Native Grass Seeding

1. Native Grass Seeding Santiago Misquez Rangeland Management Specialist NRCS-SW Area-Socorro,NM 575-835-1710 Recognition: Dave Dreesen,PMC

2. Grass Types Based onPhotosynthetic Pathways • Cool-season grasses • Stipeae tribe (needlegrasses and ricegrasses) • Warm-season grasses Los Lunas Plant Materials Center

3. Cool-Season Grasses • C-3 photosynthetic pathway • Flowering requires vernalization and/or short days followed by long days • Growth optimum near 70° F (can grow as low as 35° F) • Lower water use efficiency (less DM production/unit water) than C-4 grasses • Long coleoptiles and short mesocotyls (festucoid development) allow adventitious root development near seeding depth • Seeded during summer monsoons or dormant fall planting (expectation of moist soil in early spring) • Dominate in regions where most precipitation falls in cooler months, at higher elevations or latitudes Source: T. A. Jones, 1997 Los Lunas Plant Materials Center

4. Stipeae Tribe(includes needlegrasses and ricegrasses) • C-3 photosynthetic pathway • Lacks mechanism to store carbohydrates at cool temperatures • Many species do not require vernalization and are photoperiod insensitive • Optimal growth temperatures greater than cool-season species • Found in climates too warm for other cool-season grasses Source: T. A. Jones, 1997 Los Lunas Plant Materials Center

5. Warm-Season Grasses • C-4 photosynthetic pathway • May require short days to flower but do not require vernalization • Growth optimum near 90° F with little growth below 60° F • Higher water use efficiencies than C-3 grasses • Mesocotyl elongation (i.e., subcoleoptile internode) forces adventitious roots to develop near soil surface (panicoid development) • Seeded during summer monsoons (late spring before monsoons), generally difficult to establish because of desiccating conditions in the arid SW • Often principal grasses where summer precipitation predominates, at lower elevations and latitudes Source: T. A. Jones, 1997 Los Lunas Plant Materials Center

6. Adventitious Root Development Warm- versus Cool-Season Grasses Warm-Season Grass Panicoid Development Cool-Season Grass Festucoid Development Coleoptile Adventitious Roots Mesocotyl (Subcoleoptile Internode) Seminal Roots Seed Primary Root System Los Lunas Plant Materials Center

7. Seeding Grasses • Seed Depth – Emergence versus moisture • Dormancy – An advantageous trait for seed to persist for later precipitation events or future years • Soil Compaction – Survival is dependent on rapid root extension • Seed to Soil Contact – To facilitate imbibition (absorption of fluid by a solid results in swelling) of soil moisture by seed • Moisture Relations and Soil Texture – Infiltration depth versus water holding capacity • Mulch – Essential step in arid regions to take full advantage of the limited amount of moisture received Los Lunas Plant Materials Center

8. Seeding Depth for Optimal Emergence under Ideal Moisture Conditions • Recommended seeding depths for most native grasses are from ¼ to ½ inch deep • Some extremely small seed such as many dropseeds (Sporobolus species) and some muhlys (Muhlenbergia species) should be surface broadcast; such small seed will be buried by raindrop impact or during mulch application and crimping • A few species prefer deep burial including Indian ricegrass Los Lunas Plant Materials Center

9. Seeding Grasses and Weed Control • Reduce the weed seed bank in the surface soil by controlling weeds for several years prior to seeding (herbicides, mowing, burning…) • Application of broadleaf herbicides after seedlings are established • Mow weeds in grass sward before annual weeds set viable seed • Do not add nitrogen fertilizer at seeding because weed species will be favored Los Lunas Plant Materials Center

