Nutrient Management Plan for Organic Systems: Idaho Implementation Guide - Transition to Organic Partnership Program

This document is an instruction guide for creating and implementing a nutrient management plan (NMP) on certified or transitioning organic lands. An NMP for organically managed lands describes the amount, source, placement, form, and timing of the application of nutrients and soil amendments, generally by field, to meet crop nutrient needs while protecting water quality, improving soil health, and utilizing manure and other organically acceptable byproducts as nutrient sources.

Nutrient Management Plan (590) for

Organic Systems

Idaho Implementation Guide

June 2014
National Center for
Appropriate Technology (NCAT)
www.ncat.org
Oregon Tilth
www.tilth.org
1

Contents
Purpose and Objectives……………………………………………. 3
Relevant National Organic Standards……………………. 4
Section 1.
Determining Crop Need for
Nitrogen, Phosphorus, and Potassium…………………… 5
Section 2.
Developing Nutrient Credits……………………………………. 6
Section 3.
Determining Nutrient Application Rates………………. 10
Section 4.
Evaluating Risk of Leaching and Runoff……………….. 12
Section 5.
Calculating Nutrient Application Rates
Based on Risk Analysis…………………………………………….. 13
Appendix A.
Tables…………………………………………………………………………. 14
Appendix B.
Conversion Tables…………………………………………………….20
Appendix C.
References to NRCS Publications
and Other Resources………………………………………………..22

Figure 2. Six-foot-tall fava bean cover crop, Fong Farms,
Woodland, California 2006.

Funded by
a grant from
Western
Sustainable
Agriculture
Research and
Education
(WSARE).

Appendix D.
Implementation Requirement Worksheet……………25

ACKNOWLEDGMENTS
Authors Rex Dufour (National Center for Appropriate Technology), Sarah Brown (Oregon Tilth), and
Denise Troxell (Natural Resources Conservation Service)
Contributors and Reviewers Ben Bowell and Carrie Sendak (Oregon Tilth); Nick Andrews (Oregon State
University); Dennis Chessman, Rich Fasching, Giulio Ferruzzi and Dick Johnson (NRCS); and Jennifer Miller
(Northwest Center for Alternatives to Pesticides)
We thank Dan Sullivan, Extension Soil Scientist, Oregon State University for assistance in presenting methods
for estimating plant-available N release from organic inputs.
Editing and layout Karen Van Epen (NCAT), Robyn Metzger (NCAT)
All photos Rex Dufour (NCAT) unless otherwise noted.
Figure 1. (On front cover) A farmer evaluates soil organic matter. Photo: David Lamm (NRCS)
For more information or questions, contact Ben Bowell at Benjamin.Bowell@por.usda.gov or 503-580-4767
2

Nutrient Management Plan (590) for Organic Systems

Implementation Guide
Purpose and Objectives
This document is an instruction guide
for creating and implementing a
nutrient management plan (NMP)
on certified or transitioning organic
lands.
An NMP for organically managed
lands describes the amount, source,
placement, form, and timing of the
application of nutrients and soil
amendments, generally by field, to
meet crop nutrient needs while
protecting water quality, improving
soil health, and utilizing manure
and other organically acceptable
byproducts as nutrient sources.
Developing an NMP entails:

Figure 3. Cover crop mix of rye and phacilia. Photo: Ben Bowell (Oregon Tilth)

1) Determining a crop’s need for
nitrogen, phosphorus, potassium, and other
nutrients as appropriate
2) Crediting all significant sources of nutrients
in the system such as the nitrogen contribution
of cover crops, the mineralization of nitrogen
based on input history (previous years’ manure/
organic byproducts applications), and any nitrate
that may be contained in irrigation water

3) Determining the target nutrient application rate
(the difference between the crop need and the
nutrient credits)
4) Evaluating likelihood of nutrients moving past
the edge of a field or below the root zone (leaching
and runoff)
5) Calculating the appropriate rate of manure/ organic
product application based on this risk

Instructions

☞ This icon indicates you should fill in data on the Implementation Requirement Worksheet in
Appendix D, pages 25-29. Alternatively, you may use your state’s NM planning tool to enter the
crops grown.

☞ In the Field and Crop Information section, list the crops in the order they are grown. Check
the box for the current crop. Make additional copies of the form as needed.

Relevant National Organic Program (NOP) Regulations
National Organic Program (NOP) regulations section 205.203 should be referenced when assessing nutrient
management in organic systems. The entire NOP regulations, as well as lists of approved and prohibited materials
and other information can be found at the NOP website: www.ams.usda.gov/AMSv1.0/nop

Section 205.203 Soil Fertility and Crop Nutrient Management Practice Standard
(a) The producer must select and implement tillage
and cultivation practices that maintain or improve
the physical, chemical, and biological condition of soil
and minimize soil erosion.
(b) The producer must manage crop nutrients and
soil fertility through rotations, cover crops, and the
application of plant and animal materials.
(c) The producer must manage plant and animal
materials to maintain or improve soil organic matter
content in a manner that does not contribute to contamination of crops, soil, or water by plant nutrients,
pathogenic organisms, heavy metals, or residues of
prohibited substances. Animal and plant materials
include:
(1) Raw animal manure, which must be composted unless it is:
(i) Applied to land used for a crop not intended for human consumption;
(ii) Incorporated into the soil not less than 120
days prior to the harvest of a product whose
edible portion has direct contact with the soil
surface or soil particles; or
(iii) Incorporated into the soil not less than 90
days prior to the harvest of a product whose
edible portion does not have direct contact
with the soil surface or soil particles;
(2) Composted plant and animal materials produced through a process that:
(i) Established an initial C:N ratio of between
25:1 and 40:1; and
(ii) Maintained a temperature of between 131
°F and 170 °F for 3 days using an in-vessel or
static aerated pile system; or
(iii) Maintained a temperature of between
131 °F and 170 °F for 15 days using a windrow
composting system, during which period,
the materials must be turned a minimum of
five times.
(3) Uncomposted plant materials.

(d) A producer may manage crop nutrients and soil
fertility to maintain or improve soil organic matter
content in a manner that does not contribute to contamination of crops, soil, or water by plant nutrients,
pathogenic organisms, heavy metals, or residues of
prohibited substances by applying:
(1) A crop nutrient or soil amendment included on
the National List of synthetic substances allowed
for use in organic crop production;
(2) A mined substance of low solubility;
(3) A mined substance of high solubility: Provided,
That, the substance is used in compliance with the
conditions established on the National List of nonsynthetic materials prohibited for crop production;
(4) Ash obtained from the burning of a plant or
animal material, except as prohibited in paragraph
(e) of this section: Provided, That, the material
burned has not been treated or combined with a
prohibited substance or the ash is not included on
the National List of nonsynthetic substances prohibited for use in organic crop production; and
(5) A plant or animal material that has been chemically altered by a manufacturing process: Provided,
That, the material is included on the National List
of synthetic substances allowed for use in organic
crop production established in § 205.601.
(e) The producer must not use:
(1) Any fertilizer or composted plant and animal
material that contains a synthetic substance not included on the National List of synthetic substances
allowed for use in organic crop production;
(2) Sewage sludge (biosolids) as defined in 40 CFR
part 503; and
(3) Burning as a means of disposal for crop residues
produced on the operation: Except, That, burning
may be used to suppress the spread of disease or
to stimulate seed germination.

