24 July 2002

Low-risk, low-cost establishment

MOVING oilseed rape establishment to a single pass, one-man system has brought major benefits to a Cambs estate, without the risks associated with broadcasting into standing crops or stubble.

Rape is a key crop on the 1600ha (4000-acre) all-arable Bartlow Estate, accounting for 323ha (800 acres) of heavy boulder clay alongside cereals and sugar beet.

It used to be established using up to five passes with plough, press, power harrow, drill and rolls. "The usual and inevitable loss of moisture resulted in late and less than optimum establishment," recalls manager John Goodchild. It was also slow and expensive.

Now an Opico Variocast pneumatic seeder is used on a Howard seven-leg sub-soiler with toothed packer roller to establish the crop. The combination has an operating width of 4.2m, folds to 3m for transport, and is used behind a Claas Challenger 55.

It works directly behind the combine, on stubble and chopped straw. "The main motive was to reduce the time and cost of establishing rape and to make a better job of it," says Mr Goodchild. "We achieved that. It has released men and machines for preparing land for cereals."

Operating at about 6mph and a depth of 23cm (9in) to relieve combine wheelings, daily output is about 26ha (65 acres). "You need a reasonable turn of speed to create turbulence around the back of the leg into which the seed drops," notes Mr Goodchild.

Seed is applied at 8-10kg/ha. "That is fine with home-saved seed but a bit expensive with the bought in product." Slug pellets go in with the seed.

"One of the attractions is that some of the straw is cleared out of the way and brings up moist soil. This affords an ideal environment for the seed to germinate." This year a Simba double furrow-press will follow to give more consolidation than Cambridge rolls.

"Over the wet winter it gave good drainage, the crops looked a good colour and the roots went straight down the sub-soiler slots."

"When we have used discs in the past our heavy boulder clay could turn into paddy fields in a wet winter," adds estate foreman David Hannah. "Theres a bottom in the disc system, but not in the new system, so theres plenty of drainage for water to get away."

Timing remains critical. "We start combining our wheats about Aug 8 and hopefully get harvest wrapped up by early September," says Mr Goodchild. "Rape sowing starts in the middle of August, following winter wheat, and we aim to finish by the end of the month."

"We chose to go with this sub-soiler route to take out the wheelings and relieve surface compaction. But if you just want to go with a set of discs and drop the rape seed behind, or drop it in front of a press, it will establish. If youve got sufficient moisture and a bit of soil around the seed, rape will grow." &#42

Variocast establishment costs

Costs vary according to the machine the Variocast is mounted on. As a guide add £6/ha to the normal cost of running the machine, to account for time spent filling the seeder slowing workrates, plus depreciation, says Opico. Price of the seeder with electric fan is £2927, or £3727 with in-cab controls to adjust seed rate metering across the field.

Cambs unit cuts costs

Anthony Mawby of farming company Cole Ambrose, Ely, Cambs is using a Variocast on a 4.5m sub-soiler to cut the time and cost of rape establishment, the combined operation now costing about £35/ha (£14/acre). Crops established well last autumn and appeared no different to conventionally established crops throughout the season, he says. Yield prospects were looking good late last week, with the crop due to be harvested by the end of this week.

Establishing oilseed rape with Opicos Variocast air-seeder mounted on a seven-leg sub-soiler cut costs, saved time and produced a good-looking crop, says John Goodchild of Bartlow Estate (inset). Harvest results will be known soon.

Costs vary according to the machine the Variocast is mounted on. As a guide add £6/ha to the normal cost of running the machine, to account for time spent filling the seeder which slows workrates, plus depreciation, says Opico. Price of the seeder with electric fan is £2927, or £3727 with in-cab controls to adjust seed rate metering across the field.

Variocast costs

Cutting time

Anthony Mawby of farming company Cole Ambrose, Ely, Cambs is using a Variocast on a 4.5m sub-soiler to cut the time and cost of rape establishment, the combined operation now costing about £35/ha (£14/acre), he estimates. Crops established well last autumn and appeared no different to conventionally established crops throughout the season, he says. Yield prospects were looking good late last week, with the crop due to be harvested by the end of this week.