Since its introduction in the mid-1990s, John Deere’s 750A has become one of the most popular direct/all-till drills on the market, with a versatility that means it’s not only capable of establishing crops in untouched stubbles, but also works well in everything from fully cultivated ground to stale seedbeds to standing cover crops. With coulters running in the shadow of single disc openers, it establishes crops with the minimum of soil disturbance.
There is also the possibility of specifying spoked gauge wheels and serrated cast closing wheels to enable drilling in more tilth, allowing the soil to pass easily through the drill and preventing build-up. With a low horsepower requirement – a 6m model requires only around 150hp depending on conditions, soil type and topography – plus the ability to keep tyre pressures to a minimum, the 750A can achieve high workrates, operating at 10-12kph while using as little as 10.0 l/hr of diesel.
Capable of sowing at depths from 13-90mm, the 750A can drill at rates from 1.0-400kg/ha and more. The 3.0m models feature a centrally-mounted 1,000-litre hopper, while the 4.0m versions have 1,800 litres of seed capacity, both with a single metering system. On 6.0m models there is a 2,300-litre hopper and twin metering units.
A single 46cm angled disc opens the furrow at 16.6cm row spacings, with a depth gauge wheel mounted alongside for seeding depth control. A semi-pneumatic press wheel pushes the seed to the bottom of the furrow to maximise seed to soil contact, while a cast-iron closing wheel firms loose soil into the seed slot.
In late 2018, John Deere introduced a new ProSeries opener for the 750A, which can also be retrofitted to existing machines. Designed to reduce soil disturbance, improve seeding depth consistency and enhance seed to soil contact and slot closure, it features only one grease point for minimal annual maintenance. It incorporates a narrower seed boot more sheltered by the opener disc, for reduced soil disturbance and wear. Further updates included a flexible press wheel which is both narrower and of greater diameter to better fit the seed slot. The tab designed to prevent seed bounce in the slot was also redesigned to for better fit and wear life.
While down-pressure of up to 250kg is hydraulically-adjustable, in most situations a pressure of below 50kg is sufficient. When drilling, it is always a good idea to have a level of hydraulic down pressure on the coulters, as this will then allow the drill to follow the ground contours and put the seed in the ground at the same depth across the whole of the machine, says Scott Kirbyshire, P Tuckwell agricultural demonstrator.
“Many users will, of course, be facing damp or wet soil conditions this season. Should you be among them, consider taking the pressure off the seed press wheel and letting it float,” he advises.
“This will help to prevent picking up large amounts of soil, which could potentially block the drill.”
Some farmers may be drilling cover crops to protect and restructure soils after the wet period, notes Scott. In these circumstances, or where other small seed species and mixes are being planted, the drill fan should be operated at a speed of 2,000-2,500rpm to ensure an even feed.
“At the other end of the seed size scale, some may be still drilling winter beans, or planning to plant spring types. With this crop, remove the agitation pins from the seed tank, put the blue seed flap in, and then open up the seed venturi to about 85+. Drive no faster than 8kph, and operate the fan at 4,000-plus rpm. This will allow the beans to flow through nice and evenly.
“Maintenance-wise, simply make sure the drill is kept properly greased according to the maintenance schedule. The coulters can be greased a couple of times a week – there are three nipples per coulter on older machines, but for models built from 2019 onwards, there is only one nipple on each coulter.
“The 750A is probably best known as a direct drill, but whatever situation you find yourself in this season, this machine will work across a whole variety of situations. Versatility is one of its biggest attributes.”
Further advice and information on the John Deere 750A is available from your local P Tuckwell outlet, via any member of our agricultural sales and demonstration teams.