NIAB - National Institute of Agricultural Botany

Orson's Oracle

Giant slugs and giant problems

Posted on 23/09/2014 by Jim Orson

I’m sure I heard it first on BBCR4’s Today programme but I can’t find a record of it. Then I met a person outside our house who confirmed it. In fact, he said that his dad had mistaken one for a large stick when taking his dog for a walk late one evening. What am I talking about? Garden slugs: they are ENORMOUS this year.Giant slugs

Over the last couple of weeks I have upped my anti against slugs in the garden. This has meant rather than just relying on metaldehyde pellets, I’ve roamed the lawn in the dark picking slugs and transporting them to a large open area for the birds to eat the next morning. It’s Integrated Pest Management and encouraging bird numbers all rolled into one.

I hope that my metaldehyde use is not contaminating water. The garden is not underdrained and slopes away from any hard surfaces. However, metaldehyde in water has been an issue ever since the river companies developed a method of measuring it with sufficient accuracy to say when levels in water exceed the Drinking Water Directive limit of 0.1 parts per billion (ppb).

The problem with metaldehyde is that the processes installed at waterworks to remove small Directive exceedances of nearly all pesticides don’t do much at all in reducing the levels of metaldehyde. It’s neither strongly adsorbed by the activated carbon beds nor oxidised by the ozone treatment. Hence, unlike most pesticides, the raw water going into the treatment works has to comply with the Directive.

The very active Metaldehyde Stewardship Group has for the past few years been providing guidance in its Pelletwise campaign in order to reduce metaldehyde movement to water. This autumn’s guidance document reflects the increasing pressure on the future use of this pesticide. Quite rightly the guidance has adopted a targeted and conditional approach. There is little doubt in my mind that adopting best practice, particularly in identified high risk fields, will significantly reduce pesticide movement to water.Get Pelletwise

It comes as a surprise to most people that pesticide movement to water through the soil is not influenced by the solubility of the pesticide. Glyphosate is one of the most soluble pesticides available but does not move through the soil to watercourses. Its presence in water is largely determined by spray drift and its wide usage on hard surfaces.

The ability of pesticides to move through the soil to water is mainly determined by how strongly they are adsorbed by the soil (glyphosate is strongly adsorbed by the soil) and their persistence in the soil. There is a relatively simple calculation based on these two measurements which indicates the level of risk of movement through the soil. It’s called the Groundwater Ubiquity Score (GUS). Despite being relatively simple it’s surprisingly accurate, but of course more precise models are used in pesticide registration. It was developed by Gustafson (another reason for the abbreviation GUS), a Monsanto scientist who published the approach in 1989.

The GUS score for metaldehyde suggests that (marginally) it should not move through the soil in sufficient quantities to cause a problem. There are perhaps three possible explanations as to why it is occurring in water.

Firstly, that it is moving to water through different routes. There is little doubt that run-off from fields and the washings from contaminated equipment are a source of metaldehyde in watercourses. However, I understand that movement through soil has been confirmed as a route by the Metaldehyde Stewardship Group.

Secondly, this is an exception that proves the rule for the GUS score. This is a possibility but somehow I doubt it.

Finally, there may be something about the use of metaldehyde that the GUS score does not take into account. This may be the explanation. The GUS score assumes that the pesticide is applied directly to the soil but this is not the case with metaldehyde. It’s necessarily applied in pellet form and so is not immediately adsorbed by the soil. This may influence how long it persists in the soil environment and possibly undermines the methodology used in calculating its GUS score.

I must dash as it is now dark and I must continue with my slug patrol.

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Replacing equipment

Posted on 17/09/2014 by Jim Orson

We have just bought a new toaster. The old one had a broken handle and so it had to go. I could not help but be reminded of the contrast between replacing this slightly faulty toaster with mind-sets when we were first married in the 1970s. Then we would not dream of replacing a piece of household equipment with a slight fault. Indeed I remember going down town in Chelmsford to get a replacement heating element for our ailing toaster. Then there were glorious, but shabby and shambolic, backstreet shops selling spare parts for all kinds of electrical equipment. Sure enough in a back room of one such shop was the replacement element for the toaster, stored in a dusty cardboard box. All I had to do was to take it home and using a soldering iron remove the old element and fit the replacement. I suppose it took up half of a Saturday. Then weekends often also involved servicing our car; a relatively simple and straightforward task.

