From Martin Dunn, agronomist
In theory this might be the case in the livestock sector. However the dairy farmers supply nearly all our milk and most of the butter and cheese. Any expansion could only come from keeping imports out. Beef is an area that could show some increase, but sheep farmers who export 40% of their lambs to the EU would be in a hard place. There would be a temporary surplus before some producers go out of business due to the inevitable cheap imports from countries like New Zealand.
Now we come to the arable sector. We are already self-sufficient in some vegetables, particularly potatoes. We also produce 80% of our bread making wheat, the remaining 20% is associated with types of wheat that cannot be grown in the UK.
At present we produce 15 million tonnes a year of cereals of which a high proportion comes from winter as opposed to spring crops. The difference in yield between the two is 25%-30% in favour of winter crops. Currently the average winter wheat crops have plateaued at 8,5 t/ha and there is little if any R & D in the pipeline to help to break this figure. Pests and diseases are becoming resistant to current pesticides and there are few new pesticides on the horizon. And many existing pesticides are withdrawn for environmental reasons.
There is also a big problem on most farms with a very competitive weed called Black Grass for which the only long term control involves a switch to several sequential spring crops. Even then this farming practice depends and a weed killer called Glyphosate. This product might be banned within 5 years. Should this happen, then the only way to control Black Grass is by many cultivations prior to sowing the crop. This would greatly increase air pollution where diesel engines are used.
The DEFRA secretary wants a more environmental approach using ‘Min-Till’ i.e. sowing without ploughing or cultivations. Many farms are already doing this, but they too are dependent on glyphosate to control the weeds prior to sowing. This system as it stands is very environmentally friendly. Organic manures are regularly used; crop residues are left in the field to prevent soil erosion and to encourage worms. Cover crops are grown on fields that otherwise be left bare. However these farmers cannot match the yields of the conventional farming methods, they are usually 15% lower at 1 t/ha; organic methods produce 40% less.
Other factors inhibiting farm output for the UK include the loss of high quality soils to housing developments and infrastructure projects and the ban on the use of GM crops. Furthermore, the removal of farm subsidies could see as many as 50% of farmers going out of business. Those remaining will not grow crops on the poorer soils. All-in-all farm output will inevitably fall and the price of food will rise.
Martin Dunn. Agronomist