440 likes | 752 Views
Revitalizing Drought Stressed Pastures. Chris Teutsch Southern Piedmont AREC Blackstone, VA. State of the Pastures. Extreme drought June to present >35% below normal Above average temperatures Limited Pasture Growth Cool-season grasses dormant Overgrazing of Pastures Weaken plants
E N D
Revitalizing Drought Stressed Pastures Chris Teutsch Southern Piedmont AREC Blackstone, VA
State of the Pastures • Extreme drought • June to present >35% below normal • Above average temperatures • Limited Pasture Growth • Cool-season grasses dormant • Overgrazing of Pastures • Weaken plants • Reduce regrowth this fall • Increase weeds
Rest Pastures • Recovery dependent on rainfall • Pastures often better that they look • Pastures grow and store energy up following drought stress • Feed hay and let growth accumulate this fall • Graze stockpiled grass this winter
Fertilize Pastures • Soil Test • Lime if needed • P and K according to soil test • Nitrogen for stockpiling • 60 to 80 lb N/A • N source matters • $42 to 54 per acre • Fall Fertilization • 30 to 40 lb N/A in November • Gets grass ready to grow in spring
Stockpiling in a Drought Year • Always a risk-usually rains • Very rapid growth • Nitrogen source is important • Decrease rate as you move into fall • Quality is better than hay • Strip grazing yields more grazing days • Endophyte can be an issue
Nitrogen Source Effects on CP Stockpiled tall fescue contained 36% more crude protein than average Virginia hay!
Nitrogen Source Effects on TDN Stockpiled tall fescue contained 23% more energy than average Virginia hay!
Getting the Most Out of Stockpile • Always utilize grass-legume mixture first • Strip graze • maximizes utilization • only enough forage for <7days • no back fence needed
Drought Year-1999 Normal Rainfall-2000 Ergovaline in Stockpiled Fescue • Increases until mid–December (Kallenbach et al., 2003) • Ergovaline >150 ppb may be toxic • Decreased to safe levels by early Jan to Feb
Managing the Endophyte in Stockpile • Plant and endophyte are synchronized • Improved pasture management can increase problems • Increased soil fertility • Improved grazing management • Managing the endophyte in stockpile • Delay use until January • Use other non-toxic forages first • Feed hay in late fall • Use fescue + clover
Legumes in Grazing Systems • Benefits of Legumes • higher yields • improved quality • better summer growth • nitrogen fixation • DILLUTION of endophyte
Frost Seeding • Broadcasting seed on soil surface • late winter or very early spring • freezing and thawing incorporates seed • Works best with red and white clover • Does not work with grasses and alfalfa • Preparation begins previous summer • control broadleaf weeds • soil test and adjust fertility • reduce residue by grazing hard
No-Till Drill • More effort and attention to detail • More consistent results • putting seed in contact with soil • Can be successful in spring or fall
Best method for alfalfa and sericea • Suppress sod and reduce residue • Calibrate drill prior to seeding • Check and recheck seeding depth • don’t take somebody’s word • seeding depth should never be deeper than 1/2” • general rule: if you can’t see a little seed along slit, then you are going too deep • Control competition after seeding
Interseeding Winter Annuals into Drought Stressed Pastures Annual Ryegrass Variety Trial Southern Piedmont AREC
Winter Annuals • Works best on poor sods • Sometimes does not work well • Sods have an extensive root systems • Rainfall stimulates seed and sod • Sod out competes seedlings • Best fits • Cropland • Double cropping with summer annual • Overseeding dormant perennial warm-season grasses
Annual Ryegrass • High yielding with excellent quality • Can be grazed, hayed, or ensiled • Regrows after cutting until June • Adapted to wide range of soils • Consistent production • Requires nitrogen fertilization • Overseed bermudagrass or double crop with summer annual • Serious weed in small grains
Small Grains for Forage • Wheat most versatile • Rye least exacting soil requirements, earliest • Barley best on well-drained fertile soils • Winter oats palatable, lower yielding • Seed at 1.5 to 3.0 bu/A
