Current NZ Dairy Effluent Management Theresa Wilson Development - - PowerPoint PPT Presentation

▶
current nz dairy effluent
SMART_READER_LITE
LIVE PREVIEW

Current NZ Dairy Effluent Management Theresa Wilson Development - - PowerPoint PPT Presentation

Feb 25, 2024 769 likes •1.09k views

Current NZ Dairy Effluent Management Theresa Wilson Development Team Leader Sustainability 22 nd April 2015 ~270 staff Levy organisation and vote by farmers every 5 years (May 2014 was voting!) Receives 3.6 c per kg milk

slide-1
SLIDE 1

‘Current NZ Dairy Effluent Management’

Theresa Wilson Development Team Leader Sustainability 22nd April 2015

slide-2
SLIDE 2
  • ~270 staff
  • Levy organisation and vote by farmers every 5 years (May 2014 was

voting!)

  • Receives 3.6 c per kg milk solids from farmers (~$60M)
  • 100% farmer focused
slide-3
SLIDE 3
slide-4
SLIDE 4

Sustainable Dairying: Water Accord

  • All dairy companies and

DairyNZ

  • Has broad industry support
  • Applies to all farmers
  • Pan-industry commitments
  • National standards for our

industry

  • Time and support for

meeting commitments

slide-5
SLIDE 5

Effluent Resources

slide-6
SLIDE 6

Effluent Technical Notes

slide-7
SLIDE 7

New Zealand Dairy Industry

slide-8
SLIDE 8

25,000 35,000 45,000 55,000 65,000 75,000 1990-91 1992-93 1994-95 1996-97 1998-99 2000-01 2002-03 2004-05 2006-07 2008-09 2010-11 2012-13f

Sheep (000)

2,000 3,000 4,000 5,000 6,000

Cattle (000)

Source: Beef + Lamb New Zealand Economic Service Statistics New Zealand

Dairy +82% Beef -14% Sheep -44%

Sheep and cattle numbers

1990-91 to 2012-13

Cattle & Sheep Numbers

slide-9
SLIDE 9

Regional Milk Production, % of total 2003-04

1.25 m tons milk solids

2012-13

1.66 m tons milk solids

7 5 33 27 7 8 13 10 10 9

North Island 58 % North Island 71%

4 4 12 20 18

13

South Island 29% South Island 42 % + 32 %

Source: DairyNZ Economics Group, Dairy Statistics

slide-10
SLIDE 10

System Changes

Source: DairyNZ Economics Group

System 1 All grass self contained, all stock on the dairy platform System 3 Feed imported to extend lactation (typically autumn feed) and for dry cows System 5 Imported feed used all year round, throughout lactation and for dry cows

slide-11
SLIDE 11

Stand-off pads Free stall barns Covered housing Slatted floor

slide-12
SLIDE 12

Environmental Footprint

slide-13
SLIDE 13
slide-14
SLIDE 14
slide-15
SLIDE 15
  • Good practice plan / continual improvement
  • Sets out the farmer’s own time bound action plan to

improve performance

  • Tailored to individual farms
  • Avoids duplication & adds value to other activities
  • 5 target areas:

Sustainable Milk Plan

Nutrients Effluent Waterways Land Water use

slide-16
SLIDE 16

Where are the hot spots and risks?

slide-17
SLIDE 17

Improved Dairy Farm Effluent Systems in New Zealand

slide-18
SLIDE 18

Dairy Industry Aims

  • Keep all untreated

effluent out of surface and groundwater.

  • Keep land applied effluent

nutrients in the root zone to capture the nutrient and economic value.

  • Ensure all systems are

compliant 365 days

slide-19
SLIDE 19

Key Aspects of Land Application Systems

  • Require capital investment in variety of infrastructure
  • Requires farm labour to move/maintain irrigation system
  • Skilled design needed for cost effective solution
  • Environmental risk if not managed well
  • Land application systems can be designed for all dairy

regions (with an agreed system variation for very high rainfall areas eg West Coast)

  • Return on investment in fertiliser savings ~ 5-12 years
  • Pity to waste nutrients which grow great grass

Advice based on science knowledge and research trials

slide-20
SLIDE 20

Land Application Systems- Travelling Irrigator

slide-21
SLIDE 21

Land Application Systems- Low rate

slide-22
SLIDE 22

Land Application Systems- Pivot

(direct or underslung)

slide-23
SLIDE 23

Land Application Systems- Slurry Tanker

slide-24
SLIDE 24

Pond Treatment Systems

  • Still prevalent in Taranaki,1,700 farms with ~1,000 direct

discharge however changes coming

  • Northland with ~300 farms direct discharge and another

~600 with consent to discharge

  • Phasing out in Waikato (only being granted 2 year consents)
slide-25
SLIDE 25

How much are we actually dealing with?

