This presentation formed part of the Farming Futures workshop for Lincolnshire Cereals and Oilseed Growers (22 October 2008)

1. Insert image here
Nitrogen Use and Climate
Insert image here
Change Mitigation
Daniel Kindred
Insert image here ADAS Boxworth
www.adas.co.uk

2. Outline
Background – Global drivers
Nitrogen – problems & benefits
Optimising N for GHG mitigation
Optimising N for profitability
Maximising use of non-fertiliser N
Nitrogen Efficient crops
Biofuels & Nitrogen
Conclusion - What can the grower do?

3. A Changing World?
Climate Change
Increasing Energy
demands/Reduced
energy supplies
Economic changes

4. Agriculture driving Climate Change
Agriculture contributes ~14% to global
GHG emissions
~1/3 due to methane (livestock)
~23x more potent than CO2
~1/3 due to nitrous oxide (N fertiliser)
~300x more potent than CO2
… and drives Land Use Change ~15%
global emmissions
Pressures/Opportunities to reduce GHGs
from Agriculture
Carbon trading?
Carbon labelling?
Biofuels/Energy crops
Carbon sequestration
…. Economic incentives for mitigating
GHGs?
Total emissions 49000Mt CO2e IPCC 2007

5. GHGs from crops overwhelmed by N
fertiliser
Pesticide
P&K Diesel
Drying
10%
Seed 8% Over 70% GHG emissions
5%
from wheat crop can be due
directly or indirectly to N
fertiliser
Nitrous
oxide
? N
fertiliser
38% 38%
Sylvester-Bradley & Kindred (2008)
HGCA R&D Conference

6. Changing agriculture?
Increasing Demand for crop products
Rising population & Rising affluence,
especially in SE Asia
Increasing consumption of energy, petroleum,
edible oils & meat
Biofuels
Mainly from Maize, sugar cane &
palm oil
Constrained supply
Finite crop land globally
Yield increases have slowed or stopped
Diminished world stocks
Weather/Climate change
Floods, droughts, extreme temperatures
(Increased severity of pests, disease,
weeds)
Crop failures
Productivity shortfall

7. …Drives Land Use Change
Loss of habitats &
biodiversity
Carbon lost from soils and
canopy
• 5900 Mt CO2eq per year
• cf aviation of <3000 Mt per
year
Grassland to crop – 5t
CO2/ha
Forest to crop – 29t
CO2/ha
cf crop inputs GHG costs
~3t CO2e/ha

8. N fertiliser – the problem:
a) Manufacture
1. Fossil Fuel intensive
Haber-Bosch process
H2 from Natural Gas + N2 from
atmosphere = ammonia (NH3)
High temperatures, high pressure
3-4kg CO2/kg N
Modern plants approaching max
efficiency
2. N2O released from Nitric acid production
Ammonia oxidised to form Nitric
acid
Produce ammonium nitrate
~ 3-4kg CO2e/kg N
Can be reduced by abatement
technologies in some plants

9. GHGs of Fertiliser products
Ammonium Nitrate (AN) 30
Ammonia loss (% N applied)
7-8kg CO2e/kg N
Lower from some plants? 25
Lower for most UK AN?
20
Urea
~4kg CO2e/kg N
15
but greater volatilisation and
ammonia loss
10
Risk failing National
Emissions Ceilings Directive
(2001/91/EC) 5
Need 10-20% more fertiliser than
AN 0
Urea Urea+ UAN UAN+ AN
Use Urease inhibitors?
Agrotain Agrotain
Defra Project NT26 (Dampney et al 2006)

10. N fertiliser – the problem:
b) Soil N2O emissions
Denitrification, some nitrification
Complex microbial processes
Very variable & uncertain in the
field
Favoured by wet warm
anaerobic conditions
Needs source of C and N
~6kg N2O/ha/yr
~1800kg CO2e
Baseline emissions?
~2kg N2O/ha?
Related to crop residues?
N2O from N fertiliser additions
Artificial or organic
0.021kg N2O/kg N
~6.2kg CO2e/ kg N
www.farmingfutures.org.uk

11. N fertiliser – the problem
Leaching and
volatilisation
Eutrophication
Water quality - WFD
Nitrate Vulnerable Zones
Indirect emissions of N2O from
leached nitrate and volatilised
ammonia

12. N fertiliser – the benefits
IMPROVES YIELDS
- sometimes by more than double
- More efficient use of other high GHG inputs
- Possible sequestration benefits??
12
Grain yield (kg/ha) 10
8
6
4
2
0
0 100 200 300 400
N applied (kg/ha)
Average response curve from HGCA Project Report 438
(Sylvester-Bradley et al., 2008)

