15 Oct 2012

As you may have heard, NIAB TAG have set up a task-force to investigate the 2012 yield performance issues in winter wheat, with the aim of understanding and explaining the drop in yield across much of the country as well as significant local yield variations.

I was doing a bit of background work for the task-force when I realised that I’d made a bit of a misjudgment in a previous blog (Exceptional! 6 August 2012). I commented on the output of a model at Rothamsted Research. For their farm the major loss of nitrogen in winter wheat during this year’s exceptionally wet late spring and early summer was due to denitrification and not leaching. The model also showed that the roots of the crop during this period were largely starved of air due to waterlogging and it was this aspect that I rather brushed aside in my blog. However, this issue may have had a large impact on yields this year.

So, a couple of weeks ago I found myself in the library in Rothamsted looking up references on the impact of timing of waterlogging on wheat yields. There aren’t many studies on the impact of waterlogging during stem extension and grain fill of wheat and some of these have been done in very large containers (lysimeters) rather than in field trials.

Rothamsted LibraryHowever, they all show the same thing...

The conclusion, based on my reading of the literature, is that waterlogging alone in May and June this year must have had a significant impact on yield. As a rough guide, one day’s waterlogging in mid-May has the same impact on yield as five days waterlogging in the winter. Waterlogging during grain fill can reduce grain set and reduce grain size.

So this must be part of the explanation to the variation in yields we saw this year. There are other aspects that also need to be considered and these are being tackled by the task-force.

It was the visit to the Rothamsted library that also highlighted how the communication of science is changing. There were stacks and stacks of books and a lot of desks on which to read them but I was the only person there. The reason is that scientists now access and read papers on-line.

This will also change in the near future. Publishers have been charging non-subscribers to scientific periodicals a fairly substantial fee to access a single paper. There are now firm proposals that there should be open access in 2014 to all papers based on scientific research funded by the British taxpayer. There are similar proposals throughout Europe. This will inevitably impact on learned societies, some of which generate as much as 90% of their income from publishing papers in their periodicals. They are being offered alternative funding arrangements to peer review papers. I hope that these proposals will be realistic and allow them to continue.

These learned societies provide a structure to science and facilitate like-minded scientists to get together and debate relevant issues in an academic setting. Let us hope that the move to open access of the papers that these societies publish (a move which I wholeheartedly support) does not reduce their effectiveness in sharing and advancing knowledge.