Balanced Crop Nutrition

PRODUCED BY THE MOSAIC COMPANY

BALANCED CROP NUTRITION

Building a Foundation forBetter Performance

Supplement to

MOSC-0067 SF_Supp_r20.indd 1 10/28/10 8:49 AM

©2010. The Mosaic Company. All rights reserved. K-Mag is a registered trademark of The Mosaic Company. KMAG-0060

TUNE IN TO K-MAG.

HIGHER YIELDS.FOR

A

• Ask for K-Mag® in your next fertilizer blend

• Potassium, magnesium and sulfur — three nutrients in one

• All nutrients are readily available to the crop

• Visit www.kmag.com to view the new informational video


The recent accomplishments of North America’s farmers are truly

noteworthy. Record harvests have produced more food, fuel, feed

and fiber than at any time in our history. Optimism in agriculture

abounds — and with good reason.

But with success comes the challenge to accomplish more. Even

with bin-busting production records in 2008 and 2009, supply

merely kept pace with surging demand. Last November, the U.N.

Secretary General reported one billion people are hungry, and by

2050, the world will have two billion more mouths to feed — about

nine billion in total — meaning we’ll have to produce 70 percent

more than we do today just to keep up. Water, land, energy and fer-

tilizer are finite resources, and agriculture must develop sustainable

solutions to provide the critically needed increase in food supply.

Meeting this challenge will require new technologies, new crop

management strategies and a commitment to innovation. As the

philosopher Ralph Waldo Emerson said, we must not just “go

where the path may lead, [but] go instead where there is no path

and leave a trail.”

It’s with this pioneering spirit and quest for better information that

The Mosaic Company brings you the “Balanced Crop Nutrition”

supplement to Successful Farming. Technology continues to evolve

and promises higher levels of crop performance, but to maximize

this potential, fertility strategies also must move forward. Fertilizer is

the foundation on which all high-yield crop systems must be based.

Inside, you’ll find new thinking on building a well-balanced fertility

program, highlights from the latest research uncovering the nutrient

requirements of today’s new hybrids, real experiences of producers

implementing innovative best management practices, and facts on

the latest advancements in fertilizer.

Mosaic is committed to helping the world grow the food it needs.

We’re confident you will find information in this supplement to help

you grow more as well.

Sincerely,

Richard N. McLellan

Sr. Vice President, Commercial

The Mosaic Company

TABLE OF CONTENTS

Nutrition for

Next Generation Seed .......................................... 2

The Basics of Balanced Fertility

N and K Work Together for Higher Yields ...................................................... 4

Brush up on Soil Fertility ........................... 13

N, P, K —

the Foundation of Production

Rescue Nitrogen Application Often Boosts Corn Yields ................................... 6

Optimizing Potassium Critical for Top Yields........................................................... 5

Managing P Soil Test Values ............................18

Production Management Profiles

Prairie Pothole Production Challenges Denny Friest, Garden City, Iowa .....................10

Little Is “Typical” About Approach to Crop Production Fairholme Farms, Lewisville, Ind. ...................17

An “Edge” That Leaves Nothing to Chance Kriss Schroeder, Colby, Kan. .......................... 20

Planning Pays

Fertilizer Offers Performance With Return .... 5

Are You Ready for Higher Yields? .................................. Back Cover

Unlocking the Secrets to Higher Yields ...... 8

The Need for MicroNutrients

Magnesium—Often Forgotten, but Most Essential ................................................21

Changes Creating Need for Sulfur .................14

Understanding Zinc Deficiency ...................... 22

The Production Challenge —

Meeting Tomorrow’s

Growing Demand ..................................................24

To view these articles online or for

more balanced-nutrition information,

visit www.Back-to-Basics.net.

This information produced and presented by The Mosaic Company. 1


B A L A N C E D C R O P N U T R I T I O N

Next-Generation Seed Requires

New Approach to Fertility

B Y T O M F R Y

T h e M o s a i c C o m p a n y


The Mosaic Company is working

to bring farmers innovative fertilizer

products and information to provide

better understanding of balanced crop

nutrition. To this end, the company

surveyed farmers, fertilizer dealers and

university soil scientists across Asia,

South America and North America,

investigating their needs and wants for

fertilizers and plant nutrition services.

