Understanding and marketing digestate. Matt Taylor, ADAS David Tompkins, Aqua Enviro

Transcription

1 Understanding and marketing digestate Matt Taylor, ADAS David Tompkins, Aqua Enviro

2 Scope of this course Our focus is on: Land/soil-based markets Digestates certified to PAS110 The following are out of scope: Marketing of digestate fibre for combustion Marketing of fertiliser products extracted from digestates Marketing of other added value digestate extracts

3 Overview of digestate benefits Why digestate? Completing natural nutrient and carbon cycles

4 Overview of digestate benefits What are the main benefits? 1. Nutrients N, P, K, S, Mg Trace elements Save money Reduce carbon footprint Users are most interested in crop available nitrogen 2. Organic matter (fibre) Soil physical quality Available water capacity Workability Drainage MT

5 Overview of digestate benefits: nutrients Typical nutrient content of food-based digestate and livestock slurries (kg/m 3 ) Livestock slurry values taken from The Fertiliser Manual (RB209) Food-based digestate adapted from Taylor et al. (2010)

6 Overview of digestate benefits: nutrients Readily-available N (ammonium-n) [potentially crop-available] Foodbased digestate 80% Pig slurry 70% Cattle slurry 45% <3% 5% Green compost Green/food compost High readily available N >30% total N (NVZs) RAN Organic N

7 Application rate Norfolk experimental site Units t/ha or m 3 /ha Cattle slurry Manurebased digestate Crop (maize) baseddigestate Fibre crop (maize) baseddigestate Dry matter % ph Total N kg/ha Ammonium-N kg/ha Gleadthorpe experimental site Overview of digestate benefits: nutrients MUST be product (batch?) specific Dry matter % ph Total N kg/ha Ammonium-N kg/ha

8 Overview of digestate benefits: organic matter Organic matter additions Whole digestate (or separated liquor) applies very little organic matter Three years of additions as part of DC- Agri applied c.2 t/ha of organic matter a single compost/fym addition applied >5 t/ha (based on 250 kg N/ha application) Fibre digestate is a valuable source of stable organic matter, applying c.5 t/ha of organic matter (based on 250 kg N/ha application)

9 Overview of digestate benefits: carbon savings Potential carbon savings whole digestate Nutrient Crop available Nitrogen CO 2 e (kg CO 2 e /kg nutrient) Food-based digestate nutrient content (kg/m 3 ) CO 2 e (kg/t) saving Total phosphate- P 2 O Total potash-k 2 O CO 2 e figures from Brentrup and Paliére (2008) Based on crop available N = 60% of total N applied Total 20.0

10 Key issues in recycling digestate to land Digestate properties Liquid it flows and is heavy! Limited application windows Not odourless Need to secure local landbank Digestate is: expensive to transport awkward to store Perceptions around waste status and safety/quality

11 Non-agricultural markets for digestate Non-agricultural markets OMK004 landscape and regeneration Biomass crops on landfill (SRC, miscanthus) Energy crops on landfill (rye grass, biodiverse mixes) Soil manufacture Sports turf OMK006 horticulture Fertiliser in containerised nursery stock Growing medium (fibre digestate) for nursery stock and vegetable transplants Fertigation of table-top strawberries Hydroponic production of salad crops

12 Non-agricultural markets for digestate: Summary Digestate can work in these markets, but there are challenges Regulations Many uses not covered by AD Quality Protocol or Standard Rules Permits Chemical Electrical conductivity can be high; some crops need nitrate instead of ammonium; odour may be intolerable in some markets Physical Bulky (compared to conventional alternatives); suspended solids can clog application equipment; physical contaminants may be intolerable in some markets; heavier than growing media alternatives; water-holding in fibre digestate poorly understood

