Greenhouse gases How to reduce emissions

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1 Insert image here Greenhouse gases How to reduce emissions Ken Smith, ADAS Wolverhampton Insert image here

2 Likely future UK climate Higher temperatures C higher by 2050s C higher by 2080s More summer droughts 20-40% less rain by 2050s More winter rainfall 10-25% more by 2050s Note there is a high degree of uncertainty associated with these projections Higher CO 2 concentrations More extreme weather events Sea levels to rise by 36cm in London by 2080s?

3 Climate change - gases What causes climate change? levels of greenhouse gases (GHGs) in the atmosphere Act as blanket keeping planet warm What gases are of concern in agriculture? Nitrous oxide 298 x more potent than CO 2 Manufacture artificial N Application of organic & artificial N Livestock manures Methane 25 x more potent than CO 2 Ruminant livestock Carbon dioxide (CO 2 ) Diesel fuel use Electricity Other fossil fuels Carbon Dioxide Nitrous Oxide Methane

4 GHG emissions reduction targets Climate Change Act UK domestic ambition (from 1990) 23% reduction by % reduction by % reduction by % reduction by 2027 Ultimate goal 80% reduction by 2050 Equivalent to Mt CO 2 e Agriculture contribution 3Mt CO 2 e per year against 2008 baseline

5 Agriculture s contribution 1% carbon dioxide 37% methane 79% nitrous oxide Agriculture = 9% UK GHG emissions

6 Greenhouse Gas Action Plan Voluntary industry initiative to reduce emissions 15 on-farm actions targeting management crop nutrients & soils manure and slurry handling practices animal health, nutrition & breeding Protecting and enhancing carbon stores fuel and energy management (renewable energy)

7 Benefits from adopting best nutrient management practices Maximise or increase farm profits Improve green credentials by minimising pollution Possible earned recognition if farm shown to be low pollution risk Reduced record-keeping burden Less inspection Minimise risk of non-compliance meeting Cross compliance requirements obtaining Single Farm Payment complying with Farm Assurance Schemes for produce sales

8 Ammonia emissions from UK agriculture Fertiliser application 16% Grazing/ outdoors 13% Manure application 22% Housing 27% Manure storage 13% Hard standings 9% Inventory of Ammonia Emissions from UK Agriculture

9 GHG emissions from UK agriculture (% on CO 2 e basis) 10% Nitrous oxide Methane Carbon dioxide 38% 52% From: 2008 GHG Inventory for England, Scotland, Wales and Northern Ireland Defra (2007)

10 Checklist for good nutrient management 1. Choose appropriate cropping 2. Plan manure applications 3. Assess soil type and improve structural conditions 4. Understand and comply with relevant regulations and assurance scheme requirements 5. Adopt the Nutrient Planning cycle 6. Buy most appropriate fertiliser(s) 7. Accurately apply fertilisers and manures 8. Keep records as aid to future planning and decisions

11 Know and allow for soil nutrients ph, P, K, Mg Wide variation in soil nutrient Indices depending on soil type and field history Distribution of soil P index values High Indices possible Lots of manure applied (e.g. close to livestock buildings) Potatoes in rotation (high P) Clay soils (high K) Low Indices possible Sandy soils (low K) Cut grass (low K) History of low nutrient use Distribution of soil K index values Soil analysis every 4-5 years is essential

12 Correct nitrogen use can double crop yields 80 Biological maximum yield 10 Yield (t/ha) Rapid response The economic optimum rate of nitrogen Penalty at high rates Nitrogen leached (kg/ha) Nitrogen applied (kg/ha) 0

13 Nitrate concentrations in over-winter drainage following different previous crops ( )* *(Source: Defra NVZ AP consultation document D3, 2007)

14 N requirement for potatoes 1. Estimate N supply from soil Field Assessment Method (N index) Sampling & analysis 2. Crop variety group? 3. Anticipated season length? 4. Assess crop N requirement 5. Fine tuning? Considering. Canopy development, defoliation, skin set?; Planting conditions, adj. season length; N timing, pest/disease?