“Overwhelmingly, the results

showed farmers wanted to go beyond

existing N, P and K fertilizers to

products that offer balanced nutri-

tion,” says Dean Fairchild, assistant

vice president of Agronomy for The

Mosaic Company. “Their priorities

were products to help manage needs

for nutrients such as sulfur, zinc and

also boron,” relates Fairchild.

After intensive research, Mosaic

scientists and engineers developed

a patented process to manufacture

a fertilizer granule that incorporates

nitrogen, phosphorus, sulfur and zinc.

The product is MicroEssentials® SZ,™

and it is a major breakthrough in

dry-fertilizer technology. The unique

chemistry of this phosphorus-based

product delivers a balanced ratio

of essential nutrients for better nutri-

ent uptake by plants. In addition,

by including all nutrients in one

granule, distribution is uniform, so

every plant receives the correct

amount of each nutrient.

The MicroEssentials family of prod-

ucts delivers sulfur and phosphorus

in the proper ratio for most crops, so

these two nutrients are more available

and easier for plants to use. Nitrogen

is provided in the readily available

ammonium form to help get young

plants off to an early start. Finally,

MicroEssentials includes sulfur in both

the elemental and sulfate forms for

season-long availability.

Studies show MicroEssentials

fertilizer enhances plant uptake of

phosphorus up to 30 percent and

improves zinc uptake by up to

45 percent as compared to a typical

blend. These improvements in nutrient

utilization mean a better return on the

investment in fertilizer. For more de-

tails, visit www.microessentials.com.

decrease,” Below points out. “As

corn rootworm-resistant hybrids

become increasingly popular and are

planted every year, it will be important

to take these trends into account as

nutrient management plans and fertilizer

recommendations are formulated.”

With nearly half of U.S. corn acres

planted to transgenic hybrids costing as

much as $100 to $140 per acre for seed,

it is important growers apply the nutri tion

needed to optimize yields and generate

a good return on these genetics.

Table A.

Increased Yield of Rootworm-Resistant Hybrids Removes More Soil Nutrients

CRW-RESISTANT

vs. NON-RESISTANTDIFFERENCE %

Yield increase 14 %

N removal 14 %

P removal 24 %

K removal 19 %

S removal 17 %

Zn removal 27 %

Champaign, IL 2008; average of two hybrid pairs

Seed industry leaders Dow

AgroSciences, Monsanto, Pioneer

Hi-Bred and Syngenta have all set

aggressive goals to increase corn

yields. Doubling yields by 2030 is an

admirable and daunting goal that plant

breeding and biotechnology are sure to

play a huge role in achieving. However,

in addition to these new technologies,

new management practices also will be

required to optimize yields.

This season, 47 percent of U.S. corn

acres were planted to stacked-trait,

insect-resistant hybrids, but little is

known about the effect of technology

on corn nutrient uptake and the exact

nutrition needed to optimize yields.

That’s why researchers at the University

of Illinois—Urbana-Champaign are

comparing the nutritional needs of

these hybrids to their non-resistant

counterparts. Preliminary research

results show the nutrient uptake of

resistant hybrids is signi� cantly greater

than their non-resistant counterparts.

Intact roots absorb nutrients more ef� ciently

“CRW-resistant hybrids change every-

thing,” says Dr. Fred Below, professor

of Plant Physiology, University of Illinois.

“Because rootworm larval feeding is

suppressed, and therefore the root

system protected from damage, the

corn plant absorbs nutrients more

ef� ciently and ultimately realizes a

higher yield potential.”

More ef� cient nutrient uptake

suggests higher levels of nutrients are

needed to achieve that added yield

potential. In the University of Illinois

trials, CRW-resistant hybrids yielded

205 bu /acre, while the non-resistant

hybrids yielded 179 bu /acre, a

14 percent difference.

