Finding the balance Comparing water, energy and emissions patterns - - PowerPoint PPT Presentation

SLIDE 1

Finding the balance

Comparing water, energy and emissions patterns for irrigation in surface and ground water dependent irrigation regions

Tamara Jackson, Shahbaz Khan, Mohsin Hafeez

Australian Irrigation Conference & Exhibition 2010

SLIDE 2

The water-energy-emissions nexus

• The links between water, energy and emissions
• Evident at many levels
• Characterised by current issues:
• Growing population, therefore a need to

increase food supply

• Competition for water
• Global warming and climate change
• Rising energy prices
• Rising energy prices
• Increasing environmental awareness
• Biofuel production

SLIDE 3

Energy use in irrigated agriculture

• Direct energy use ~ 30%
• Indirect energy use ~ 70%
• Direct energy consumption, dependent
• n

– Total dynamic head (watertable depth/lift height, pressure for system)

energy use in developed countries

system) – Water requirement of crop – System efficiency

• Indirect energy consumption,

dependent on – System type – Water source

SLIDE 4

Greenhouse gas emissions

• Major GHGs affected by

agriculture:

• CO2
• CH4
• N2O

Contribution of various stages of maize production to GHG emissions

• Nitrogen fertiliser application

and water pumping are largest source of emissions on-farm

SLIDE 5

Methodology

• Selection of irrigation regions
• Survey of case study farms
• Energy and emission budgets constructed (land

preparation – harvest)

• Regionally accepted data sets used to predict the
• Regionally accepted data sets used to predict the

consequences of converting to pressurised irrigation methods

• Model developed in Excel and linked to the @Risk

software to determine the level of uncertainty

SLIDE 6

Study areas

SLIDE 7

Limestone Coast

• Irrigated area ~79 118 ha (3.6% total

land area).

• ~ 459 007 ML pumped for irrigation

(2003-04)

• 70% of irrigation systems are

pressurised

• Dependent on groundwater for 95%

irrigation water as well as for industry, stock & domestic and town industry, stock & domestic and town water supplies.

• Currently moving from area-based

allocation system to volumetric based system.

• Groundwater depth and quality

variable.

SLIDE 8

Coleambally Irrigation Area

• Regional irrigated area ~79 000 ha

(65% total land area)

• Predominantly uses surface water
• 98% of irrigation systems surface

irrigation methods

SLIDE 9

Factors influencing the energy-water-greenhouse nexus

SLIDE 10

Steps to determine an energy or carbon budget

• 1. Determine a boundary around the process to be evaluated. Narrow

boundaries may be necessary in order to allow meaningful results to be

• btained by Step 5.
• 2. Identify and quantify all inputs crossing the boundary.
• 3. Assign energy and emission coefficients to all inputs, including both direct

and indirect inputs. and indirect inputs.

• 4. Identify and quantify all outputs.
• 5. Relate total embedded energy to outputs.
• 6. Apply the energy analysis results.

SLIDE 11

Energy and CO2-equivalent emission equivalents

Input Unit Sequestered energy (MJ) Total emissions (gCO2/MJ) Human labour hr 2.3 n/a Fuel Diesel l 38.6 75.2 Avgas l 33.1 72.4 Electricity NSW kWh 11.93 295.0 SA 272.0 Fertiliser N kg 66.14 50.0 P kg 12.44 60.0 K kg 11.15 60.0 S kg 5 60.0 Chemicals Herbicides kg 240 60.0 Insecticides kg 200 60.0 Insecticides kg 200 60.0 Fungicides kg 92 60.0 Soil improvements Lime kg 0.6 720.0 Manure tons 303.1 0.025 Seed General kg 14 Rice kg 14.7 n/a Cereals & pulses kg 25 n/a Wheat kg 15.7 n/a Maize kg 15.7 n/a Oil seed kg 36 n/a Machinery hr 64.8 n/a

SLIDE 12

Energy and water relationships in surface and ground water irrigated regions

SLIDE 13

Water application patterns – surface water region

8 10 12 14 16 18 ater applied (ML/ha) 2 4 6 Lucerne seed Wheat Rice Oats Lucerne hay Rice Rice Maize Rice Maize CIA 1 CIA 2 CIA 3 CIA 4 CIA 5 Wate

SLIDE 14

Energy consumption patterns – surface water region

10,000 15,000 20,000 25,000 gy consumption (MJ/ha) 5,000 Lucerne seed Wheat Rice Oats Lucerne hay Rice Rice Maize Rice Maize CIA 1 CIA 2 CIA 3 CIA 4 CIA 5 Energy c