From Saggar et al NZ J Agri Res 2004 Vol 47, 513-544 “A review of emissions of methane, ammonia and nitrous oxide from animal excreta deposition and farm effluent application in grazed pastures”

Animal Type Diet Methane emitted (mg CH4m-2) Dairy cow Grass-clover (grazed) 1702 Dairy cow Silage and concentrate (housed) 716 Dairy cow Fertiliser grass and concentrate 2040 Table 3. Total methane emissions from dung in the field over measurement periods of c. 10 days

Quantity cow-1 day -1 Characteristic Typical Range Annually cow-1 Total volume produced (litres) 50 30-70 13,500 Total solids (kg DM) 0.55 0.3-0.6 148.5 BODs (kg) 0.12 0.04-0.13 32.4 pH 8.5 8.0-8.5

  • Total N (g)

22 7-30 5940 Total P (g) 2.5 0.5 to 0.45 675

Table 9. Characteristics of fresh dairy-farm effluent

“Effluent from the dairy shed is highly variable in nature, being a combination of manure and urine, spilled milk, soil and feed residues, detergents and other chemicals and wash down water, varying form day to day and within individual farming practice”

slide-26
SLIDE 26

330 cow herd and wash down effluent (270 days) = 6,888 m3 per year Assume roof diverted but no storm water. All concrete catchment area (600 m2), with 1,100 mm rainfall = 660 m3 of liquid Total volume into pond = 10,239 m3 per year Evaporation at average of 2.8 m3/day = 1,022 m3 per year So 9,217 m3 to be pumped Pond is 25 m by 40 m and 3 m deep so 3,000 m3, with 1,100 mm rainfall receives 1,100m3 At 5 l/sec or 18 m3 per hour need to be pumping 512 hours per year Feedpad (1155 m2, 3.5 m2/cow), volume produced= 1,591 m3

‘Effluent Balance’

slide-27
SLIDE 27

NZ Dairy Effluent Trends

  • Stand-off, feedpads, housing on the increase
  • Increasing moving to single storage ponds

(although barn systems often need separate effluent storage/management)

  • More pond stirrers being used; helps reduce
  • dour & sludge buildup, more consistent

effluent applied on land

  • More solids separation (weeping walls,

screw press, slope screens etc) which useful for large herds and high risk soils for ease of irrigation of liquids

  • Solids usually managed by application to

cropping paddocks but can be sprayed thinly to pasture

slide-28
SLIDE 28

DairyNZ Storage Recommendations

  • Dairy effluent irrigated fresh is best
  • Use storage pond/tank when soil conditions are

unsuitable for irrigation

  • Storage volumes differs widely due to:
  • Regional variation eg 12-15 days in Canterbury to up

to 100 days in Northland

  • Within region by soil risk profile
  • Within region by irrigation method
  • Biggest source of non-compliance is ‘ponding’ due to

poor irrigation decisions, often because insufficient storage and forced to irrigate

  • This time of the year all farms should be going into winter

with empty storage ponds!!

slide-29
SLIDE 29

Energy Capture Role in NZ

  • To be built other than project being a neat idea?
  • Point person/organisation in charge?
  • Is there long term storage available?
  • Is there acreage to receive effluent nutrients?
  • Will the industry be alive in 10 years?
  • Food waste proximity to the site?
  • Is the biogas usable
  • Etc
  • DairyNZ trying to understand value proposition for energy capture
  • Many excellent reports from US, UK, Australia that outline the risks
  • One such report from Australia has a self-assessment and scoring

system that is of value

From “Assessment of methane capture and use from the intensive livestock industry”, a report by GHD Ltd for Australian Government (June 2008)

slide-30
SLIDE 30

Your questions?