Section 1.
Determining Crop Need for Nitrogen, Phosphorus, and Potassium
This section outlines the process and resources to be used
to calculate the demand of a particular crop for N, P, K,
and other nutrients. Sources of information about crop
nutrient needs can be found in Appendix C, Section 1.
It is common for organic farms to grow many different
crops on relatively small acreages and for soil texture
to vary across the farm. In order to develop a practical
nutrient management plan for small plot acreages, it
may be helpful to work with the grower to develop
groupings of crops that have similar growth habits and
nutrient needs, and manage the grouping’s nutrient
needs as a single entity. Crop rotations are required in
organic systems. Growers should have a crop rotation
plan as part of their organic system plan.
Additional information to guide soil sampling strategies
and crop rotations on diverse organic vegetable farms
can be found in Appendix C, Section 1. Some possible
groupings include:
➢ Nitrogen Needs (Ideal): Low/Medium/High N.
See Table 1.
➢ Plant Family: For example, all solanaceous or all
brassica crops
➢ Timing: Early season, mid-season, and late
season plantings. Timing will impact nutrient
availability from soil N mineralization. Early
season crops will be unlikely to pull much from
the soil and should be fertilized accordingly.
➢ Crop Growth: Short-season crops, long-season crops
➢ Crop Type: Grains, legumes, vegetables, fruits
➢ Other: Growers also take other considerations into
account such as irrigation system layout, pest cycles,
and soil type.

Table 1. Nitrogen requirement of vegetable
crops based on seasonal nitrogen uptake
Low Total
Medium Total
N Need
N Need
<120 lb/acre <120-200 lb/acre Baby greens Carrot Beans Corn, Sweet Cucumbers Garlic Radish Lettuce Spinach Melons Squashes Onion Peppers Tomatoes High Total N Need >200 lb/acre
Broccoli
Cabbage
Cauliflower
Celery
Potato

— Gaskell et al. 2006, Soil Fertility Management for
Organic Crops

Western states grow a great variety of specialty crops.
Your state cooperative extension has horticulturists and
agronomists who can point you in the right direction
for informational resources about the nutrient needs of
less commonly planted crops. Some specialty crops may
require higher amounts of particular micronutrients,
which if not present will limit quality and yields. Other
crops may be more sensitive to excess micronutrients, such
as citrus sensitivity to boron. If no University recommendations are available for a crop, an acceptable strategy is
to balance N, P and K applied with N, P and K expected
to be removed by the crop.

☞ Enter crop nutrient requirements and yields

under Recommended Nutrients to Meet Yield.

Resources for Nutrient Requirements of Crops
Idaho Cooperative Extension and Idaho Nutrient
Management: www.extension.uidaho.edu/nutrient
NRCS Crop Nutrient Tool:
http://plants.usda.gov/npk/main

NRCS Agricultural Waste Management Field
Handbook provides data on N, P and K content of a
wide variety of crops.
ftp://ftp.wcc.nrcs.usda.gov/wntsc/AWM/handbook/ch6.pdf

Oregon State University Fertilizer/Nutrient
Management Guidelines for Crops:
http://extension.oregonstate.edu/catalog/details.
php?sortnum=0134&name=Fertilizer+Guides&cat=
Agriculture

Section 2.
Developing Nutrient Credits
This section outlines some methods to calculate the
nutrient contributions of:
➣ Soil Organic Matter (SOM) N mineralization
➣ Cover crops
➣ Organic amendments such as manure, compost,
and some specialty fertilizers
The input history of a field is valuable, because many
sources of organic N continue to mineralize over several
years. As part of their organic recordkeeping requirements, organic farmers will have records of their soil
fertility inputs, as well as yield data, and these can help
to make a more comprehensive nutrient management
plan. Transitioning farmers may have no records if they
are early in their transition. Recent soil test information
will provide information about what is present in the
soil. Sources of information about organically acceptable
fertilizers can be found in Appendix A, Tables 4, 5, and 6.

in soil with high P and K concentrations usually do not
respond to P and K fertilizers. When large amounts of
crop biomass are removed at harvest (i.e., alfalfa, or corn
silage) significant amounts of P and K are removed from
the soil. Other crops such as raspberries or blackberries
do not remove large amounts of P and K.

Soil Test Information and Resources

☞

Soil test and leaf test results taken at different times of
year provide valuable data for monitoring the performance
of nutrient management plans. This is especially useful
for refining N fertilizer rates. Pre-Side-dress Nitrate Tests
(PSNTs) can ensure a grower that N levels are sufficient
for the crop. PSNTs are generally done in the late spring
and allow the grower to respond to early spring weather
conditions that impact N mineralization. End-of-season
soil nitrate tests can determine whether N fertilizer rates
were higher than necessary. In most perennial crops, leaf
tests are used to determine crop nutrient status. These
naturally incorporate non-fertilizer nutrients taken up by
the crop.
Mineralization from “native” SOM is generally not
included in NRCS nutrient management plans because
land-grant university recommendations for N fertilizer
application rate assume typical soil N mineralization
already (under conventional management). However
under long-term management with consistently high
organic-N inputs, soil N mineralization may supply a
significant portion of crop N needs.
P and K should be managed by soil tests and attention
to P and K removal through harvest of crop biomass.
P and K fertilization decisions typically do not require
consideration of target yield for the crop. Crops grown
6

Soil test results can come in either text or graphical
formats. Discuss with the producer which format is
preferred. University nutrient management guides
provide more accurate crop-specific sufficiency levels
than general ranges. Refer to your state’s Conservation
Practice Standard 590 for the required soil tests. A
listing of accredited (NAPT-PAP certified labs) soil
testing labs can be accessed at: www.naptprogram.
org/pap/labs. Tests of plant tissue, water and organic
materials must be conducted by labs that are certified by
organizations noted in the state’s 590 practice standard.
Enter soil test results under the Soil Test
Information section.

Nitrogen (N)
Nitrogen in organic systems is often tied up in organic
matter, and not in a form that is immediately available
to plants. Most organically acceptable sources of N have
lower N concentrations than chemical fertilizers, and
typically release less of their total N in the first cropping
season. In contrast, PAN for chemical fertilizers such as
urea, ammonium sulfate, and others, is 100%. That is,
the N is available to the plant shortly after application as
either nitrate (NO3 —this is the form most plants take
up N), or ammonium (NH4+). Possible sources of N for
organic systems include compost, manures, cover crops,
organic matter mineralization, organic approved fertilizers (fish meal, feather meal, etc.), and irrigation water.
In some locations, irrigation water can have significant
levels of nitrates, so it’s a good idea to have the irrigation
water tested. The nitrate contribution from irrigation water
should be taken into account when developing nutrient budgets, but there are many variables to consider:
uptake by plant, irrigation water going beyond root
system, and nitrate variability in water during the season.
Table 12 provides conversions to calculate parts per
million to lbs/acre inch.

PAN Plant-Available Nitrogen —
Nutrient Source: Soil N Mineralization
This is the process whereby the stock of N that is “stored”
in SOM decomposes to release plant-available nitrogen
(PAN). Because organic farmers typically apply more
organic matter than conventional farmers, PAN provided
by soil N mineralization generally increases under organic
management. The most recent organic inputs have the
most influence on PAN release from soil organic matter.
Most University nutrient management guides account for
some background soil N mineralization, but not usually
the high levels often found on established organic farms.
The potential rate of soil N mineralization is a function of
temperature, tillage, type of soil, and other factors. Any
figures developed for PAN from soil N mineralization
must be considered approximate.
While organic growers are required to record applications
of materials, they might not have the nutrient analyses
they need to do a calculation. Approximate numbers can
be used in this situation.

How to Estimate Soil N Mineralization
1. Organic amendments (composts, manure, cover
crops, fertilizers, etc.) applied to the soil will continue
to provide PAN in subsequent years, but in ever-smaller
quantities. Organic fertilizers such as blood meal,
and feather meal, which are higher in N, will provide
roughly 75% of their N in the first year and up to 50%
of their N within a week of application (Gaskell, 2007).
Assuming some materials have been applied, first calculate total N application per year. To determine the PAN
for the current year, refer to Tables 7-9. The estimation
rule for PAN available in years 1, 2, and 3 post-application
are 8%, 5%, and 3% of total N applied, respectively. See
Table 2, below. Although a soil with more organic matter contains more total N, SOM levels are not a good

indicator of PAN as soil temperature, moisture, and
many other soil management factors are not considered.
Laboratories that estimate PAN based on SOM typically
do not have calibration data to support their estimates
(Horneck, 2011).
2. If previous organic input history is not available,
then credit 50 lbs N/acre if the field received substantial
organic inputs (i.e. cover crops and manure or compost)
for at least three consecutive years.

