Healthy soil and sustainable growing

["TradingPostPaul" <tradingpost@riseup.net>]

Finally found the fatal flaw in the IPCC recommendations.  So the Bali
conference was on the wrong track anyway. Dr. Mae-Wan Ho's report was
released Dec.12.  Many more hard hitting ISIS reports at
http://www.i-sis.org.uk/susag.php

paul, webmaster@fedworkerscomp.net
----------------------

"It is therefore rather astonishing that the Intergovernmental Panel on
Climate Change should fail to mention organic agriculture as a means of
mitigating climate change in its latest 2007 report [4]; nor does it
mention localising food systems and reducing long distance food transport
[5]."
------------------

ISIS Press Release 05/12/07
Mitigating Climate Change through Organic Agriculture
http://www.i-sis.org.uk/mitigatingClimateChange.php

There is much scope for mitigating climate change through sustainable
agriculture and localising the food supply chain. Dr. Mae-Wan Ho and Lim Li
Ching

A fully referenced version of this article is posted on ISIS members’
website. Details here

An electronic version of this report, or any other ISIS report, with full
references, can be sent to you via e-mail for a donation of £3.50. Please
e-mail the title of the report to: report@i-sis.org.uk

Modern industrial agriculture of the “Green Revolution” contributes a
great deal to climate change. It is the main source of the potent
greenhouse gases nitrous oxide and methane; it is heavily dependent on the
use of fossil fuels, and contributes to the loss of soil carbon to the
atmosphere [1] (Feeding the World under Climate Change, SiS 24), especially
through deforestation to make more land available for crops and
plantations. Deforestation is predicted to accelerate as bio-energy crops
are competing for land with food crops [2] (Biofuels: Biodevastation,
Hunger & False Carbon Credits, SiS 33). But what makes our food system
really unsustainable is the predominance of the globalised commodity trade
that has resulted in the integration of the food supply chain and its
concentration in the hands of a few transnational corporations. This
greatly increases the carbon footprint and energy intensity of our food
consumption, and at tremendous social and other environmental costs. A UK
government report on food miles estimated the direct social, environmental,
and economic costs of food transport at over £9 billion each year, which
is 34 percent of the £26.2 billion food and drinks market in the UK [3]
(Food Miles and Sustainability, SiS 28).

Consequently, there is much scope for mitigating climate change and
reversing the damages through making agriculture and the food system as a
whole sustainable, and this is corroborated by substantial scientific and
empirical evidence (see below). It is therefore rather astonishing that the
Intergovernmental Panel on Climate Change should fail to mention organic
agriculture as a means of mitigating climate change in its latest 2007
report [4]; nor does it mention localising food systems and reducing long
distance food transport [5].

Reducing direct and indirect energy use in agriculture

There is no doubt that organic, sustainable agricultural practices can
provide synergistic benefits that include mitigating climate change. As
stated in the 2002 report of the United Nations Food and Agriculture
Organisation (FAO), organic agriculture enables ecosystems to better adjust
to the effects of climate change and has major potential for reducing
agricultural greenhouse gas emissions [6].

The FAO report found that, “Organic agriculture performs better than
conventional agriculture on a per hectare scale, both with respect to
direct energy consumption (fuel and oil) and indirect consumption
(synthetic fertilizers and pesticides)”, with high efficiency of energy
use.

Since 1999, the Rodale Institute’s long-term trials in the United States
have reported that energy use in the conventional system was 200 percent
higher than in either of two organic systems - one with animal manure and
green manure, the other with green manure only - with very little
differences in yields [7]. Research in Finland showed that while organic
farming used more machine hours than conventional farming, total energy
consumption was still lowest in organic systems [8]; that was because in
conventional systems, more than half of total energy consumed in rye
production was spent on the manufacture of pesticides.

Organic agriculture was more energy efficient than conventional agriculture
in apple production systems [9, 10]. Studies in Denmark compared organic
and conventional farming for milk and barley grain production [11]. The
energy used per kilogram of milk produced was lower in the organic than in
the conventional dairy farm, and it also took 35 percent less energy to
grow a hectare of organic spring barley than conventional spring barley.
However, organic yield was lower, so energy used per kg barley was only
marginally less for the organic than for the conventional.

