Closing the Knowledge Gap: How the USDA Could Tap the Potential of Biologically Diversified Farming Systems

Abstract

Modern agriculture has proven highly productive, yet has simultaneously generated environmental and social impacts of global concern. Pressing environmental issues call into question the ability of the current model of industrial agriculture to sustain adequate yields without undermining the natural resource base upon which it depends. Meanwhile, global food needs are projected to double by 2050, raising questions over the need to further intensify agricultural production. Current research demonstrates that biologically diversified farming systems can meet global food needs sustainably and efficiently, as they outperform chemically managed monocultures across a wide range of globally important ecosystem services while producing sufficient yields and reducing resource waste throughout the food system. Research and development related to diversified systems, however, commands less than two percent of public agricultural research funding. We argue that this “knowledge gap” is at the crux of the “yield gap” that is often raised as the impediment to transitioning a greater share of global agriculture to diversified, agroecological production. If United States Department of Agriculture (USDA) research, education, and extension were to shift significantly toward agroecology and biologically diversified farming systems, the potential to address global resource challenges would be enormous. Here we present a broad framework for how the USDA could use existing infrastructure to address the challenges of food and farming in the twenty-first century and beyond.

Full text

Journal of Agriculture, Food Systems, and Community Development
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RESEARCH COMMENTARIES: FOOD SYSTEMS RESEARCH PRIORITIES OVER THE NEXT 5 YEARS
Closing the knowledge gap: How the USDA could tap the potential
of biologically diversified farming systems
Liz Carlisle a * and Albie Miles b †
University of California-Berkeley
Submitted August 4, 2013 / Revised September 13, 2013 / Published online September 24, 2013
Citation: Carlisle, L., & Miles, A. (2013). Closing the knowledge gap: How the USDA could tap the
potential of biologically diversified farming systems. Journal of Agriculture, Food Systems, and Community
Development. Advance online publication. http://dx.doi.org/10.5304/jafscd.2013.034.025
Copyright © 2013 by New Leaf Associates, Inc.
Abstract
Modern agriculture has proven highly productive,
yet has simultaneously generated environmental
and social impacts of global concern. Pressing
environmental issues call into question the ability
of the current model of industrial agriculture to
sustain adequate yields without undermining the
natural resource base upon which it depends.
Meanwhile, global food needs are projected to
double by 2050, raising questions over the need to
further intensify agricultural production. Current
research demonstrates that biologically diversified
farming systems can meet global food needs
sustainably and efficiently, as they outperform
chemically managed monocultures across a wide
range of globally important ecosystem services
while producing sufficient yields and reducing
resource waste throughout the food system.
Research and development related to diversified
systems, however, commands less than two percent
of public agricultural research funding. We argue
that this “knowledge gap” is at the crux of the
“yield gap” that is often raised as the impediment
to transitioning a greater share of global agriculture
to diversified, agroecological production. If United
States Department of Agriculture (USDA)
research, education, and extension were to shift
significantly toward agroecology and biologically
diversified farming systems, the potential to
address global resource challenges would be
a Department of Geography, University of California-
Berkeley, Berkeley, California 94720 USA.
b Department of Environmental Science, Policy, and
Management, University of California-Berkeley, Berkeley,
California 94720 USA.
* Corresponding authors: lizcarlisle@berkeley.edu,
albiemiles@berkeley.edu
† The authors wish to be regarded as joint first authors.
N
ote: This work was supported by a grant from the Center
for Diversified Farming Systems at UC Berkeley. We also
received funding from the AGree initiative to develop a
related concept paper.

