Russell McKenzie: Beating black-grass in Cambridgeshire

Farm manager Russell McKenzie is fighting black–grass with no-tillage and rotations that avoid second wheats.

Russell McKenzie manages 995ha of owned and contracted land north of Bedford in Cambridgeshire. The business grows wheat, oil seed rape (OSR), winter beans, winter barley, spring barley and spring oats.

What are the challenges with your soils?

We have heavy clay – traditional sandy clay loam with relatively high pH levels and high magnesium in some places. Our potassium levels are decent and phosphate levels are generally ok.

Black-grass is the primary issue, so it’s all about improving the soil. We’ve done a good job in recent years getting its prevalence down and we know where the hotspots are. It’s a problem over about 15-20% of the land, so we’re scheduling later October plantings for those areas.

How do you deal with these challenges?

We spread the rotations out and avoid growing any second wheats. We include OSR one year in every five and we might do two spring barleys in a row in the worst scenarios.

If we jump too early back towards wheat and a more traditional rotation, then that’s when problems can start. But two consecutive competitive spring crops can normally get us in a good position.

If black-grass is a very serious issue then we put spring barley in straight away so that we have the most competitive crop in the spring. Or we might use spring oats followed by spring barley, potentially followed by hybrid winter barley in year 3. We’ve not had to do that yet though.

We’re moving the farm towards no till, so less invasive techniques, such as direct drilling and shallow cultivations.

We also apply cattle manure, monitor earth worm activity and use cover crops – I like multi-species mixes that contain phacelia, linseed and buckwheat as some of the core base products.

We’ve found that looking after our soil in this way has meant it retained more moisture and had less run-off when it rained after the dry summer this year.

At the same time, we’ve learnt from the wet autumn of 2012 that soil compaction can be a real problem, so we try and avoid getting on the land when wet as much as possible.

Find out more about Russell’s approach at The CropTec Show on 28 and 29 November where he will be part of a panel discussion on improving soils in the Crop Establishment seminar.