PAN Plant-Available Nitrogen —
Nutrient Source: Manures and Compost
To determine PAN from manure and compost products
you must first analyze the nitrogen content. Table 7,
Appendix A, based on Oregon State University’s Organic
Fertilizer and Cover Crop Calculator (Andrews, et al.),
identifies the PAN % or pounds after four weeks for
manure, compost, and other organic amendments. In
Idaho, the University of Idaho Cover Crop Calculator is
available and applicable for southern regions of the state
(Moore).
In order to obtain the full N benefits of manure,
applications should be incorporated immediately.
Significant amounts of ammonia-N can be lost within
one to two days of application through volatilization
(see Table 5 Appendix A). Significant amounts of N may
also be lost if manure is applied too far in advance of the
period of rapid N uptake by the crop, even if the manure
is incorporated. For fall manure applications, up to
half of the N may be lost by the time of greatest crop
demand the following year (Magdoff, 2009).
Poultry litter is a popular organic amendment because of
high N and P levels, but it may be high in arsenic, copper
and zinc due to additives in their feed. Analysis of poultry
litter should include Zn, Cu, and As to ensure that soil is
not being contaminated.

Table 2. PAN Credits.
PAN, Percent of Total N
(general rule)
45% x total N lbs/acre
8% x total N lbs/acre
5% x total N lbs/acre
3% x total N lbs/acre

Years After
Application
current year
1
2
3

Manure and Compost
Refer to page 4 for additional National Organic Program
regulations related to the use of manure and compost on
organic farms. It should also be noted that manure and
compost inputs from non-organic sources are allowed as
long as there is no risk of contamination.

PAN Plant-Available Nitrogen —
Nutrient Source: Cover Crops
Cover crops and green manures provide both nitrogen
and organic matter to the soil. The amount of N and
organic matter provided will depend on the cover crop
species, or mix, crop biomass, and growth stage when
killed. These same factors will influence how rapidly the
cover crop will decompose, and whether it will release,
or immobilize PAN. Most PAN is released in four to six
weeks after cover crop termination. For a comprehensive
guide on this topic see ‘Estimating Plant Available
Nitrogen Release from Cover Crops, PNW 636’. In
this publication we will review the shortcut method as
outlined in that document.
PAN from any cover crop is minimal when the cover
crop is very small. For solo cover crops, the best time to
terminate the cover crop to maximize PAN depends on
whether the cover crop is a legume or a non-legume.
➣ PAN from a robust stand of legumes (Figure 4)
peaks at budding growth stage. PAN declines slowly
as reproductive growth continues.
➣ PAN from cereal residues is positive early in the
spring (through tillering, mid- to late March). As stem
elongation proceeds (jointing), PAN from cereal residues declines. By the time the flag leaf (uppermost
leaf) emerges (Feekes growth stage 8 or Zadoks 37),
PAN from cereal crop residue is near zero. When
cereal heads are visible, PAN from cereals is negative.
To maximize PAN, kill cereal cover crops early, but
wait until bud stage to kill legumes. In cereal/legume
mixtures, the best crop growth stage for maximum
PAN benefit depends on the percentage of legume in the
stand. Figure 4 illustrates how PAN changes over time
in solo and mixed cover crop stands.
➣ When the cover crop is mostly legume, it behaves
much the same as does a pure legume cover crop—
the PAN from crop residue increases until cereal boot
stage. (Feekes stage 10; Zadoks stage 45). After pure,
or majority cereal stands reach jointing stage, PAN
declines.
➣ When a cover crop has more cereal than legume
(25 percent legume line in Figure 4), it follows a
similar PAN curve as a solo cereal crop, but negative
PAN is usually not seen until the cereal reaches boot
stage (around mid-May).
Seeding legume/cereal mixes instead of a solo cereal
crop allows greater flexibility in timing of cover crop
8

Figure 4. Effect of kill date on typical plant-available N (PAN)
release from cereal, legume, or mixed stands. Based on
compilation of field data from Willamette Valley cover crop
trials. Figure from PNW 636, Estimating Plant-available
Nitrogen Release from Cover Crops (Sullivan and Andrews,
2012), ©Oregon State University. Used by permission.

termination without consequences of negative PAN.
Cover crop mixes also combine the N fixation benefits of
legumes with weed suppression and soil benefits of cereals.
The percent N in cereals varies with field history. Fields
that have a history of manure/compost application and/or
legumes in rotation often have higher percent N in cereal
than do fields with a history of only N fertilizer application.
Biomass determination. The first step in estimating PAN
from a cover crop is determining how much cover crop
biomass is present. Visual estimates of cover crop biomass
are not very accurate, especially for multi-species cover
crop mixes. Cutting and weighing cover crop biomass is
the preferred method to estimate PAN. Generally, cover
crop roots are not included in this calculation. Harvest
the above-ground cover crop with quadrats or a sickle bar
mower (see Sullivan et al. 2012, Appendix C, Section 5 for
additional sampling instructions). Any harvest method can
be used that gives you a clean plant sample with a known
harvest area.
To determine the PAN you’ll need to estimate the percent
dry matter (DM; Tables 3 and 9). You will need to either
use a ballpark estimate of DM or oven dry the sample
that has been collected. Mixed, vegetative cover crop DM
will usually be between 12 and 18%. Very wet clover
samples are usually 10 to 12 % DM. Cereals after head
emergence are usually 20 to 25% DM.

Table 3. Estimated plant-available N (PAN) release from decomposition of crop residues in soil
at 4 and 10 weeks
Total N
C:N
4 wk
10 wk
4 wk
10 wk
% N, dry wt
PAN, % of residue total N
lbs PAN/dry ton
Cereals after head emergence
1
40
-40
<0 -8 <0 2 20 5 20 2 8 Cereals, tillering/jointing 3 13 35 40 21 24 50/50 Cereal/Legume Mix or Flowering Legumes 4 10 50 55 40 44 Legumes, vegetative Adapted from OSU Extension publication EM9010-E (2010): Nutrient management guide for sweet corn (western Oregon). See “Biomass determination” on page 8 for a discussion of estimating the percent of dry matter. Negative PAN values indicate immobilization of N by cover crop residue. With a good stand and cover crop kill near bud or head emergence stage of plant development, the typical cover crop PAN credit is 50 lb N/acre for cereal legume mixtures, and up to 100 lb PAN/acre for legumes. Shortcut method. Harvest and measure cover crop biomass and use typical values for cover crop DM and percent N (Table 3) to estimate PAN. See Table 9 for information and sample calculations about how to estimate cover crop contributions to PAN. More accurate estimations can be made with lab analysis (Sullivan & Andrews, 2012). ☞ Enter figures for PAN available from previous applications of manure, compost and cover crops under Nutrient Sources section. Alternatively, use the rates established in your state’s Nutrient Management Planning tool. Phosphorus (P) In nature, most plants, except brassicas, receive much of their phosphorus through mycorrhizal interactions with the soil. This is particularly true in perennial systems. In organic systems, with regular cover crops, this interaction may be more prominent than in conventionally managed systems because organically managed soils can provide better conditions for mycorrhizal survival. If manures, or composted manures, have been regularly applied at rates to meet a crop’s N needs, this may result in more P (and K) than the crop requires. After many years, this can result in over-accumulation of P and K, and any solution requires some combination of reduced applications and/or increased uptake and removal of these nutrients. Potassium (K) Potassium is available as a positive ion, or cation, and soils with a high cation exchange capacity (CEC) will generally have more capacity to store K. Most soils with high clay content, high organic matter levels (>3%), or both will

Figure 5. Assessing the biomass of a cover crop.

have high CEC. There are thousands of pounds per acre
of potassium in an average, non-sandy soil, but most
of that is unavailable to plants—usually only 1-2% is
available. Repeated applications of manures can lead to
over-abundance of K (as well as P) in the soil.