The same philosophy used to apply to farm equipment. At that time large arable farms, perhaps those above 400 hectares (1,000 acres), generally had a substantial workshop and a full time mechanic. Some of these workshops were shambolic but others as immaculate as they could be in the circumstances. At that time farm machinery was far simpler, yet seemed to require constant attention and maintenance. I remember particularly that there was at least an hour spent greasing a combine every morning during harvest.New farm machinery

Nowadays, our car is so complicated that it is impossible for me to service it. Likewise, farm machinery is also much more reliable, but complicated enough that it has to be maintained by off-farm specialist mechanics.

In general arable farms are now equipped with a narrow range of relatively new machines. However, what are the short term prospects for the machinery trade with the market price of combinable crops now being below the cost of production? It seems likely to me that most specialist arable farmers could continue a year or two at least without replacing any machinery - but will they?

During the bad times at the turn of the millennium, the machinery trade was partially sustained by the necessary increase in the productivity of arable farming, including the changes in primary cultivations that were taking place. In particular, sales of large tractors and primary non-inversion cultivators seemed to be the order of the day. This may not be true this time around but the move by some farmers towards controlled traffic farming is stimulating some machinery replacements. Now, at last, not only is the width of cultivators more likely to fit in with this practice but also combines as well. The latter have in the past been commonly difficult or impossible to fit into a controlled traffic system.

I’ve been asking farmers about their views on machinery replacements in the context of the current commodity prices. A minority have said that they will continue to renew and upgrade machines regardless of the current financial situation. However, they add that if things get particularly nasty they could probably continue their businesses for five years or so without any machinery purchases.

The majority have told me that the current farmgate prices will result in some reduction of machinery purchases. A couple of farmers have said that they will stop replacing non-essential machines. I have a problem with this; should there be non-essential machines on farms or have I slightly misinterpreted the description of ‘non-essential’?

There generally appears to be the intention to keep core equipment up to date but the timings for replacements may slip a year or two. This is particularly true for new combines where I’m told that the relative prices of one and two year-old machines have declined and so the replacement costs have increased.  

One or two farmers have told me that black-grass (well I had to mention it at some stage!) may result in changes in their machinery strategy. The introduction of significant areas of spring cropping has changed the machinery and labour profiles on their farms and they are considering what this may mean for machinery complements in the future.

However, one thing is for sure. No arable farmers are contemplating employing full-time mechanics when eating their toast in the morning!

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Food sales fall for the first time

Posted on 08/09/2014 by Jim Orson

Last week the papers reported that for the first time since the monthly statistics were gathered (January 1989), the quantity of food sold in a particular month in GB fell when compared to the same month in the previous year. In July 2014 the quantity of food sold fell by 1.5% when compared to July 2013, sales were 1.3% down and food prices inflated by 0.2%. It’s interesting that food was the only section of retail to have higher prices in July 2014 compared to July 2013 (see Table).

There were more than a few column inches written about austerity and the lack of real wage increases being the cause of this first recorded fall in the volume of food bought. This may partially be the cause but there may also be other more positive explanations.

Some of the fall might be explained by a reduction in food waste and hopefully, this will have an impact on food sales in the future. Much has been made of the ‘best before’ dates increasing food waste and I am sure that they are understandably super-precautionary. My own experience suggests that yoghurts can be eaten a week after the ‘best- before’ dates with no ill effects! Another possible contribution to the fall in food volumes sold might be that we are eating less and hopefully better quality food because of the increasing concerns over obesity.

These newspaper articles encouraged me to look at the monthly reports on retail sales produced by the Office for National Statistics. Each report is huge with page after page of statistics and it is easy to be put off trying to read and understand it. However, there are very well written summaries for each retail sector and things become clearer after a while.

I picked up some interesting facts (well, they’re interesting to me!). In July 2014, for every pound spent in the whole of the retail industry (including online), £0.42 was spent in food stores, £0.41 in non-food stores, £0.06 pence in non-store retailing (e.g. mail order, catalogues and market stalls) and £0.11 in stores selling automotive fuel (i.e. petrol stations). This demonstrates that food still is the largest retail sector, but not by much. The only other of these main retail sectors to experience a fall in volumes over the year was ‘automotive fuel’ which fell by 4.7% (see Table). In fact the quantity of fuel sales seems to fall regularly, perhaps explaining the rapid loss of rural petrol stations.