13 Non-agricultural markets for digestate: Summary Financial High value of crop vs low cost of nutrients (and hence low value of digestate) Land restoration operators expect to be paid Biological Human and plant pathogens must be demonstrably absent Inherent variability of material May need bespoke approaches for each AD site Need to stabilise fibre before use in growing media Separating out fibre still leaves majority of volume behind

14 Providing a service to farmers Farmers need: A reliable service Digestate delivered and spread when needed Confidence They can make adjustments to fertiliser application rates with confidence Use of the product will not adversely affect their business Communication Sufficient information is provided for farmers to make decisions quickly and easily Any concerns are addressed promptly Assurance There will be no issues with selling their produce Using digestate can add value to their business Quality A product which will not contaminant their land or harm their crop

15 Providing a service estimating available landbank/market size ALOWANCE landbank estimator

16 Providing a service estimating available landbank/market size Different crops have different nutrient requirements Crop nutrient requirements vary through the year Grassland may offer multiple spreading windows Oilseed rape has an autumn nitrogen demand There are various tools to help including the RB209 fertiliser planning manual ions/fertiliser-manual-rb209

17 Providing a service understanding nutrients in digestate How can we assess nutrient content? Standard values?? Effect of: Different feedstocks Post-digestion processes Where do you look? Measure it! Laboratory analysis Rapid on-the-spot analysis Quantofix Agros

18 Providing a service understanding nutrients in digestate Total, readily available or crop-available? Essential to understand difference, as this impacts on crop nutrient planning and the price you can charge for digestate Total Readily available Crop-available

19 Providing a service understanding nutrients in digestate Total nutrients (kg/m 3 ) Livestock slurry values taken from The Fertiliser Manual (RB209) Food-based digestate adapted from Taylor et al. (2010)

20 Providing a service understanding nutrients in digestate Readily-available N (ammonium-n) [potentially crop-available] Foodbased digestate 80% Pig slurry 70% Cattle slurry 45% Green compost <3% 5% Green/food compost High readily available N >30% total N (NVZs) RAN Organic N

21 Providing a service understanding nutrients in digestate Overall cross-site N-use efficiency

22 There are tools to help Providing a service understanding nutrients in digestate

23 Providing a service understanding Codes of Practice and Regulations End of waste for digestate in E, W & NI End of waste for defined sourcesegregated biodegradable wastes Two parts: Anaerobic Digestate Quality Protocol Approved specification (PAS110) If an operator complies with both and is independently certified to both, then the biofertiliser is no longer a waste and can be used as a product

24 Providing a service understanding Codes of Practice and Regulations End of waste for digestate in E, W & NI Agriculture and forestry and soil/fieldgrown horticulture Quality separated fibre only may be used for land restoration Use of digestate as a growing medium and for amateur or hobby gardening and similar uses is specifically prohibited

25 Providing a service understanding Codes of Practice and Regulations End of waste for digestate in Scotland

26 Providing a service understanding Codes of Practice and Regulations Cost waste route vs product route

27 Providing a service understanding Codes of Practice and Regulations Using digestate: ABPR Legal ban on grazing (or harvesting herbage for feed) land treated with ABPderived digestates You must alert users to this when supplying digestate (keep a paper trail) In England the grazing ban is 8 weeks for pigs and 3 weeks for all other farmed animals Check with APHA whether need to register to haul digestate User of digestate needs to keep records of their use to demonstrate grazing/harvest ban compliance

28 Providing a service understanding Codes of Practice and Regulations Supplying digestate to Organic farms What they can accept is covered by Regulation (EC) 889/2008 Annex I lists accepted inputs, including digestate Can only be derived from household food waste PTE limits are different to PAS110 Annex I was amended in 2014, but no guidance yet agreed Not of factory farming origin Farmers should consult with their Organic CB before accepting digestate It is in your interests to ensure this happens (fit-for-purpose)

29 Providing a service understanding Codes of Practice and Regulations NVZs organic manure N field limit In each field, in each 12 month period: no more than 250 kg N/ha of total N from all organic manures includes digestate, composts, biosolids, FYM etc.