Secondary Macronutrients and
Micronutrients
Micronutrients are important to plant health, and can
be limiting factors for both yield and quality in some
production systems, or, when present in excessive
amounts, can reduce availability of other nutrients or
have a negative impact on plant health. Soil tests should
provide information on the levels of the secondary
macronutrients Calcium (Ca), Sulfur (S), and Magnesium (Mg), as well as micronutrients, such as Manganese
(Mn), Iron (Fe), Zinc (Zn), Copper (Cu), and Boron (B).
Documented soil deficiency, either through soil or tissue
tests, is required per NOP regulations prior to applying
any synthetic micronutrients.
9

Section 3.
Determining Nutrient Application Rates
Determining nutrient application rates consists of taking
your crop’s nutrient needs and subtracting any credits
from the system. If the credits are less than the crop’s
nutrient need, the grower will need to apply supplemental
nutrients in order to achieve the desired yield. Not all of
the N applied this year will be available to the crop in
the first year. A balanced nutrient program will supply
sufficient PAN, P2O5, K 2O, and other nutrients while
avoiding excesses. The example below demonstrates this
approach.

Example
Assume that after all the nutrient credits are subtracted,
the values for the Nutrients Recommended for Yield are:
80 lbs PAN, 40 lbs P2O5, and 60 lbs K2O per acre.
The manure analysis is 3% N, or 60 lbs total N per dry ton.
According to Table 7, PAN Estimates for Uncomposted
Manure, at 10 weeks PAN released is about 30% of the product, or 18 lbs PAN per dry ton. This material is 60% dry matter
(therefore, 40% water), so to make consideration for this:
18 lbs PAN x 0.60 = 10.8 lbs PAN per “as is” ton
80 lbs PAN/ac ÷ 10.8 lbs PAN/Ton = 7.4 T/ac
This is the application rate that meets the crop’s
nitrogen need.
The manure also contains 20.6 lbs P2O5/dry ton (reported
on a dry basis this time) and 37.8 lbs K2O/dry ton according
to the analysis.

☞

Add up all the PAN nutrient credits from the
previous applications of manure, compost, cover
crops, as well as what can be expected from the
irrigation water for this season’s crop. This total
should be subtracted from the total Nutrients
Recommended for Yield.

To calculate how much P2O5 the 7.4 T/acre manure
application rate will provide:
Application rate: 7.4 T/ac x .6 (60% dry matter) x 20.6 lbs P2O5/
dry ton = 91.5 lbs P2O5/ac
91.5 lbs P2O5/ac is being applied with the 7.4 T/ac manure.
Note that this is over twice as much P2O5 as is required by the
crop. What are some other fertilizer options that would supply
sufficient N, but less P2O5?
To calculate how much K2O the 7.4 T/acre manure
application rate will provide:
Application rate: 7.4 T/ac x .6 (60% dry matter) x 37.8 lbs K2O/
dry ton = 168 lbs K2O/ac
168 lbs K2O/ac is being applied with the 7.4 T/ac manure. This is
nearly three times as much K2O/ac as is required.
What are some other fertilizer options that would supply
sufficient N and P, but less K2O/ac?
Refer to Tables 4-6 for additional organic fertilizer
options.

Please note: Calculations here use lbs N/ton or PAN/ton because litter and compost are commonly delivered by the ton.

☞

Enter planned NPK applications to the
right of line 7 (Manure), line 8 (Compost), or
line 9 (Specialty Fertilizers) in the appropriate
nutrient column.

Timing and Application Method
The timing, application, and incorporation methods
of nutrients is most important relative to conserving N
and P. Manure applications can provide significant N to
the soil if they are incorporated within 12 hours of application. If the manure is broadcast and left on the surface, between one half and two thirds of the available
N can be lost to volatilization after one week (see Table
5, Appendix A). Even in reduced-till systems, application
close to the time of planting will decrease the likelihood
of loss by runoff or erosion. Manures are generally best
applied just before soil tillage, but diligence is needed to
ensure that National Organic Program harvest-interval
regulations related to manure applications are followed.
N mineralized from manures during a rainy period may
leach N into the water table or, if eroded, may carry into
surface waters. Fall applications of manure on annual row
crops do risk considerable N loss, even if incorporated
in regions with significant winter/spring precipitation.
The ammonium is converted to nitrate, and then is subject
to leaching and denitrification before the N is available for
next year’s crop (Magdoff & Van Es, 2009). Denitrification
is the microbial conversion of nitrates to nitrous oxides,

and mostly occurs in soils that become anaerobic due to
high water tables, poor drainage, or surface sealing. But
regardless of the mechanism of N loss, the loss of N to
water or air should be minimized through applications of
N appropriate to plant needs. The forms of N applied, as
well as its time of application can influence the percentage
N taken up by plants, and lost to leaching or the atmosphere. The goal of N management is to have minimal
nitrate-N present in soil that could be leached through
rainfall or irrigation or denitrified. This may allow for
fall manure applications with low risk of N leaching
due to winter rains. Manures mixed with large amounts
of high-carbon bedding (straw or wood shavings) may
immobilize N during the early stages of decomposition,
and should be composted prior to application, or be
applied long enough prior to planting to reduce the risk
of immobilization.
Cover crop incorporation can be considered a fertilizer
application and as Figure 6 shows, the peak PAN generally
occurs after four weeks. That may be two or more weeks
before the crop has its highest demand for N. Attempting
to plant too soon after cover crop incorporation risks pest
and pathogen problems associated with the decomposing
cover crop.

Figure 6. Timing of nitrogen (N) mineralization from cover crop residue in relation to crop N uptake (adapted from Gaskell et al., 2006). From
Gaskell, M., and R. Smith. 2007. “Nitrogen Sources for Organic Vegetable Crops.” HortTechnology October-December 2007 vol. 17 no. 4, 431441) Note: Soil temperature plays an important role in the rate of N mineralization from soil organic matter.

Section 4.
Evaluating Risk of Leaching and Runoff
Risk factors associated with N leaving the field are not
quite the same as P leaving the field, although erosion
and runoff are risks common to both nutrients. These
elements act differently in the environment—P does
not volatilize and typically does not leach in significant
quantities.
Soils with active biology and good aggregate stability
will tend to absorb rainfall more easily. While this might
reduce the likelihood of P runoff through soil erosion,
leaching of N may still be a problem. Good aggregate
stability also encourages airflow into the soil, reducing the
risk of anaerobic conditions which cause denitrification
and loss of soil N.

Assessing Risk of N Leaving the Field

Risk Factors for P Leaving Field
Soil texture (sandy vs. clay)
Slope of land
Amount of cover on the soil
Amount and timing of nutrient application
Amount and timing of rainfall events
and irrigation
➣ Distance to perennial surface water
➣ High P levels in the soil
➣
➣
➣
➣
➣

Mitigation Practices to
Reduce P Loss from Field
➣ Keep crop residues on soil surface.
➣ Minimize duration of bare soil exposure to weather.

Nitrates (NO3), and ammonium (NH4+) are both easily
dissolved in water. As noted above in the ‘Timing’ section, ➣ Reduce length of slope using terraces, berms
(vegetated with grass or hedgerows).
application and incorporation of manures close to time of
planting will help reduce risks from volatilization, leaching, ➣ Tailwater ponds reduce sediment in runoff.
➣ Reduce amount of P in soil surface over time by
and runoff. Fall manure applications risk significant N
reducing the application rates for manure, compost
loss even if incorporated.
or other products with high P content.
➣ No-till or minimum till may increase water soluble P
Phosphorus Indices
loss from a field via heavy rainfall or irrigation
Many states are updating their P-indices. In some
events, even though no-till does reduce total P loss
states the interim index is available in Section IV of
from erosion.
the eFOTG.

Figure 7. Organic management builds a soil full of aggregates and organic
matter. Photo: Oregon Tilth

Section 5.
Calculating Nutrient Application Rates Based on Risk Analysis
In previous sections, you developed numbers for nutrient levels already in the ground from previous manure/
compost applications, cover crops, and irrigation water.
You also developed numbers for nutrient levels required
by the crop. If crop nutrient requirements exceed your
nutrient availability estimates, then additional nutrients
are required. Refer to Tables 4-6, Appendix A for a listing of organic nutrient sources and their N-P-K values.
Review the P-Index for your state for detailed guidance.