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enormous. Here we present a broad framework for
how the USDA could use existing infrastructure to
address the challenges of food and farming in the
twenty-first century and beyond.
Keywords
agricultural policy, agricultural research,
agroecology, diversified farming systems, land
grant university system, sustainability, U.S.
Department of Agriculture
odern agriculture has proven highly pro-
ductive, yet has simultaneously generated
environmental and social impacts of
global concern. Pressing environmental issues call
into question the ability of the current model of
industrial agriculture to sustain adequate yields
without undermining the natural resource base
upon which it depends. Meanwhile, global food
needs are projected to double by 2050, raising
questions over the need to further intensify agri-
cultural production. Current research demonstrates
that biologically diversified farming systems can
meet global food needs sustainably and efficiently,
as they outperform chemically managed monocul-
tures across a wide range of globally important
ecosystem services while producing sufficient
yields and reducing resource waste throughout the
food system. Research and development related to
diversified systems, however, commands less than
two percent of public agricultural research funding.
We argue that this “knowledge gap” is at the crux
of the “yield gap” that is often raised as the impedi-
ment to transitioning a greater share of global
agriculture to diversified, agroecological produc-
tion. If United States Department of Agriculture
(USDA) research, education, and extension were to
shift significantly toward agroecology and biologi-
cally diversified farming systems, the potential to
address global resource challenges would be enor-
mous. Here we present a broad framework for how
the USDA could use existing infrastructure to
address the challenges of food and farming in the
twenty-first century and beyond.
The Problem with Business-as-Usual
Agriculture
While achieving impressive levels of crop produc-
tivity over the past six decades, modern agricultural
systems have accomplished this feat with signifi-
cant ecological and social costs (Hazell & Wood,
2008; Millennium Ecosystem Assessment [MEA],
2005; Committee on Twenty-First Century Systems
Agriculture, Board on Agriculture and Natural
Resources, Division on Earth and Life Studies, and
National Research Council [NRC], 2010; Presi-
dent’s Council of Advisors on Science and Tech-
nology [PCAST], 2012; Tilman, Cassman, Matson,
Naylor, & Polasky, 2002). With the industrializa-
tion of agriculture, biologically diversified farming
systems have been gradually replaced with biologi-
cally simplified monocultures that are highly
dependent on fossil energy and industrial inputs
(Dodson, Sipe, Rickson, & Sloan, 2010;
Tscharntke, Klein, Kruess, Steffan-Dewenter, &
Thies, 2005). The industrialization of agriculture
and the loss of biodiversity in and around agro-
ecosystems has significantly reduced the provision-
ing of globally important ecosystem services to and
from agriculture, including crop pollination, natural
pest control, soil and water quality maintenance,
efficient nutrient cycling, carbon sequestration, and
biodiversity conservation (Zhang, Ricketts,
Kremen, Carney, & Swinton, 2007). Further, the
suite of practices and agrochemical inputs that sub-
stitute for ecosystem services in much of modern
agriculture contribute to significant environmental,
social, and economic impacts, including soil and
water quality degradation, eutrophication of surface
and groundwater, loss of wild biodiversity,
increased greenhouse gas emissions, marine
hypoxic zones, and occupational and dietary expo-
sure to agricultural chemicals (Diaz & Rosenberg,
2008; Gomiero, Pimentel, & Paoletti, 2011; Hayes
et al., 2010; Marks et al., 2010; PCAST, 2012). In
short, the “maximal production” approach to
agricultural research and development has indeed
delivered benefits, but these are being outpaced by
its costs. To sustain yields — and the resources
they depend on — we need to shift to a “net gain”
approach. A fundamentally new model for agri-
cultural research, education, and extension is
needed to meet growing demand for food, fiber,
and fuel in a manner that is ecologically sustainable,
socially equitable, and economically viable over the
long term (Gliessman, 2004; Koohafkan, Altieri, &
M

