Sustainable Agriculture - Philosophy and approaches

Question 1

What is sustainable agriculture?

Answer 1

Producing abundant food without depleting the earth’s finite resources or polluting its environment whilst providing dependable incomes to growers.

A sustainable agricultural system should be able to be maintained for the foreseable future of the Anthropocene and not compromise the abilities of future generations to feed themselves.

Question 2

Can we feed the world without destroying The Earth?

Answer 2

SEARCH “Living beyond our means” “Running down the account”

Question 3

How to reduce the amount of land and resources needed to feed us

Answer 3

How do we measure sustainability?

Life cycle analysis
Carbon, water, nutrients, energy, soil footprints?
Greenhouse gas footprints?
Ecological footprints?
Earths? (unsustainable resource use by earth capacity)

Question 4

Life Cycle Analysis

Answer 4

Greenhouse gases
Carbon footprints
Non-renewables
Pollution 
Resource reuse
Energy efficiency

The environmental costs and benefits of food production are complex to quantify and for consumers to understand.

For example, most UK apples purchased in July will have been in long-term cold storage from the previous year often requiring more energy than importing from crops harvested in New Zealand

Question 5

Key Issues-
Sustainability
Feeding the World without destroying the Earth.
Not reliant on non-renewable inputs
Protecting ecosystem services- soil, water, air, climate
Protecting profits and viable farming communities

Answer 5

Motivations
Selfish-Genes- altruism driven by concern for ourselves and our children
Abrahamic Religion - love God - love your neighbour - care for creation
Neopaganist nature worship – love of ‘Mother Earth’
Anthroposophy ‘nurture the soul, the individual and human society’
Organic Movement: Fear of ‘artificial’ chemicals, and GMO
Permaculture Movement: Learn from nature and self-sufficient human societies- use science to develop true sustainability.
Transition Movement: Do it yourself- trust no-one else- adapt to
impending crises of resource depletion (e.g. oil)

Question 6

Sustainable agriculture needs to deliver food more efficiently with less inputs and less waste

Answer 6

“Addressing climate change and achieving sustainability in the global food system need to be seen as dual imperatives. Nothing less is required than a redesign of the whole food system to bring sustainability to the fore” (Foresight 2011)

Question 7

Reduce waste
Increase nutrient and water use efficiency of crops
Increase soil nutrient and water storage capacity
Recycle nutrients through the food chain

Answer 7

Use of biological nitrogen fixation
Effective pest / disease/ weed management
Knowledge, skill, understanding, experience

Question 8

Current ‘alternatives’ to conventional intensive agriculture

Answer 8

“Sustainable intensification”
Precision Agriculture
Integrated Crop Management and conservation tillage
Organic
Biodynamic
Permaculture
Agro-forestry
Kitchen gardens, allotments and urban agriculture

Question 9

Scientific American November 2011

Answer 9

SEE SLIDES

Farms in many areas could become more productive through improved crop genetics, seeds, irrigation, fertilizer and markets being improved

Question 10

Close yield gaps on underperforming lands, increasing cropping efficiency,

Answer 10

Shifting diets and reducing waste. Could double food production (Foley et al)

Question 11

1. Sustainable intensification

Improving yields using sustainable resources.

Improving soil quality- managing organic matter, nutrients, structure, biology.

Improved crop genetics.

Answer 11

Better biological control of pests and diseases.

Smart crop rotations such as legumes to build N fertility.

Rock-dust fertilizer.

Recycling organic matter to soil rather than biomass and manure burning in stoves

Solar-desalination of sea water for irrigation and solar powered pumps.

Question 12

Sustainable intensification

Using crops to feed humans not farmed animals or producing fuels from food crops.

Answer 12

12 crops provide most of human food
Royal Society 2009
Reaping the benefits

We already produce enough food to feed a double the population- the main problem is unequal access of all people to this food.
That is a economic / political / ethical / justice issue since we have the technology to get food to everyone.

Question 13

2. Precision Agriculture-
   Combining remote sensing, GPS technology with crop physiology, agronomy, IT, agricultural technology – to ensure optimal production and applications of chemicals, water and nutrients most effectively.

Answer 13

Increasing technological sophistication and dependency- underlying philosophy- total human control of production- leaving nothing to chance, but trying to optimise profit for input – not normally seeking sustainability goals. Ultimately if this approach is used to legitimize unsustainable resource depletion it remains “unsustainable intensification”.

Question 14

3. Integrated farming systems- employing scientific rigour to minimise inputs where possible, but not abandoning successful chemical and other approaches that have provided high yields,

Answer 14

whilst seeking to minimise such inputs and maximise ecological benefits e.g. from enhancing natural predators of crop pests etc.