10. Mulch Application after Seeding • Native grass hay (some residual seed OK) is the most desirable mulch for large seeding projectsApply in a layer of sufficient depth to shade soil and reduce wind desiccation, but thin enough to allow seedlings to emerge without restriction (porous hay layer with some soil visible) • Hydromulch wood fiber applied as slurry • Erosion control blankets • Wood or bark chips applied in a thin layer • Gravel mulch (1” deep aids emergence of galleta, 1.5” to 2” prevents emergence) Los Lunas Plant Materials Center

11. Mulch Effect on Seedling Establishment – Slender Wheatgrass Broadcast at 50 PLS/ft2 and Sprinkler Irrigated Source: M. Majerus, Plant Materials Center, Bridger, MT Los Lunas Plant Materials Center

12. Precipitation - “The Master Input” • Seeding success is dependent on sufficient soil moisture following germination to allow seedling establishment • Species having both early and late germinating seed are favored in variable environments • Consistent rainfall for a prolonged period is necessary for warm-season grasses to establish • Survival of first dry period following a biologically significant rain requires seedlings to have • sufficient vigor to survive the subsequent dry period or • viable but un-germinated seed remaining after first wet period Los Lunas Plant Materials Center

13. Establishment • Blue grama requires 21 days after germination for adventitious roots to reach a 4-inch depth and the seedling to have 6 leaves and 2 tillers • Adventitious roots arise up to 9 days after germination and reach seminal root depth in approximately 21 days Los Lunas Plant Materials Center

14. Frequency Analysis of Size of Precipitation Individual Events or Storms (precipitation on successive days) in the Northern Chihuahuan Desert from 1915 - 2000 Source: Reynolds et al. 2004 Los Lunas Plant Materials Center

15. Soil Moisture Distribution in Arid Environments • Upper 2” to 4” of soil dries out rapidly by evaporation following a precipitation event (little water available for plant uptake) • Soil moisture in the top 4” to 12” can persist for several weeks • Moisture under unsaturated conditions at depths below 12” is primarily lost by plant transpiration (no evaporation and no drainage) Los Lunas Plant Materials Center

16. “Inverse Texture Effect” • The depth of wetting is proportional to the amount of infiltrating precipitation soil moisture storage capacity • The storage capacity is 4 to 9% for sands, 11 to 15% for sandy loams, and 17 to 23% for fine-textured soils • The depth of soil wetting will be greater for coarse-textured soil than for fine-textured soils. • Coarse-textured soils hold less water per unit depth but much of the water is sufficiently deep to avoid evaporation, whereas in a fine-textured soil most of the water can be lost to evaporation • Therefore, sandy soils often have more useable soil moisture in arid environments Source: Noy-Meir 1973 Los Lunas Plant Materials Center

17. Influence of Soil Texture on Moisture Penetration – One Inch Infiltration Event and Dry Soil (Wilting Point) Los Lunas Plant Materials Center

18. Influence of Soil Texture and Surface Sealing on Average Water Infiltration Rates (inches/hour) Los Lunas Plant Materials Center Source: Pair 1983

19. Variables Related to Drying Rate and Grass Seedling Establishment in a Sandy Loam Soil Source : Roundy et al. 1997 Los Lunas Plant Materials Center

20. Patterns of Soil Water Loss over TimeSandy Loam Surface Soil (0.4 to 1.2 inch depth) Soil Water Content (% vol.) Source : Roundy et al. 1997 Drying Time (hr) Los Lunas Plant Materials Center

21. Irrigation from Mid-July through August to Enhance Establishment on Abandoned Farmland in the Sonoran Desert (Supplementing Precipitation of 2.8 inches) NA – high density not achieved Source: Roundy et al 2001 Los Lunas Plant Materials Center

22. Seed Source Islandsor Resource Islands • Focus limited resources on small areas • Rely on natural seed dispersal to allow expansion into outlying areas • Apply intensive resources in a small area to enhance establishment • Weed control • Supplemental water (rainfall harvesting or minimal irrigation) • Exclosures to control grazers/browsers (rodents to elk) • Use transplants of grasses, forbs, and shrubs to assure establishment and provide immediate diversity Los Lunas Plant Materials Center