“Results of our initial trials show

that the per-acre removal rates of

nutrients [N, P, K, S, Zn] are from 14 to

27 percent greater for hybrids with the

rootworm-resistant gene,” adds Below.

“In fact, both the yield and the concen-

tration of nutrients in the grain were

higher for the transgenic hybrids.”

“As we look at these results, we see

very large increases of zinc (Zn) and P

removal, in particular, which means soil

test levels of these nutrients may rapidly

Innovation in Fertilizer Technology



By understanding how nutrients

work together, farmers can optimize

production and investment in fertilizer

while minimizing the opportunity for

excess nutrients to negatively impact

the environment. Potassium (K) and

nitrogen (N) are two vital nutrients that

create greater bene� ts working together

than alone.

Research studies from the University

of Illinois illustrate how potassium

nutrition and fertilizer N interact to

markedly increase yields, response to

fertilizer N and N use ef� ciency (Figure

1). It is important to keep in mind that

these same types of P and K interac-

tions will also occur with other nutrients

and non-nutrient crop inputs.

Illinois

Application Rate (lbs N/acre)

0 lb K20/acre

96 lbs K20/acre

144 lbs K20/acre

Co

rn G

rain

Yie

ld (

bu

/ac

re)

200

150

100

50

00 80 120 180 240

Figure 1. Potassium improves yield response to N fertilizer and N ef� ciency.University of Illinois

Adapted from Better Crops, Vol. 82 (1998, No. 3)

What do these interactions mean for the future?

With technology and production

changes, U.S. corn yields have

increased from about 100 bu /acre in

1985 to approximately 160 bu /acre

in 2009. Many farmers are growing

corn yielding more than 200 bu /acre.

But can traditional nutrient recom-

mendations meet the demands of

tomorrow’s high corn yields? Evidence

suggests the levels of inputs and

management necessary for corn yields

in the 150 bu /acre range may not be

enough for modern yield levels of

250+ bu /acre.

A Kansas study combined higher

plant populations and an enhanced fer-

tility program to maximize irrigated-corn

Table B.

Higher Nutrient Levels Required for Plant Population ResponseKansas State University

CORN YIELDS BU/ACRE

PLANT POPULATIONTRADITIONAL1

FERTILITYENHANCED2

FERTILITYFERTILITYRESPONSE

28,000 202 225 23

42,000 196 262 66

Population Response – 6 37

1 230 lbs N /acre, 30 lbs P2O5 /acre P and K Soil Tests = High2 230 lbs N /acre, 100 lbs P2O5 /acre, 80 lbs K2O /acre and 40 lbs S /acre

Source: Kansas State University

yields (Table B). With traditional

university nutrient recommendations,

the higher plant populations yielded

slightly less than the traditional, lower

populations. However, when the fertility

program included additional P, K and

sulfur (S), the higher plant population

yielded 37 bu /acre more than the tradi-

tional, lower plant population. Likewise,

corn response to the enhanced fertility

program was only 23 bu /acre at the

lower plant population, but swelled to

66 bu /acre at the higher population!

Balanced and fully adequate fertility

programs will be fundamental com-

ponents of optimizing return from

improved genetics and new tech-

nologies/practices in the future while

protecting the environment.


Nitrogen and Potassium Work

Together for Higher Yields

B Y D A L E L E I K A M , P h . D .

L e i k a m A g r o M a x

4 This information produced and presented by The Mosaic Company.


Survival in today’s competitive

economic environment depends

upon each investment ultimately

providing a positive return. In corn

production, fertility is responsible

for about 40 percent* of the crop’s

yield—and fertilizer is proven to

provide a positive return on invest-

ment (ROI). Use the formulas below

the table to calculate the return from

fertilizing your own corn crop.

Fertilizer Offers Performance That Pays

Few investments offer this level of return

Optimizing Potassium Critical for Top YieldsSoil test trends coupled with environ-

mental factors indicate applying

potassium (K) fertilizer may be more

important than ever for optimum crop

yields. According to studies from the

International Plant Nutrition Institute

(IPNI), soil test K levels continue to de-

crease, and as a result, the percentage

of soils across North America in nega-

tive balance for K continues to rise.