Retail sales for GB, July 2014

Overall, online sales grew by over 11% over the last year. Only 3.7% of food sales were online in July 2014 compared to exactly two thirds of non-store retailing.

Food retailing seems to be in transition despite the relatively low proportion of online sales. The business sections of newspapers have all been giving the big food retailers advice on how to handle the fact that consumers are getting savvier and can now seem better able to work out if they are getting good value for their money. This means that consumers are becoming less loyal to one supermarket chain and as a consequence, they are less likely to do a ‘big shop’ at their previously favoured superstore. The supermarkets that are suffering are those that bridge the gap between the discounters (Aldi and Lidl) and the high end of the market (Waitrose and Marks & Spencer) [As an aside, I remember Alan Coren saying that Sainsbury’s existed to keep the riff-raff out of Waitrose]. A fall in the total volume of food sales is probably the last thing any food retailer needs, particularly those that are already suffering from decreased sales.

The general advice offered by the newspapers (as if they know best!) is that those supermarket companies that are stuck in the middle will have to become more price competitive and offer greater value. The papers also say that they will achieve this with lower margins and less spend on store refurbishment. Well, I hope that this is the case rather than further squeezing their suppliers. In many cases market prices for farmers are already below the cost of production and the room for a further squeeze on farm prices is just not there.

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If all else fails – do a trial

Posted on 28/08/2014 by Jim Orson

Is Woody Allen a genius who saw through the food police’s plot to stop us enjoying life? His 1973 film ‘Sleeper’ was about civilization 300 years hence and it derived great amusement from the 1970s trendy issue of not eating saturated fats. It seems he may well have been correct. An Israeli scientist has carried out a well designed and run trial which has shown that those on a diet that did not constrict the use of foods containing saturated fats lost more weight and ended up healthier than those on a Mediterranean diet or those on a low fat diet. Now the medics are lining up to explain why this result is plausible.Milk

Possibly this means that the decades I have spent consuming semi-skimmed milk and using vegetable oil-based  spreads rather than butter may have had the double whammy not only of me enjoying less the food I ate but also of it potentially doing me harm. My wife is also impressed with the evidence from the trial and there is now blue-topped milk in the fridge along with a more packs of butter. Life is already better.

Sugar is the real ‘enemy’ in diets. It is clear that in many cases the ‘low-fat’ alternatives are stuffed full with sugar in order to replace the role of fats in making a tasty and stable product.  

If these results are to be believed it shows that we have all been misled by theories based on limited or incomplete knowledge because nobody carried out trials. In all realms of life we might benefit from doing more trials. Development economists and social scientists are increasingly doing more trials which often provide answers that, at first, sound counter-intuitive. However, real progress has been made when the results of these trials are analysed and are used to form the foundation for new strategies.

Luckily, arable agriculture has a long history of field trials. Hopefully, these are well designed and executed and the results analysed and interpreted for the benefit of the industry. I suppose this usually occurs but there are exceptions, usually at the analysis and interpretation stage.

There was the classic misinterpretation of the recent HGCA-funded trials on the use of micronutrients in wheat production. I hasten to say this misinterpretation was not done by HGCA or the scientists doing the trial. I’m not sure whose fault it was but it is clear that farmers are being told that on average there was an economic response.

In fact this was disingenuous. In the fifteen trials that were carried out, each measuring the impact of three different micronutrients, there were only two responses out of 45 comparisons and these would have been expected from soil analyses. In the remaining situations there were no responses but there was inevitably the variation that occurs in biological systems. This variation meant that there were small numerical but not statistically significant decreases in yields from the use of micronutrients in some trials and these were almost exactly matched by small numerical increases in other trials.

The disingenuous interpretation was that on average the ‘responses’ would have paid for the input. I talked more fully about the results in my blog ‘Micronutrients fail the ‘common sense’ test’ published in October last year.

