NIAB - National Institute of Agricultural Botany

Orson's Oracle

Conquering hunger

Posted on 13/11/2013 by Jim Orson

In the late 1990s I gave a talk at a highly charged conference on GMs at which I stated that there was progressively less hunger in the world. Naturally, I checked my facts with some aid agencies before making such a statement. I attributed this good news to a more plentiful supply of food because of higher yields, but didn’t highlight the role of any specific agricultural technology. I didn’t even think of GM crops being a factor because at that time they had only just been introduced in the USA.

This did not stop the fledgling anti-GM movement from saying, both at the conference and in follow up statements, that I was lying. Their implication was that ‘modern agriculture’ was failing to meet the challenge of a rapidly expanding world population.

Nowadays, the FAO publishes estimates of world hunger which provide hard data rather than opinion. It shows that A gradually decreasing proportion of the world population is described as undernourished - falling from around 19% in 1990 to around 12% in 2013. The percentage of undernourished people has fallen in all regions, but not in all countries, of the world. Tragically, there’s still around 20% of the population in sub-Saharan Africa and in South Asia that does not have sufficient food.

Whilst the percentage of undernourished people has fallen significantly over the last 20 years or so the world population has increased significantly.  So the question has to be asked as to whether there are now fewer undernourished people than then? Rather amazingly the world population has increased from just over 5 billion in 1990 to around 7 billion in 2013, almost as much of a proportional increase as the decrease, over the same period, in the proportion that is undernourished. Hence, the absolute number of people that are recorded as undernourished (now 842 million) is not dramatically below that in 1990 (1,015 million). So whilst modern agriculture can pat itself on the back for feeding the world’s rapidly expanding population there are still many challenges ahead.

This emphasises the need to be very careful when quoting statistics. I would have been absolutely correct to say in my talk that the proportion of the world population that is undernourished was falling but this would have ignored the fact that the fall in the number of people in this category was not so significant. There are plenty of instances where ill-defined statements can be misleading. For example, a recent report showed that the UK has reduced carbon dioxide emissions by 20% since 1990. Great news, until you read in the same report that the UK has increased its carbon footprint by 10% over the same period because of the carbon dioxide emissions associated with the production and transport of the goods we’re importing in increasing amounts.

There’s an active debate about how farming should be structured in the less developed parts of the world in order to meet these food security challenges of the future. There appear to be two contrasting views. The first, which is being championed by some charities, is that very small scale family units are the solution. The opposite view, taken by some of the more industrially-based organisations, is that very much larger and professionally managed units are necessary. I can’t really comment on this dichotomy other than to say that the farms need to be sufficiently large to provide a surplus of food in order to create a market and to stimulate other parts of the economy. It is precarious, to say the least, to rely solely on barely self-sufficient units. This was the objective in Cambodia when Pol Pot tried to impose his communist-based agrarian Utopia.

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Can we afford any more revocations?

Posted on 05/11/2013 by Jim Orson

One of life’s treats for me is to settle down with a cup of coffee (or two) and read The Sunday Times. The process starts by throwing away all the bits we don’t read, then finding out about the latest cars and gadgets and then onto the sport and then business. I reach the news later in the day and so by that time I am very relaxed.

I was rudely roused from my relaxed state a couple of Sundays ago by an article that attributed all losses in UK amphibian life over the last few decades to pesticides. It quoted research sources that were said to have proved this state of affairs. The pesticides mentioned were atrazine, DDT, dieldrin and malathion.

My immediate reaction was that no other possible causes of losses of amphibians were mentioned, perhaps loss of habitat or other possible toxins. This seemed an extraordinary oversight in light of the fact that the pesticides mentioned have not been used in the UK for years.Female great crested newt

It is now clear that the bold accusations were made by an anti-pesticide group and not the researchers themselves whose methods appear not to reflect the type of exposure that would occur outside the laboratory. I’m rather disappointed that a quality newspaper acted as a mouthpiece for this group rather than investigating more thoroughly the facts.

