Mid Atlantic Dairy Grazing Conference Grass Legume Mixtures: Dairy grazing is high value grazing. Persistence (seedbank or root system), Quality (digestibility) Productivity per acre and per animal
Perennials Annuals Warm season Grasses Bermudagrass Dallisgrass NWSG Legumes Lespedeza Grasses Crabgrass* Sorghum and Millet Legumes Lespedeza Forage Soybeans Cowpeas Arrowleaf Clover North Carolina Forages Cool season Grasses Tall fescue Orchardgrass Kentucky bluegrass Legumes Alfalfa White clover(s) Red clover Birdsfoot Trefoil Grasses Annual ryegrass* Prairie grass (Matua)* Small grains: Oats, wheat, triticale, rye Legumes Crimson clover * = naturally reseeding annual Most pastures and hayfields have mixtures of species. Mixtures are the natural order of nature. Mixtures should be managed as a diverse competitive community of desirable plants to provide year round pasture. Three six species dominate most mixtures. Perennials, annuals grasses, legumes, forbs. persistent and transient species
Multiple seasons late fall early winter Stored Forages early fall late summer early spring Pasture early summer late spring Photosynthesis as many days of the year as possible
% weeds 16 14 12 10 8 6 4 2 0 Pasture Weed Contamination 2 SP 3 SP 6 SP 9 SP Forage Diversity (# of forage types in the pasture) Soder et al. 2005 *Averaged over two years Forage Legume inflorescence peduncle leaflets petiole stipule leaf node internodes node stem stolon stipule nodule Lateral roots taproot Adventitious roots
Legumes contribute to high value grazing dairies Nitrogen: N fertilizer costs Organic N source Soil organic matter Biodiversity pollinator habitat NC: 120 lbs/acre/yr N as amines moves directly from nodule into the roots
Good nodulation is the result of roots finding the correct rhizobia bacteria. Using inoculants is insurance that legume roots will come into contact with the correct nodule forming bacteria. What limits nitrogen fixation? Acid soils (low ph) Poor fertility lack of P, K, Mo, B, S Compaction poor aeration (no pore space) Absence of live inoculating rhizobia bacteria no root nodules Wrong type of rhizobia inactive root nodules Flooded or droughted or overheated soils Nitrogen fertilizer
INOCULATE Nodulation apparent 3 6 weeks after planting/green up Check for effective nodulation Active nitrogen fixing nodules are pink inside [muddy brickyard pink] Check at least 3 sites in every field. Dig, do not pull roots! A good number is 20 nodules per plant. Healthy plants are not proof of nodulation! Check nodulation every season.
Source? Correct Soil Fertility: LIME to reduce soil acidity as measured by ph minimum = 6 maximum = 7.2 target = 6.5 Lime effects complicated, but lime is best insurance that Soil nutrients will be available Legume nodulation will be successful Good clover stands possible (old dry lots) where nutrients And organic matter have accumulated over years even if ph below 6, but above 5.2 P K S Mg as recommended
Species N Fixed N Value in $/acre/year lb/a/year N cost = 45 cents /lb N cost = 60 cents /lb Alfalfa 150-250 68-113 90-150 Red Clover 75-200 34-90 45-120 White Clover 75-150 34-68 45-90 Economics: N fertilizer price vs. seed cost vs. lbs forage/acre Carrying capacity: Cash flow constraints Legumes contribute to high value grazing dairies Forage quality: Digestibility Milk Digestibility Intake Milk
Beef steer performance as affected by white clover in KY-31 tall fescue. (Hoveland et al., 1981). Average daily gain, lbs. Gain/Acre, lbs. Tall fescue 1.06 374 Tall fescue + clover 1.53 582 Table 2. Potential milk production per acre of pasture from monoculture grasses and mixtures with kuraclover or birdsfoottrefoil. Nitrogen fertilizer Grass or legume Kentucky bluegrass Smooth bromegrass Orchardgrass pounds milk / acre 100 lbs/acre N 2,166 3,234 3,361 300 lbs/acre N 3,708 4,534 4,363 Kura clover 5,507 5,095 4,318 Birdsfoot trefoil 4,751 5,435 4,467 Milk production per acre was estimated from forage yield and quality with the MILK90 spreadsheet (Undersander, et al., 1993). Values are means from data collected over 3 years at Arlington and Lancaster, WI.
