New Holland is the latest manufacturer to explore direct drilling in the UK. Lucy Stephenson reports on an Essex trial.
NORTH AMERICAN growers need little persuasion about the virtues of direct, or no-till, drilling; conserving water is the key. But here it is staging a revival as growers attempt to cut cultivation costs.
New Hollands Canadian Flexi-Coil is a tad too big for European farms at the moment. It has a transport width of 5.2m, row width of 7in and is geared for 300hp.
However, last year the company selected three farms in Europe – France, Germany and the UK – to see how well it would deal with our grass weeds, chaff and stubble residues and make it suitable for European conditions.
Last autumn the Flexi-Coil 5000 Air Drill, 1330 Air Cart and 85 heavy harrow bar was put to the test on 1,416ha (3,500 acres) at Dunsteads Farm in Essex. A 240hp tractor was sufficient to pull the drill at its operating speed of 6-8km/hour.
No-till fields were harrowed as soon as possible after combining to promote even weed germination. Weeds were sprayed off twice with glyphosate before drilling to give a sterile seedbed.
Tramlines were deep last year because of the harvest conditions. "We subsoiled the tramlines to lift them up so the drill worked on level ground," explains the farms agronomist, Richard Martin.
Forty hectares of winter oilseed rape (Apex) was no-till drilled in mid-August at 5kg/ha; 20ha of winter wheat (Soisson) followed in mid-October, at 250kg/ha; and 5ha of peas were drilled in early April.
Currently there are only two wheats in the rotation, but the time saved with no-till gives the flexibility to increase the amount of wheat grown on the farm.
And the cultivation savings? About £30/acre, estimates Mr Martin. Theres also scope to save on fertiliser; two tank sections are metered separately so that fertiliser or slug pellets can be added at drilling, points out Mr Martin. "25-30kg/ha P alongside the seed is worth 80-100kg/ha mixed in the top 15cm of soil," he says.
No-tilled rape at Dunsteads Farm was top-dressed with just 25kg/ha nitrogen; half that applied to conventionally drilled fields. And if rape is drilled early enough to get off to a good start it could do without any at all, he says.
Mr Martin is impressed with the drills performance but cannot make any comparison to other direct drills currently on the market. "It did an excellent job even in thick bands of wheat chaff, and there were no stoppages caused by wet straw and dead weeds. We drilled in the most awful conditions but we didnt need to redrill at all," he says.
The drill uses cultivator tines rather than discs. "People still think of discs for direct drilling but here even though it was wet it didnt leave the same sort of sideways smear that a disc would."
The tines cultivated the soil lightly. Mr Martin prefers to roll wheat to encourage even germination, prevent slug damage, and so that residual herbicide is more effective. But this year it was too wet to roll. He was concerned that the press wheels at the back of the drill wouldnt apply enough downward pressure to sufficiently consolidate the soil round the seed, so used a gang press after drilling.
As well as reducing costs, Mr Martin says direct drilling helps to maintain soil microbes. "We have to do a lot of cultivation to get a good seedbed, and ploughing can cause severe soil damage when things are moist."
Weed control and compaction are the only barriers to continual no-tillage, he says. "If we can stay on top of the blackgrass and brome theres no need to use a plough. I think we could no-till for five to seven years."
"The evenness of emergence was good. Theres nothing special about the trial fields except that theyre near the farm for convenience. But emergence on the no-till fields was faster than on conventionally drilled fields," says Mr Martin. Oilseed rape was up in four to five days, two to four days earlier than conventionally sown fields.
Mr Martin puts the early emergence down to two things: first, higher levels of available nitrogen for the no-till seed placed below the layer of chaff decomposition, where bacteria remove nitrogen from the soil; and second, because the straw mulch held moisture in the soil after harvest.
It looks promising, but it will take at least three years of trials before New Holland begins to design the European model.