☞

Estimates for PAN and nutrient applications
should be reviewed, and sources and amounts of
nutrients to be applied should be revised as appropriate in light of P-Index policy. Add up lines 7, 8,
and 9 under Nutrient Sources for “planned” and follow instructions in line 11, and the text in red at the
bottom of the table.

Record keeping
Organic farmers are required to maintain extensive
records about their crops, crop rotations, inputs, and
other practices used on their farms, including a soil
fertility management plan. The 590 implementation
requirement developed by following this guide

can likely be used to meet many of the requirements
related to soil fertility. Additionally, this information
can be used to help organic growers track the trajectory of the SOM because organic rules state that the
grower must maintain or improve SOM content.

Figure 8. A diversified organic farm manages nutrients in blocks to ensure the varying conditions and crops are appropriately considered.
Photo: Sarah Brown (Oregon Tilth)

Appendix A. Tables
Table 4. Nutrient analysis (percent by weight) of common organic fertilizer materials
(Gaskell et al., 2007)
Potassium (% K2O)
Material
Nitrogen (% N)
Phosphorus (% P2O5)
Chilean nitrate
Blood meal
Feather meal
Fish meal/powder
Seabird & bat guano
Meat and bone meal
Soybean meal
Processed liquid fish residues*
Alfalfa meal
Pelleted chicken manure
Bone meal
Kelp
Soft rock phosphate
Potassium-magnesium sulfate
Cocoa shells
Cottonseed meal
Granite dust
Hoof & horn meal
Seaweed, ground
Muriate of potash (KCI)

