design of resilient agro-ecosystems | trenton franz
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Design of resilient agro-ecosystems
Trenton FranzHydrogeophysicist and Asst. Professor
Acknowledgements:
Justin Gibson (PhD), Catie Finkenbiner (MS), William Avery (MS), Matt Russell
(Undergrad), Tiejun Wang (Research Scientist), Jacob Fritton (TNC)
September 19th, 2017
• Long-term Goal: • Build a decision support tool that serves producers in western Nebraska and can
be scalable and transferable to expand to the whole US irrigated regions
The Big Picture
• Long-term Goal: • Build a decision support tool that serves producers in western Nebraska and can
be scalable and transferable to expand to the whole US irrigated regions
• Embrace the complex social-ecological system of irrigation
agriculture in Western Nebraska• Physically based surface and groundwater models will only take us so far
• Design conservation efforts to be simple and economically sustainable for
producers
• How do we get to switch point where it is more costly to not use conservation
strategies?
The Big Picture
• Long-term Goal: • Build a decision support tool that serves producers in western Nebraska and can
be scalable and transferable to expand to the whole US irrigated regions
• Embrace the complex social-ecological system of irrigation
agriculture in Western Nebraska• Physically based surface and groundwater models will only take us so far
• Design conservation efforts to be simple and economically sustainable for
producers
• How do we get to switch point where it is more costly to not use conservation
strategies?
• Ecological theory tells us that complex patterns emerge from
simple local interactions• What are these local interactions?
• Are we able to describe their rules mathematically?
• How do we invest in technology and human capital to change these rules in
order to achieve a more desirable emergent pattern?
The Big Picture
Prof. Trenton Franz
2004-BS in Civil Engineering, University of Wyoming
2005-MS in Civil Engineering, University of Wyoming
2001-2004-Starting center for UW football team
2007-MS in Civil and Environmental Engineering, Princeton University
2011-PhD in Civil and Environmental Engineering, Princeton University
2011-2013-Postdoctoral researcher in Hydrology and Water Resources,
University of Arizona
Sept. 2013- Asst. Professor University of Nebraska-Lincoln, Faculty Fellow of
Daugherty Water for Food Global Institute
60% Research, 40% Teaching
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What do I study?
Ecology/Agronomy:
Mechanisms,
Processes
Hydrology:
Conservation
Equations
Geophysics:Measurements,
Tools
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Our goal is to monitor and model the flow of water through natural and
human dominated ecosystems in order to understand how ecosystems
function and how to utilize water more efficiently for food production.
Bring together academic, industry, and stakeholders
to design a low cost, scientifically accurate, and
functional monitoring system
Hydrogeophysics Science Lab Mission
Water for Food Support/Impacts
• Hired as part of Water Cluster in 2013
• Direct support of salary and startup
• Supported 1 MS and 1 PhD through DWFI grant program
• Co-PI on 300k NSF Water literacy IUSE grant
• Co-developed SCIL 109 Water and Society course (Spring 2017)
• Organized session at 2016 Water for Food Conference
• Contribution to various grants, matching, conference presentations
and publications
DWFI Supported Students
2014-2016: William Avery, University of Nebraska-Lincoln, School of Natural Resources, MS
Primary Advisor. Awarded 1-year internship with FAO/IAEA in Vienna, Austria.
2016-2019: Justin Gibson, University of Nebraska-Lincoln, School of Natural Resources, PhD
Primary Advisor. Awarded 3-month internship with The Climate Corporation (Spring 2017).
Example of emergent properties in complex
systems
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Properties of Dryland Ecosystems
Soil
Climate Topography
Vegetation
Complex system,
stochastic and
nonlinear properties
System dynamics
governed by strength of
interactions
Strength of interactions
are dependent on
spatial and temporal
scale
Vegetation pattern is an indicator of interactions
Tiger Bush Labyrinths Spots Gaps
Borgogno et al. 2009
Emergent Property of Ecosystem
Hypothesis: Length scales of competition and facilitation for resources
(light, water, nutrients)
What is controlling pattern formation?
Borgogno et al. 2009
Key resource in drylands is plant available moisture!
What do we know about the long-term
sustainability of the HPA?
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14Butler et al. 2016
15Butler et al. 2016
• Each aquifer has an annual water use limit that
leads to ~0 water level decline
• Need long-term well monitoring program to
determine sustainable withdrawals
• Gives you an annual total volume of water target
• Furthermore, you can break volume down by
irrigated acres and irrigation depth!
Other than reducing irrigated acres how do
we get to this “sustainable” volume of water?
How do we positively change day-to-day
local interactions of irrigation depth?