Question 15

Herren points out that 50% of the world’s food comes from small to medium sized, traditional, low-input farms; 20% comes from back gardens and from the wild (as in fishing); so that only 30% comes from industrialized farms.

Answer 15

So industrialized farming is the minority. Yet almost all the grant and research money goes into industrialized farming (now known anomalously as “conventional” farming) and the small, traditional farms that in reality deliver the goods are neglected and indeed derided

Question 16

In more developed countries the contribution of agriculture to GDP is so low and profits so small relative to wages that the only way for farms to be economically viable is to minimize labour- and farm large areas with machinery- industrial agriculture.

Answer 16

Agricultural products are undervalued- undervaluing the work of farmers and their stewardship of the land and natural resources such as carbon storage, soil health and water resources that we also depend upon.

Question 17

4. Organic- has become synonymous with sustainability in the public perception- but is this perception true?

Organic agriculture (OA) is not consistently better performing environmentally than conventional agriculture, and newer forms of agriculture such as no-till cropping using herbicides may outperform OA with respect to soil quality and fossil fuel use because the reliance of OA on ploughing.

Answer 17

Unscientific fear of ‘chemicals’ and genetic modification

Organic agriculture has 34% lower yields than conventional agriculture, so needs more land area to produce the same amount of food.

Question 18

Questioning the assumptions regarding the productivity of organic agriculture- need to consider land area and food production over full crop rotation cycles.

Answer 18

But- what about growing legumes and non-legumes together rather than sequentially?
Living clover mulches?
Legume agro-forestry?
Intercropping?

Do we need to replace all the fertilizer N by N fixation to maintain yields given >50% fertilizer is not used by crops

Question 19

“Permaculture offers a radical approach to food production and urban renewal, water, energy and pollution. It integrates ecology, landscape, organic gardening, architecture and agro-forestry in creating a rich and sustainable way of living. It uses appropriate technology giving high yields for low energy inputs, achieving a resource of great diversity and stability. The design principles are equally applicable to both urban and rural dwellers” - Bill Mollison

Answer 19

Mollison met his later co-author David Holmgren, an environmental design student. They started to discuss why the agriculture of indigenous people had survived the centuries and why modern agriculture was only good for a relatively short time.

Question 20

Agroforestry

Answer 20

Timber
Fruits
Nuts
Legume trees- nitrogen fixation and enhanced P cycling

Question 21

8. Kitchen gardens and allotments

More than half the worlds population lives in cities
By 2030 in developing countries more than 84% of the population is likely to be urban dwellers. Own-grown is a necessity for many.

Answer 21

In developed countries many people are interested in reconnecting with nature- and concerned about issues such as peak oil, food security and food safety- and want to grow their own food.
In the UK this is often linked to ‘transition town’ communities concerned with oil depletion and aspirations to permaculture systems

Question 22

800 million people are involved in urban agriculture world-wide and contribute to feeding urban residents.

Answer 22

In the 1990’s 15-20% of world food production occured in urban and peri-urban agriculture. Urban agriculture has major benefits but some health risks.

Question 23

UK urban food production. Over 300,000 allotments (not all in cities)
These can yield over 36 tonnes of food per hectare per year
Over 90,000 people on waiting lists (2009 NSALG survey)

Answer 23

Over 1 million allotments in Germany

But there are allotment waiting lists indicating unmet demand

Question 24

We could be self-sufficient in much of our food production
Only 7% of agricultural land in the UK is used for horticulture (fruit and vegetables)

*Updated https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/341921/hort-report-07aug14.pdf

Answer 24

And we are 55% self sufficient in vegetables (2013) and 10% self-sufficient in fruit
75% of the potatoes marketed in the UK are grown here
Source: Garnett (2006) Fruit and vegetables and UK greenhouse gas emissions: exploring the relationship.

Question 25

Case study: Leicester’s allotments cover 1.5% of the city and at current levels of cultivation feeds

Answer 25

1.2 – 1.5% of the populations vegetable (and fruit) requirements – rising to 2.0% if plots fully cultivated. (Edmondson et al., in prep.)

Question 26

Low wages in other countries (even within the EU) drives down prices of food products and makes it cheaper to import produce that is labour-intensive even if the climate and soil conditions are appropriate in the UK.

Answer 26

Own-grown yields similar to commercial horticulture
Yields ranged from 0.5 – 7.3 kg m-2 with a median of 2.6 kg m-2
= 26 tonnes ha-1
(Edmondson et al., in prep.)

Question 27

Are vertical aquaponic farms the future

Answer 27

RESEARCH