AttachmentsEffi­cient and versa­tile: This is how farmers work with the 750A seed drill

Whether its beans or rape, on clay or sand, across open hectares or in trial plots, the accu­rate and versa­tile John Deere 750A drill has won many fans. David Purdy puts its popu­larity down to a number of factors.

Chief among those is the accu­racy of seed place­ment across a wide range of soil-types and condi­tions. One of the reasons for that is that the depth control wheel is posi­tioned next to the coulter rather than behind or in front of it on other drills, explains David.

The seed, then, can be placed precisely at the set depth and is less influ­enced by stones or clods as in systems where the wheel is mounted before or after the coulter. The opener disc; canted at seven degrees, and the press wheel provide good slot closure and the vital seed-to-soil contact needed for uniform emer­gence.

The depth control wheel right next to the disc coulter ensures precise seed place­ment.

A rubber back wheel and a slanted cast wheel ensure good soil contact and good coverage of the seed.

Recently the drill has seen a renais­sance in sales as growers moved into min- and no-till systems, says David. “It’s nimbler than heftier alter­na­tives so compaction is reduced, suiting it well to low-distur­bance set-ups,” he explains.

The 750A can, there­fore, operate over an extended season, getting on to land earlier in the spring and later into the autumn, adding to its versa­tility. A further advan­tage of its scale is in poten­tial fuel savings. The six-metre version of the 750A can easily be pulled by a 150hp tractor unit which means fuel costs are kept to a minimum. “Added to that, it’s simple to main­tain and reli­able, virtu­ally bomb-proof in fact, which cuts out down­time at crucial stages in the season,” David says.

These factors are all key to producers who already own a 750A. Here, some of those give their views on what it’s like to live with it.

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The farm also has grass­land for horses and wood­land areas. Signif­i­cant areas are under a Coun­try­side Stew­ard­ship Scheme higher tier agree­ment and the farm has taken part in the pilot Sustain­able Farming Initia­tive.

David and the team at Thriplow went fully no-till in 2016 and have been using multi­species cover crops including vetch, linseed, buck­wheat and phacelia since 2011. David wanted a disc drill to be able to drill into cover crop residues. To find out which drill worked best, he carried out a trial of the 750A, along with two others, before making a purchase.

While on heavier land there was only a 50kg/ha yield differ­ence across the three machines, on lighter land wheat sown with the John Deere 750A produced 0.8t/ha (8%) more grain.

That was a result of a higher plant estab­lish­ment, with 50-80 more plants/sq m than the other two drills on lighter land, and 120-130/sq m on heavier soil.

The 750A was chosen and seven years on, it is still the main­stay of the drilling oper­a­tion at Thriplow Farm. “We use it to drill about 75% to 80% of the crops including winter wheat, beans, spring oats and spring barley,” David says. “It copes easily with 500ha of winter crops in the autumn, it’s robust and we get good estab­lish­ment when drilling into crop residue.”

Although only a rela­tively small amount of drilling is into taller cover crops, yields have been better than the wider settings on the farm’s other drill.

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James bought a six-metre 750A about six years ago with part-funding from a Leader grant during the farm’s tran­si­tion from a plough-based setup, through min-till to a no-till system.

In a careful selec­tion process, James tried a number of other no-till drills on the market.

“The reason we chose the 750A was because every other drill we tried required rela­tively high horse­power,” he says. “And, because of the weight of the drills on a heavily culti­vated or ploughed field, the others quickly buried them­selves, while the 750A didn’t.”

While getting the soils right for no-till, the farm was able to use the 750A for the whole tran­si­tional period. Now the farm is fully no-till and the 750A places seed very effec­tively in that system.

“We drill through stub­bles and some­times chase the combine with a disc harrow then drill directly into that,” says James. “The disc harrow is more of a chit­ting and trash manage­ment tool rather than for cultivation, so we’re only pulling it at about 20mm depth.”

The drill has enabled the busi­ness to expand the conser­va­tion agri­cul­ture area and can get seeds in at the optimum time – there is less pres­sure on timing because the 6m drill provides extra capacity, James notes.

The farm uses biolog­ical controls to tackle fungal diseases and the 750A has been fitted with a liquid appli­cator kit supplied by TT Engi­neering. Liquid containing the micro­bials is pumped from a tank attached to the front of the drill through pipes and into the slot. This avoids coating the seed – a process that would inhibit growth.

“Our aim is to maximise the health and vigour of the crops while reducing depen­dency on ‘bags and bottles’ of arti­fi­cial fertiliser and chem­ical controls,” James says.

Another attribute of the drill is that it’s highly adapt­able. Every­thing is put through the 750A – grain, AB15 mixture, peas. “The other reason I love the drill is its reli­a­bility,” says James. “It has the Accord seeding unit which has been around for ever, and while the depth adjust­ments and coulter manage­ment are included, mechan­i­cally it is very straight­for­ward.

We have had no break­downs in six years, and it drills in every condi­tion, which makes life a hell of a lot easier.”

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Above all, arable trial work at NIAB’s Cambridge research station requires accu­rate seed place­ment and consis­tent estab­lish­ment from its drill. Research agron­o­mist, Will Smith, is completing a PhD in interrow cultivation while he manages weed, seed and regen­er­a­tive agri­cul­ture trials.

The 750A is used for direct drill trials. “It works really well for this because we get good seed place­ment and the reli­able crop­ping we need,” Will says. “It is just so good at placing seed, at a more consis­tent slot depth than any other drill we have tried.”

Slot closure is also a key feature – the 750A provides excel­lent seed-to-soil contact. “When we have looked at other machines the slot closure is less than perfect. But the 750A is versa­tile too; it is not just a one-trick pony. We can use it on light or heavy land, even in wet condi­tions, and the seed still goes in accu­rately,” he adds.

Plot sizes range from 2mx12m for statu­tory seed variety work, to wider acreages for larger scale studies, with about 30ha devoted to research issues like tram­line effects and diges­tate use.

The team at NIAB also appre­ci­ates the working width. “The drill offers us a useful working width at 16.7cm row spacing, which is a good balance between the tradi­tional 12.5cm and the much wider 25cm that is becoming more common,” notes Will.

“The width is right to make the most of working with an interrow hoe, so you are making the most of crop compe­ti­tion, along­side the ability to hoe a reason­able amount of your ground.”

The rela­tively compact size for a trailed drill is another feature that appeals. “For trials work the 750A is big at 6m, but it is still manoeu­vrable enough to turn it around in 12m; with some of the bigger units we couldn’t do that.

“The 750A makes our work easier. We have a fantastic arrange­ment, whereby John Deere provide us with a unit which sits with us at Cambridge for the whole season,” he adds. “It is a huge asset which allows us to cut out some key vari­ables that would affect trial data, and so provides us with reli­able results which are vital for the sustain­ability of the arable sector.”