23. Seeding Rates and Mixes • 20 to 60 PLS per lineal foot – drilled • 20 to 60 PLS per square foot – broadcast (rates usually higher because fewer seeds are at optimum soil depth) • Common usage - 40 PLS per square foot • Total seeding rate for a mix should be 40 to 60 PLS – percentage of each species will depend on desired plant community, vigor of the seedling (competition between species), seed size, PLS seed cost Los Lunas Plant Materials Center

24. An Example of a Seed Mix Calculation for a Sandy Arid Site No. of PLS/ Common Name Type Pound PLS Moisture Use Avail. • Indian ricegrass (IR) Stipeae 160k very xeric yes • Black grama (BG) WS 1,300k very xeric maybe • Sand dropseed (SD) WS 5,600k xeric yes • Spike dropseed WS 2,800k xeric ? • Mesa dropseed WS 3,300k very xeric ? • Giant dropseed WS 1,400k very xeric ? • Mix percentages based on seed and seedling characteristics • IR 25% (large, dormant seed; vigorous seedling; moderate cost per pound) • BG 15% (small seed; low vigor seedling; high cost per pound) • SD 60% (very small seed; low survival; inexpensive) • PLS rates per square foot – IR 10, BG 6, SD 24 • PLS per acre – IR 435k, BG 260k, SD 1,050k • PLS per pound – IR 160k, BG 1,300k, SD 5,600K • Pounds PLS per acre – IR 2.7, BG 0.20, SD 0.19 • Hypothetical PLS from seed testing – IR 0.70, BG 0.40, SD 0.85 • Bulk pounds per acre – IR 3.9, BG 0.50, SD 0.22 Los Lunas Plant Materials Center

25. Mean Annual Precipitation <8 8-10 10-12 12-14 14-16 16-18 18-20 20-24 24-28 32-36 36-40 40-44 Los Lunas Plant Materials Center

26. Annual Lake Evaporation (inches) >80 70-79 60-69 50-59 40-49 30-39 <30 Los Lunas Plant Materials Center

27. NewMexicoAridEcoregions<10 inchesMeanAnnualPrecipitation Los Lunas Plant Materials Center

28. Soil Texture Triangle Texture Classes Coarse Intermediate (Loam) Fine Los Lunas Plant Materials Center

29. Soil Texture Influences Species Used in Seed Mixes forChihuahuan (ch) and Colorado Plateau (cp) Desert (<10” ppt.) Sites ** Likely available * Possibly available Los Lunas Plant Materials Center

30. NewMexicoSemi-AridEcoregions10 - 14 inchesMeanAnnualPrecipitation Los Lunas Plant Materials Center

31. Soil Texture Influences Species Used in Seed Mixes for Dry Plains, Sagebrush (sb), and Piñon/Juniper (10-14” ppt.) Sites ** Likely available * Possibly available Los Lunas Plant Materials Center

32. NewMexicoPrairie (High Plains)Ecoregions>14 inchesMeanAnnualPrecipitation Los Lunas Plant Materials Center

33. Soil Texture Influences Species Used in Seed Mixes for Prairie (>14” ppt.) Sites ** Likely available * Possibly available Los Lunas Plant Materials Center

34. NewMexicoMontaneEcoregions> 16 inchesMeanAnnualPrecipitation Los Lunas Plant Materials Center

35. Soil Texture Influences on Species Used in Seed Mixes for Montane Sites ** Likely available * Possibly available Los Lunas Plant Materials Center

36. Soil Texture Influences Species Used in Seed Mixes for Wet Meadow Sites ** Likely available * Possibly available Los Lunas Plant Materials Center

37. Resources • www.nm.nrcs.usda.gov • Standards/Specs: Critical Area Planting & Range Planting • http://efotg.nrcs.usda.gov/references/public/NM • Los Lunas Plant Materials Center 505-865-4684