15 Nitrogen use on maincrop potatoes grown in Britain between 1990 and Source: BSFP

16 Phosphate use on maincrop potatoes in GB 1990 and With recommended P rates at index 1, 2 and 3. (Source: BSFP)

17 Percent of potato crop area by variety group & notional recommended N rates (Potato Council, 2010) Variety group % total crop area Notional N rec (<60day season)* Notional N rec (>120day season)* N/A N/A * Assuming SNS index 0 or 1 (Ave N use mc potatoes kg/ha N, BSFP, 2010)

18 Know and allow for soil nutrients Soil N Supply (SNS) Field Assessment Method (FAM) Based on soil type, rainfall and cropping history Provides a good guide but take account of farm experience Measuring SMN More worthwhile if likely SNS is higher than 120 kg N/ha (Index 4 and over) Organic manures regularly used Grass ploughed out (not year 1) After field vegetables leaving high-n residues Spring (0-90cm) or autumn (0-60cm) sampling, not within 2-3 months of a nitrogen application sub-samples, carefully mixed Sample kept cool (not frozen) and sent to lab for analysis within 3 days

19 FAM - Excess Winter Rainfall To February 2012 Long term Average (whole winter to 30 March)

20 Proportion of cropping area receiving manure applications in recent years % crop area receiving manures Winter wheat Winter barley Winter OSR Spring barley Potatoes (main) Grassland (Source: BSFP, )

21 Impact of manure use on fertiliser nitrogen input maincrop potatoes (Source: BSFP 2008) Overall N use kg/ha no manure with manure

22 Impact of manure use on fertiliser inputs maincrop potatoes (Source: BSFP 2010) N P 2 O 5 K 2 O Manure rate for 250 kg/ha N (t/ha) Est. nutrient allowance (kg/ha) Supplied by FYM (t/ha) Supplied by P litter (t/ha)

23 Fertiliser value of organic manures Manure type (dry matter) App rate (m 3 or t/ha) Crop available N (kg/ha) Total P 2 O 5 (kg/ha) Total K 2 O (kg/ha) Value ( /ha)* Pig FYM (25%) Cattle slurry (6%) Broiler litter (60%) Biosolids digested cake (25%) * Assumes spring surface application N = 92p/kg; P 2 O 5 = 95 p/kg; K 2 O = 56 p/kg

24 Make the most of organic manure nutrients Create a farm manure application plan 1. Select fields/crops that will benefit most from the nutrients and organic matter applied 2. Determine the supply of organic manure nutrients 3. Choose best application equipment 4. Choose best application timing and incorporation 5. Reduce application rates of manufactured fertiliser

25 Manure nutrient content Typical figures Fertiliser Manual PLANET Analysis Laboratory Wet chemistry NIRS On farm Slurry hydrometers N meters (Agros/Quantofix)

26 Cattle slurry, total nitrogen 8 Total N (kg/t FW) Range of N content at 6% DM kg/m Dry matter (%) Fertiliser Manual standard N 2.3 kg/m 3 at 6% DM

27 It should be remembered that The costs of manure handling and application are likely to be similar whether done badly or well Risks of over application; Nutrient losses to water Nutrient losses to air Lost Risks of under application; Reduced crop yield Lost

28 Analysis of slurry samples from a dairy farm in Oxfordshire (33 samples, ) 5 Total N (kg/t) y = 0.25x +1.3 R 2 = Dry matter (%)

29 Further reasons for manure analysis Livestock manure N efficiency values for N max compliance in NVZs Manure type Crop avail N (% N total ) pre 1 st Jan 2012 Crop avail N (% N total ) from 1 st Jan 2012 Cattle slurry 20% 35% Pig slurry 25% 45% Poultry manure/litter 20% 30% Other manures 10% 10%

30 Rapid on farm slurry testing Slurry hydrometers Nitrogen meters Quantofix Agros

31 Sampling of solid manures?

32 Chemical analysis of NIRS calibration samples homogenisation procedure

33 Quick freezing in liquid nitrogen and homogenisation

34 Manure analysis (total N) - benefit of sample homogenisation (a) before homogenisation (b) after homogenisation Analysis y = x R 2 = Analysis y = x R 2 = Analysis 1 Analysis 1 Total N (g/kg DM) (Poultry, Pig & Dairy manures)

