Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Sward Improvement 12.3MB
Document related concepts
Transcript
Level II Agricultural Business Operations 92% of agricultural land in Northern Ireland is in grass Grass is the cheapest feed for dairy cows Maximise grass output from every acre Introduce more productive swards Earlier grass growth Increased grass yield Better response from fertiliser nitrogen Improved grass digestibility & palatability Higher grass sugars and improved ensilibility The sheaths and backs of the leaves are smooth and shiny Red stem base Upper surface of leaf is strongly ribbed High PRG Moderate Meadow foxtail Low Bent grass IRG Rough stalked meadow grass Smooth stalked meadow grass Crested foxtail Timothy Cocksfoot Meadow fescue White clover Red fescue Annual meadow grass Couch grass Hybrids Red Clover Yorkshire fog Walk a ‘W’ and assess at points how much PRG is in a sward. If PRG below 70% - then some work to improve sward will be required If PRG below 50% then reseed needs to be considered If the percentage of broadleaved weeds is high, then take action Before improving sward quality consider Cleaning sheughs Drainage Compaction Soil fertility pH Fencing Hedges 1. 2. 3. Sward Replacement – destruction of old sward and replacement by reseed (plough) Sward Renovation - introduction of seed into an existing sward with minimum cultivation Sward Rejuvenation - gradual improvement to sward by better management. Required if % of PRG in sward is low Most reliable method of replacing a sward Spring reseed is usually end March to mid May Autumn reseed between mid July to late August Spring reseeds often have a heavier weed burden than late summer reseed If high % of scutch/bent grasses or weeds like dock/thistles then old sward should be destroyed by Glyphosphate herbicide Poor seedbed preparation is most common cause of failure Seedbed to be fine and firm Consolidate without compacting Sow 6-12mm deep Roll to maintain moisture in top layer of soil Watch out for pests (slugs, frit fly, leatherjackets) Alternative to conventional method of plough and reseed Suitable for; 1. Stony soils 2. Heavy land that takes time to dry out 3. Where rapid establishment is required 4. Thin swards (silage ground) Specialist drills/equipment required Control perennial weeds before over-seeding Minimise competition from existing sward. Graze hard or cut silage beforehand. Prepare a shallow tilth by discing and/or harrowing prior to broadcasting or drilling of seed Conditions need to be good (not too dry or wet) Graze lightly when grass seedlings are 10cm high. Graze often for short periods thereafter. Do not allow long intervals between grazings or closing for silage Identification and correction of poor management practices Poor drainage Poor soil fertility Weeds Under-stocking Poor integration of cutting and grazing Poaching Excessive use of slurry Compaction After these issues have been addressed consider reseeding/ stitching-in Sward Renovation by stitching-in (Over-seeding) Sward Replacement with ploughing Sward Replacement without ploughing £/acre 1 23 67 98 £/acre 1 23 42 98 £/acre 1 Fertiliser sowing 38 38 38 Lime – 2t + application 51 51 51 Total/acre 278 253 174 Soil analysis Spray Cultivations Seed & sow 20 64 Factors to be considered 1. Sward life – short, medium or long term 2. Sward purpose – Grazing or cutting 3. 4. Growth season/area – early, intermediate, late Soil type – dry & light or heavy & wet Use varieties with similar heading dates and dates which correspond with intended cutting date Short term leys – use Italian ryegrass Long term leys – perennial ryegrass Clover inclusion of little benefit if intensive silage system (2-3 cuts) Hybrids and tetraploids to be considered for high sugar content Consider Timothy on heavier land Mixture of 3-4 varieties is normal Do not need to be similar heading date – can include intermediate and late varieties together Persistence and ground cover are very important to ensure that sward lasts and can withstand poaching or trampling Clover can have a role to play Use mostly diploid varieties (more persistent) Include some Timothy if ground is heavy Always use from recommended lists Why include clover? Improves digestibility and intakes Increased animal performance Higher protein % than grass Increased mineral content of sward Can reduce need to spread chemical N fertiliser Weeds cause economic loss in several ways; 1. Compete with grass for nutrients and light 2. Less area available for grass growth 3. Poorer quality silage 4. All lead to reduced animal performance 1. 2. 3. 3 types of weed; Annual weed – these complete their life cycle in one year from germination (e.g. Redshank) Biennial – complete their life cycle in two years from germination (e.g. Ragwort) Perennial – live year after year and develop strong underground roots (e.g. Docks) Annual plant Can be grazed out by cattle or sheep Herbicides needed if high infestations in silage swards Annual plant Common in spring or early summer reseeds Hard to graze out if becomes established Spraying necessary if infestation is severe Biennial plant Develops leaves in first season Flowers and grows to maturity in second season Poisonous to livestock (in silage or dead) Cutting not advised Pulling or spraying best control Perennial weed Can spread by underground roots Topping can help but not kill Spraying best way to eradicate Perennial weed Develop deep tap roots and can spread quickly Topping not effective control Spraying required but often one spray programme not enough Perennial weed Common in acidic wet ground with low fertility Repeated cutting gives some control Spreading lime and improving fertility helps Spraying very effective Take care to ensure adequate: Drainage and aeration Soil fertility Use of organic manures Weed control Stocking levels Assess existing sward Check for underlying problems Select improvement method Select suitable grass seed mixture Careful management of new sward
