Grass ley breaks are a valuable management tool on one Hants unit. Rebecca Austin reports
WHEN Mark Melly and his wife Jane took over Box Farm, Vernhan Dean, Hants, seven years ago the land had been in continuous cereals for 18 years.
As a result, there was a serious black grass, onion couch and wild oat problem. Soil structure had disintegrated and there was little organic matter. Soil types range from clay caps to flinty chalk. Nutrient erosion was a particular concern on the lighter soils with top soil, as shallow as 15cm (6in) in some fields.
So it was immediately apparent the Mellys needed to introduce a rotation. As they both had an interest in sheep, they included 500 Mules as well as 35 suckler cows in the new system.
The rotation, which has just entered its second cycle, is wheat; wheat; winter barley; stubble turnips; spring barley or set-aside; grass; and grass.
Stubble turnips act as a catch crop for store lambs on ground which is going into set-aside or spring barley. The latter is undersown with grass so it runs into the first-year ley. At any one time there will be 73ha (180 acres) of cereals, including set-aside, with the rest of the 117ha (290 acres) down to grass. A further 24ha (60 acres) of permanent pasture is rented, mainly for the suckler cows which frees up clean grazing. Three years of cereals within the rotation also help to keep grazing clean, although the second year of a two-year ley is treated as dirty grazing.
Two grass seed mixtures are used (see table). The clover-based mixture, included to keep a lid on forage costs, is sown over 5ha (12 acres), costs £69/ha (£28/acre) and requires only 75kg/ha (60 units/acre) of nitrogen in March and adequate P and K indices. Mr Melly feels this crop would probably reach its potential in a third year but allowing that would upset the rotation.
The cutting ley costs £59/ha (£24/acre) and receives the same level of nitrogen as the clover mixture, plus 3kg/ha (25 units/acre) of sulphur and 125kg/ha (1.3cwt/acre) of ammonium nitrate. When cut at the end of May/beginning of June, it yields 37 round bales of silage/ha (15/acre). The second cut, at the end of July, produces about 1500 conventional hay bales for the sheep.
The benefits of including grass leys in the rotation are far reaching. Not only have cereal yields increased and weeds been controlled, but soil structure has also improved as well as its organic matter content.
"The four year average for cereals after a rotation is 6.9t/ha whereas when in continuous cereals it was 5.5t/ha," says Mr Melly.
"Fertility has been generated behind the sheep and soil structure has improved after grass has been ploughed back in and muck from the sheep and cow sheds incorporated. And weeds have been kept under control by keeping sward height in hand. The use of Glyphosate (Round-up) to spray off swards and during set-aside has helped keep weeds under control.
"In short, the land is starting to be more fertile and easier to work. Our philosophy is not a short-term fix. I dont want to leap in and out of enterprises chasing high margins or subsidies. You have to want to do what we are doing because it is more work and at any one time any one of the enterprises may not be looking too clever – like beef at the moment – so in fact we are spreading our risks."
Grass compares favourably
When treated as a break crop the sheep enterprise, and hence the two-year grass ley, compares favourably with cereals.
For example, malting barley gross margin is £689/ha (£279/acre), excluding IACS, and wheat £576-£617/ha (£233-£250/acre) under the same circumstances after contractor costs for spraying and combining. Last year the gross margin/hectare was £731 a ewe (£296/acre a ewe) and the previous year £692/ha (£280/acre).
Theoretically Mr Melly compares that result with a text book gross margin for winter rape, beans and linseed at £692/ha (£280/acre), £642 to £741/ha (£260 to £300/acre) and £734/ha (£297/acre), respectively, including area aid payments. But he is convinced the grass break is more beneficial.
Mr Melly is keen to point out he can only achieve that result with a lambing percentage which regularly exceeds at least 170% and when hes not forced to sell store lambs on a weak market. Topping Signets regional Flockplan league two years running is evidence that attention to detail allows the sheep enterprise to compete successfully within the rotation and enhance the other enterprises.n
Benefits of grass leys in rotation:
• Cereal yields increased.
• Weeds have been controlled.
• Soil structure also improved.
High clover grazingCutting ley
1.5Port Stewart5 Danergo
1.0Huia (White clover)
0.5Alice (White clover)
1.5Yellow Trefoil (legume)
Mark Melly took over a farm which had been continuously cropped with cereals for 18 years.
Both Mark and Jane Melly had an interest in sheep, so 500 Mules were introduced as well as 35 suckler cows.