13. N fertiliser
– Reduces land requirement
yield, t/ha
land required, ha/tonne
Deforestation 0 N applied, kg/ha

14. N effects on GHG emissions
1200 12
GHG emissions (kg CO2 e/t)
1000 10
Operations Agrochemicals
800 8
Yield (t/ha)
Grain yield
600 6
400 4
200 2
0 0
0 50 100 150 200 250 300 350 400
N fertliser applied (kg/ha)
Kindred et al. (2008) In prep

15. N effects on GHG emissions
1200 12
GHG emissions (kg CO2 e/t)
1000 10
N fertiliser emissions
800 Agrochemicals 8
Yield (t/ha)
Operations
600 Grain yield 6
400 4
200 2
0 0
0 50 100 150 200 250 300 350 400
N fertliser applied (kg/ha)
Kindred et al. (2008) In prep

16. Optimising N to minimise GHGs
1200 12
GHG emissions (kg CO2 e/t)
1000 10
Soil N20 emissions
800 N fertiliser emissions 8
Agrochemicals
Yield (t/ha)
Operations
600 Grain yield 6
400 4
Optima to minimise GHGs?
200 2
0 0
0 50 100 150 200 250 300 350 400
N fertliser applied (kg/ha)
Kindred et al. (2008) In prep

17. Optimising N to minimise GHGs
1200 12
GHG emissions (kg CO2 e/t)
1000 10
Land use change
Soil N20 emissions
800 8
N fertiliser emissions
Yield (t/ha)
Agrochemicals
Operations
600 Grain yield 6
400 4
Large uncertainties in ILUC
200 calculations, depending on assumptions 2
– optima can be >300kg/ha
0 0
0 50 100 150 200 250 300 350 400
N fertliser applied (kg/ha)
Kindred et al. (2008) In prep

18. Optima N to minimise GHGs
Depends on your views of whether what
you do on your farm effects what happens
elsewhere in the world
If ignore LUC, then need to cut back N fert
dramatically to minimise GHGs
If account for LUC, may need to increase N
fert, depending on the assumptions made

19. Optimising N for profitability
Economic optima dependent on
Soil N supply
Shape of response curve
Price of grain and fertiliser
Breakeven ratio
Amount of grain needed to
pay for amount of N fertiliser
Grain quality

20. Change in prices
500
500 15
Straight Nitrogen
Straight Nitrogen
Straight Nitrogen
Feed Wheat
price index (2000=100)
price index (2000=100)
Feed Wheat
400
400 break-even ratio
400 12
price index (2000=100)
break-even price ratio
300
300 9
( N:grain )
200
200 6
100
100 3
0
0 1985 1990 1995 2000 2005 0
2010
1985 1990 1995 2000 2005 2010

21. Adjusting N for BER
12
10:1 5:1 3:1
15:1
400
14:1 10 15:1
Grain yield (kg/ha)
13:1
350
12:1 8
300 11:1
AN price £/t
10:1 6
250 9:1
8:1
Economic optima
4 close to GHG
200 7:1
6:1 optima?
150 2
5:1
4:1
100 0
3:1
50 75 100 125 150 175 200
2:1 0 100 200 300 400
Grain price £/t
N applied (kg/ha)
10kg/ha less per point increase in BER
~0.07t/ha decrease in yield

22. Soil N Supplies
Maximise use of non-fertiliser N
20% of sites in HGCA Project Report 348
did not respond to N
Soil organic matter
Previous crop residues
Peas & Beans
Animal manures/compost/sludge
Atmospheric deposition
Over-winter leaching
ADAS Terrington

23. Soil analysis: the best index of soil N
300
Look-up tables (in
N uptake with nil N applied (kg/ha)
RB209) being revised
Measuring SMN & crop N 200
Nov. to Feb.
indicates soil N supply
available to the crop
100
Rarely under-estimates
crop-available N
New HGCA Project 0
to improve soil N 0 100 200 300
measurements. SNS from soil analysis in autumn (kg/ha)

24. N efficient crops N Use Efficiency
(kg DM harvested per kg crop-available N)
0 20 40 60 80
Sugar beet
Potatoes - maincrop
Potatoes - seed
Triticale
Rye
Triticale instead of second Spring barley - feed
wheat? Winter oats
Winter wheat - feed etc.
Peas/beans instead of OSR Winter barley - feed etc.
– GHG free N? Spring wheat - milling
Potatoes - early
Possible Spring oats
Winter wheat - milling
intercropping/under- Spring barley - malting
sowing with clover etc? Winter barley - malting
Oilseed rape - winter
Oilseed rape - spring
Linseed
Peas - harvested dry
Faba beans - winter
Peas - vining
Sylvester-Bradley & Kindred 2008 J Exp Bot

