NIAB - National Institute of Agricultural Botany

Orson's Oracle

Reversing the decline

Posted on 28/12/2011 by Jim Orson

There was a very thoughtful reply to my blog on the impact of predators on the numbers of farmland birds including two key statements: ‘the predators have as much right to exist as their prey’; and ‘….controlling a species to benefit another is just wrong. It's manipulating nature, not conservation’.

I have sympathy with these statements, but there remains the need to reverse the slide in farmland bird numbers in order to meet one of Defra’s quality of life indicators.

Since the baseline year of 1970 there has been a fall of over 50% in farmland bird numbers. Over the same period populations of magpies and sparrowhawks nearly doubled.

Now, I’m not saying that this is by any means a cause and effect. However, the increase in predator numbers must have had some influence on farmland birds. Is it really fair to ask for a return to the numbers of farmland birds recorded in 1970 when there were significantly fewer predators?

The response referred to earlier also stated ‘the fact that they [predators] are still doing well is because actually there is plenty of prey out there on our farms for them to flourish’. I suppose the tongue-in-cheek response must be perhaps we should be using predator numbers as the indicator rather than the population of farmland birds?

There is no doubt that much of the decline in farmland birds has been due to changes in land use. The reduction in mixed cropping and the increase in winter crops at the expense of spring crops have been major factors. We’ve seen publically-funded schemes try to reverse these declines, but they don’t seem to have worked.

Research by the University of Reading has concluded that take-up of ELS options is very much out-of-line with the requirements of farmland birds. There needs to be more clarity on which options are required in order that declines can be reversed.

But this clarity will bring some unpalatable news to some farmers. There will be a need to devote land to wildbird seed mixes for winter food and for flowers for insects in the summer. These in-field options have not been popular, but really are the essence of trying to get a balance between biodiversity and food production.

The Government is examining future options under ELS and also has consulted on new quality of life indicators. Previous experience and research like the University of Reading’s hopefully mean that we not only get realistic and pragmatic indicators but also the means of achieving them.

I say pragmatic partly because I have to ask why we cannot currently use pesticides or fertilisers to optimise the biodiversity gain from the hopefully limited area we have to devote to this aim.

Reducing the area needed will have wide support from farmers. It’s not these inputs that have been directly responsible for the decline in biodiversity, but they could in the future make a significant contribution to reversing it.

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Is British weather a basket case?

Posted on 20/12/2011 by Jim Orson

We reviewed all our 2011 experimental results recently. One trial result particularly interested me - chlormequat increased wheat yield in the absence of lodging. This doesn’t typically occur, despite what many are led to believe. So why did it this year?

The yield increase was found at a trials location that witnessed a lengthy spring drought from late-February to late-May. It then rained in June and July and this, combined with low temperatures, provided very good conditions for grain fill.

This is the ideal scenario for chlormequat to increase yields. The growth regulator increases potential grain sites, usually by reducing tiller loss during the period of rapid growth. This year there was a very high loss of tillers in the drought conditions, often resulting in sub-optimal populations of heads. Hence, the additional extra grain sites, from the use of chlormequat, were able to exploit fully the excellent grain filling conditions.

Mind you, the opposite can occur.

Yield losses from chlormequat can happen following good growing conditions in the early spring followed by hot and dry weather before and during grain fill. So, the impact on yield from chlormequat use is a gamble on the weather.

This is true, to a greater or lesser extent, for most decisions on crop input management. If we knew future weather conditions then it would be a lot easier. But we don’t, which means compromises, in the guise of risk management, have to be made.

Everyone can quote examples where decisions are compromised by having to take into account the weather not doing what we would wish it to do. One good example is nitrogen application timing for wheat. If we knew that there was going to be a decent amount of rain at flag leaf emergence then we would apply most of the nitrogen just before that stage to optimise yield.

The unpredictability is not just restricted to input decisions. This year’s spring drought followed by rain in late-May reduced the relative yield of early winter wheat varieties in many cases. Obviously these varieties were less able to compensate for the spring drought than the varieties that were less advanced when the drought broke, which is just sod’s law!