“Research at Ohio State shows

that yields increased as soil test K

increased above critical soil levels,”

explains Dan Froehlich, agronomist

with The Mosaic Company. “A standard

benchmark is that potassium uptake for

a 180-bushel corn yield is 240 pounds

of potassium per acre. The critical level

of potassium in the soil for optimum

performance is approximately 165 ppm.

“The Ohio State results show yields

increased as K increased to 200 ppm

and 278 ppm. Nitrogen use also was

enhanced as soil K levels increased,”

Froehlich adds.

Agronomic and environmental condi-

tions also play a role in the availability

of nutrients for plant uptake. These

factors make supplemental K even

more important to optimize yields.

“Cool, wet years set up agronomic

challenges for crops that exacerbate

the impact of limited soil nutrients,”

says Steve Phillips, Southeast U.S.

region director with IPNI, a not-for-

pro� t, science-based organization

with a focus on agronomic education

and research support. “Season-long

excess soil moisture and resulting

compaction from planting, spraying

and harvest cause poor soil aeration.

“Oxygen is required for root nutri-

ent uptake; damp, compacted soils

are lower in soil oxygen, thus limiting

plants’ ability to uptake K. Continued

wet conditions make the situation more

complex,” Phillips explains.

Insuf� cient K may lead to reduced

nitrogen uptake, less developed roots,

lower protein content, greater suscep-

tibility to water loss and wilting, as well

as weaker stalks that are more prone

to lodging.

Prolonged cool temperatures plus

wet, compacted soils can cause

irreparable damage to yield potential

since more than 50 percent of the total

K is taken up by corn plants in the � rst

50 days. Compaction and wet soils

also may limit K uptake shortly before

pollination when corn plants remove

more than 15 pounds of K2O per acre

per day.

“Over time, continued removal of K

without annual fertilizer application will

lower soil test levels, and yield loss will

occur because K removal is a direct

contributor to crop yield,” says Phillips.

Visit www.Back-to-Basics.net for

more information about the importance

of K in a balanced fertility program.

Ohio

Application Rate (lbs N/acre)C

orn

Gra

in Y

ield

(b

u/a

cre

)

250

200

150

100

50

0

0 80 160 240 320

160 ppm K Soil Test

200 ppm K Soil Test

278 ppm K Soil Test

Figure 2.

Table C.

YEAR

FERTILIZER INVESTMENT/

ACRE($ /acre)

ESTIMATED YIELD

(bu /acre)

FERTILIZER COST($ /bu)

NEW CROP

PRICES($ /bu)

BUSHELS NEEDED TO

PAY FOR FERTILIZER

DOLLAR RETURN

PER DOLLAR SPENT

2008 $140.27 180 0.78 3.82 36.7 $1.96

2009 $145.63 180 0.81 4.09 35.6 $2.02

2010 (estimated) $ 96.94 180 0.54 4.29 22.6 $3.19

2011 (projected) $113.77 180 0.63 4.04 28.2 $2.56

As of Oct. 1, 2010

Corn—180 bu /acre corn following soybeans; N-P-K = 140–70–55

Fertilizer cost assumptions—N = $0.39 /lb, P2O5 = $0.68 /lb, K2O = $0.40 /lb

Fertilizer cost per bushel = fertilizer cost /yield

Bushels needed to pay for investment in fertilizer = fertilizer cost per acre/new crop price per bushel

*ROI assumes 40 percent of yield comes from fertilizer (based on university studies)

Dollar return per dollar invested = (0.40 x yield x new crop price)/cost of fertilizer

For updated info, visit www.Back-to-Basics.net.



In really wet years, a lot of preplant nitrogen is lost.

Wet weather causes nitrogen losses

somewhere virtually every year. In 2008

and 2009, very wet weather caused

major nitrogen losses in a huge chunk

of the Corn Belt.