16
12
12
10-11
9-12
8
7
4
4
2-4
2
<1 0 0 1 6 0 11 1 0 0 0 0 6 3-8 5 2 2 1 1.5 15 0 15-30** 0 1 2 0 2 0.2 0 0 0 0 2 1-2 1 1 2 1 1.5 0 4 0 22 3 2 5 0 2 60 Values given for general information purposes only. Use the actual N-P2O5-K2O analyses provided by supplier in preparing the nutrient management plan. * All analyses are % by weight, as specified in state fertilizer laws. For liquids, product density (weight per gallon) should be used to calculate nutrient application rate: (g/ac)*(lb nutrient/g)=(lb nutrient/ac) * *Soft rock phosphate provides only 1-3% of its P in acid soils, and little or no P in soils with pH over 7. 14 Table 5. Nutrient Content of Common Animal Manures and Manure Composts This table includes general estimates of nutrient availability for manures and composts. These can vary widely depending on animal feed, management of grazing, the age of the manure, amount and type of bedding, and many other factors. Manure applications must be done in accordance with NOP 205.203 C.1-3. See page 4. Production Guide for Organic Snap Beans for Processing. 2012. (A. Seaman, ed.) Cornell University Coop¬erative Extension. 50 p. http://nysipm.cornell.edu/organic_guide/bean.pdf Total N P2O5 K2O Nutrient content lbs/ton Dairy (with bedding) Horse (with bedding) Poultry (with litter) Composted dairy manure Composted poultry manure Pelleted poultry manure 3 Swine (no bedding) N1 1 N2 2 P2O5 K2O Available nutrients lbs/ton in first season 9 14 56 12 17 80 4 4 45 12 39 104 10 14 34 26 23 48 6 6 45 3 6 40 2 3 16 2 5 40 3 3 36 10 31 83 9 13 31 23 21 43 10 9 8 8 3 7 7 Nutrient content per 1000 gal Available nutrients per 1000 gal in first season Swine finishing (liquid) 50 55 25 25 * 20 + 44 23 Dairy (liquid) 28 13 25 14 * + 10 23 11 1. N1 is an estimate of the total available for plant uptake when manure is incorporated within 12 hours of applications. 2. N2 is an estimate of the total N available for plant uptake when manure is incorporated after 7 days. 3. Pelletized poultry manure compost. * injected + incorporated 15 Table 6. Pounds of fertilizer/acre needed to provide 20 to 100 pounds of N, P, K per acre. This table is divided into three sections. Production Guide for Organic Snap Beans for Processing. 2012. (A. Seaman, ed.) Cornell University Cooperative Extension. 50 p. http://nysipm.cornell.edu/organic_guide/bean.pdf Sources of Nitrogen Blood meal 13% N Soy meal 6% N (x 1.5*) also contains 2% P and 3% K2O Pounds of fertilizer per acre to provide 20 to 100 pounds of N per acre 20# N 40 60 80 100 150 310 460 620 770 500 1,000 1,500 2,000 2,500 Fish meal 9% N (also contains 6% P2O5) 220 440 670 890 1,100 Alfalfa meal 2.5% N also contains 2% P and 2% K2O 800 1,600 2,400 3,200 4,000 Feather meal, 15% N (x 1.5*) Chilean nitrate 16% N cannot exceed 20% of crop’s need. 200 400 600 800 1,000 125 250 375 500 625 Sources of Phosphorus Pounds of fertilizer per acre to provide 20 to 100 pounds of P2O5 per acre 20# P205 40 60 80 100 Bonemeal 15% P2O5 130 270 400 530 670 Rock Phosphate 30% total P2O5 (x 4*) 270 530 800 1,100 1,300 Fish meal 6% P2O5 (also contains 9% N) 330 670 1,000 1,330 1,670 Sources of Potassium Pounds of fertilizer per acre to provide 20 to 100 pounds of K2O per acre 20# K2O 40 60 80 100 Sul-Po-Mag 22% K2O (also contains 11% Mg) 90 180 270 360 450 Wood ash (dry, fine, grey) 5% K2O, also raises pH 400 800 1,200 1,600 2,000 Alfalfa meal 2% K2O also contains 2.5% N 1,000 2,000 3,000 4,000 5,000 Greensand or Granite dust 1% K2O (x 4*) 8,000 16,000 24,000 32,000 40,000 40 80 120 160 200 Potassium sulfate 50% K2O * Application rates for some materials are multiplied to adjust for their slow-to-very-slow release rates. 16 Table 7. Plant-Available Nitrogen (PAN) Estimates for Uncomposted Manure This table is based on Oregon State University’s organic fertilizer calculators, which compare the nutrient values and cost of cover crops, organic and synthetic fertilizers, and compost. One calculator is for larger acreages, providing numbers on a per-acre basis, and one is for smaller plots, providing numbers on a per-square-foot basis. These tools help calculate organic fertilizer needs and can be accessed at http://smallfarms.oregonstate.edu/node/175833/done?sid=476 Total N analysis (percent dry weight) of uncomposted fresh manure or other uncomposted organic fertilizer product Your value Total N (% dry weight) 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 7.0 8.0 9.0 10.0 11.0 12.0 PAN Estimate After After 4 weeks 10 weeks % PAN % PAN -23 -15 -8 0 8 15 23 30 38 45 53 60 60 60 60 60 60 60 -8 0 8 15 23 30 38 45 53 60 68 75 75 75 75 75 75 75 Total N analysis (lbs N per dry ton) of uncomposted fresh manure or other uncomposted organic fertilizer product Your value lb total N per dry ton 10 20 30 40 50 60 70 80 90 100 110 120 140 160 180 200 220 240 PAN Estimate After After 4 weeks 10 weeks lbs PAN lbs PAN per dry ton per dry ton -2 -1 -3 0 -2 2 0 6 4 11 9 18 16 26 24 36 34 47 45 60 58 74 72 90 84 105 96 120 108 135 120 150 132 165 144 180 17 Table 8. Estimated Plant Available Nitrogen (PAN) from Finished Compost This table is based on the PAN equation used with the Oregon State University Organic Fertilizer and Cover Crop Calculator, http://smallfarms.oregonstate.edu/calculator Total N analysis of finished compost Your value Total N (% dry wt) 1.0 1.5 2.0 2.5 3.0 PAN Estimate 10 wk % PAN 0 5 10 10 10 Total N analysis of finished compost Your value lb total N per dry ton 20 30 40 50 60 PAN Estimate 10 wk lb PAN per dry ton 0 1.5 4.0 5.0 6.0 Source: OSU Fertilizer & Cover Crop Calculator (online; 2013) Instructions 1. 2. 3. Find %N analysis of the compost in “Total N analysis” column. PAN estimates are listed on the same row in units of “%PAN” or “lb PAN per dry ton.” To get PAN estimate for “as-is” moisture content, multiply Table PAN estimate (given for oven dry product; 100% dry matter) x %DM/100 in “as-is” manure. Example Lab analysis of a compost is 1.5% N or 30 lb N per ton (dry weight basis). The “as-is” fertilizer product contains 40% dry matter and 60% moisture. From the Table above, PAN released in soil after 10 wk is estimated to be 5% of product total N analysis (dry weight basis), or 2 lb PAN per dry ton. At “as-is” dry matter content (40% in this example), the product provides about 0.8 lb PAN per “as-is” ton (calculated as 2 lb PAN per dry ton x 0.4). Use this table only when you are sure that compost is “finished”. Many poultry litter “composts” that smell of ammonia are not “finished” and they have PAN similar to fresh manure. Additional Considerations Compost analysis for mineral N (ammonium + nitrate-N) can provide useful data to guide application rate. First year PAN release from compost is approximately equal to the sum of ammonium + nitrate-N applied. Very little first-year PAN comes from mineralization of organic N in finished compost. Composts usually contain less than 3% total N. “Composts” with more than 3% N are often not finished, they are dried manure. 18 Table 9. Estimated Plant Available Nitrogen (PAN) from Cover Crops Table from PNW 636, Estimating Plant-available Nitrogen Release from Cover Crops (Sullivan and Andrews, 2012), ©Oregon State University. Used by permission. Total N analysis of cover crop Your value Total N (% dry wt) 1.0 1.5 2.0 2.5 3.0 3.5 4.0 PAN Estimate After 10 weeks % PAN Total N analysis of cover crop Your value lb total N per dry ton PAN Estimate After 10 weeks lb PAN per dry ton 0 13 23 32 40 47 54 20 30 40 50 60 70 80 0 4 9 16 24 33 43 Rationale Cover crop PAN can be estimated by a variety of methods. A general approach to estimating cover crop PAN is provided in the SARE publication “Managing Cover Crops Profitably.” The SARE approach uses “rule of thumb” estimates of cover crop biomass and N concentration and PAN. The approach described here is for growers who are willing to make some on-site measurements to estimate PAN from cover crops. Considerations • A laboratory analysis for cover crop total N as a percentage in dry matter (DM) is a good predictor of a cover crop’s capacity to release PAN for the summer crop. See “Biomass determination” on page 8 for a discussion of estimating the percent of dry matter. • When cover crops contain a low N percentage (<1.5% N in DM), they provide little or no PAN. • When cover crops contain a high N percentage (3.5% N in DM) they provide approximately 35 lb PAN per ton of dry matter. • PAN release increases linearly, as cover crop N percentage (in DM) increases from 1.5 to 3.5%. • Cover crops decompose rapidly, and release or immobilize PAN rapidly. Most PAN is released in 4 to 6 weeks after cover crop kill. • Values for cover crop PAN listed here are most applicable to winter cover crop/summer vegetable crop rotations in western Oregon and Washington. • The timing of PAN release will differ in regions outside of western WA and OR, but we expect a strong relationship between cover crop N% and PAN to be found in most locations. Instructions The table above is reproduced from PNW Extension publication 636, Estimating Plant-available Nitrogen Release from Cover Crops. To use these tables you will need to have either taken a lab analysis of your cover crop to identify the total %N or will be using an estimate based on Table 3. 