Nafferton
Ecological Farming Group
.
Resource use efficiency
and productivity in
in organic and low input farming
Organic and low input farming is
the only approach to maintain
high crop yields in the future
Total global cereal production
Tillman et al. (2002) Nature 418, 671-677
Total global use of nitrogen, phosphorus and
area of irrigated land
Tillman et al. (2002) Nature 418, 671-677
Total global pesticide production and global
pesticide imports
Tillman et al. (2002) Nature 418, 671-677
Diminishing
returns
of fertiliser
applications
2.8
Global
cereal 2.4
Yield
t ha-1 2.0
1.6
1.2
80
N-efficiency
of cereal
Production 60
(t cereal/
t fertiliser)
40
Tillman et al. (2002)
Nature 418, 671-677
20
1960
1970
1980
1990
2000
“Anyone who believes exponential
growth can go on forever in a finite
world is either a madman or an
economist”
Kenneth Boulding, economist
Yield for major food crop have not
been increasing since 2000
What will limit food production in the
future?
Cost and availability of:
Nitrogen (N) = energy
Phosphorus (P)
Potassium (K)
WATER
Pesticides
N-fertiliser - Energy use – CO2 emissions
• 1 kg Nitrogen-fertiliser = 36,000kJ = 1 L fossil fuel
• The production of 1 kg nitrogen fertiliser (NH3NO3) results in
= 2.38 kg CO2 (equivalents of CO2, CH4 and N2O)
• UK Nafferton Farm = 50 ha wheat x 200 kg N/ha/annum
= 10,000 Litre fuel used
= 23,800 kg CO2 into the atmosphere
• Global level = 120 Million t N fertiliser/annum*
= 120,000 Million Litre fuel used
= 10% of total GHG emissions from agriculture
are due to the manufacture of N-fertiliser
* FAO stats
Why will Phosphorus become a
bottleneck for productivity?
Phosphorus (P) fertiliser is a mined mineral
 Numerous scientific studies conclude that
phosphorus (phosphate rock) reserves-resources will
be depleted in the 21st century
 Pessimistic: in 30-40 years
 More optimistic: in 70-100 years
 IFDC (International Fertilizer Development Centre)
prediction: 300-400 years
 Based on current consumption
 Global P-consumption is likely to increase at least
2 fold (especially in the developing world)
Peak Phosphorus
World Phosphate Rock Reserves by Country
50,000 Jasinski (2013) US Geological Survey
Will these countries be reliable suppliers in the future

 

  
Main NEFG research challenge:
What will limit food production in the
future?
Cost and availability of:
Nitrogen (N) = energy
Phosphorus (P)
----------------------Potassium (K)
WATER
Pesticides
Law of the minimum (Justus von Liebig)
Water level
represents yield
Ca
Mg
S
P
K
Barrel
represents soil
N
Planks
represents
individual
nutrients in soil
Mineral fertiliser use and yield of
winter wheat (Germany)
Fertiliser
used
(kg ha-1)
100
80
60
40
20
0
yields
without
P-fertiliser
inputs
3
.
Start of
intensive
pesticide
use
5
4
Nafferton
Ecological Farming Group
5
4

3

2
Yield
(t ha-1)
2
N
P
K
1
1
0
1800
1840
1880
1900
1920
1936
1960
1980
0
year
Finck A. (1979) Dünger und Düngung (Fertilisers and Fertilisation). Verlag Chemie, New York
What are the solutions?
Nafferton
Ecological Farming Group
.
The main approaches available are:
1. More efficient recycling of NPK via
 animal and green manures,
 crop residues, food processing waste
 communal and domestic organic waste
 human toilet waste/sewage
2. Reduction of losses of fertiliser from soils
3. Breeding/selection of more nutrient (especially N and
P) efficient crop varieties (EU-NUE crops project)
4. Reduce meat, egg and dairy production and
consumption
For details of NEFG R&D see: www.nefg-organic.org
Organic winter wheat yields 9.9t/ha in Scottish Borders (Farmers Weekly 2015)
http://www.fwi.co.uk/arable/organic-winter-wheat-yields-99tha-in-scottish-borders.htm
The most recent meta-analyses of comparative yield
data by Ponisio et al. (2015) estimates that the use
of “diversification practices” on organic farms
reduces the yield gap (between organic and
conventional crops) to less than 10%
Ponisio LC, et al. (2014) Diversification practices reduce organic to conventional yield
gap. Proceedings of the Royal Society of London B: Biological Sciences. 282;
DOI: 10.1098/rspb.2014.1396.
Amount of cereal (corn-equivalents)
necessary to produce 1 kg of livestock
products
Thank you
We gratefully acknowledge funding from the
European Community financial participation
under the Sixth Framework Programme for
Research, Technological Development and
Demonstration Activities, for the Integrated
Project QUALITYLOWINPUTFOOD,
FP6-FOOD-CT-2003- 506358.
Influence of different crop types on organic-to conventional yield ratios.
Seufert et al. (2014) Comparing the yields of organic and conventional
agriculture. Nature 485, 229-232
temperature
population
CO2
GDP
Water use
Loss of rainforest
Species
extinction
Cars
Ozone
depletion
Peak of Oil Production
URR= Ultimate
Recoverable
Resource
(Proven + Provable)
(Sorrell et al.,2010)
Proven global reserve: 1,333Gb:
45.7 years-consumption of 2009
(BP, 2010)
Law of diminishing returns
• The “law of diminishing returns” states that in all
productive processes, adding more of one factor of
production (e.g. mineral fertilisers, pesticides),
while holding all others constant (”ceteris paribus"),
will at some point yield lower incremental per-unit
returns.
• The law of diminishing returns does not imply that adding
more of a factor will decrease the total production, a
condition known as negative returns,
– though in fact this is often the case (including for
mineral fertilisers and pesticides)
Samuelson, P.A. & Nordhaus, W.D. (2001). Microeconomics (17th ed.). McGraw-Hill. p. 110
Law of diminishing returns
units output
(e.g grain yield)
¯
1
¯
1
¯
| 1 |
4
units input
(e.g. N-fertiliser)
|
Relative Energy, fertiliser, mineral and agricultural
commodity costs (2000-2008)
(Source: Piesse and Thirtle, 2009)