Some crop physiologists say that a way to help combat the warmer and drier summers forecast is to have earlier flowering and ripening wheat. It goes to prove that no-one should put all their eggs in one basket when the basket is as fickle as our climate.

After saying all that, we have little to complain about regarding the variable impact of weather on yields and crop input decisions. In parts of Australia the yields between seasons can vary from nothing to around five or six tonnes per hectare. In some seasons much of this variation is explained by rain falling after the time most input decisions are made. This is risk management in the raw.

By the way, I accept that the main reason for the use of chlormequat in winter wheat is to help keep it standing. Another unpredictable risk.

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Trust me; I am a scientist...

Posted on 14/12/2011 by Jim Orson

I have always associated the Houses of Parliament with robust, and sometimes aggressive, debate. With this in mind, I attended a recent meeting of the All Party Parliamentary Group on Agroecology. I was disappointed because of the complete absence of debate. This group appears to have been established solely to forward the views of those opposed to technology in food production, with virtually all the delegates representing so-called ‘green’ groups.

The outcome was that the vehement anti-GM views expressed by the only speaker were readily accepted, and naturally, the delegates wanted to agree with him. This was despite the ‘evidence’ presented being, in my opinion, largely based on hearsay. Their acceptance was in complete contrast to their lack of acceptance of the best scientific evidence that called their opinions into question.

The speaker was a retired Professor from Purdue University. He started with a passionate attack on GM and then associated Roundup Resistance with a destruction of the soils in the USA, increased disease in soybean and maize, and infertility and botulism in animals fed on GM maize. 

There were other accusations as well, the most remarkable of which was that a new ‘organism’ has developed as a result of growing Roundup Ready crops. He considered that this organism was the cause of many of the negative effects he was reporting.  He added that it was first isolated in 2002, but it has yet to be described and named. In an age when it takes less than a week to DNA sequence a living being, I think it is remarkable that this organism cannot yet be described after nine years.

Under questioning he said that he had a list of 130 refereed papers that support his case. The only example he quoted from the UK was, in my view, a total misinterpretation of the facts and the conclusions expressed in that paper.

He deflected possible questions on why other scientists do not agree with him (his own University refute many of his claims on their website) by implying that other scientists cannot be trusted as they are dependent on short-term contracts. The implication is that they have to toe some invisible line to get continued funding.

He did not mention that the yields of maize have gone up by 20% and soybean yields by 15% in the USA over the past 10 years or so, which has also seen the widespread adoption of GM, notably Roundup tolerance. Also ignored was that the recorded level of disease in soybeans in the 28 US states surveyed has not shown an upward trend since the introduction and widespread adoption of GM. Unfortunately, as far as I know, there is no equivalent survey for maize.

In an era when there is always some dispute over the facts, common sense needs to come to the fore. Dare I say that farmers can have a lot more common sense than some scientists? US farmers have adopted GM and I am sure they are as discerning as UK farmers. They would not have continued to adopt it unless it was financially attractive and it was not threatening the fertility of their soil or their animals.

The concern that some US farmers have reported, even the champions of GM technology, is the potential power of the companies that sell the technology. This is because the highest yielding varieties tend to contain a GM trait, but the trait itself does not necessarily contribute to the high yield. Also GM herbicide tolerance has resulted in conventional herbicide development being reduced or completely stopped in the crops where GM herbicide tolerance has been introduced. Perhaps this is the real potential challenge to the farming industry?

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The only good magpie is a...?

Posted on 06/12/2011 by Jim Orson

Back in the late 1950s, when I was about 12-years-old, the local NFU office gave you a crispy 10 shillings note for a dead magpie. Now 10 shillings (equivalent to 50p) doesn’t sound a lot, but then you could take a bus into town, go to the cinema, have fish and chips and still get home with change. Or is that the opening line from a Monty Python sketch...?

I also remember waking up to deafening dawn choruses. According to statistics it was the halcyon days of farmland birds.

Can these two observations be just coincidental? Did a lack of predators, like magpies, enable farmland birds to flourish? Or, are there other factors involved in the decline in farmland bird numbers over the past forty years? 