25. Consider N efficient varieties?
Seems to be little difference in N requirement in
modern wheat varieties
Breadmaking wheats needs more N than Feed wheat
Question N efficiency and profitability of growing
milling wheat at high fertiliser costs (economic and
environmental)?
Modern higher yielding wheat have higher N optima
than older varieties
But, NUE at optima no different
Higher yielding varieties less GHG per t
Modern spring barley varieties higher yielding, but
optima not higher than older varieties
HGCA Project Report 438 – Sylvester-Bradley et al 2008

26. GREEN grain project
Genetic Reduction of Energy use and Emissions of Nitrogen through
cereal production
Facilitate breeding of varieties
that require less N fertiliser
and are suitable for distilling,
bioethanol and animal feed
Cheaper to grow
Greater end-use value
Reduced N pollution
GHG & Energy savings for
bioethanol

27. Breeding oilseed rape with a low requirement for
nitrogen fertiliser
Primary Objective
Northeast
Biofuels Breed varieties
which require half of
Elsoms Seeds the N fertiliser of
current varieties
www.adas.co.uk

28. Breeding for N capture: new innovations
Biological Nitrification
inhibitors
Root exudates can inhibit
soil conversion of
ammonium to nitrate
Useful with urea fertilisers
Stops leaching in wet soils
CIMMYT, Mexico
GM technology – faster
ammonium assimilation
Alanine aminotransferase
OSR: 50% N required
Now being transferred to
rice, maize & wheat
Arcadia Biosciences, CA

29. Consider growing biofuels?
Biodiesel – OSR
Bioethanol – wheat/sugar beet
Displace petrol/diesel
Reduce GHG emissions
But, over 50% of GHG intensity of
biofuel comes from growing the crop
Need to minimise GHG emissions
from growing crop
Need low inputs…
And high yield!!!
N strategy very important for growing
Biofuel crops

30. An ‘ideal’ biofuel wheat
field-dry Minimum
grain ... non-starch
Minimum
Nitrogen High
Inputs
yields
50% lots of >70% starch
GH straw
Ea Sav G
sy
ac c
ed Efficient
processing
r
Low land ed
i
requirements tatio
n

31. Nitrogen for biofuels 12 236 13
Grain N x 5.7 (% DM)
10 12
(t/ha @ 85%DM)
Grain yield
500
8 8.6% 11
6
protein 10
Alcohol yield (litres / tonne, dry basis)
480
4 9
2 8
460
0 7
5,000 0 100 200 300 470
184
yield (litres / dry tonne)
Alcohol production
Alcohol processing
440 4,000 N applied (kg/ha)
460
(litres/ha)
3,000
420 450
2,000
440
1,000
400
4 6 8 10 12 14 16 18
0 430
grain protein (%, dry basis)
8,000 0 100 200 300
Greenhouse Gases
N applied (kg/ha)
(kg CO2 eq per ha)
total saving
Reduced protein = increased biofuel 6,000
91 cost
4,000
2,000 net saving
0
0 100 200 300
N applied (kg/ha)

32. Improving N efficiency
Targets:
N capture
Rooting
Soil N ‘processing’
N assimilation
N utilisation
crop N storage
canopy N activity
oilseed photosynthesis etc.
wheat rape
Breeders and testers have used ample nutrients
Now we must minimise crop ‘profligacy’ & ‘gluttony’

33. Cultivations & straw
Minimising fuel use
No grain drying
saves ~0.2 t/ha/yr CO2e
early ripening crops
ample combine capacity
Minimum tillage
saves ? ~0.6 t/ha/yr CO2e
Can increase N2O?
Straw disposal ?
Incorporation
saves ? ~0.7 t/ha/yr CO2e
Bale, cart and use for fuel
saves ? ~2.0 t/ha/yr CO2e

34. Conclusions
– Mitigating climate change on-farm
Buy low GHG intensity fertiliser?
Urea rather than AN? Use Urease inhibitors?
Avoid applying more than the economic optimum
This may be lower than you think!
Make full use of non-fertiliser N
Use SMN testing where appropriate
Make full allowance of N in muck/sludge/compost etc
Allow for N after peas & beans/potatoes/veg etc

35. Conclusions
– Mitigating climate change on-farm
Consider changes to crops/ rotations
Grow cereals with lower N requirements – oats & triticale
Grow more legumes/less OSR
Use of fertility building leys/undersowing/inter-cropping?
Grow biofuels?
Nitrogen use will be important
Breeding likely to provide more N efficient varieties
5-10 years +