Seeding Rates • Small Grains (1.5 to 3 bu/A) • Oats: 50 to 100 lb/A • Wheat: 90 to 180 lb/A • Cereal Rye: 85 to 170 lb/A • Barley: 75 to 150 lb/A • Triticale: 75 to 150 lb/A • Annual Ryegrass • 20 to 40 lb A • Annual Ryegrass + Small Grain • 15 to 20 lb/A + 60 to 90 lb/A • Red clover: 4 to 6 lb/A • Ladino: 1 to 2 lb/A
Drought Proofing Pastures Chris Teutsch Southern Piedmont AREC Blackstone, VA
CAN NOT PREDICT OR PREVENT A DROUGHT MANAGE FOR RECOVERY
Maintaining Healthy Pastures • Soil Fertility • Healthy Roots • prevent overgrazing • Positive CHO Status • rest period • Residual Leaf Area • energy for regrowth & osmotic adjustment • AVOID MULTIPLE STRESSES
Red Clover • Key pasture legume • Short-lived perennial • 2 to 3 years • Easily established • high vigor • frost seeding • Needs good fertility • pH 6.0-6.5 • Does not reseed • Seeding rate 4-12 lb/A
Alfalfa • Long-lived perennial • High yielding • Drought tolerance • Needs high fertility • pH 6.5 -7.0 • Rotational grazing • Does not reseed • Does not frost seed • must be drilled • Seeding Rate 8-20 lb/A
Sericea Lespedeza • Long-lived WS legume • Good quality & nonbloating • Palatability? • Well drained soil • Tolerant of low fertility and pH • Poor seedling vigor • Rotational grazing • New variety • ‘AU Grazer’ • Seeding Rate 15-30 lb/A
Sericea Lespedeza • Tall fescue growth has slowed or stopped, but sericea lespedeza is still going!!
Annual Lespedeza • Warm-season annual • Nonbloating legume • Tolerant to low pH • Seeding rate 10-25 lb/A • Two types • Striate (Jap Clover) • prostrate growth • does not reseed as well • Korean • responds to fertility • higher yields • drought tolerance • susceptible to diseases • dependable reseeding
Photosynthesis • Converts light energy to chemical energy light, chloroplast CO2 + H2O SUGAR + O2 Major Pathways • C3 (cool-season grasses) • adapted to cooler temperatures • growth in spring and fall • C4 (warm-season grasses) • more efficient at higher temperatures • more efficient water use
JAN MAR MAY JUL SEPT NOV KY Bluegrass Orchardgrass Tall Fescue Ladino Clover Red Clover Alfalfa Small Grains Ryegrass Bermudagrass Switchgrass Caucasian Bluestem Sorghum-Sudan Pearl Millet Cool-Season Grasses Legumes Cool-Season Annual Grasses Warm-Season Grasses Warm-Season Annual Grasses Adapted from Controlled Grazing of Virginia’s Pastures, Publication 418-012 Growth Curves for Common Forages
Seeded Bermudagrass • Bermudagrass is adapted to VA and NC • Relatively little planted in VA • Sprigs and sprigging • do not have equipment and sprig sources • Seeded bermudagrass • establish like any small seeded forage • Cultivar • single pure variety • Blend • mixture of several varieties, AZ common, giant • same trade name, but different mixture
Annual Forages • Supply forage during summer and winter deficit periods • Advantages • fast germination and emergence • rapid growth • high productivity and quality • flexibility of utilization • Disadvantages • Establishment cost: $120 to $140 • increased risk of stand failures • hard to cure Profitable grazing systems will be based on well adapted perennial sods that are supplemented with annuals.
Crabgrass • Well adapted to southern and eastern VA • Annual that acts like a perennial (reseed) • Double cropped with winter annual • Species of opportunity • Good yield potential • Excellent forage quality • Higher than bermudagrass • No prussic acid • Nitrate accumulator • ‘Red River’ only variety
Lower Stocking Densities • Most pastures stocked at 2 A/cow-calf + some hay • Why not stock at 3 to 4 A/cow-calf and feed less hay • Let forage stand in spring rather than clipping
JAN MAR MAY JUL-AUG OCT DEC Stockpiling Tall Fescue for Summer Grazing? • Novel endophyte may work well for summer stockpiling • Possible stockpiling scenario • Graze or harvest first cutting • Apply 40-60 lb N/A and allow to regrow • Utilize growth during summer
Conclusion Drought resistant pastures will be based on forage species that well adaptedand well managed.