A disc at a slight angle, a coulter with a mini-plough share and a depth wheel, all cleverly set up to give even depth of placement, good soil-seed contact and very even crop emergence. We are growing crops, not just plants.
In the farming program, morning of 27th on BBC Radio 4, mention was of the dry summer and problems with seedbeds this autumn. I was reminded of one of the privileges of my life as in meeting and working with an agricultural engineer who designed a grain drill. The first really clever bit (a strong patent) was that whatever the quantity of grain in the bin, the pressure on the coulters remained constant. Secondly, a very shallow disc at a slight angle cut a shallow slit. Behind the disc was a coulter with a head like a small plough share which wiped any straw out of the slit (I did camera work on this action – it did work) and planted the seed. This was followed by a depth wheel to press the soil round the seed to get good seed-soil contact.
The result was minimal disturbance of the soil (and chitting of weeds in the seedbed), very even depth of placement and the most even emergence of the crop that I have yet seen. Importantly this year (and most years) with minimum soil moisture loss from the seedbed. That man was Sam Moore and, I am happy to say, he still has happy memories of a golden age in farm machinery development but, I guess, leaves Sam Jnr to captain the ship that is still Moore Unidrill.
Bill Butterworth, Land Research Ltd 27 October 18
Zero till with a Moore Unidrill; note the independent discs and seed coulters (right) and press wheels on the rear (left) giving even depth of placement and good seed-soil contact. (Photo courtesy Agri-Linc.)
Direct drilling comes in two guises; drilling after a little cultivation (“min till” really), and what in the USA would be called “zero till”. Each has its own consequence in terms of weed control. Maybe I learned, years ago, most from a farms manager called Richard Noyce, he always had clean bottoms to his crops simply because, after harvest, he cultivated the surface several times to get weeds seeds to germinate, before putting the next crop in. The alternative of one pass to put the crop in does imply more work to do with selective herbicide – but that is probably going to happen anyway, so it is not an extra cost. Generally, in the hands of a sensitive husbandry man, zero till costs less and gives higher yields.
Good husbandry and using the right machinery is aiming at even depth of placement, good seed-soil contact, giving even emergence.
Bill Butterworth, Land Research Ltd, 20 August ‘18
Conventional, plough-based cultivations certainly have a place but with a high time and energy cost.
When not to direct drill? Some years, it is wet but the harvest still has to be got in and the result is ruts. They may have to be cultivated out but it is as well to remember that direct drilled soils are less likely to rut because of the resilience of organic matter and a “blocky” structure which distorts less under load, even when wet. Also, some soils naturally form pans which may need to be cultivated out. Last reason is to bury weed seeds – but try not to plough them up next year. Rotational cultivations may be the answer with a progression to long term direct drilling.
Persist with direct drilling next year wherever possible to help build up organic matter. (Actually it is more a question of avoiding the oxidation of organic matter from conventional cultivations which could be 35% pa while direct drilling will be as little as 10% or less.)
Bill Butterworth, Land Research Ltd. August 18