Grassland – Part 4 Grassland Management

 Good Grassland Management involves the following: 1. Finding out the amount of herbage required. 2. The application of ample fertiliser to achieve this. 3. Maximising the DMD of the sward by managing grazing and conservation.  The amount of herbage output required is calculated by the amount / type of stock on the farm.  Generally 1 livestock unit consumes 12 tonnes of herbage dry matter per year.

 The amount of fertiliser applied to grassland greatly depends on the grazing level and the level of establishment.  Fertiliser should be applied to newly established grassland where grazing is light, in the following proportions:  N – 48 kg / ha  P – 20 kg / ha  K – 38 kg / ha  Intensely grazed pastures should receive additional fertiliser as outlined by Teagasc.

 Land set aside for silage or hay should also be fertilised in advance of each harvest.  Hay is only cut once over the grazing season while silage can be cut repeatedly.  The following is recommended by Teagasc:

CropFertilizer Application (kg / ha) Silage 1 st Cut N P K 2 nd Cut N P K 3 rd Cut N P K 1 Cut Cuts Cut Hay

 Good grazing management requires young leafy digestible grass to be available for grazing at all times.  An efficient system of rotational grazing allows the farmers achieve this.  There are various systems available including Paddock Grazing, Strip Grazing, Block Grazing, Set Stocking, Creep Feeding and Mixed Grazing.

Paddock Grazing  Paddock grazing is the most efficient form of rotational grazing, whereby 20 – 25 paddocks are created using electric fencing.  The paddocks are created to suit the herd, using the rule: 120 cows will graze 1 ha of young leafy grass in one day.  The herd graze one paddock per day in a rotational manner.  Nitrogen is applied to the paddocks as soon as they are removed.

 By the time they return to the paddock, the grass should be at the height of its digestibility.  This system can be quite expensive but is widely used on dairy farms.  Silage fields are usually kept independent of the paddock system, as the small areas may be difficult to cut.  Calves & replacement heifers graze any replacement grass.  Paddock grazing systems are sometime called rotational grazing systems

Strip Grazing  This system involves the use of a movable electric fence, to give the stock a fresh strip of leafy grass per day.  Grass strips are fertilised in the same way as the paddock system.  A back fence should be used however, as to allow the grass recover sufficiently.  This system is cheap, but requires a lot of labour time and is therefore rarely used by itself.

Set Stocking  This is simplest, cheapest but least effective form of grazing management.  It simply involves allowing the stock free access to all areas throughout the grazing year.  This allows set – stocked areas to become patchy, with areas of highly un-productive grasses evident.

 Set stocking has a number of particular advantages.  Fencing and water troughs can be kept to a minimum and the continuous general nature of the grazing encourages a close dense sward that is usually rich in clover.  Set stocking is often practices in a modified way with beef, dairy and sheep systems utilising a few large blocks of pasture on a farm ( Block Grazing).

Block Grazing  This system is the most common system used in Ireland, as it is cheap, effective and low on labour.  It involves the division of the grazing area into blocks that provide grazing for 7-8 days.  Pasture management can be improved by using strip grazing in each block.  Larger blocks can be set aside for silage once or twice a year.  This system is cheap and is suitable for dairy, beef and sheep grazing.

 This system involves allowing young animals access to the best grass by means of a fence with a hole only large enough for a calf or lamb.  The calf or lamb can “creep” through the small opening to the good grass but the adult cannot.  This allows the young animals to get the best grass, avoid worm infection and still allows the animals to suckle their mother.

 This basically involves allow the younger animals onto a paddock, strip or block before the adults.  This again allows the younger animals to get the best grass and avoid picking up intestinal diseases.  It involves less “set up” than creep feeding.  It is common practice on dairy farms, when replacement heifers lead the main herd.