The total energy used in agriculture accounts for about 2.7 percent of
UK’s national energy use [12], and about 1.8 percent of national
greenhouse gas emissions [13] based on figures for 2002, the latest year
for which estimates are available. Most of the energy input (76.2 percent)
is indirect, and comes from the energy spent to manufacture and transport
fertilizers, pesticides, farm machinery, animal feed and drugs. The
remaining 23.8 percent is used directly on the farm for driving tractors
and combine harvesters, crop drying, heating and lighting glasshouses,
heating and ventilating factory farms for pigs and chickens.

Nitrogen fertiliser is the single most energy intensive input, accounting
for 53.7 percent of the total energy use. It takes 35.3 MJ of energy on
average to produce each kg of N in fertilizers [14]. UK farmers use about 1
million tonnes of N fertilisers each year. Organic farming is more energy
efficient mainly because it does not use chemical fertilizers [15].

The Soil Association found that organic farming in the UK is overall about
26 percent more efficient in energy use per tonne of produce than
conventional farming, excluding tomatoes grown in heated greenhouses [15].
The savings differ for different crops and sectors, being the greatest in
the milk and beef, which use respectively 28 and 41 percent less energy
than their conventional counterparts.

Amid rapidly rising oil prices in 2006, with farmers across the country
deeply worried over the consequent increase in their production costs,
David Pimentel at Cornell University, New York, in the United States
returned to his favourite theme [16]: organic agriculture can reduce
farmers’ dependence on energy and increase the efficiency of energy use
per unit of production, basing his analysis on new data.

On farms throughout the developed world, considerable fossil energy is
invested in agricultural production. On average in the US, about 2 units of
fossil fuel energy is invested to harvest a unit of energy in crop. That
means the US uses more than twice the amount of fossil energy than the
solar energy captured by all the plants, which is ultimately why its
agriculture cannot possibly sustain anything like the biofuel production
promoted by George W. Bush [17] (Biofuels for Oil Addicts, SiS 30).

Corn is a high-yield crop and delivers more kilocalories of energy in the
harvested grain per kilocalorie of fossil energy invested than any other
major crop [16].  `

Counting all energy inputs in fossil fuel equivalents in an organic corn
system, the output over input ratio was 5.79 (i.e., you get 5.79 units of
corn energy for every unit of energy you spent), compared to 3.99 in the
conventional system. The organic system collected 180 percent more solar
energy than the conventional. There was also a total energy input reduction
of 31 percent, or 64 gallons fossil fuel saving per hectare. If 10 percent
of all US corn were grown organically, the nation would save approximately
200 million gallons of oil equivalents.

Organic soybean yielded 3.84 kilocalories of food energy per kilo of fossil
energy invested, compared to 3.19 in the conventional system and the energy
input was 17 percent lower. Organic beef grass-fed system required 50
percent less fossil fuel energy than conventional grain-fed beef.

Lower greenhouse gas emissions

Globally, agriculture is estimated to contribute directly 11 percent to
total greenhouse gas emissions (2005 figures from Intergovernmental Panel
on Climate Change) [18]. The total emissions were 6.1Gt CO2e, made up
almost entirely of CH4 (3.3 Gt ) and N2O (2.8Gt). The contributions will
differ from one country to another, especially between countries in the
industrial North compared with countries whose economies are predominantly
agricultural.

In the United States, agriculture contributes 7.4 percent of the national
greenhouse gas emissions [19]. Livestock enteric fermentation and manure
management account for 21 percent and 8 percent respectively of the
national methane emissions. Agricultural soil management, such as
fertilizer application and other cropping practices, accounts for 78
percent of the nitrous oxide emitted.

