Black-grass matrix

25 July 2014

Just before I mention harvest – to be fair it’s only the oilseed rape been cut around here – let’s talk about black-grass. Have you got it? What have you done so far? Got it all rouged? Sprayed it all off so your fields look like a two tone quilt donated by a 1970’s Blue Peter viewer? Now returning with the combine, more black-grass has turned up?

Well one thing’s for sure. Of the billions of seed shed back onto the ground on every hectare (either picked up by your combine and spat back onto the ground or simply shed straight from seed head to the ground we have not seen the worst of this problem).

What are you going to do differently? It’s no good looking over the neighbour’s hedge – they are in no better a situation than you, and they are partaking in ‘drive-by-agronomy’ just like yourself.

No, it’s down to you. No one else got you into this situation and no one else is going to get you out of it. All the information is on hand, and there is no new information worth waiting for that will stop you acting right now.

I say all this because I spotted a Case Quadtrac 550 pulling a six-metre TopDown after oilseed rape with blackgrass. After one pass it was bringing up brick rubble sized chocks of damp soil ready to dry out in the newly arrived sun and wind.  The answer to the drying out was another pass with the Quadtrac and press. The TopDown was in at a goodly depth and with probably 150hp to spare Case powered on without issue. So rather than getting the black-grass to germinate as close together as possible, it is now mixed up in 30cm of soil, ready to germinate at a whole host of different times extending into next spring, dodging every bullet you have. Think of it as Neo from the Matrix Trilogy films being able to stop bullets by simply waving his hand. Black-grass is waving at you from your sprayer cab with much the same effect!  Look up ‘Neo stops bullets’ on YouTube and you’ll get the idea.

The term ‘minimum tillage’ has given way to maximum tillage. Short rotations, poor sprayer nozzle choice, compaction of heavy soils have all lead to where we are now.  The plough, like Barbara Streisand has even made an expensive comeback.

So, again, what are you going to do differently? Bigger Quadtrac? I hear they make a 680hp one now. Up to now I’ve used the word ‘you’ 16 times, and that’s it. It is down to you. No one else has the power to bring all the tools, however small in to play on your farm.

It will be a key focus for a number of our Monitor Farms in the coming years and there is good sensible information on not only our website:


But Rothamsted Research’s website too

Whilst combining (not randomly TopDown-ing), give these points some consideration, form a robust plan using all methods and practices available to you, adopt a ‘can do’ attitude. . . . . . .

. . . . .  And go get’em tiger!  Wishing you a safe and happy harvest.

Black -grass In Lincolnshire Wolds (c )Gary Naylor

Black-grass on the Lincolnshire Wolds (c)Gary Naylor



Based at Ashkam Bryan near York, Harry grew up on a beef farm in his native north Wales. Subsequently, Harry developed an interest in farm machinery that took him around the world working in agriculture. Having managed a plant breeding farm near Cambridge for Monsanto, in 2005 Harry joined John Deere as Crop Systems Specialist, from where he was recruited by AHDB Cereals & Oilseeds.