February 2021 - 14

PLANT & SOIL HEALTH
4R fertilizer management,
nutrient stewardship
By Anthony Fulford
University of California
Sustainable agriculture minimizes
risks and optimizes beneficial economic,
social and environmental outcomes.
Proper fertilizer management is crucial to
sustainable agriculture because it not only
optimizes profitability, but guards against
the pollution of surrounding natural
ecosystems and groundwater resources.
The 4R concept has been used for
decades and remains a cornerstone of
nutrient management used by consultants,
agronomists and conservationists. More
recently, there has been a focus on
broadening the 4R concept by considering
factors related to nutrient management
that go beyond the 4Rs. This much
broader nutrient stewardship perspective
places the 4Rs within the wider landscape
and recognizes the role of soil health
and conservation in sustainable nutrient
management.
What is 4R fertilizer
management?
4R fertilizer management matches
fertilizers, or other plant nutrient inputs,
to crop needs. The " 4Rs " of fertilizer
management refers to the right rate,
right source, right timing and right
placement of plant-available nutrients.
4R fertilizer management is at the core of
best management practices in sustainable
cropping systems because it does not
focus on the importance of an individual
component, rather it recognizes
the connection among individual
components (Diagram 1).
The 4Rs support on-farm production
practices by aligning fertilizer
management decisions with optimal
crop nutrient use efficiency, crop
production, and harvestable yield. The
initial focus of 4R fertilizer management
was on improving crop nutrient use.
Consequently, 4R fertilizer management
was mainly viewed as a way to support
farm-level profitability. The pressure
to meet the consumption demands of
a growing population as well as the
simultaneous need to eliminate negative
environmental impacts has led to a
renewed vision of the 4R concept for
modern-day cropping systems.
The " 4Rs " of fertilizer
management refers
to the right rate, right
source, right timing and
right placement of plantavailable
nutrients.
This newer 4R concept, known as 4R
Nutrient Stewardship (4RNS), emphasizes
how field-level decisions can be linked to
ecosystem-level sustainability indicators
such as soil health, air and water quality.
What is 4R nutrient
stewardship?
4R Nutrient Stewardship links sitespecific
fertilizer management to
landscapes and ecosystems using
indicators of economic, social and
environmental sustainability. The 4RNS
concept still emphasizes 4R fertilizer
management at the field-level, but the
overall benefits and deficits of this
approach are evaluated using indicators
of sustainability that occur beyond the
boundaries of an individual field. This
idea is nicely conceptualized in the
4RNS schematic design (Diagram 2).
The placement of the 4Rs within
the wider landscape indicates that in
addition to fertilizer management,
conservation planning to reduce soil
erosion and greenhouse gases, or
increase biodiversity should also be
considered best nutrient management
practices. 4RNS is only the beginning
of the fertilizer management decisionmaking
process, further refinement
of these general guidelines should be
Diagram 1. Graphics: University of California
Diagram 2.
based on the limitations of site-specific
nutrient use efficiency.
The 4Rs provide a general approach
to nutrient management that can
serve as a starting point for fieldlevel
fertilizer application decisionmaking.
While the 4R concept is useful
for guiding fertilizer management
practices, the more recent desire to
connect fertilizer management to
broader sustainability indicators using
the 4RNS concept will help identify
when and where 4Rs succeed and
what improvements may be needed to
support 4R nutrient management.
Resources, more information
USDA-NRCS Conservation Practice
Standard Nutrient Management
(590); https://efotg.sc.egov.usda.gov/
api/ CPSFile/26404/590_CA_CPS_
Nutrient_Management_2016.
Note: USDA-NRCS periodically
reviews and updates conservation
practice standards A Brief Account of
the Genesis of 4R Nutrient Stewardship;
https://doi.org/10.1002/agj2.20315.
Anthony Fulford is an area nutrient and
soil quality advisor for the University of
California Cooperative Extension. VGN
Do You Also Grow Fruit?
If so, Fruit Growers News is your No. 1 resource for industry
insight and information.
Print and digital subscriptions available at a special price
exclusively for VGN subscribers.
Subscribe at fruitgrowersnews.com. Use discount code FGN21 at checkout.
14 | VegetableGrowersNews.com
Labor crunch fuels
automation, H-2A
growth
Quebec growers
raise strawberries
on substrate in high
tunnels
8
12
26
Tree Fruit Variety
Showcase
November 2019 | Volume 58 |
Issue 11
GRAPE
EXPECTATIONS
Napa grower's enterprise,
sustainability efforts honored
Andrew Hoxsey, a Napa Valley grower of organic winegrapes, is a strong advocate of sustainability. Photos: Joanna Salazar/Snapped With Love Photography
By Stephen Kloosterman
Associate Editor
A career of enterprise and
advocating for sustainable growing
led to Andrew Hoxsey being named
Grower of the Year.
Hoxsey, a fourth-generation
grower, and part owner of Yount Mill
Vineyards, Yountville, California,
and Napa Wine Co. in Oakville,
is credited for his work on the
California Sustainable Winegrowing
Alliance in its formative years, and
also for launching the Napa Valley's
first custom-crush operation, which
gives winegrape growers more
options for their crop.
The Grower of the Year award is
the highest award bestowed by the
California Association of Winegrape
Growers (CAWG). It recognizes an
" efficient and successful producer of
quality winegrapes " who is a leader
and innovator in the industry.
" Over a period of three decades,
Andy has exemplified the best in
grape growing with his commitment
to sustainable winegrowing,
agricultural preservation, habitat
See HOXSEY, page 5
Anderson to lead Michigan Hort Society
By Stephen Kloosterman
Associate Editor
For more than a century, the
Anderson family has grown apples on
a ridge in west Michigan, and in 2020,
the farm's current leader will serve
as president of the Michigan State
Horticultural Society (MSHS).
Brett Anderson of AB Orchards will
take a turn in leading the industry
group that represents 1,600 growers in
the Great Lakes State.
AB Orchards itself has more than 150
acres in the Sparta, Michigan, area, in
addition to an orchard in neighboring
Oceana County. The Anderson Farm
settled in west Michigan in 1908, and
Brett's grandfather and great-uncles
studied agriculture at Michigan State
University (MSU) during the Great
Depression.
" It was during the Depression era
that they decided to focus mainly on
tree fruits and get rid of the cows, " he
said. Anderson Brothers Orchards first
grew stone fruit in addition to apples,
but when Brett's father took over in
the early 1980s, he focused the farm
mostly on apples.
Today, Brett grows only apples. He has
transitioned his family farm away from
growing varieties meant for processing
- Jonathan, Golden Delicious, Ida Red,
Rome and Red Delicious.
In the late 1990s, with the Chinese
dumping apple juice concentrate into the
American market, Brett began tearing
out old orchards and selling applewood
to Grand Rapids-area restaurants
See ANDERSON, page 6
BRETT ANDERSON

https://efotg.sc.egov.usda.gov/ https://www.doi.org/10.1002/agj2.20315 http://www.fruitgrowersnews.com http://www.VegetableGrowersNews.com

February 2021

Table of Contents for the Digital Edition of February 2021