In the UK, agriculture is estimated to contribute directly 7.4 percent to
the nation’s greenhouse gas emissions, with fertilizer manufacture
contributing a further 1 percent [20], and is comprised entirely of methane
at 37.5 percent of national total [21] and nitrous oxide at around 95
percent of the national total [22]. Enteric fermentation is responsible for
86 percent of the methane contribution from agriculture, the rest from
manure; while nitrous oxide emissions are dominated by synthetic fertilizer
application (28 percent) and leaching of fertilizer nitrogen and applied
animal manures to ground and surface water (27 percent) [23].

The FAO estimated that organic agriculture is likely to emit less nitrous
oxide (N2O) [6]. This is due to lower N inputs, less N from organic manure
from lower livestock densities; higher C/N ratios of applied organic manure
giving less readily available mineral N in the soil as a source of
denitrification; and efficient uptake of mobile N in soils by using cover
crops.

Greenhouse gas emissions were calculated to be 48-66 percent lower per
hectare in organic farming systems in Europe [24], and were attributed to
no input of chemical N fertilizers, less use of high energy consuming
feedstuffs, low input of P, K mineral fertilizers, and elimination of
pesticides, as characteristic of organic agriculture.

Many experiments have found reduced leaching of nitrates from organic soils
into ground and surface waters, which are a major source of nitrous oxide
(see above). A study reported in 2006 also found reduced emissions of
nitrous oxide from soils after fertilizer application in the fall, and more
active denitrifying in organic soils, which turns nitrates into benign N2
instead of nitrous oxide and other nitrogen oxides [25] (see Cleaner
Healthier Environment for All, SiS 37).

It is also possible that moving away from a grain-fed to a predominantly
grass-fed organic diet may reduce the level of methane generated, although
this has yet to be empirically tested. Mike Abberton, a scientist at the
Institute of Grassland and Environmental Research in Aberystwyth, has
pointed to rye grass bred to have high sugar levels, white clover and
birdsfoot trefoil as alternative diets for livestock that could reduce the
quantity of methane produced  [26].

A study in New Zealand had suggested that methane output of sheep on the
changed diet could be 50 percent lower. The small UK study did not achieve
this level of reduction, but found nevertheless that  “significant
quantities” of methane could be prevented from getting into the
atmosphere. Growing clover and birdfoot trefoil could help naturally fix
nitrogen in organic soil as well as reduce livestock methane.
Greater carbon sequestration

Soils are an important sink for atmospheric CO2, but this sink has been
increasingly depleted by conventional agricultural land use, and especially
by turning tropical forests into agricultural land. The Stern Review on the
Economics of Climate Change commissioned by the UK Treasury and published
in 2007 [27] highlights the fact that 18 percent of the global greenhouse
gas emissions (2000 estimate) comes from deforestation, and that putting a
stop to deforestation is by far the most cost-effective way to mitigate
climate change, for as little as $1/ t CO2 [28] (see The Economics of
Climate Change, SiS 33). There is also much scope for converting existing
plantations to sustainable agroforestry and to encourage the best
harvesting practices and multiple uses of forest plantations [29, 30]
(Multiple Uses of Forests, Sustainable Multi-cultures for Asia & Europe,
SiS 26)

Sustainable agriculture helps to counteract climate change by restoring
soil organic matter content as well as reducing soil erosion and improving
soil physical structure. Organic soils also have better water-holding
capacity, which explains why organic production is much more resistant to
climate extremes such as droughts and floods [31] (Organic Agriculture
Enters Mainstream, Organic Yields on Par with Conventional & Ahead during
Drought Years, SiS 28), and water conservation and management through
agriculture will be an increasingly important part of mitigating climate
change.

The evidence for increased carbon sequestration in organic soils seems
clear. Organic matter is restored through the addition of manures, compost,
mulches and cover crops.

The Sustainable Agriculture Farming Systems (SAFS) Project at University of
California Davis in the United States [32] found that organic carbon
content of the soil increased in both organic and low-input systems
compared with conventional systems, with larger pools of stored nutrients.
Similarly, a study of 20 commercial farms in California found that organic
fields had 28 percent more organic carbon [33]. This was also true in the
Rodale Institute trials, where soil carbon levels had increased in the two
organic systems after 15 years, but not in the conventional system [34].
After 22 years, the organic farming systems averaged 30 percent higher in
organic matter in the soil than the conventional systems [31].