I’m now old enough to know that nothing is that simple, but there is now a vigorous debate on the role of predators with regard to the decline of farmland birds. As a non-expert reading experimental results and listening to both sides of the debate, I think those who argue for predator control have the stronger case.

However, resolving this issue appears to be challenging for the RSPB. Sometimes it seems that it is totally against predator control, and sometimes the charity appears to say that if you want to control predators then go ahead; after all predator control is carried out on some of the RSPB’s reserves. The lack of a clear message might be due to differing internal views.  And, of course, predator control could be unpalatable for many of those who support the charity organisation.

But as I suggested earlier, the decline in farmland birds is bound to be much more complicated than just a single factor.

Pesticides seem to be the first port of call by the media when any environmental problem is reported. The 1950s and 1960s were also the halcyon days of organochlorine and organophosphate availability. And there’s proof that some of these insecticides may have had a direct impact on bird fertility, including reducing the thickness of egg shells. DDT was also used as a herbicide as late as the mid-1970s; in wheat DDT could control susceptible barley varieties.

The generally agreed position is that pesticides didn’t directly contribute to the decline in UK farmland bird numbers. However, one of the major factors in the decline has been land use change facilitated by pesticides.

I was reminded of the extensive availability of organochlorine and organophosphate insecticides in the late 1960s and early 1970s by reading the 1970 Approved Products for Farmers and Growers Guide. Someone lent me it as a result of my previous blog ‘What’s in a name?’ I hope say more about the contents of this publication at a later date.

By the way, as I walked back from the paper shop this morning there were five magpies standing on the road...

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Candidates for confusion?

Posted on 28/11/2011 by Jim Orson

Well it seems a good idea in theory.  The new EU pesticide legislation includes the concept that where there are a few products available for a particular use then only the least hazardous ones should be authorised.  The legislation accepts that the products that remain authorised should be significantly safer than those that are not-authorised.  In addition, there should not be a significant economic disadvantage to the withdrawal of authorisation of products and that resistance management and product availability for minor crops should be considered.

There are two stages to this process.  Firstly, identifying those active substances that could be withdrawn because they may be significantly more hazardous than the alternatives for the same use.  These are called Candidates for Substitution and are selected by the European Authorities.  Secondly a Comparative Assessment is performed when an application for a product containing an active substance approved as a Candidate for Substitution is made.  This is done at the Member State level because the decision will depend on what products are locally available.

The European Authorities have to define the list of Candidates for Substitution by the end of 2014. The process for their selection is not yet completely clear nor is the process of how Comparative Assessment will be done in practice!  However our CRD have had a go at identifying possible Candidates for Substitution based on the information they have on the possible criteria.  In this study, virtually all the most effective black-grass herbicides in cereals are Candidates for Substitution.  Well, virtually all those that they expect to clear the first hurdle and get approved under the new EU legislation!

There is growing realisation that this process may be too difficult to introduce into practice.  There are several issues to resolve in practice, including:

• What does ‘significantly more hazardous’ mean?
• Once active substances are approved under the higher standards of the new legislation, will there be products based on these that are significantly more hazardous than others?
• Will all active substances have to be approved as meeting the standards of the new EU legislation before this process can kick in (this will mean no decisions on substitution before 2021)?
• How many active substances or modes of action are required for effective resistance management?
• How to define a significant economic impact?
• Finally and perhaps most significantly, will the process withstand legal challenge because of the difficulty of translating this process into practice?  There is now an example where there has been a successful legal challenge to the non-approval of an active substance in the EU.

Hence, after much heat and energy will this process become a candidate for confusion?

There is the option in the legislation that all pesticides for a particular use could be withdrawn if there was a non-chemical option available.  This reminds me what a former chairman of the Government’s Advisory Committee on Pesticides once said.  He had calculated from the record of the instances of farm deaths that if herbicides were banned and replaced by mechanical weed control there would be an extra 6 or 26 deaths/annum (I cannot remember which of the two, but you get the drift).  And he should have known; he was a Professor of Morbid Pathology.

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