Since the article was published, I’ve been thinking a little more about my immediate reaction to it. I remember saying to my wife that the article was ill-founded because the pesticides had already been withdrawn because of fears over their safety in the environment. However, perhaps this makes me a bit of a hypocrite because I may have lamented and, at least subconsciously, defended these pesticides when they were first threatened with revocation. I realise that it is difficult to defend DDT and dieldrin, but please remember that DDT is still being used in a very targeted way to fight malaria (see my April 2013 blog ‘The Impatient Optimist’).

The new EU pesticide regulations have further increased the standards of environmental protection, particularly for aquatic life. I blogged only a couple of weeks ago about wider aquatic buffer zones (‘Two in one will go’).  The issue of endocrine disruptors is also coming to a head and it’s hard to imagine that there will not be further losses of active ingredients as a result.

As standards increase the reasons for revocation become more marginal. Preventing the widespread use of DDT and dieldrin was perhaps an easy decision compared to the possible withdrawal of active ingredients due to the hazard (not the risk) posed to endocrine disruption. So getting the correct balance between food production and any threat that may exist to environmental and human health will become more challenging.

It’s also getting harder to achieve the right balance when there are single issue groups who are hell bent on getting their own way. To achieve this, truth and scientific facts become the first casualties. I suppose the prime example of this is Greenpeace’s campaign against GM Golden Rice (see January 2013 blog ‘A golden future’), the cultivation of which may prevent widespread disability and death amongst children.

Fortunately, we’ve continued to produce the same amount of food despite all the pesticide withdrawals which we’ve seen over recent years. Unfortunately, this may have given the impression that food production will continue to be maintained despite even further pesticide withdrawals. However, there are many of us in the industry who now feel that we cannot suffer more losses of pesticides without a significant fall in production. Hence, I sympathise with those at the sharp end of decision making on pesticide approvals. They’re trying to achieve the right balance between food production and the environment, which is of course a political as well as a scientific issue.

Politicians are becoming increasingly aware of the challenges to future food supplies and they also seem more aware that NGOs and single issue groups may not be as righteous as they themselves think they are. It is my firm belief that the debate on achieving the right balance between food production and the environment will be heightened as food supplies get tighter resulting in more votes being swayed by food availability and prices.

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Seeing is believing?

Posted on 29/10/2013 by Jim Orson

It’s always been said that many farmers adopt or adapt techniques by ‘looking over the hedge’ at their neighbours. Nowadays ‘looking over the hedge’ should not be taken too literally as it is a process that includes all forms of communication. However, seeing should not always necessarily mean believing.

I don’t think we’ll ever regain the world wheat record from New Zealand now that they’ve really got their act together. In this context, this year’s UK record wheat crop was a real achievement. NIAB TAG’s monitoring of weather variables suggested that the area where the UK record crop was grown was favourably treated by nature this spring; higher than average levels of solar radiation and sufficient rainfall were recorded.   

Much is being made of the level of foliar nutrition that was received by the wheat crop that broke the UK wheat record. There’s the assumption that this significantly contributed to the high yields and it appears that the farmer, whose attention to detail is impressive, is convinced of this.

Now, I don’t want to be a killjoy but I’m not quite so convinced. Perhaps this is inevitable from a boring science-based agronomist whose views have been coloured by similar (and eventually proven to be unsubstantiated) claims throughout his career. Perhaps this time it is different but I should like it to be validated in field trials where yields with and without the foliar nutrition are compared.

What was different about the approach to the record UK wheat record crop is that the farmer applied foliar nutrition from early post-emergence onwards. I don’t think that’s been assessed experimentally in the past. Usually these products have been tested in single applications rather than in a multi-application, multi-year approach. The farmer’s high yields suggest that this approach needs to be evaluated experimentally.

There are yield benefits from splitting the total season-long dose of ‘bag’ nitrogen. In trials in years gone by, there were yield benefits from increasing the number of spring nitrogen applications. The biggest yield benefit was going from one application to two. The yield benefit got progressively less with each additional application. The current standard of three applications is a pragmatic approach bearing in mind labour and machinery costs but there would be yield benefits from having one or two additional applications. However, it must be remembered that we farm to optimise margins and not to maximise yields.Wheat

In press reports, the farmer who grew the UK record crop laments the fact that he cannot use, for environmental reasons, the very high dose of applied nitrogen that was used to grow the world record crop of 15.64 t/ha in New Zealand. He is reported to have used 220 kg N/ha. In fact he may not have had to use much or any more because Eric Watson, who also farms in South Island New Zealand, has achieved a field yield slightly higher than the world record with around 250 kg/ha of applied nitrogen. The level of soil mineral nitrogen in this case was 100 kg/ha. 