The neutral detergent fiber (NDF), acid detergent fiber (ADF), and Net Energy Lactation (NEL) content of pastures in the Northeast (average + standard deviation) (adapted from Rayburn 1994 and Sirois 1995). Pasture NDF ADF TDN NEL NEM Grass 1 53±10 28±4 70±5 0.67±0.08 0.74±0.09 Mixed mostly grass 2 48±10 27±4 69±5 0.69±0.08 0.73±0.09 Mixed mostly legume 3 44±10 28±4 69±5 0.68±0.08 0.73±0.09 Legume 4 31±10 23±4 70±5 0.76±0.08 0.74±0.09 Corn 46±6 26±4 70±3 0.73±0.03 0.68±0.06 1 Grass= less than 15% legume 2 Mostly grass= 15-49% legume 3 Mostly legume = 50-85% legume 4 Legume= Greater than 85% legume NCSU Budget Forage Costs, $/ton of DM GEOFF BENSON, ARE, NCSU Crop $2006 $2008 Perennial cool season grass clover pasture 45 53 Rye/ryegrass 60 69 Perennial cool season grass pasture 60 71 Corn silage 67 74 Small grain silage 101 112 Hay, cool season grass 124 139 NOTE: Costs based on DM lbs not quality [protein and digestibility] Digestible DM is important to high value dairy grazing
Managing Grass Legume Mixtures Nutrient intake is the goal Water available Pasture palatability Species mix mix match diets Rotations Search time; bite size weeds? Fresh un fouled pasture Fertility?
A 30 50% stand is a good legume stand. 20% stand WI 70% stand WI
Grazing heights: Initiation and residual stubble heights Blaser VPI 1986 Pre graze Regrowth from leaf blade Post graze 3 Regrowth from stolon
Jim Green Two species mixtures not as effective as more diverse mixtures
Botanical composition of organic and conventional alfalfa with and without prairiegrass Seasonal surpluses and shortfalls???
Steve Washburn Selecting, designing and evaluating a grass legume mix:
Adding a legume to an established grass stand: 1. More grazing, protein, digestibility, intake, nitrogen, cover? 2. Fill forage gap or shortfall 3. Other species in the mix 4. Management level or skill and inputs Pasture micro sites Mixtures of plants (forages and weeds) fit into the micro sites above and below ground. Overseeding, spot seeding drill or broadcast most economic. Remove herbage prior to seeding.
Spot seed, Interseed, Overseed whenever possible Arkansas [Jennings group] concentrated overseeding Usual drill or broadcast Seed concentrated in strips on 25% of total field area Better stands of legume; equal nitrogen contribution and distribution MINIMIZE TILLAGE Which legumes? Perennials? White, Red Clovers or alfalfa or BFT Annuals? Clovers, Soybeans, Cowpea, Lespedeza
Superintendent Home Cool Season Legume Overseed of Established Grasses 2008 Replication 1 Prairie Orch1 Orch 2 TF KY31 KYBG Mix1 Mix 2 Natrl W PT RS RG O D BFT F F RS O BFT RG W D PT PT O W D RS BFT RG F BFT PT O F RG D W RS BFT W RG PT O D RS F PT RS F RG BFT W O D BFT W D PT O RS RG F W BFT RG O D PT F RS F D RS W O BFT PT RG Spring Planted Plots Lane Waynesville, NC Offices Testing pasture mixtures on your farm:
Testing in an established perennial forage field: Leave most of the field in the established forage as background for comparison. Test overseeding : Overseed 3 to 6 strips through the established forage. Established forage Test strip Established forage Test Strip Established forage Test Strip Established forage Test Strip MINIMUM TEST : Repeat strips of each mixture or variety at least three times; not in same order across the field. At least two strips are of each mixture are needed; 4 to 6 strips of each mixture is ideal. Comparing more than 3 mixtures or species or varieties is complicated. MIX 1 MIX 2 MIX 3 Mix 2 Mix 1 Mix3
What Doesn t Work: Using one area of the field for each variety or practice. Why: Each third of the field will have a different yield even if the same mix or legume is planted. Mix 1 Mix 2 Mix 3 What Doesn t Work: Using one field for each variation. Why: Each field will have a different yield even with the same practice. Better to put half of each field into each mix or overseeded variety. PRACTICE or MIXTURE ONE PRACTICE or MIXTURE TWO Field A Field B
What Doesn t Work: Testing one practice one year and another variety the next year. Comparing different years is comparing different years, not practices. Whether in the same or different fields not a useful comparison. WHY: Each year will have different management and weather. A fair comparison is NOT possible, unless you have detailed historic records for the field and repeat multiple years and fields Year 2011 Year 2012 Testing new options: Side by side comparisons Use at least two fields for an honest evaluation! Mix 1 Clover 1 Mix 1 Clover 1 Mix 1 Clover 1 Examples: Overseeded white clover Five species mix: orchard, prairiegrass, crabgrass, two white clovers and an BFT Commercial mixture
Map: Using two or more permanent points in or near the field. Measure actual distances to fixed points. Markers in the field alone are not as reliable. Variety 2 Variety 1 Variety 3 Variety 1 Variety 3 Variety 2 Variety 3 Variety 2 Variety 1 Variety 1 Variety 2 Variety 3