I have spent the last three weeks on holiday in the USA. This came about because we got tickets for the final practice day and par 3 competition of the US Masters (golf) which is held in Georgia. As a consequence we toured south east USA. There was little farming but an awful lot of swamps in the areas we visited, but we did manage to visit a cotton plantation; fascinating.
There is no doubt that you haven’t visited the NIAB website to read about the holiday of one of its staff. However, whilst we were out there the Boston bombing occurred. This appalling act of terrorism was a severe blow to the American public, and the news was dominated by this tragedy. CNN spent virtually all of its airtime on the subject for the following two weeks, most of it live from a nearby street in Boston. A speaker at the White House correspondents’ dinner said something like ‘CNN likes to cover all angles of a story, in the hope that one of them is correct’.
It was the CNN coverage of the bombing that led me to re-evaluate the meaning of ‘breaking news’. Invariably an interview with yet another witness of the bombing, who said something very similar to the previous witnesses interviewed, was classified as ‘breaking news’ and I’m sure the other news networks did the same.
In fact there is a ‘breaking news’ mentality in all news media including the UK agricultural press. There are plenty of instances where the same story is printed year after year as if it was hot news. Let me give you an example: every year I read that volunteer potatoes on dumps need to be controlled as they are a source of blight.
This is not to demean a valuable advisory message but the breaking news element is that someone new appears to make the statement. However, the sheer familiarity of such reports that are repeated annually results in little scrutiny of what has occurred in previous years or updating of the approach being covered. A good example of this is the annual coverage of canopy management of oilseed rape. The same old coverage occurs annually but there have been a lot of lessons learnt.
First of all, I have to say that OSR canopy management has enormous potential to optimise the nitrogen dose. This is no mean feat when you consider how contrary this crop can be. However, we’re falling short of this potential because of the difficulty in measuring nitrogen in the canopy. Despite the apparent sophistication of the rapid assessment techniques, the errors can be so large as to negate the value of the approach. The only sure way of getting an accurate assessment is the approach taken in the original trials; harvesting all the above ground green area, measuring it and then analysing it for nitrogen content. I am sure NIAB TAG is not alone, because of the potential reward of an accurate assessment of the optimum nitrogen dose, in trying to shortcut this tedious and expensive approach.
You may have noted that I’ve not mentioned yield as a potential reward. This is difficult to ascertain because it depends on what you compare canopy-managed OSR with.
If it’s against the same nitrogen dose, but with conventional timings, then the initial trials only recorded a significant yield increase from canopy management in one instance, where it avoided an excessive dose being applied early to a largish canopy. This resulted in crop lodging. Where lodging was avoided by the use of a triazoles fungicide there was no significant yield advantage from canopy management. And where the comparison was between canopy management and 240 kg N/ha with conventional timings then surprisingly there was still little difference in yields.
This leads me to the conclusion that unless lodging is avoided by canopy management, the overriding reason for its adoption is to optimise nitrogen doses and margins over nitrogen cost. So let’s hope that in the near future there will be some true breaking news on nitrogen for OSR. NIAB TAG has obtained a wealth of data over the last couple of years and I’m sure that soon we will be better able to assess quickly the nitrogen contained in the OSR canopy at the end of the winter.