high precipitation events

23 High Salinity Don t add to the problem by adding salts to the system Can consider irrigation as a short-term fix to improve germination

24 High Sodicity Activity of added gypsum and elemental sulfur will be delayed If associated with high clay areas, increase infiltration to maximize use of precipitation

25 High ph Generally associated with high sodicity What works there should work here

26 High Lime Don t add to the problem by adding salts to the system Activity of added elemental sulfur will be delayed

27 Low Organic Matter Incorporation or application of man-made products Incorporation of straw, hay, wood chips, manure at commercially available quantities Increase microbial populations to enhance decay Cover or nurse crops

28 Potential Tools or Products

29 Enhance moisture infiltration and retention Hay or Straw Mulch Provides erosion protection Reduces surface soil temperatures during the day and provides buffer at night Biosol Slow release organic fertilizer Dry broadcast or applied with hydro-seeding equipment Sustane Slow release organic fertilizer Different formulations commercially available Dry broadcast or applied with hydro-seeding equipment Organifix High in organic carbon Contains humates Biotic Earth High in organic carbon

30 Enhance moisture infiltration and retention (cont.) AM 120 Enhance mycorrhizal fungi growth in the soil Incorporation of straw or hay mulch with tackifier Wood chips Research on bentonite areas of NE Wyoming recommended 30 ton/acre of sawmill by-products Little Snake River Conservation District project in Carbon County used aspen chips in conjunction with gypsum and sulfur amendments Source and transportation costs need to be considered

31 Minimize chemical effects Gypsum Plus and Sulfur Plus by Encap Polymerized products to amend SAR and lower ph, respectively Rates are about ¼ the rate of typical agricultural applications due to high surface area interaction with soil particles Currently undergoing empirical trials by Encap

32 Reduce erosion PAM12 Plus Temporary soil stabilizer Short and long-term release polyacrylamide impregnated into a paper pellet Applied dry using broadcast spreaders or wet-applied with hydro-seeding equipment Applied as stand-alone or in combination with other mulch products

33 Others Irrigation Consider if available Minimize amount to kick-start germination Do not want as long-term solution Be careful in sodic areas Adapted Species Usually cheapest solution May have to consider two-phase seeding to get site established and diversity at a later date

34 Audience Participation Additional products that have worked based on audience experience: Compost A1 Organics products Terra Biologics products Biochar Langbeinite

35 Summary

36 How to minimize effects of drought Expect drought at a regular recurrence level (multiple consecutive years) and appreciate the wet years Regularly check NRCS snowpack information for your area in late fall and throughout the winter months: wrds.uwyo.edu/wrds/nrcs/snow-pack/snowmap.html Proper moisture in the fall before the ground freezes can help you through an upcoming drought year Be aware of those soil issues that will cause you trouble and be diligent in salvaging all available suitable material

37 How to minimize the effects of drought (cont.) Plan ahead and be the eternal optimist don t wait for the wet year and proceed Always minimize effects of drought which cannot hurt in the wet years Seed in the winter months, if ground conditions are favorable, especially shrubs and forbs And last but not least.

38 Business as usual just won t work!

39 QUESTIONS