36. Thankyou

38. Developing N efficiency testing
N efficiency yield
RL trials breeding breeding
RB209 N levels
some 1st wheats
10
+ 80 kg/ha N
grain yield (t/ha)
HGCA N-opts 8
Yield breeding: control
+ 15-20 kg N / t 6
NUE breeding 4
Needs low-N testing
2
0
0 100 200 300
N applied (kg/ha)

39. Developing yields
Light limit for UK wheat, 19 t/ha
18
On-farm
No increase for >10 years
Grain yield (t/ha, 3-year means)
16 Water limit
Recommended varieties
Increasing: 0.7 tonne / ha / decade
14
Possible causes
Economics: low prices, cost cutting 12
Climate change ? new varieties
in RL trials
Technology gap ? 10
Can yields respond fast enough to
farms
cancel extra land requirements ? 8
6
4
1970 1990 2010

40. UK agriculture: Nitrogen
efficiency
N inputs .. 1.8 Mt/year
Deposition
Imports in
feeds
Denitrifica-
Food &
Fixation tion
Fertilisers materials
Sewage
Nitrate
leached
Ammonia
N outputs .. 1.8 Mt/year

41. UK agriculture: Nitrogen
legislation
Climate
Change
Nitrate & Water measures
Framework
Directives
Denitrifica-
Food &
tion
materials
EC National
EC National Nitrate
leached
Emission Ceilings
Emission Ceilings Ammonia
Directive
Directive N outputs .. 1.8 Mt/year

42. 14
UK wheat: efficiency 12
Grain yield (t/ha, 3-year means)
10
Potential UK yields
are over 14 t/ha 8
6
4
Breeders increasing
yields by 0.7 t/ha 2
per decade
0
1970 1980 1990 2000 2010
No yield increase
on-farm for >10
years

43. UK wheat: efficiency 200
100
No increase in
N applied
0
1970 1980 1990 2000 2010
3.0
2.5
No trend in 2.0
grain N%
1.5
1.0
1970 1980 1990 2000 2010

44. Nov / Jan:
N management on-
AssessMar: N
Feb / soil
farm
example: wheat
&ApplyNApril:
plan 40rates
Early kg/ha
except if: st half
Apply 1
Late April /
.. of canopy N
high soil N
early May:
Late May:
.. too many shoots
.. high lodgingN half
Apply 2nd for
Apply risk
July:
.. low take all riskN
of canopy
high yields /N to
spray urea
After harvest:
…protein boost
but adjust
boost proteins?
according to yields
Review
canopy& grain yield
…… depends on
if expected
size N%
over 9 t/ha
premiums, yields,
& … Were rates about
past proteins
right?
… Adjust N strategy?

45. Products: N efficiency
Ammonia Emissions 10 cereal trials
30
Ammonia loss (% N applied)
25
20
15
10
5
0
Urea Urea+ UAN UAN+ AN
Agrotain Agrotain

46. N efficiency : effect of high prices
? Break-even ratios
10 (kg grain per kg N) 13
7 5 3 1
8 12
Yields only
6
slightly less 11
grain yield grain protein
(t/ha) lower (N x 5.7, % )
4 proteins 10
optimums
2 9
0 8
0 100 200 300
N applied (kg/ha)

47. Setting N rates 50 recent HGCA trials
Recommended N (difference from optimum)
kg / ha
-200 -100 0 100 200
£0
Average -£50
-9 kg/ha N
-£14/ha
-£100
Net profit
£ / ha
-£150

48. Late N, to boost protein – 9 HGCA
trials
14 Foliar urea 10%
Foliar urea 20%
AN + urea 10%
grain protein (%)
AN + urea 20%
13
AN at GS39
12
11
0 40 80 120
extra late N (kg/ha)

49. Late N, to boost protein – 9 HGCA
trials
16 Boxworth 2003
Essex 2005
15 Rosemaund 2003
High Mowthorpe 2004
14
grain protein (%)
Boxworth 2004
13 Terrington 2004
High Mowthorpe 2005
12 Rosemaund 2004
Terrington 2003
11
10
New HGCA
9
research
8 to predict
0 40 80 120 protein
extra late N (kg/ha)

50. Reviewing Farm N efficiency
Applying N cannot be
accurate on every field
every year
But avoid cumulative
errors
Important for profit &
environment
To monitor overall N
strategy, check:
Soil mineral N
Canopy sizes
nil N patches ?
Grain N% … above or