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Holt-Giménez, 2011; NRC, 2010; Pretty et al.,
2010).
A Promising Solution: Biologically
Diversified Farming Systems
A large body of scientific research demonstrates
that biologically diversified farming systems out-
perform chemically managed monocultures across
a wide range of globally important ecological and
social services (Bacon, Getz, Kraus, Montenegro,
& Holland, 2012; Gomiero et al., 2011; Kremen &
Miles, 2012). Biologically diversified farming
systems are agricultural systems that integrate a
suite of agronomic practices and/or landscape
management strategies that incorporate functional
biodiversity at multiple spatial or temporal scales to
enhance the ecosystem services that provide key
inputs to agriculture (Kremen, Iles, & Bacon,
2012). Thus, from the diversified farming systems
perspective, economic and ecological sustainability
go hand in hand.
Compared to monocultures managed with
agrichemicals, biologically diversified farming
systems support significantly greater biodiversity,
soil quality, carbon sequestration, soil water-
holding capacity, energy use efficiency, and
resistance and resilience to climate change. When
contrasted with conventional agriculture, biologi-
cally diversified farming systems also tend to
enhance the biological control of weeds, diseases,
and arthropod pests, while increasing pollination
services from native insects. Importantly, the avail-
able evidence also indicates that the degree to
which these later ecosystem services are provided
by farming system diversification alone may be
insufficient to consistently control pests and dis-
eases or provide pollination services at the levels
required by growers. However, the above findings
illustrate the potential of biologically diversified
farming systems to reduce or ameliorate many
pressing global environmental impacts caused by
modern agriculture, while enhancing key ecosystem
services and producing similar yields (Davis, Hill,
Chase, Johanns, & Liebman, 2012; Kremen &
Miles, 2012). Given the very high rates of return on
investment for government expenditures on agri-
cultural research and extension (Alston, 2009), we
recommend significant increases in USDA
research, extension, and educational support for
agroecological research and development, so as to
realize the full ecological and economic potential of
biologically diversified farming systems.
Promising — But Woefully Underresourced
Despite the well documented performance of bio-
logically diversified farming systems, funding to
advance such farming systems remains only a small
fraction of agricultural research and development
budgets, both nationally and globally (International
Assessment of Agricultural Knowledge, Science
and Technology for Development [IAASTD],
2008; Lipson, 1998; Sooby, 2001; Vanloqueren &
Baret, 2009). Current USDA data, for example,
demonstrate that certified organic farming systems
research accounts for only 1.68% of total Research,
Extension and Education (REE) funding (Organic
Farming Research Foundation, 2012). Moreover,
while organic farming systems frequently utilize
biological diversification as a key soil fertility and
pest management strategy, both the lack of
research and extension support and the selective
pressure of organic markets have pushed much of
U.S. organic agriculture toward monoculture sys-
tems supported by a process of input substitution
(Guthman, 2004). Because monocultures of
organic crops do not necessarily meet the targets of
ecological and social sustainability, we have under-
taken an analysis of the USDA Current Research
Information Systems (CRIS) database to identify
and quantify the total REE support for agroeco-
logical research that facilitates the development of
biologically diversified farming systems that pro-
vide multiple ecosystem services and meet specific
targets of ecological and social sustainability. Our
findings indicate that, to date, such support makes
up an even smaller fraction of total REE funding
than that allocated to organic farming systems
research.
The most prominent criticism of the biologi-
cally diversified approach to agriculture is that
there is insufficient data to support its capacity to
produce equivalent yields and “feed the world”
(Phalan, Onial, Balmford, & Green, 2011). As a
recent meta-analysis (Ponisio, M’Gonigle, Mace,
Palomino, de Valpine, & Kremen, 2013) suggests,
however, such “insufficient data” is not an