In NIAB TAG trials the optimum applied nitrogen dose is not reduced by this level of soil mineral nitrogen. To reinforce this point, Craige MacKenzie, who farms a few miles from Eric Watson has also achieved a field yield higher than the world record from a total of 262 kg/ha of applied nitrogen where the soil mineral nitrogen was 35 kg/ha. Unlike Mike Solari, the world record holder, both Eric and Craige have the benefit of variable rate irrigation.

This suggests that, while the amount of nitrogen that a crop can access may limit yield, very high wheat yields can be achieved by not exceptionally high doses of applied nitrogen. What is essential is the correct crop structure, prolonged ripening with high levels of sunlight and an ample supply of moisture. The final and critical element must be the skill of the farmer with particular emphasis on attention to detail. I remember vividly having a prolonged discussion with Mike Solari about seed rates and tiller numbers and what constitutes a ‘too thick’ crop. 

As an aside, one intriguing observation can be made when looking at the results of UK trials on trace elements and/or plant vigour sprays. Usually these trials have two control treatments. One control treatment is standard crop management and the other is the same but receiving a spray of just water applied at the same timing and volume of application as that used for the trace element and/or plant vigour sprays. It’s not unusual to see a yield benefit from all the spray treatments, with or without the trace element and/or plant vigour products. I’ve often pondered why such a small amount of applied water can make such a difference.

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Science backs straw burning

Posted on 23/10/2013 by Jim Orson

I recently received an email from a farmer who forwarded a Tweet providing a link to a report in New Zealand. The heading on the linked website was “Science Backs Use of Stubble Burning”. My immediate thought was “was it ever thus?” Crop science has always backed straw burning. I was closely involved with MAFF’s machinations on the straw burning issue in the late 1980’s. The crop science clearly backed straw burning but the practice was banned despite that knowledge.

Perhaps a couple of issues have changed since the 1980’s. Only a few years after the ban was imposed, many farmers commented that their soil had become easier to work where they incorporated the straw. I think this was the result of regular incorporation of straw increasing soil fungal biomass; to a certain extent this acts as a proxy for organic matter.

The big change since the 1980s relating to issues around straw burning is herbicide resistance in black-grass. This has increased the reliance on cultural measures. The ban on straw burning removed one cultural option. Straw and stubble burning can reduce the number of viable seed by up to 50%. That sounds impressive but this loss of viable seed would only reduce the annual chemical control required in continuous winter wheat, established by non-plough tillage to 20 cm depth, from 97% to 94%.Burning straw stubble

In addition to killing viable seed, straw burning reduces the dormancy in surviving seeds. This may provide potentially the most significant impact on black-grass control particularly where a ‘hot’ burn is not possible. However, this latter statement comes with a huge proviso. To benefit fully from reduced dormancy, drilling will have to be delayed. Going by the record of this year, you have to ask the question whether farmers are willing or able to delay drilling for a sufficient time in order to exploit fully the benefit of straw burning.

This year, even without straw burning, we have had the potential advantage of low dormancy. Despite this, many farmers drilled fields with known high levels of black-grass in mid-September. The subsequent dry conditions in many areas resulted in poor herbicide control and some of these fields have now been sprayed with glyphosate prior to re-drilling.

This suggests that there is no simple silver bullet for black-grass control. So whilst straw burning would be beneficial, particularly where drilling is delayed, the real answer is hard to swallow. Black-grass populations have to be reduced to low levels by adopting far-reaching cultural control measures, perhaps the most important of which, in this context, is spring cropping. With lower background levels of black-grass, the penalties of poor herbicide control in some seasons will be minimised. Once background levels of black-grass have been reduced to manageable numbers, there are less daunting cultural measures that may enable continuous autumn cropping, provided that it is not all early drilled. The issue of defining a more durable approach will depend on soil type, the farmer’s attitude to cultivation practice and crop choice and, as well, their attitude to risk.