1. Find %N analysis of the cover crop in “Total N analysis” column (far left). PAN estimates are listed on the same row in units of “%PAN” expressed as a percentage of total %N, or “lb PAN per dry ton.” Example The fresh weight of a rye/vetch cover crop is about 16.5 tons/ac (33,000 lbs/ac). With 15% dry matter the cover crop produced 4,950 lbs dry matter/ac. If total %N is analyzed or estimated to be 3%, percent PAN is approximately 40% (table 9). Multiply 4,950 lbs dry matter x (3/100) x (40/100) = 59 lbs PAN/ac. 19 Appendix B. Conversion Tables Table 10. Converting pounds per acre to pounds per 1000 square feet Pounds per acre 50 75 100 125 150 175 200 225 250 275 300 325 350 375 400 Pounds per 1000 square feet 1.1 1.7 2.3 2.9 3.4 4.0 4.6 5.2 5.7 6.3 6.9 7.5 8.0 8.6 9.2 One acre = 43,560 square feet X lbs per acre = Y lbs per 1000 square feet Example Example 100 lbs per acre = 3.7 oz per 100 square feet (100 lbs = 1,600 oz; 1,600 divided by 43,560 = .037 oz per sq. ft.; multiply by 100 to get 3.7 oz per 100 sq. ft.) Table 11. Converting percentages of material per dry ton to pounds of material per dry ton Percent of material Pounds of material dry weight basis per dry ton 0.5 10 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 X percent of material per dry ton = Y lbs of material per dry ton Example .5% per dry ton = 10 lbs per dry ton (.5% of material per dry ton = .005 x 2,000 lbs per dry ton = 10 lbs of material per dry ton) 20 Table 12. Nutrient Management Conversion Factors Measurement Unit Symbol Multiply by To Obtain Symbol Volume acre-inch gallon ac-in gal 27000 8.35 gallon pound gal lb Concentration parts per million ppm or mg/ kg ppm or mg/L ppm or mg/L % % % % lb/1000 gal 0.002 pound/ton lb/t 0.00835 0.227 20 83.5 2266 10000 27 pound/1000 gallon pound/acre-inch pound/ton pound/1000 gallon pound/acre-inch parts per million pound/acre-inch lb/1000 gal lb/ac-in lb/t lb/1000 gal lb/ac-in ppm lb/ac-in parts per million parts per million percent percent percent percent pound/ 1000 gallon Dry or wet Nutrients percent dry matter (total solids) percent moisture manure, dry wt. basis % DM 0.01 solids fraction DM % moisture 0.01 100/(%DM) moisture fraction manure, “as-is” basis MF phosphorus P 2.29 phosphate P2O5 potassium K 1.20 potash K 2O nitrogen in nitrate form nitrogen in ammonium form NO3- N 1 nitrogen N NH4- N 1 nitrogen N 21 Appendix C. References to NRCS Publications and Other Resources National Organic Program www.ams.usda.gov/AMSv1.0/nop Section 1. Determining Crop’s Need for N, P, and K (page 5) Baldwin et al. Crop Rotations on Organic Farms. www.cefs.ncsu.edu/resources/organicproductionguide/ croprotationsfinaljan09.pdf California Department of Food and Agriculture’s (CDFA) Fertilizer Research & Education Program. www.cdfa.ca.gov/is/fflders/frep.html Collins, D. Washington State University, Soil Testing: A Guide for Farms with Diverse Vegetable Crops. https://pubs.wsu.edu/ItemDetail.aspx?ProductID=15520 &SeriesCode=&CategoryID=&Keyword=EM050E Cornell Guides for Organic Fruits, Vegetables and Dairy. http://nysipm.cornell.edu/organic_guide/ Gaskell, M., R. Smith, J. Mitchell, S.T. Koike, C. Fouche, T. Hartz, W. Horwath, and L. Jackson. 2006. Soil Fertility Management for Organic Crops. University of California. 8 p. http://anrcatalog.ucdavis.edu/pdf/7249.pdf Idaho Nutrient Management, www.extension.uidaho. edu/nutrient. Look under Crop Nutrient Requirements. Oregon State University Nutrient Management Guidelines for Crops. http://extension.oregonstate.edu/catalog/details.php?searc h=nutrient+management&submit.x=0&submit.y=0 Nutrient Management for Commercial Fruit & Vegetable Crops in Minnesota. http://www.extension.umn.edu/ garden/fruit-vegetable/nutrient-management-for-commercial-fruit-and-vegetables-in-mn/ Mohler, et al. 2009. Crop Rotation on Organic Farms. http://palspublishing.cals.cornell.edu/nra_order.taf?_ function=view&ct_id=40 Section 2. Developing Nutrient Credits (pages 6-9) Andrews, N., D. Sullivan, J. Julian, and K. Pool. Oregon State University Organic Fertilizer and Cover Crop Calculators. http://http://smallfarms.oregonstate.edu/ calculator Bowman, G., C. Shirley, and C. Cramer. 1998. Managing Cover Crops Profitably. SARE Publication. 212 p. www.sare.org/publications/covercrops/ covercrops.pdf California Department of Food and Agriculture’s (CDFA) Fertilizer Research & Education Program. www.cdfa.ca.gov/is/fflders/frep.html Cornell Guides for Organic Fruits, Vegetables and Dairy. http://nysipm.cornell.edu/organic_guide/ Gaskell, M., R. Smith, J. Mitchell, S.T. Koike, C. Fouche, T. Hartz, W. Horwath, and L. Jackson. 2006. Soil Fertility Management for Organic Crops. University of California. 8 p. http://anrcatalog.ucdavis.edu/pdf/7249.pdf Horneck, D.A., Sullivan, D.M., Ownen, J.S., and Hart, J.M. 2011. Soil Test Interpretation Guide. Oregon State University. 9 p. http://extension.oregonstate. edu/sorec/sites/default/files/soil_test_interpretation_ ec1478.pdf Idaho Nutrient Management. www.extension.uidaho. edu/nutrient, look under Crop Nutrient Requirements Jackson, B.P., P.M. Bertsch, M.L. Cabrera, J.J. Camberato, J.C. Seaman, C.W. Wood. 2003. Trace element speciation in poultry litter. J Environ Qual. 2003 MarApr., 32(2):535-40. Magdoff, F., and H. Van Es. 2009. Building Soils for Better Crops. SARE. 292 p. www.sare.org/Learning-Center/Books/Building-Soilsfor-Better-Crops-3rd-Edition Moore, Amber. University of Idaho Cover Crop Calculator. http://www.extension.uidaho.edu/nutrient/ CC_Calculator/CC_page.htm 22 Miyao, G., P. Robbins, and M. Cain. 2001. Winter cover crops before late-season processing tomatoes for soil quality and production benefits. Final Report Summary, CDFA Fertilizer Research and Education Program (FREP). Oregon State University Fertilizer/Nutrient Management Guidelines for Crops http://extension.oregonstate.edu/catalog/details.php?sortn um=0134&name=Fertilizer+Guides&cat=Agriculture Schonbeck, M.W. 1988. Cover Cropping and Green Manuring on Small Farms in New England and New York: An Informal Survey. East Falmouth, MA. New Alchemy Research Report #10. Sullivan, D.M. and N.D. Andrews. 2012. Estimating plant-available nitrogen release from cover crops. Pacific Northwest Extension Publication 636. Oregon State University Extension. Corvallis, OR. 23 p. Zimmer, Gary F. 2000. The Biological Farmer. Acres, USA. 352 p. Section 3. Determining Nutrient Application Rates (pages 10-11) Andrews, N., D. Sullivan, J. Julian, and K. Pool. Oregon State University Organic Fertilizer and Cover Crop Calculators. http://http://smallfarms.oregonstate.edu/calculator Gaskell, M., and R. Smith. 2007. Nitrogen Sources for Organic Vegetable Crops. HortTechnology OctoberDecember 2007 vol. 17 no. 4, 431-441) Section 4. Evaluating Risk of Leaching and Runoff (page 12) Magdoff, F., and H. Van Es. 2009. Building Soils for Better Crops. SARE. 292 p. www.sare.org/Learning-Center/Books/Building-Soilsfor-Better-Crops-3rd-Edition Section 5. Calculating Nutrient Application Rates Based on Risk Analysis (page 13) Organic Fertilizer Association of California. www.organicfertilizerassociation.org Available N, P and K in Organic Fertilizer Available N in Organic Fertilizers (in Production Guide for Organic Snap Beans for Processing). 2012. Cornell University Cooperative Extension. 50 p. http://nysipm. cornell.edu/organic_guide/bean.pdf NRCS Agricultural Waste Management Field Handbook. www.nrcs.usda.gov/wps/portal/ nrcs/detailfull/national/technical/ecoscience/ mnm/?&cid=stelprdb1045935 Plant-Available Nitrogen (PAN) from Cover Crops Selected characteristics of important cover crops for California, in: Selecting the right cover crop gives multiple benefits, Ingels, C., et al. October 1994. http://ucce.ucdavis.edu/files/repository/calag/ tab4805p45.jpg Sullivan, D.M. and N.D. Andrews. 2012. Estimating plant-available nitrogen release from cover crops. Pacific Northwest Extension Publication 636. Oregon State University Extension. Corvallis, OR. 23 p. http://small- 23 farms.oregonstate.edu/sites/default/files/WNMC11_Sullivan_p55.pdf Other Resources eOrganic provides resources for people seeking information about organic agriculture. The website is part of eXtension, which draws on the expertise of staff at American land-grant universities and extension programs. www.eorganic.info ATTRA’s Sources of Organic Fertilizers and Amendments Database. https://attra.ncat.org/attra-pub/org_fert/ Building Soils for Better Crops and Crop Rotation on Organic Farms: A Planning Manual. These and many other useful publications are free to download from the USDA’s Sustainable Agriculture Research and Education SARE. www.sare.org/Learning-Center/Books Cornell’s Soil Health Assessment Training Manual Free to download at: http://soilhealth.cals.cornell.edu/ extension/manual.htm Manures for Organic Crop Production. George Kuepper. 