35 Scanning of manure samples and estimation of nutrient content by NIRS

36 NIRS calibration for total N Total nitrogen ( g/kg ) Calibration fit. R RPD y = x R 2 = NIRS fit True

37 NIRS analysis AHDB information sheet NIRS analysis offered by Eurofins; Pig/cattle FYM & slurry, biosolids DM, total N, NH 4 -N, P 2 O 5, K 2 O, SO On-line ordering;

38 Sampling strategy - manure N application rate** & associated variability* (cv%) (* Simulated variability for 3 replicates - cv%) (Tidy heap) Manure N rate kg/ha cv% Manure N rate cv% (means) Sample number (** based on FYM N content and notional application rate 20t/ha)

39 Sampling strategy - manure N application rate** & associated variability* (cv%) (* Simulated variability for 3 replicates cv%) (Untidy heap) Manure N rate kg/ha Manure N rate cv% (means) 10.0 CV% Sample number (** based on FYM N content and notional application rate 20t/ha) 0.0

40 Nutrient management tools

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42 Use manures to supply up to 40-50% of nitrogen recommendation Fertiliser N supply Grain yield (t/ha) Target N Manure N supply Soil N supply Nitrogen supply (kg/ha)

43 Nitrogen fertiliser types Ammonium nitrate ( % N) Most common, straight N or NPK compound 30 Reliable and rapidly available Safety hazard Liquid urea ammonium nitrate (UAN, 37% w/v) Common in arable as easy handling and accurate Urea granules (46% N) Often cheap but high risk of ammonia loss Agrotain urease inhibitor reduces ammonia loss Ammonia loss (% N applied) Urea Urea+Ag AN Source: Chambers & Dampney (2009).

44 Fertiliser Spreaders maintenance, calibration, use Spread Pattern Before Calibration Spread Pattern After Calibration %CV Spreader Condition Increase in Nitrate Leached < Excellent Respectable Poor can be improved 4% 6% 8% >20 Serious 13%

45 Spreaders maintenance, calibration, use Area of overlap Area of overlap

46 Green manures Cover crop grown primarily to add nutrients and organic matter to soil Typically, autumn - late winter (4 months?), destroyed while still green

47 Oilseed rape + manure treatments (ADAS Boxworth, sampled 21 November 2008) Autumn, post emergence pig slurry applied 29 Sept (173kg/ha N) Crop N 75kg/ha SMN 62kg/ha Nil nitrogen Crop N 8kg/ha SMN 31kg/ha

48 Green manures: N uptake Species and over-winter weather influence N retention by green manures

49 Green cover: N uptake NO 3 loss is smallest (& N uptake greatest) when cover established early Cover crops can reduce NO 3 loss over-winter by 50 kg/ha N

50 Potato Council Green Manures Grower Field Trial (pre- potatoes, spring 2012) plot crop target sowing date seed rate kg/ha seedbed fert. kg/ha N 1 rye early Sept Natural n/a n/a - regeneration 3 mustard (std) mid Aug 20-4 bare stubble n/a n/a - 5 oil radish mid Aug caliente mustard mid Aug 8 50 (WB Daw & Son, Rugeley, Staffs)

51 Green manures grower field trial LH stubble; RH mustard (1st Feb 2012)

52 Green manures: promoting greater resource efficiency Green Manures take up c kg N/ha otherwise leached over-winter conserve water and nutrients otherwise lost from land reduce risk of erosion, loss of topsoil and water pollution can supply available N and soil aeration benefits when used prior to spring-sown crops suppress weeds; some species discourage pests &/or diseases species choice, management methods and ELS points can keep costs down and minimise limitations establish by mid-sept; destroy mid-dec to mid-feb

53 Summary Benefits of good nutrient management Business profitability Environmental impact Principals of good nutrient management Assess crop nutrient requirements Allow for soil nutrients Allow for manure nutrients Allow for P/K residues from previous years Apply fertilisers and manures evenly Comply with regulations NVZ & Cross compliance

54 Potato Council South West Potato Day, 26 April 2012 Reducing greenhouse gas emissions Thank You!