In the longest running agricultural trials on record of more than 160
years, the Broadbalk experiment at Rothamsted Experimental Station,
manure-fertilized farming systems were compared with chemical-fertilized
farming systems [35]. The manure fertilized systems of oat and forage maize
consistently out yielded all the chemically fertilized systems. Soil
organic carbon showed an impressive increase from a baseline of just over
0.1 percent N (a marker for organic carbon) at the start of the experiment
in 1843 to more than double at 0.28 percent in 2000; whereas those in the
unfertilized or chemical-fertilized plots had hardly changed in the same
period. There was also more than double the microbial biomass in the
manure-fertilized soil compared with the chemical-fertilized soils.

As Pimentel stated [16]: “..high level of soil organic matter in organic
systems is directly related to the high energy efficiencies observed in
organic farming systems; organic matter improves water infiltration and
thus reduces soil erosion from surface runoff, and it also diversifies
soil-food webs and helps cycle more nitrogen from biological sources within
the soil.”

Reducing energy and greenhouse gas emissions in sustainable food systems

Agriculture accounts only for a small fraction of the energy consumption
and greenhouse gas emissions of the entire food system.

Pimentel [16] estimated that the US food system uses about 19 percent of
the nation’s total fossil fuel energy, 7 percent for farm production, 7
percent for processing and packaging and 5 percent for distribution and
preparation. This is already an underestimate, as it does not include
energy embodied in buildings and infrastructure, energy in food wasted, nor
in treating food wastes and processing and packaging waste, which would be
necessary in a full life cycle accounting.

Similarly, when the emissions from the transport, distribution, storage,
and processing of food are added on, the UK food system is responsible for
at least 18.4 percent of the national greenhouse gas emissions [36], again,
not counting buildings and infrastructure involved in food distribution,
nor wastes and waste treatments.

Here’s an estimate of the greenhouse gas emissions from eating based on a
full life cycle accounting, from farm to plate to waste, from data supplied
by CITEPA (Centre Interprofessionnel Technique d’Eudes de la Pollution
Atmosphérique) for France [37].
Greenhouse gas emissions from eating (France)
Agriculture direct emissions    42.0 Mt C
Fertilizers (French fertilizer industry only, more than half imported.) 0.8
Mt C
Road transport goods (within France only, not counting export/import)   4.0
Mt C
Road transport people   1.0 Mt C
Truck manufacture & diesel      0.8 Mt C
Store heating (20% national total)      0.4 Mt C
Electricity (nuclear energy in France, multiply by 5 elsewhere) 0.7 Mt C
Packaging       1.5 Mt C
End of life of packaging (overall emissions of waste 4 Mt)      1.0 Mt C
Total   52.0 Mt C
National French emission        171.0 MtC
Share linked to food system     30.4%

The figure of 30.4 percent is still an underestimate, because it leaves out
emissions from the fertilizers imported, from pesticides, and transport
associated with import/export of food. Also, the emission of electricity
from established nuclear power stations in France is one-fifth of typical
non-nuclear sources. Others may argue that one needs to include
infrastructure costs, so that buildings and roads, as well as the building
of nuclear power stations need to be accounted for.

The tale of a bottle of ketchup

A hint of how food transport, processing and packaging contribute to the
energy and greenhouse gas budgets of the food system can be gleaned by the
life-cycle analysis of a typical bottle of ketchup.

The Swedish Institute for Food and Biotechnology did a life-cycle analysis
of tomato ketchup, to work out the energy efficiency and impacts, including
the environmental effects of global warming, ozone depletion,
acidification, eutrophication, photo-oxidant formation, human toxicity and
ecotoxicity [38].

The product studied is one of the most common brands of tomato ketchup sold
in Sweden, marketed in 1 kg red plastic bottles. Tomato is cultivated and
processed into tomato paste in Italy, packaged and transported to Sweden
with other ingredients to make tomato ketchup.