2003. ATTRA publication IP127. www.attra.ncat.org/soils.html Ohio State University’s The Biology of Soil Compaction Fact Sheet (2009). ohioline.osu.edu/sag-fact/pdf/0010.pdf Organic Center’s Assessing Soil Quality in Organic Agriculture (2006). www.organic-center.org/reportfiles/ SoilQualityReport.pdf NRCS Soil Quality/Soil Health website. www.soils.usda.gov/sqi Soil Fertility in Organic Systems: A Guide for Gardeners and Small Acreage Farmers (2013). Pacific Northwest Extension Publication 646. https://pubs.wsu.edu/ItemDetail.aspx?ProductID=1558 5&SeriesCode=&CategoryID=&Keyword=646 Web Soil Survey. http://websoilsurvey.nrcs.usda.gov/ app/HomePage.htm 24 Regional Organic Fertilizer Vendors IDAHO C & R Organic Topsoil 10791 Iowa Ave. Payette, ID 83661 Phone: (208) 642-3545 Ida-Ore Inc. 3778 McGonigull Street Boise, ID 83703 Phone: (208) 515-6933 Appendix D. Implementation Requirement Worksheet 590 Organic NMP Implementation Requirement (IR) Natural Resources Conservation Service NUTRIENT MANAGEMENT SPECIFICATION SHEET Client: County: Prepared by: Jan-13 Tract: Fields: Date: Acres: DESIGN APPROVAL: Practice Code NO. 590 PRACTICE LEAD DISCIPLINE Nutrient CED-EE& Management BSCD-Agron JOB CLASS CONTROLLING FACTOR UNITS I II III IV Area Acres 160 320 640 All This practice is defined as Job Class: Design Approved by: /s/ Job Title: Date: CLIENTS’ ACKNOWLEDGEMENT STATEMENT: The Client acknowledges that : a. They have received a copy of the specification and understand the contents and requirements. b. The following information must be provided to NRCS by the client before this practice can be certified as applied : ❏ Nutrient management application records including soil, water plant and organic byproduct test results as specified in the plan; ❏ Documentation of quantities, analyses, sources, dates, and application methods of nutrients applied; documentation of weather conditions and soil moisture at the time of application, documentation of lapsed time to manure incorporation, rainfall, or irrigation. ❏ Periodic review of nutrient management including adjustments made; at a minimum this plan will be reviewed with each soil test cycle. c. It shall be the responsibility of the client to obtain all necessary permits and/or rights, and to comply with all ordinances and laws pertaining to the application of this practice. Accepted by: /s/________________________________________ Date: _____________________ CERTIFICATION I have completed a review of the information provided by the client and certify this practice has been applied. Certification by: /s/______________________________________________ Date:______________________ Job Title: _____________________________________ The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 25 Organic Nutrient Management Specification Natural Resources Conservation Service NUTRIENT MANAGEMENT PLAN Client: Tract Number: Field Number(s): Select all purposes that apply ❏ Budget and supply adequate nutrients for plant production ❏ ❏ ❏ ❏ ❏ Minimize ag nonpoint source pollution of surface and groundwater resources (water quality) Properly utilize manure/organic materials as a plant nutrient source Maintain or improve soil condition Protect air quality by reducing nitrogen emissions (ammonia and NOx compounds) and the formation of particulates Attach an aerial photo or site map showing fields where nutrient management is being implemented NOTE: You may have criteria to meet that are NOT handled in this job sheet, please refer to the standard. FIELD AND CROP INFORMATION List crop rotation. Identify current crop with a check. P Index: No Data Field Current Crop ❏ ❏ ❏ ❏ ❏ ❏ Date: Depth: N (NO3 + NH4) Soil Map Unit: Yield units SOIL TEST INFORMATION* Laboratory Used: Certified Lab ❏ P** K Buffer pH OM% Other nutrients: Use ppm for units, refer to last page of job sheet for conversions * For some crops (e.g., berries and tree fruit), Extension recommends using leaf analysis rather than soil tests. ** Use either Bray P1 or Olsen sodium bicarbonate tests consistently. RECOMMENDED NUTRIENTS TO MEET YIELDS P2O5 PAN (lbs/acre) Reference (See p.5): Notes on Adjustments: 26 (lbs/acre) K2O (lbs/acre) pH NITROGEN SOURCES Credits PAN (lbs/acre) 1. Adjustment to soil N Mineralization (See p. 7; Table 2) 2. Nitrate from irrigation water (See p. 6; Table 12) 3. Nitrogen from previous cover crop (See p.8-9; Tables 3 and 9) 4. Other source(s) 5. TOTAL N CREDITS NUTRIENTS TO APPLY Nutrients to be applied to the field. Rate (lbs/acre) PAN (lbs/acre) P2O5 (lbs/acre) K2O (lbs/acre) Other (lbs/acre) 6. Manure** rate per acre (See p. 7; Table 7) 7. Compost*** rate per acre (See p. 7; Table 8) 8. Specialty Organic Fertilizer (See Table 4) Product: Analysis: 9. Total Organic Inputs and Credits (add lines 5-8 for PAN; 6-8 for others) 10. Re-enter recommended nutrients to meet yields (See p.5) 11. NUTRIENT STATUS (subtract line 9 from line 10) If the number on line 11 is positive, this indicates over application. If the number on line 11 is negative, this indicates under application. If the number is 0, then planned applications meet and do not exceed crop requirements. Include an explanation of these numbers, especially as they relate to the Phosphorus Index (see Agronomy Technical Note no. 26 and worksheets are in Section IV of the Oregon FOTG under CPS 590 Nutrient Management). Describe Timing (when organic applications are and are not going to occur) and Application Methods (surface applied with or without incorporation, time lapse until incorporation, applied at planting with tillage, injected, and other details relevant to how the organic amendments are applied). Other Information/ Considerations to Nutrient Management Plan: 1) Calibration of application equipment is required. See Calibration tab for guidance on equipment calibration. Fillable calibration worksheets are available on Oregon’s eFOTG, Section IV, Conservation Practices, WasteUtilization (633) Job Sheet and shall be attached to this nutrient management plan and reviewed with the producer. **Manure: Manure can be applied to organically grown crops, but with pre-harvest interval (PHI) restrictions (See page 4). ***Compost: Only agricultural products can be certified. Thus, soil and compost are not eligible for organic certification. However, see page 4, §205.203, C.2i-iii relating to how compost can be used and produced on organic farms. 27 Additional information/requirements ❑ ❑ Location of sensitive areas Soil test schedule including designation of critical fields Nutrient Application Bullets ❑ ❑ ❑ ❑ * Apply nutrient materials uniformly to application area(s). * Nutrients shall not be applied to frozen, snow-covered, or saturated soil if the potential risk for runoff exists. *Nutrient applications associated with irrigation systems shall be applied in a manner that prevents or minimizes resource impairment. *Calibrate application equipment to ensure recommended rates are applied. See attached information on equipment calibration. Operation and Maintenance The client is responsible for safe operation and maintenance (O&M) of the practice. O&M includes: • Periodic plan review: At a minimum, plans will be reviewed and revised with each soil test cycle. • Conduct additional manure analyses when there are significant changes in animal numbers and/or feed management. • Calibrate application equipment to within __% of the recommended rate. • Document the actual rate at which nutrients were applied. • Handle all nutrient material with caution. • Wear appropriate protective clothing. • Clean up residual materials from equipment and recycle or dispose of properly. • Recordkeeping: soil/water/organic materials analyses, quantities/analyses/sources of nutrients applied, dates and methods of application, weather conditions and soil moistures at the time of application, lapsed time to incorporation/rainfall/irrigation, crops planted, planting/harvest dates, crop yields, crop residues removed, and the specifics of plan reviews. 28 The Waste Utilization Worksheet below can be used to develop estimates for the lbs/acre of nutrients applied to a field in the form of “waste,” an unfortunate term in this context. Proper calibration of application machinery is needed to know how much material has been applied, but the nutrient analysis of the material must also be known in order that the lbs nutrient/acre can be calculated. 633 OR-Specification Natural Resources Conservation Service May 2003 WASTE UTILIZATION WORKSHEET Spreader Equipment Calibration (Using a Full Spreader Load) Name: Date: Operator: Spreader ID: Perform the following operations to calibrate the solids spreader equipment: ! Determine the weight of the waste material loaded in the spreader by using truck scales to weigh the spreader equipment when it is empty and full. ! Spread the loaded spreader on the field using consistent speed and spreader settings to cover the field uniformly. Spread in a rectangular pattern so the area calculation will be simple. Record engine rpm and gear settings used. ! Measure the length and width covered by the full load and compute the application rate in tons per acre using this worksheet. Data and Calculations: Steps A B ID of Calibration Test C D E F 1. Date of calibration test2. Engine RPM during spreading 3. Gear selected during spreading 4. Weight of empty spreader (lb) = 5. Weight of loaded spreader (lb) = 6. Weight of Waste in spreader (lb) line 5 – line 4 = 7. Length of spreading area (ft) = 8. Width of spreading area (ft) = 9. Area spread (sq ft) line 7 x line 8 = 10. Waste applied (lb/sq ft) – line 6 ! line 9= 11. Convert to tons per acre Line 10 x 21.78= 12. Average Application Rate (tons per acre) – Sum of values in cells A11 through F11 divided by the total number of calibrations completed = Additional Notes: 29

Northwest

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3980, 3980, Nutrient-Management-in-Organic-Systems-Idaho-Implementation-Guide.pdf, Nutrient-Management-in-Organic-Systems-Idaho-Implementation-Guide.pdf, 2390732, https://cms.organictransition.org/wp-content/uploads/2024/01/Nutrient-Management-in-Organic-Systems-Idaho-Implementation-Guide.pdf, https://cms.organictransition.org/resource/nutrient-management-plan-for-organic-systems-idaho-implementation-guide/nutrient-management-in-organic-systems-idaho-implementation-guide-pdf/, , 1, , , nutrient-management-in-organic-systems-idaho-implementation-guide-pdf, inherit, 3979, 2024-01-08 08:09:11, 2024-01-08 08:09:11, 0, application/pdf, application, pdf, https://cms.organictransition.org/wp-includes/images/media/document.png
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