Grassland Management - Organic Forage System
Rotations
Two separate rotations have been adopted in the organic system (see Organic Arable System for details). Each of the rotations includes a different forage ley: grass/white-clover in the fields near the steading for grazing, and grass/red-clover for silage in the outer fields.
Grazing
Careful selection of varieties of both grasses and white clovers is important for attaining a balanced sward that can provide high quality grass throughout the whole grazing season. Zero nitrogen systems generally have problems with providing sufficient forage in the early part of the season when nitrogen provided by clover is at its lowest. Clover is not an early season grower but generally provides good growth in mid-season when the rate of grass growth declines. The mixture of white clovers used at Nafferton includes medium leaved varieties to suit bovines rather than the small leaved varieties more suitable for sheep grazing. The grass varieties shown in the table below are mixtures of diploids and tetraploids to provide a balance of quality and yield. The farm will be experimenting with slurry and composted Farmyard Manure (FYM) applications to the organic grazing swards in the early spring. Slurry injection may permit application during the growing season without problems of rejection by the cows.
Organic Grazing Leys |
Kg/ha |
Aberecho (Hybrid Tetraploid PRG) |
12.35 |
AberExel (Hybrid Tetraploid PRG) |
2.59 |
Aberstorm (Hybrid Tetraploid PRG) |
12.35 |
Aberdai White Clover |
4.82 |
|
|
Total |
32.11 |
Some of the land at Ouston (the farm north of Nafferton) has been entered into the Organic Farming Scheme. This permanent pasture is of poor quality in terms of grass species and clover content and there are widespread infestations of nettles and thistles which cannot now be eradicated with chemicals. The fertility will gradually be improved by testing the soil for pH, and P and K indices, and by selective grazing, topping, liming and application of FYM .
Silage
Current research evidence suggests that Grass/Red clover swards or Grass/Lucerne mixtures give yields comparable to grass systems receiving 200kg N/ha. These yields are significantly greater than Grass/white clover swards with zero nitrogen. Red clover is accepted as being less persistent in swards and has a more upright structure than white clover. Silage mixtures for the organic system have had a small amount of white clover added to help with legume persistency and ground cover. The table below shows the most recent mixture sown for organic silage production. Establishment of all organic forages is by undersowing in a crop of spring barley.
Organic Ley Seeds Mixtures
Organic Silage Leys |
Kg/ha |
AberEcho ( Tetraploid Hybrid PRG) |
10.23 |
Aberstorm (Tetraploid Hybrid PRG) Organic |
10.23 |
AberExcel (Tetraploid Hybrid PRG) Organic |
1.78 |
Milkanova (White Clover) |
0.37 |
|
|
Total |
29.65 |