Integrated Whole Farm System Modeling

UC Davis Sustainable Agriculture Modeling Laboratory

Integrated Whole Farm System

Modeling

Ermias Kebreab

Department of Animal Science

University of California, Davis, USA


Growing global demand

• Population growth

• Life expectancy & disposable

income rising

• 70% in urban centers by 2050

Introduction

Production need to increase by 70%

Animal protein consumption to double (465

million tons of meat, > 1B tons milk)

Living beyond our means


Agriculture has a large footprint

• Climate change (greenhouse gas emissions)

• Nutrient pollution (N & P) from animal production

Measurement of emissions expensive

Modeling offers a way of understanding and

evaluating mitigation options

Environment


Sources of pollution

Animal feed

Soil organic

matter

Animal

production

Manure

Animal

Feces

Plant

Manure storage

Soil

Urine

methane

NH3, N2O

N, C, P

N, C, P

CH4,NH3, N2O

NH3, N2O, NOx

av N, P N, P

leaching

C, N, P seq

N, C, P


Greenhouse gas emissions


Sources of emissions


Sources:

Enteric fermentation

Largest proportion of emissions from the

dairy sector

Methane is the main gas from enteric

fermentation

~1-11% of dietary gross energy (Moraes et al. 2011)

Sources and opportunities - Animal


Dietary manipulation

• Type of carbohydrate

• Lipid supplementation

Ionophores

Plant secondary compounds (e.g. tannins)

Defaunation

Biotechnologies

Opportunities - Animal

UC Davis Sustainable Agriculture Modeling Laboratory 9

Potential reductions

Cow of the Future project, 2011


Animal Models

Empirical:

• Simple relationships, e.g.

75.42 + 94.28 × DMI (Kriss, 1930)

Mechanistic:

• MOLLY (UC Davis),

• COWPOLL (Europe, Canada)

Semi-Mechanistic:

• CNCPS…


Sources:

Manure storage

Significant emissions

from manure lagoons

Sources and opportunities - Manure

Methane is the main gas

from manure storage


Conversion and use as an energy source

Heat and biofuels

gaseous (biogas)

liquid (alcohols from fermentation) and

solid fuels (densified pellets)

Biological and thermochemical conversion

Innovative and emerging products

Alternative use of manure


Anaerobic digestion


Soil and crop systems

Nitrous oxide (N2O) produced by

nitrification and denitrification processes

Emissions of ammonia

Timing of manure (solid and liquid)

application

Use of a nitrification/urease inhibitor (e.g.

Agrotain® Plus) on GHG (CH4, N2O, and

CO2) and NH3 emissions


Models

Manure level:

• Very limited models available - Manure DNDC (under development)

Soil level:

• Most models are process-based including, DNDC, DAYCENT, CENTURY, COMET-VR…


Sources and Opportunities


Whole farm integrated models are required to evaluate net emissions.

Economic and environmental sustainability of the farm can only be assessed with an integrated whole farm model.

Work funded by Canadian government underway at Davis to integrate animal models with manure and soil/crop models.

Proposal for NIFA/AFRI in preparation.

Integrated model


Thank you

Questions?

[email protected]

Integrated Whole Farm System Modeling

Documents

Transcript of Integrated Whole Farm System Modeling