The aseptic bags used to package the tomato paste were produced in the
Netherlands and transported to Italy; the bagged tomato paste was placed in
steel barrels, and moved to Sweden. The five-layered red bottles were
either made in the UK or Sweden with materials from Japan, Italy, Belgium,
the USA and Denmark. The polypropylene screw cap of the bottle and plug
were produced in Denmark and transported to Sweden. Additional low-density
polyethylene shrink-film and corrugated cardboard were used to distribute
the final product. Other ingredients such as sugar, vinegar, spices and
salt were also imported. The bottled product was then shipped through the
wholesale retail chain to shops, and bought by households, where it is
stored refrigerated from one month to a year. The disposal of waste
package, and the treatment of wastewater for the production of ketchup and
sugar solution (from beet sugar) were also included in the accounting.

The accounting of the whole system was split up into six subsystems:
agriculture, processing, packaging, transport, shopping and household.

There are still many things left out, so the accounting is nowhere near
complete: the production of capital goods (machinery and building), the
production of citric acid, the wholesale dealer, transport from wholesaler
to the retailer, and the retailer. Likewise, for the plastic bottle,
ingredients such as adhesive, ethylenevinylalcohol, pigment, labels, glue
and ink were omitted.  For the household, leakage of refrigerants was left
out. In agriculture, the assimilation of carbon dioxide by the crops was
not taken into consideration, neither was leakage of nutrients and gas
emissions such as ammonia and nitrous oxide from the fields. No account was
taken of pesticides.

We estimated the energy use and carbon emissions for each of the six
subsystems from the diagrams provided in the research paper, and have taken
the energy content of tomato ketchup from another brand to present their
data in another way (Tables 1 and 2), taking the minimum values of energy
and emissions costs.
Table 1. Energy Accounting for 1 kg Tomato Ketchup
Subsystem       Energy GJ
Agriculture     1.3
Processing      7.2
Packaging       7.8 (without waste incineration)
        6.0 (with waste incineration)
Transport       1.0
Shopping        1.2
Household       1.4 (refrigeration for one month)
        14.8 (refrigeration for one year)
Total (minimum) 18.1
Energy in 1 kg tomato paste     0.00432
Energy use per GJ tomato paste  4 190

Table 2. Carbon Dioxide Accounting for 1 kg Tomato Ketchup
Subsystem       Carbon dioxide equivalent kg
Agriculture     190
Processing      500
Packaging       1 275 (without incineration)
        2 315 (with incineration)
Transport       130
Shopping        195
Household       0
Total (minimum) 2 290

As can be seen, it takes at least 4190 units of energy to deliver 1 unit of
ketchup energy to our dinner table, with at least 2 290 kg of carbon
dioxide emissions per kg ketchup.

Packaging and food processing were the hotspots for many impacts. But at
least part of the packaging is due to the necessity for long distance
transport. Within the household, the length of time stored in the
refrigerator was critical.

For eutrophication, the agricultural system is an obvious hotspot. For
nitrous oxide emissions, transportation is another hotspot. For toxicity,
the agriculture, food processing and packaging were hotspots, due to
emissions of sulphur dioxide, nitrogen oxides and carbon monoxide; also
heavy metals, phenol or crude oil. If leakage of pesticides, their
intermediates and breakdown products had been considered, then agriculture
would have been an even worse toxicological hotspot.

As regards the capital costs for tomato cultivation omitted from the study,
literature from France gave a value of 0.180GJ/kg. As regards the wholesale
and retail step left out of the study, literature data indicate
0.00143GJ/kg beer for storage at wholesale trader in Switzerland and
0.00166GJ/kg bread in the Netherlands.

There is clearly a lot of scope in reducing transport, processing and
packaging, as well as storage in our food system, all of which argue
strongly in favour of food production for local consumption in addition to
adopting organic, sustainable agricultural practices. An integrated organic
food and energy farm that turns wastes into resources can be the ideal
solution to reducing greenhouse gas emissions at source, decreasing
environmental pollution, reducing transport, and increasing energy
efficiencies to the point of not having to use fossil fuels altogether [39]
(How to Beat Climate Change & Be Food and Energy Rich - Dream Farm 2, ISIS
Report).


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