Then there is the situation where the results of trials are clear but they are ignored because they do not confirm current theories. This is reminiscent of attitudes in the Dark Ages. I know that  I’ve said this many times before but it is absolutely clear from all the data that have been generated over the past 20 years that the efficiency of use of soil mineral nitrogen by wheat is not the 100% that is assumed in ‘official ‘ recommendation systems. The figure is more like 50%.

The assumption of 100% efficiency means that, currently in ‘RB209 – The Fertiliser Manual’, for every increase in N index from 1 to 3 the amount of applied N recommended falls by 30 kg/ha. I have been told that one reason for not adopting a system that more closely reflects reality is that it is too complicated. Well I hate to disagree because all that is required is to reduce the recommendation by 15 kg/ha rather than 30 kg/ha. It is certainly not rocket science.

Going back to diets, I just wonder if the new information challenging the low fat culture will reflect on the popularity of a coffee option in Australia. There is the ‘why bother latte’ which consists of organic decaffeinated coffee, fully-skimmed milk and no sugar. Are its days numbered?

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Hope versus fear

Posted on 22/08/2014 by Jim Orson

I read recently, possibly in the Farmer’s Weekly, that a Scottish farmer said their Independence Referendum is a choice between hope and fear. Thinking about it, I suppose it was always going to be so. The ‘yes’ campaign is bound to be espousing their hopes for an independent Scotland and the ‘no’ campaign is bound to be expressing their fears. The art is to try to identify whether the hopes and fears expressed are realistic or unrealistic.

There are choices between hopes and fears to be made in arable agriculture, particularly at a time when market prices are less than the cost of production. As an aside, I am slightly amused that I have yet to hear from a farmer who has not sold a substantial proportion of this year’s cereal harvest a few months ago when market prices were considerably higher!

I am sorry to fall on familiar territory but many farmers’ approaches to black-grass control over the last few years have been based more on unrealistic hope than realistic fear. I gave talks a few years ago where the farmer audience seemed hostile to my concerns over future control. There is no doubt that it is easier to ‘sell’ hope rather than fear.

I remember one particular meeting where farmers appeared to be convinced that more competitive varieties were the answer to the impending crisis. I explained that if such varieties behaved consistently in reducing black-grass seed shed by 25-50% then the herbicide control required in order to stand still in black-grass plant numbers was only reduced from 97% to 95-94%. It was clear that they did not want to believe me.

However, the maths of black-grass control only shows the huge challenge for cultural control. By the way, varieties vary between years in their relative competiveness against black-grass; there is no consistency. Indeed, the lack of consistency of cultural measures is a major issue but it is clear that when you are in the mire with black-grass, increasing crop competitiveness is not sufficient alone to turn the tide. Perhaps the most consistent and effective cultural control measure is spring cropping but even then, in 2013, there was a huge black-grass emergence in some spring drilled crops.

There have been unrealistic fears expressed over the cultural control measures of ploughing and growing spring barley on heavy soils. The doubt expressed about ploughing is that it will destroy the soil structure built up over the years by non-inversion tillage to about 20cm depth. The evidence produced by NIAB TAG’s NAC STAR project, on medium clay in Suffolk, suggests that in crop yield terms this is not a concern.

The other fear is that it is impossible to establish consistently spring barley on heavy soils. As I said in my previous blog (Climate and rotation), this year was particularly challenging in this respect but the machinery now available is better able to establish great spring barley crops. I have to admit that spring cropping on heavy soils is always going to be more risky than early autumn drilling but the level of fear in some farmers’ eyes is perhaps too high.  

Many farmers have now given up realistic hope of continuing with early drilled continuous autumn cropping established after non-inversion tillage. Personally I am convinced that to get to a more stable situation there is a need on many infested farms to reduce dramatically background black-grass populations by taking radical cultural control options rather than hoping to manage moderate populations from year to year. The realistic fear, even with a huge expenditure, is that chemical and cultural control measures will not be consistent from year to year and the economic consequences of a moderate population not being controlled are very significantly higher than a low population not being controlled. In addition, herbicides give higher levels of control of black-grass heads in low populations when compared to moderate populations.

So whilst we have to give up realistic hopes, at least over the next few years, of being able to control black-grass in rotations that consist only of early autumn drilled crops, perhaps the fears associated with some cultural control measures are unrealistically pessimistic.     


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