Pasture Management Andrea Lawseth, M.Sc., P.Ag. COABC Conference February 29, 2015
Outline Benefits of Good Pasture Management Pasture Degradation Pasture Renovation Seed Mixtures Weed Management Grazing Management
Benefits of Good Pasture Management Animal health is maintained Reduced feed and fertilizer costs Increased flexibility of season of use Decreased weeds and control costs Prevention of soil erosion Water quality protection Eliminates bare spots in pasture
Degradation of Pasture Degradation of pasture land is caused by: Poor soil structure and drainage Over-grazing too many animals Improper pasture rotation Soil compaction from tromping hooves (destroys aggregate structure)
Impact of Grazing on Root Growth Percent Grazed by Horses Percent Root Mass Lost 10% 0% 20% 0% 30% 0% 40% 0% 50% 2-4% 60% 50% 70% 78% 80% 100% 90% 100%
Pasture Establishment Best to plant in the fall so that the pastures are ready for spring Keep livestock off pasture until the plants are well established (15 to 20 cm tall 6 inches)
Partial Renovation Take an inventory of what is present (Percentage of desirable species - >25%?) Lime pastures if ph is below 6.5 Apply manure compost Harrow field to break up clumps Overseed with an appropriate grass mixture Do not overgraze fields! Leave ~8cm (2-3 )
Complete Renovation Starting from square one Can be expensive Need to keep animals off for some time Are there fewer than 25% desirable grass species?
Complete Renovation Steps for completely renovating pastures: Preparing seed bed Seeding Fertilizing Weed management Pasture establishment Pasture maintenance
Complete Renovation Prepare an adequate seed bed Plowing Discing Rotovating No-Till
No-Till Practices Only cultivating the seed bed (top 2 ) Prevents: Soil erosion and loss of topsoil Loss of structure Nutrient leaching Damage to microorganisms Cultivating can bring up and distribute weed seeds
Broadcast Overseeding Seeding over plants already covering a field Spring and Fall are the best times for seeding: Well-drained soils March Wet soils April/May All soils August/September Allows seedling establishment before end of November (end of growing season)
Overseeding Seed must have contact with soil to grow Use a harrow to break up soil Tine harrow Chain harrow
Seed Mixtures Need the most appropriate seed mix for your microclimate Topography varies Good quality seed is important! Quality Seeds West
15 lbs perennial ryegrass/acre 100 seeds/ft 2 of acre seeded Spreaders: Chest spreader (small acreages) Mounted spreader (tractor, truck, mower) Seeding Rate
Seed Incorporation Use a chain harrow or roller to incorporate the seed Graze with livestock shortly afterwards
Soil Testing Plants get all of the nutrients they need for growth from the soil ph, organic matter, M, P, K, Ca, Mg and micronutrients Salinity and soil texture Makes it easier to determine application rates
Spreading Compost First do a soil test to determine pasture fertility Test compost too! Harrow in using a chain harrow or drag
Application Rates Complicated calculation, but doable: Need fertilizer recommendation from soil test (lbs N, P2O5, K2O per acre) convert to lbs/ton (% x 20) Assume only 20% of N is plant available in the first year, P 40%, K 60% - multiply compost analysis by these factors Calculate your N, P2O5, and K2) by dividing lbs/acre required by lbs/ton in compost gives tons of compost to apply per acre
Example: Application Rates The soils lab recommends 100 lbs N/acre and 40 lbs P2O5/acre. The compost results show 1.7% N, 1.3% P2O5, and 1.5% K2O. How much compost should you apply? First, convert compost results to lbs/ton. 1.7% N x 20 = 34 lbs N/ton 1.3% P2O5 x 20 = 26 lbs P2O5/ton 1.5% K2O x 20 = 30 lbs K2O/ton Then, correct for availability. 34 lbs N/ton x 0.20 = 7 lbs available N/ton 26 lbs P2O5/ton x 0.40 = 10 lbs available P2O5/ton 30 lbs K2O/ton x 0.60 = 18 lbs available K2O/ton Finally, divide the fertilizer recommendations by the available nutrients. 100 lbs N/acre / 7 lb av. N/ton = 14 tons/acre 40 lbs P2O5/acre / 10 lb av. P2O5/ton = 4 tons/acre
Weed Management Weeds need to be managed for health reasons Many species are poisonous to livestock: Creeping buttercup Horsetail Tansy Ragwort
Weed Management Lime fields with dolomite lime to eliminate acidic conditions Apply horse manure compost Overseed with an appropriate seed mixture (make sure it is certified weed-seed-free) Goal: To out-compete weed species Mechanical control: pulling, mowing, tilling, burning Other control methods: bio-control, natural herbicides
Pasture Maintenance Mow pastures when necessary Drag or harrow pastures from time to time to break up manure Keep animals off wet pastures Remove animals when grass is less than 8cm in height Rotate pastures when possible
Rotational Grazing Dividing the pasture into smaller sections Remove when pasture is 2 to 3 inches high Each pasture rests for 3 to 5 weeks Can use portable electric fence or tape Alter grazing patterns (location of feed, water, minerals)
Rotational Grazing Benefits of rotational grazing: Increases amount and quality of forage Can support more animals on smaller space Decreases spot grazing Promotes growth of desired species Helps control parasites and diseases Provides better manure distribution Allows for frequent horse-human contact
Resources Grazing Management Guide: http://www.agf.gov.bc.ca/resmgmt/envirofarm Planning/EFP_Grazing_Mgmt_Guide/Grazing_M gmt_guide_toc.htm Cool Forages: http://farmwest.com/node/1303 Nutrient Management Guide: http://www.agf.gov.bc.ca/resmgmt/envirofarm Planning/EFP_Nutrient_Guide/Nutrient_Guide_t oc.htm