Versatile grass mixture provides grazing and silage on Somerset dairy

Close up of Megabite grazing and silage ley
Close up of Megabite grazing and silage ley

The cold, wet spring has delayed turnout for Mark Humphry’s 240 crossbred dairy cows at Manor Farm, Isle Abbots near Ilminster.

The 163ha (400 acres) of grass and maize lie on the edge of the Somerset levels, with water off the Blackdown Hills running through the fields as the River Isle.

"We are often flooded," admits Mr. Humphry. "This year we went underwater on Easter Sunday and only just got the cows out in mid-April. But we had to be very careful of the ground and we buffer fed them too. It has not been a good spring at all."

Mr. Humphry relies on medium to long-term grass mixtures to provide grazing and silage to feed the autumn block calving herd. Currently yielding 8,400 litres at 4.4% butterfat and 3.5% protein, the milk goes to Wyke Farms to be made into farmhouse cheddar.

Maize fields are generally reseeded in the autumn with Megabite from Oliver Seeds, a grazing mixture of late perennial ryegrasses, Timothy, white clover and birdsfoot trefoil, which reduces risk of bloat.

The high percentage of diploid varieties with top disease resistance and Timothy, makes the grass particularly palatable when grazed or ensiled.

Formulated for full season production with good drought tolerance is important, as Manor Farm dries out in summer. This is one of the main reasons the herd calves in the autumn, so that the cows are dry if grass runs short.

Mr. Humphry carries out regular soil testing and keeps phosphate and potash topped up by spreading separated solids and slurry onto the grass.

Nitrogen fertiliser in the form of urea until the end of April, and ammonium nitrate after, is applied every 30 days on grazing land, and after each cut of silage.

The cows are grazed rotationally behind an electric fence. Grass growth is measured weekly, with the data inputted into the AgriNet grazing package. This works out grass supply across the grazing platform and highlights any looming surpluses or shortfalls.

Some of the Megabite is cut for silage, depending on how far away the field is from the parlour. Last year, Mr. Humphry came second in the Somerset Grassland Society Silage Competition with a sample from one of the Megabite swards.

New leys are sown after early maturing maize varieties have been harvested, hopefully at the end of September.

Mr. Humphry is thinking about the grass reseeding when preparing the soil for maize planting in April, and keeps the maize free of weeds throughout the summer. Once the maize has gone, grass seed is sown with an Einbock seed harrow.

The grass establishes well and is left un-grazed in its first winter. The rest of the grass is grazed by in-lamb ewes from November until the end of January.

While there is 5% white clover in Megabite, Mr. Humphry adds more clover in a quarter of the reseeds, in an effort to reduce the amount of artificial fertiliser he applies.