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Agriculture & Environment - Counter-Intuitive Truths

January 6, 2019 11:51 AM
By Synopsis of Phil Bennion's presentation by Steve Bolter

Green Liberal Democrats Conference, May 2018, Nottingham

Agriculture & Environment - Counter-Intuitive Truths

A presentation by Phillip Bennion


After leaving school Phillip took a degree in Agricultural Botany at Aberdeen followed by a PhD on oilseed rape, agronomy and plant breeding at Newcastle University.

He lectured in Crop Science for 2 years before taking over the family farm in Staffordshire in 1985. The farm is arable with 21 years history of environmental schemes and has a biomass district heating scheme as a diversification. He has held various NFU posts. .

Phillip was MEP for the West Midlands from 2012-14 and has been involved practically and as a committee chair in various EU and UK Government backed and research projects.

Extracts from Phil Bennion's introduction

"Born into Farming - I inherited my farm from my Father and Grandmother. My forbearers were famers as long as I can trace back….

"Politically I got quite concerned about emissions from agriculture; and from power stations when the renewable incentives came in. I contacted Fiona Hall, who was then an MEP." …...

"Low and behold Fiona Hall and the National Farmers' Union put forward the same text that I put forward. It went in almost un-amended…. The Council watered it down and brought the carbon saving act that was set.. …… I was quite proud of having orchestrated it and got it through. I was good that I got that done, even before I was a Member of the European Parliament."

There follows an approved Synopsis of the presentation,

The whole 44 minute presentation will be on the GLD website.

Agriculture & Environment - Counter-Intuitive Truths by Phillip Bennion

  1. Green-House Gas (GHG) Emissions

    • Land and Fertiliser

    • Biomass

    • Livestock and grass

  2. Habitat-Biodiversity

    • Intensive versus extensive farming

    • Focussed habitat management

  3. Agrochemicals

1) Green-House Gas (GHG) Emissions

According to Government statistics, agriculture was responsible for 10% of UK GHG emissions in 2015. However fertiliser manufacture is ascribed to industry so this starting point is an underestimation. Fertiliser manufacture is important as the best plants are over 30% more GHG efficient than some others.

Only 1% of CO2 emissions, but 53% of methane emissions and 71% nitrous oxide (N2O) emissions, come from agriculture. Nitrous oxide is a very potent greenhouse gas.

Fuel use in agriculture has fallen by 30% since 1990.

How do we mitigate the GHG emissions?

Land and fertiliser

Research shows that reducing fertiliser inputs is almost ineffective in reducing emissions due to Indirect Land Use Change (ILUC) effects.

Reduced fertiliser Þ reduced yield Þ greater land requirement Þ higher emissions per tonne of output. Wild grassland or Rain forest has to be cleared.

Optimum fertiliser levels, to minimise emissions per tonne, are only marginally below the economic optimum.

Nitrous oxide (N20 ). - recent research challenges the Intergovernmental Panel on Climate Change (IPCC) assumption that a default of 1% fertiliser Nitrogen is lost as N20 . Our research showed it as 0.46%, but that result was strongly influenced an extreme result when the research schedule required oil seed rape to be dressed with Nitrogen in an unusually wet February , when the ground so waterlogged no farmer would have applied fertiliser. The real result would be even less. We now know which conditions produce N2O spikes, and can avoid them.

The IPCC 1% figure was arrived at by calculating emissions form industry and other sources and putting the rest down to agriculture. The industry calculations could be flawed, but the main cause of the IPCC's high result was ignoring natural background emissions, from land and sea, which are independent of fertiliser use. Rain forest vegetation falling on the ground and decaying is an important example of a source of natural N2O.emission.

Not all Legumes, but the majority of the beans and peas we grow here, can fix nitrogen. Both as arable crops and in pasture, legumes can reduce N fertiliser requirement.

In pasture it can replace about 70%.

The yield of these crops is less than that obtained with artificial fertilisers.
Swards of clover and ryegrass can give 85% of the yield of fertilised rye grass.

In arable rotations, legumes can only be grown 1 in 4 years at best in this country, otherwise disease builds up.

The downside is erratic production and thus higher leaching and N2O emissions.

Tillage- No till and min till disturbs land much less, so reduces oxidation of soil organic matter and reduces fuel requirement to grow crops. This acts as a carbon sink. The downside is that it is more reliant on agrochemicals. Glyphosate is almost the only chemical approved for replacing ploughing to kill of vegetation. If that is banned, weeds will have to be killed by ploughing, exposing the built up organic material to oxidation, with the release of CO2.

The NGOs do not tell you that. Green Liberal Democrats seek a balance.

