Peak wheat

Posted by Jim Orson, NIAB TAG and BCPC Board of Management 2 December 2016

The Soil Association was making a huge fuss over ‘Peak Oil’ around the new Millennium. Subsequently, new technology has resulted in the fears of an oil shortage evaporating. The reason for highlighting Peak Oil was that the Soil Association appeared to believe that conventional agriculture is more vulnerable to energy prices than organic agriculture. This may have been good PR at the time for the organic industry but the fact is that organic agriculture is possibly more vulnerable to energy shortages and price. Herbicides and fungicides produce huge yield benefits from relatively little energy use which may more than counteract the high amounts of energy that are needed for nitrogen fertiliser production.

Until recently the Soil Association was making ‘Peak Phosphate’ a feature in its campaigns and on its website. It was stated that we have only around another 30 years of phosphate in reserve. It is true that the mining companies have approximately 30 years of declared reserves in their accounts but the US Geological Survey estimates that there are at least 1,500 years of phosphate reserves to meet current demand. Peak Phosphate was to publicise the organic movement acting responsibly by recycling nutrients. Another PR exercise which is not borne out by the facts. Conventional farmers also recycle nutrients, possibly to the same extent, but are admittedly not so dependent on this source of plant nutrition when achieving significantly higher yields/ha.

I think it is my turn to introduce a Peak, in this case Peak Wheat. Has the UK passed its Peak Wheat production? We produced 17.2 million tonnes in the 2008 harvest year; a combination of planting more than 2 million hectares of wheat and of what was then a record average yield/ha. In 2014 and again in 2015, we surpassed the record average yield/ha set in 2008 but the 5-10% lower area of the crop resulted in a total production of around 16.5 million tonnes.

The smaller area of wheat production in recent years can be attributed to a number of factors which now include herbicide resistance in black-grass. Effective and relatively cheap weed control makes it more likely that rotational and crop management restraints can be eased thus allowing farmers to maximise the area and potential of the most profitable crops. Take that away and there is a necessity to take the traditional rotational restraints more seriously. In this case, herbicide resistance in black-grass means less autumn-sown crops and also a higher proportion of later autumn-sown wheat. All this results in a smaller heap of wheat unless the yield potential of wheat increases very significantly.

Then there is also the issue of how agriculture will be supported in the future. It seems to me that there may be less overall support and perhaps a greater proportion of that support will be devoted to environmental enhancement. This may mean less crop production in parts of the country where yields are average or below, particularly where there is also an intractable black-grass problem. In these circumstances the temptation may be to restrict the area of crop production to the highest yielding parts of fields or farms and to increase the area devoted to environmental enhancement.

A realistic total cost of growing a hectare of wheat is around £950-£1,000/ha, which at current prices means that a yield of around 8 tonnes/ha is required to make a profit. Our 5 year rolling average yield is about 7.9 t/ha: food for thought. It is also worth pointing out that winter wheat and winter oilseed rape are the only two crops that many farmers can grow which will turn a profit without support from the Government.

All this sounds gloomy but there are scenarios that will mean we have not passed Peak Wheat. Plant breeding breakthroughs are now more likely with the accumulating knowledge of the genetic makeup of the crop and the new breeding techniques that are currently being used or being developed. There is also the possibility that wheat prices may reach a higher plateau as a result of an increasing world population and increasing climate uncertainty. Finally, an effective black-grass herbicide in wheat or herbicide-tolerant crops may be around the corner. Would I bet my shirt on these happening in the short to medium term? ……. perhaps not.