30 Providing a service understanding Codes of Practice and Regulations NVZs Nmax Crop available N from all organic manures now count towards Nmax No standard figures for digestate, so have to provide evidence: MANNER-NPK

31 Providing a service understanding Codes of Practice and Regulations NVZs closed spreading periods Applies to all soil types and all organic manures with a high readily available N content defined as over 30% of the total N content e.g. slurry, poultry manure, food-based digestate (potentially even fibre digestate)

32 Providing a service understanding Codes of Practice and Regulations NVZs closed spreading periods Grassland Tillage land Sandy or shallow soils All other soils Sandy or shallow soils All other soils 1 Sept 31 Dec (4 months) 15 Oct 31 Jan (3½ months) 1 Aug 31 Dec* (5 months) 1 Oct 31 Jan (4 months) *Tillage land: On sandy or shallow soils, application is permitted between 1 Aug and 15 Sep inc., provided a crop is sown on or before 15 Sep From end closed period until end of February, no more than 30m 3 /ha of slurry or 8 t/ha of poultry manure in a single application and no repeat applications within 3 weeks

33 Providing a service understanding Codes of Practice and Regulations Codes of Good Agricultural Practice/cross compliance Some farmers may not have manure risk map

34 Nutrient and financial value of a typical food-based digestate application (30 m 3 /ha) kg/ha Food-based /ha b Crop available N a Total phosphate Total potash Total 118 Providing a service addressing myths and risks: digestate value a Assuming spring bandspread application b Assuming N = 85 p/kg, P 2 O 5 = 65 p/kg, K 2 O = 45 p/kg

35 Providing a service addressing myths and risks: digestate value Financial issues Spring bandspread application worth c. 4/m 3 Transport 3/m 3 (based on 10 miles) Application 3/m 3 (based bandspread) Therefore Need to maximise value to break-even (demonstrate value to farmer) But Autumn bandspread application worth c. 1.50/m 3

36 Providing a service addressing myths and risks: digestate quality Metal loadings to soil Zinc Copper kg/ha/yr Food-based digestate Cattle slurry Pig slurry Source: Taylor et al. (2010); Defra Metals in Soils project

37 Source: Taylor et al. (2010); Defra FIO-FARM project Providing a service addressing myths and risks: digestate quality E. coli [ABPR/PAS 110 upper limit 1000 CFU/g FW] CFU (g/fw) <10 Food-based digestate 2700 Manure-based digestate Pig slurry Cattle slurry

38 Providing a service addressing myths and risks: digestate quality Film plastic in digestate PAS110 limits may not meet the demands for all markets This can apply to a range of digestate parameters, not just plastics: Stability PTEs

39 Providing a service addressing myths and risks: digestate quality BOD (biochemical oxygen demand) [ Typical sewage works discharge consent = 20 mg/litre] BOD (mg/litre) Food-based Manure-based Pig slurry* Cattle slurry* Dirty water* digestates digestate Source: Taylor et al. (2010); Defra Water Code (1998)

40 Providing a service addressing myths and risks: digestate safety Confidence in digestate Risk-based guidance for the use of source-segregated anaerobic digestates in GB agriculture Project code OAV

41 Providing a service addressing myths and risks: digestate safety Other relevant work Check WRAP website for publication

42 Bandspreading/shallow injection reduces ammonia losses and odour nuisance

43 Providing a service different spreading techniques Precision spreading Trailing hose Surface broadcast

44 Providing a service digestate storage Digestate storage Digestate needs to be applied at the correct time (legal restrictions plus beneficial use) Therefore storage is required, but: Where? (site production, on farm) How much? (landbank dependent) How? (uncovered, aero cover, fixed)

45 Overall how to market digestate to farmers Highlight digestate benefits Address any objections Consider the local landbank Work out the logistics Use the local farming community Target appropriate farm types / farmers Build a business model and marketing plan Roll it out!