The diversity of crop rotations in the South West puts growers in a good position to deal with the challenges faced from tight gross margins, managing problem weeds and meeting new Greening rules.

But before finalising cropping plans for 2015/16 it is worth spending a little time weighing up the merits of the different options to ensure rotations deliver the best results for your business, as Hutchinsons Cornwall-based agronomist Amie Horner explains.

From cereals and pulses to vegetable brassicas and potatoes, there is no shortage of crop diversity in this region. This variation has helped avoid many of the issues increasingly affecting growers elsewhere in the UK where tight wheat and oilseed rape-based rotations have contributed to a build-up of black-grass and other weed, pest and disease problems.

Prioritise and pick strengths

But despite this underlying diversity, it is still worth weighing up the relative advantages and disadvantages of the main crops before making final cropping decisions. Key to this is deciding what factors drive crop choice. For example, is it aimed primarily at:

• Maximising gross margin

• Reducing input costs

• Supplying feed and/or straw requirements to a dairy or other livestock enterprise

• Helping to manage weeds, such as brome or broad-leaved weeds

• Making a contribution to the Ecological Focus Area (EFA)?

Barley still a firm favourite

Barley remains a key crop given its use in livestock enterprises, as well as potential to deliver a healthy gross margin and a host of other management benefits. Alongside the obvious advantages of grain and straw for mixed farms, the crop helps to ease workloads at key times, with winter barley providing an excellent opportunity for early establishment of following crops. Cassia remains a popular variety, despite its relatively low 4 rating for rhynchosporium.

Brome is becoming a problem due to the lack of herbicide options for control, so it is worth avoiding winter barley in high pressure situations.

While conventional varieties are still a good option for growers on traditional barley-growing land, hybrid varieties such as Volume or Fletcher are proving popular, for their higher yields of both grain and straw and the extra competitiveness against weeds.

The only downsides to consider are the higher growing costs for hybrid barley over conventional, and the potential for lower specific weight in high-yielding crops, although this is unlikely to pose an issue where grain is fed to livestock instead of going to a more selective end-user.

Spring barley is an ever-popular crop, but where it has been heavily relied on – especially in coastal areas unsuitable for winter cropping – we are seeing increasing issues with ALS-inhibiting herbicide resistance in broad-leaved weeds, such as chickweed. Finding an alternative to spring barley where this is an issue is the ideal way of tackling the problem, but in many cases this is not practical, so the answer may well remain with more tailored herbicide applications, focussed on pre-emergence products, mixed active ingredients and avoiding the use of sulfonylureas.

There are of course some unique malting barley contracts still available, so opportunities remain in certain areas for less mainstream varieties, such as Maris Otter for local breweries, so it is always worth checking what is out there.

Spring wheat aids logistics

Spring wheat can assist with storage logistics and workload, but although it is a spring crop, it can still be difficult to manage in high grassweed situations due to the lack of herbicides registered for use. Spring cereals offer an excellent opportunity to establish cover crops overwinter though, helping to build fertility and qualify for EFA, albeit that the area is only 0.3 of the cover crop area.

Spring beans may be an option

While winter and spring beans or spring peas provide a useful break crop opportunity further east, the wet and mild climate in this region does not really suit these crops.

Spring beans are a good option however, if growers are willing to spray regularly to stay on top of chocolate spot. Some are grown to feed livestock and there are other crops grown for human consumption, but growers have to factor significant haulage costs into any margin.

Leaving land fallow offers the opportunity to qualify for EFA and an excellent opportunity to control severe weed populations, but it must be managed. Fallow can provide an excellent opportunity for mole draining or any remedial drainage work, however, the negative margin from fallow remains the largest hurdle for most.

Oats offer effective break

Oats are a very good take-all break and grow very well in the southwest.

The absence of significant grassweed problems also means that the lack of herbicides is not generally a problem, as it is elsewhere, especially as the crop is very competitive.

Winter oats can provide a good gross margin, particularly if a milling sample can be achieved. But, with a relatively low input cost and also a limited demand, the market can easily be over-whelmed so they are usually best grown on contract, unless going to a livestock enterprise.

Spring oats are another good option, with similar yield potential to winter varieties and the added benefit of helping to spread drilling workloads.

Potatoes are another very good break crop, with early varieties allowing a good opportunity to establish a following wheat crop.

The final decision about what to grow and where to grow it has clearly become much more complex than ever before. It takes careful planning to ensure you make the right choice, for the right reasons. Discussing your thoughts with your agronomist before the final decision is made can often help steer you towards the most appropriate choice for your specific situation. More information on EFA’s is available in the CFE leaflet Voluntary Measures – getting the most out of Ecological Focus Areas.