SLIDE 15

Emission patterns – surface water region

0.3 0.4 0.5 0.6 0.7 0.8 0.9

valent emissions (tCO2e/ha)

0.0 0.1 0.2 0.3 Lucerne seed Wheat Rice Oats Lucerne hay Rice Rice Maize Rice Maize CIA 1 CIA 2 CIA 3 CIA 4 CIA 5

Case study farm & crop type Carbon equiva

SLIDE 16

Water application patterns – groundwater region

4 6 8 10 12 14 Water applied (ML/ha) 2 4 Flood Centre Pivot Drip Flood Centre Pivot Centre Pivot Flood Centre Pivot Lucerne seed Pasture Clover pasture Pasture Lucerne seed SESA 1 SESA 2 SESA 3 SESA 4 SESA 5 W

SLIDE 17

Energy consumption patterns – groundwater region

15,000 20,000 25,000 30,000 35,000 40,000 45,000 nergy consumption (MJ/ha) 5,000 10,000 Flood Centre Pivot Drip Flood Centre Pivot Centre Pivot Flood Centre Pivot Lucerne seed Pasture Clover pasture Pasture Lucerne seed SESA 1 SESA 2 SESA 3 SESA 4 SESA 5 Energ

SLIDE 18

Emission patterns – groundwater region

1.5 2.0 2.5 3.0 3.5 4.0 4.5

nt emissions (tCO2e/ha)

0.0 0.5 1.0 Flood Centre Pivot Drip Flood Centre Pivot Centre Pivot Centre Pivot Flood Lucerne seed Pasture Haifa Pasture Lucerne seed SESA 1 SESA 2 SESA 3 SESA 4 SESA 5

Case study farm, crop and irrigation method Carbon equivalen

SLIDE 19

Energy consumption – groundwater region

10,000 15,000 20,000 25,000 30,000 35,000 40,000 Seed Human labor Machinery Diesel - machinery Diesel - pumping Avgas Electricity - pumping Chemicals Fertiliser 5,000 Flood Centre Pivot Drip Flood Centre Pivot Centre Pivot Centre Pivot Flood Lucerne seed Pasture Haifa Pasture Lucerne seed SESA 1 SESA 2 SESA 3 SESA 4 SESA 5

Crop and irrigation method

Fertiliser Soil improvements

SLIDE 20

Energy consequences of converting to pressurised irrigation systems

Region Case study farm Crop Flood Centre Pivot Drip Irrigation (ML/ha) Energy consump tion (MJ/ha) Irrigation (ML/ha) Energy consumption (MJ/ha) Irrigation (ML/ha) Energy consumption (MJ/ha) % change from flood % change from flood % change from flood % change from flood CIA (Surface water) Farm 1 Lucerne seed 5.0 3,186 4.5

• 10

8,392 163 4.5

• 10

7,606 139 Wheat 3.0 5,157 1.1

• 63

6,430 25 1.1

• 63

6,238 21 Farm 2 Oats 2.0 8,406 1.1

• 45

9,678 15 1.1

• 45

9,486 13 Farm 2 Oats 2.0 8,406 1.1

• 45

9,678 15 1.1

• 45

9,486 13 Farm 3 Lucerne hay 11.0 9,811 9.9

• 10

21,264 117 9.9

• 10

19,534 99 Farm 4 Maize 8.3 7,975 7.5

• 10

16,651 109 7.5

• 10

15,340 92 Farm 5 Maize 8.0 14,075 7.2

• 10

22,404 59 7.2

• 10

21,146 50 SESA (Ground water) Farm 1 Lucerne seed 11.0 20,325 5.6

• 49

16,255

• 20

3.8

• 65

11,346

• 44

Farm 2 Pasture 12.0 41,759 6.1

• 49

36,779

• 12

4.2

• 65

31,476

• 25

Farm 3 Clover pasture 11.2 22,954 5.7

• 49

18,316

• 20

3.9

• 65

13,377

• 42

Farm 4 Pasture 7.8 20,647 4.0

• 49

17,392

• 16

2.7

• 65

13,926

• 33

Farm 5 Lucerne seed 12.0 28,465 6.0

• 50

22,907

• 20

4.1

• 66

17,708

• 38

SLIDE 21

Conclusions

• There are strong links between irrigation water use and energy consumption, and

water source and irrigation method impact on these relationships

• Decisions made at the paddock level have wider environmental consequences
• Pressurised irrigation methods can reduce energy consumption in regions where

groundwater is used, while the opposite can be true in surface water regions

• The identification of accepted trade-offs between resource inputs and

environmental effects

SLIDE 22

Acknowledgements

• Co-operative Research Centre for Irrigation Futures
• CSIRO Land and Water
• Farmer participants
• Farmer participants