Plant breeding - breeding for yield has major component of resource efficiency. Other breeding objectives can contribute include less waste, increased versatility, disease and pest resistance. We need to be little bit more relaxed about pant breeding methods. Some popular lobbying is based on misunderstanding. Traditional breeding can produce undesirable plants. Some NGO seem to be using false news techniques.
Verified scientific fact should not be overridden by belief without evidence.

[Biomass (The time limit meant not all of this section was presented at Nottingham)

Biofuels debate has been dishonest on all sides. Firstly on the pro side the potential was exaggerated. Production of biomass and biofuel can contribute to decarbonising fuel requirements, but other technologies offer bigger gains.

Biofuels are currently the only replacement for liquid fuels

Carbon saving of are 20-60%, but there is a question on whether fuel crops are a good use of scarce land.

Scares over raising food prices largely false and "fuel versus food" is a false dichotomy. Concentration of protein in meal, base price etc. needs to be examined.

Biomass can be from energy crops, crop residue, forestry or waste. All have a place. Energy crops can produce carbon saving of 90%, hence land use question not so acute. Best used for heat and close to source of production. ]

[Livestock (The time limit meant not all of this section was presented at Nottingham)

Conversion of grass to meat necessarily produces methane, but ruminants produce more than others and cattle worse than sheep.

Some advocate extreme measures such as afforesting the grasslands and banning meat. I think we have to work around our interest in eating meat and our grasslands are an intrinsic part of our heritage. We should take a more liberal approach.

Eating less meat and more sustainable meat should be part of the solution but not through "Green Fascism".

Dietary research has shown methane emissions can be reduced through management.

All management changes that improve efficiency, reduce GHG emissions per unit of output.]

2) Habitat and Biodiversity

10 years ago, "extensive farming", with stubble left and short term set-aside , was being pushed as an environmental answer. I was always opposed. ILUC effects meant pressure put on virgin land elsewhere. It was difficult to produce quality required. It gave poor delivery of biodiversity outcomes.

It is better to farm some land for high production, but reserve a small amount for focussed habitat creation and enhancement. This gives less ILUC effects and better biodiversity outcomes.

This became the principle of Pillar 2 of the Common Agricultural Policy and is also behind some of the Gove proposals, which are not at all new, except for the funding mechanisms. (Lib Dems oppose certain aspects).

It is now well established that focussed habitat management works better, including winter bird seed, Pollen and nectar; wild flower meadow; water protection; corridors; wetland.

Gove wants to get rid of the single farm payment and load it onto environmental schemes. Doubts exist about whether the proposed biodiversity payments are complying with WTO rules, resulted in the Government making lower payments so that farmers cannot make an income on these schemes, but farmers need as living.

Thus needs to be addressed. Farmers need a living, but do not want rules that could be challenged. Say a challenge by Brazil resulted in farmers being asked to pay grants back 10 years down the line. Without the single farm payment our farmers are at a disadvantage compared with those in the USA and in the rest of Europe. What we would end up with is one farmer running 3000 + acres not able to worry about running environmental schemes.

Thus we need to encourage environmental schemes and make sure we have farmers with enough time to run them. We need to keep productive agriculture alongside it, for every bit we do not farm threatens natural habitat elsewhere.

3) Agrochemicals

These chemicals are largely misunderstood by public.

Their effects on emissions are almost universally positive. Every bit of added yield reduces the GHG emissions per tonne of output. Additionally this reduces ILUC pressures of converting more land to agriculture.

Glyphosate - much in the news - is a necessary tool in no-till agriculture. Without it every arable acre would need to be ploughed, disturbing the soil and releasing CO2.

On pollution their record is not so good. Hence the need for a strong regulatory framework.

Neonicotinoids do affect ground nesting bees in field margins; but it is not at all clear that they affect honeybees. Quoting the results of LD50 tests is simply not legitimate. The neonicotinoids are applied as seed treatment, so there is a big question on how they reach bees. Possibly dust from seed is blown into the field margins where wild bees nest. If so this is a formulation issue and should be solvable. Neonicotinoids save on several sprays and slug pellets on cereals.

Generally banning substances has two problematic effects: it requires additional applications of other chemicals; and it narrows the range of active ingredients available creating selection pressure and resistance to those that remain.

REACH has been a problem in both of these respects. All selective materials are hazardous and safe protocols have to be the route to safe use, not outright bans.


Horses for courses. I eat organic yoghurt but not organic bread. The diversity of farming styles brings innovation into mainstream.

(This Synopsis was made by attendee S Bolter, by extending Phil Bennion's speaking notes. It has been approved by Phil.)