Going back to the New Zealand report, I think it is important to look at it in context. It is in fact a report commissioned by Environment Canterbury and it is focussed on the farming systems of the Canterbury Plain in South Island. This area produces a lot of specialist seed crops that are sown after straw crops and are of huge value to the local economy. Herbicide options are limited in these seed crops and straw residues can affect their establishment. Hence, straw burning significantly increases the chance of optimising crop establishment and achieving the high levels of weed control necessary in order to remove weed competition and minimise harvested seed contamination. One obstacle that does not apply on the Canterbury Plain is that soil organic matter levels are high, and therefore the potential benefit to soil structure from incorporating straw is minimal.

Over the last few months I have become very familiar with the issues relating to straw burning on the Canterbury Plain. I was one of the authors of the report and had many hours of stimulating discussion with my fellow authors.  Not that I visited New Zealand to do this; I was at home and sat round the table via Skype…

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Two into one will go

Posted on 14/10/2013 by Jim Orson

LERAPs (Local Environment Risk Assessment for Pesticides) was introduced in 1999 in order to meet the standards for protection of the aquatic environment from spray drift as laid out in the then pesticides registration directive. I’ve always been a fan of this scheme because it is practical, logical and rewards farmers by enabling reductions in buffer zone width through good spray application practice and responsible pesticide use.

The new EU pesticide registration regulations were introduced in 2011. These significantly increased the standards for protection of the aquatic environment. I’m not qualified to say whether these standards are realistic or far too precautionary but they could result in more unproductive land than is necessary unless we have a similarly successful approach to that demonstrated by LERAPs.

Initially the Chemicals Regulation Directorate (CRD) introduced some Interim Arrangements to cope with the requirements of the new regulations. If it weren’t for these interim measures we would have lost some valuable products from the market. However, to keep these products on the market wider buffer zones than those under LERAPs were introduced. These buffer zones stretch up to 20m from the edge of the watercourse but unlike LERAPs, cannot be reduced with the adoption of good spray practice or lower than label recommended doses. In addition, the size of the watercourse cannot be taken into account.

This, in effect, is resulting in the adoption, for each individual product, of one of two separate sets of rules in order to reduce the impact of spray drift on the aquatic environment; LERAPs or the Interim Arrangements. CRD is carrying out a consultation on possible changes to the Interim Arrangements that may allow even more products to meet the new regulations (albeit with wide buffer zones) or may reduce the buffer zone widths. It’s envisaged that these benefits will be delivered by the adoption of spray nozzles which reduce spray drift by more than 75% when compared to a standard conventional nozzle. These are designated as 3-star nozzles in LERAPs.

These proposals can only be welcomed but they don’t resolve the issue that there will still be effectively two separate sets of rules which govern the width of a buffer zone. Tank mixing could become a nightmare. Logically, these two separate sets of rules should be combined, not only for simplicity and clarity but also for achieving support from the farming industry.

The most logical way to combine them is, in my opinion, to incorporate the Interim Arrangements into LERAPs. This would mean taking into account the adoption of lower than label recommended doses (better described as appropriate doses) and the size of water course in addition to the adoption of 3-star nozzles in a unified scheme.

There also needs to be a coming together on the width of buffer zones.Crop spraying

Currently, the maximum in LERAPs, when applied through conventional nozzles from the top of the bank of the watercourse, is 5 metres. This width can be reduced for many products when applied though 3-star nozzles. The Interim Arrangements are 10 metres, 15 metres or 20 metres from the top of the watercourse. This means that those buffer zones which have currently been set at more than 5 metres and less than 10 metres when applied through conventional nozzles cannot possibly be reduced to 5 metres when applied through 3 star nozzles. So there needs to be an additional buffer zone width of 5 metres when applied through 3-star nozzles.

This is a very important issue for many farmers who have established 5 to 6 metre permanent grass based buffer zones next to water courses. Buffer zones wider than these strips but less than 10 metres may result in weeds, diseases and insects establishing on the untreated edge of the crop, which in turn may necessitate further pesticide use.

Hence, I would argue that two into one will go not only in terms of protecting water but will also reward good spray practice as well as gain greater support from the arable industry.  

Replies to the consultation need to be submitted by 21st October and it is available here.

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