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ontological problem fundamental to agroecological
production (which results in yields comparable to
conventional systems when both are subject to
equivalent “best management practices”). Rather,
“insufficient data” for the yield potential of
diversified farming systems on a global scale is an
epistemological problem, arising from the paucity
of well designed studies that could help identify
and improve the productivity of such systems.
Given the substantial evidence that such systems
can achieve significant efficiencies and even
overyield conventional monocultures in some
instances by exploiting biological complemen-
tarities (Davis et al., 2012; Kremen & Miles, 2012;
Li, Li, Sun, Zhou, Bao, Zhang, & Zhang, 2007;
Vandermeer, 2011; Zhu et al., 2000), we see this as
yet another argument for increased funding for
agroecological research and development. Con-
ducting this much-needed research will provide the
empirical basis for the design and management of
biologically diversified farming systems that spon-
sor a wide range of ecosystem services, reduce or
eliminate yield gaps where they exist, and sustain
agricultural productivity and environmental quality
over the long term (Tscharntke et al., 2012).
A Twenty-First Century Model for USDA
Research, Education, and Extension
In order to tap the full potential of biologically
diversified agriculture, we suggest that the USDA
redirect and strengthen research, extension, and
education at three major levels.
1. Beginning at the highest level, we propose
shifting the strategic vision of research,
extension, and education toward the objective
of ecological and social sustainability in
food and agriculture. We imagine a USDA in
which all programming would be directed and
evaluated according to this overarching goal.
2. Accordingly, new targets and metrics for
assessing the ecological, social, and economic
performance of farming systems would guide
the allocation of funds among program areas
and competitive grants, as well as evaluations
of program success. We encourage the USDA
to develop these targets themselves — through
an ongoing process — but key criteria should
certainly include the following characteristics
of sustainable farming systems. Such systems
(1) maintain or enhance the natural resource
base upon which they depend, (2) rely on a
minimum of off-farm and artificial inputs, (3)
manage pests and pollination services through
internal biological mechanisms, (4) are resistant
and resilient to environmental and human-
induced disturbances, (5) contribute minimally
to environmental externalities while sustaining
high levels of productivity over the long term,
and (6) promote socially equitable and
nonexploitative relations.
3. Significant progress in meeting such targets
can be achieved through a new set of strategic
research emphases. Multidisciplinary teams,
conducting long-term agroecological
studies, would provide key data for directing
food and agriculture toward greater ecological
and social sustainability. Such research would
assess whole systems, across social, eco-
nomic, and ecological dimensions. Full life-
cycle analysis would provide a comprehen-
sive “net gain” accounting of the constraints,
costs, and benefits of biologically diversified
farming systems. Research would focus on
regionally adapted varieties and farming
systems, would frequently be conducted on-
farm in partnership with producers, and would
be integrated with interdisciplinary educa-
tion and training at land-grant universities.
In our research to date, we have identified sev-
eral pilot research and development projects in
USDA’s CRIS database that could serve as models
for such an approach:
• Shennan et al.’s “Collaborative Research
and Extension Network for Sustainable
Organic Production Systems in Coastal
California”;
• Myers et al.’s “Northern Organic Vegetable
Improvement Cooperative”;
• Grossman et al.’s “Evaluating the Potential
of Winter Cover Crops for Carbon Seques-
tration in Degraded Soils Transitioning to
Organic Production”;

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• Hatfield et al.’s “Reducing Tillage Intensity
in Organic Crop Systems: Ecological and
Economic Impacts of Targeted Sheep
Grazing on Cover Crops, Weeds, and Soil”;
and
• Barbercheck et al.’s “Improving Weed and
Insect Management in Organic Reduced-
Tillage Cropping Systems.”
We are encouraged that the USDA is adopting
multidisciplinary, Long-Term Ecological Research
(LTER) methodologies and believe developing
such research sites is a pragmatic investment for
the USDA. As part of this process, we encourage
the USDA to expand upon the sound models for
medium-term studies of diversified farming sys-
tems that have already been developed within the
REE system. A recent study conducted at Iowa
State University’s Marsden Farm (Davis et al.,
2012) is one such model, as is the research con-
ducted by John Teasdale at the USDA experiment
station in Beltsville, Maryland. We would also
encourage both in-house USDA facilities and land-
grant universities to engage with long-term
research models developed outside the public agri-
cultural research system by organizations such as
the Land Institute and the Rodale Institute. Model
international case studies of socio-ecological
research include Farshad & Zinck’s (2000)
“Assessing agriculture sustainability using the six-
pillar model: Iran as a case study,” and Khan,
Midega, Pittchar, Pickett, & Bruce’s (2011) “Push-
pull technology: A conservation agriculture
approach for integrated management of insect
pests, weeds and soil health in Africa.” The
National Science Foundation’s Coupled Human-
Natural Systems program provides another prom-
ising model for such interdisciplinary research.
While such agroecological research and devel-
opment projects account for a very small percent-
age of total REE grants to date, much greater
social and ecological benefits could be realized if a
stable base of financial and infrastructural support
was provided to expand this scope of critically
important work.
As one of the most successful public agricul-
tural research systems in the world, the USDA is
uniquely positioned to generate and disseminate
agroecological knowledge at a meaningful scale. By
shifting its strategic focus and supporting cutting-
edge, multidisciplinary research on biologically
diversified farming systems, USDA research,
extension, and education can position the United
States to take a responsible leadership role in a
truly sustainable approach to meeting global food
needs.
Acknowledgments
The authors would like to thank Annie Shattuck,
Maywa Montenegro, Claire Kremen, Nathan Sayre,
and Kris Havstad for their comments on earlier
drafts of this work. We also benefitted greatly from
feedback and ideas offered by Mark Lipson, the
members of the Diversified Farming Systems
working group at the University of California,
Berkeley, and the attendees at an AGree convening
on USDA Research, Education, and Extension
held at the Meridian Institute in February 2013.
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