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Irrigation In Central Nebraska
17K. Gibson et al. 2016, in review, Agricultural Water Management
~1400 maize fields over 9 yrs
18Gibson et al. 2016, in review, Agricultural Water Management
Irrigation In Central Nebraska
19Gibson et al. 2016, in review, Agricultural Water Management
Irrigation In Central Nebraska
• Rainfall and irrigation depths are not surprisingly
interconnected
• Only 45% of irrigation depths explained by soil and
plant biophysical needs
• Producers are consistent water users year to year
and influenced by what their neighbors are doing
What are we finding from the Western
Nebraska Irrigation Project (2014-2016)?
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1. Growing season rainfall varies considerably across WNIP study area, affecting day to day
management decisions
Need for spatially distributed network (~ 1 gage per 4 sq. miles)
From Gibson et al. 2017 HESS
2. Because of location next to front range, about 70% of rain events occur at night
Lag in rainfall to time to shutoff costs producers, money, water, energy, travel time.
At ~$10/hr energy costs and water use may be significant
Distribution of rainfall over the hour of day for 2015 growing season (April-September)
for WNIP project John Deere weather station. Yellow rectangle represent light hours and
blue rectangles represent dark periods.
3. Producers tend to hit irrigation plus precipitation target of 700 mm/yr (28 inches)
Better local realtime rainfall data + pivot telemetry can lead to actionable decisions and
reduced pumping
From Gibson et al. 2017 HESS
4. Crop model with 4 different irrigation triggers indicates pumping savings with no impacts on yield
up to 100 mm/yr of reduced pumping with <3% yield losses
From Gibson et al. 2017 HESS
5. Preliminary results of WNIP cost share indicate realized reductions in pumping
~100 mm/yr (2014-2016) vs. (2009-2013) for 1300 acres in western corner according to NRD
flow meters
Anticipate similar savings across other NRDs over several years and continued
support of extension/liason services (J. Fritton TNC)
Preliminary results from TNC WNIP, based on South Platte NRD database and Brule
AWDN gage
Where are we going with Western Nebraska
Irrigation Project (2017-2019)?
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Next generation of low cost
met. and crop water
demand sensors
Observations (5 min):
• rain gauge (disdrometer)
• leaf wetness
• shortwave and longwave up and
down
• 6-band spectrometer
• air temp
• humidity
• pressure
• GPS
• digital level and compass
• plug for peripherals, i.e. camera, soil
moisture, pressure
• Telemetry, Cell, Wifi, or Bluetooth
• Hourly updates
• Solar powered
• Cost: ~$600 hardware +
~$50/month telemetry, sotfware, API
http://arable.com/
1. A smart rainfall network
Network of Arable Stations
Data view as of July 2, 2017
30 km
Network of Stations
2017 Rainfall Data Totals
Support of Precision Agriculture
How can we best use CRNP to support precision
agriculture?
Can the technology provide cost effective spatial
information to make a management decision?
In review, Precision Agriculture
• Paulman Farms located near Sutherland, NE
• Center-pivot irrigated corn
Hydrogeophysical Mapping
SWC (cm3cm-3)
03/25/2015 05/18/2015
05/26/2015 06/08/2015
06/10/2015 06/15/2015
02/24/2016 05/09/2016
05/11/2016 06/06/2016
Soil Sampling
• Collected 31 undisturbed soil cores at 20cm depth
• Sample locations chosen based on SSURGO soil
boundaries, EOFs, and EM surveys
• Samples were placed in a cooler in the field and
then stored in a freezer at the lab
SSURGO EOF1 EOF2 ECa
Spatial Products Useful for Irrigators
a) SWC (cm3cm-3)
at FC
R2 = 0.697
RMSE: 0.043
b) SWC (cm3cm-3)
at FC
R2 = 0.321
RMSE: 0.014
WP
c) AWC (cm3cm-3)
R2 = 0.677
RMSE: 0.039
Precision Agriculture Summary
1. CRNP mapping + EOF is best environmental covariate
predictor of lab derived soil properties
2. Economically viable (?) for high value crops or areas with
severe water allocation
Take home messages
1. Society cares about past, present and future water fluxes (i.e. recharge,
runoff, evapotranspiration, irrigation)
2. Strong extension/liason program with introduction of irrigation technology
shows irrigation savings of ~100 mm from 2014-2016 WNIP numbers
3. Targeting producers with distribution of smart, localized, and easy to use
rainfall network (Arable Marks) to get better P+I numbers in 2017+. Hope
to reduce pumping, reduce energy use, maintain yields across study area
(affect local decisions to change emergent patterns)
4. Using mobile CRNP to get better spatial soil properties for coupling with
precision ag. technology
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