“My rule of thumb is that more than

16 inches of rain from April through

June – or more than a foot in May and

June – will lead to nitrogen de� ciency

problems in a substantial number of

corn� elds,” says University of Missouri

agronomist Peter Scharf.

According to Scharf, last year nearly

all of Missouri, Arkansas, Kentucky,

and Tennessee, plus most of Illinois,

southern Indiana, and eastern Kansas

all had over 16 inches of rain from April

through June. In 2008, nearly all of Iowa

and Missouri, plus southern Illinois,

southern Indiana, southern Wisconsin,

eastern Nebraska, eastern Kansas, and

southeastern Minnesota received over

16 inches of rain during those three

crucial months.

“The level of risk depends on nitro-

gen fertilizer management and soil

properties as well as rainfall,” says

Scharf. “Among preplant applica-

tion strategies, spring application of

anhydrous ammonia has the lowest risk

of nitrogen loss. But any nitrogen-man-

agement strategy can be overwhelmed

by weather.”

Scharf developed a Nitrogen

Loss Scoresheet to help growers

identify � elds apt to respond to rescue

nitrogen based on nitrogen source,

date applied, soil type and degree of

wetness. It’s online at http://ppp.mis-

souri.edu/newsletters/ipcm/archives/

v17n10/ipmltr9.htm.

Farmers who went through back-to-

back wet years have been concerned

that the wet fall and winter of 2009-10

was setting the stage for another year

of nitrogen (N) losses and yield losses.

“My � rm belief after the last two years

is that every producer and every retail

organization need to have a plan for

making rescue N applications in place

before the season starts,” says Scharf.

“Rescue applications of nitrogen fertil-

izer can be highly pro� table when earlier

nitrogen applications have been lost

due to wet weather.”

Scharf cites the experience of Wayne

Flanary, a University of Missouri agron-

omy specialist in northwest Missouri.

Flanary applied 180 pounds of N as

anhydrous ammonia in late-November

2008. Nevertheless, corn in a low area

appeared to lack N early in the 2009

growing season. Where Flanary applied

an additional 60 pounds of N as dry

urea in June, the corn yielded 200 bu /

acre. Where he applied an additional


Rescue Nitrogen ApplicationOften Boosts Corn Yields

B Y R I C H F E E

C r o p s a n d S o i l s E d i t o r , S u c c e s s f u l F a r m i n g

Ryan Britt used a high-clearance

applicator to apply rescue nitrogen

for neighbors last year.

Reprinted from the May – June 2010 issue of Successful Farming magazine. © 2010 Meredith Corporation. All rights reserved.


Figure 3. University of Missouri research agronomist Kelly Nelson developed this chart to show which sources of nitrogen can be used at different growth stages of corn.

Rescue N Application Chart

1 ft. 2 ft. 3 ft. 4 ft.

Between Rows

Broadcast

Ammonium Nitrate, 32% UAN,or Urea + NBPT (Agrotain)

Ammonium Nitrate

Urea

32% UAN

Urea or Urea + NBPT (Agrotain)

120 pounds of N as urea, the corn

yielded 220. Where he didn’t apply any

rescue N, it yielded 170 bu /acre.

Aerial photographs are Scharf’s rst

choice for diagnosing N de ciency. “You

can get through all your acres much

more quickly and thoroughly based on

aerial photos than by ground-based

inspection,” he says.

“At fairly early stages (knee high),

aerial photos can help you identify likely

problem areas but should be ground-

truthed. At later stages (waist high or

taller), aerial photos provide reliable

indicators of which areas are experi-

encing N stress and how severe it is,”

Scharf says.

“My research suggests that aerial

photographs can be translated into

yield loss maps that make it easier

to decide how much can be spent

to correct the problem,” says Scharf.

“Aerial photographs can also be trans-

lated into variable-rate N maps that can

be plugged into a variable-rate appli-

cator. Nitrogen loss is nearly always

patchy, resulting in some areas that

need rescue nitrogen and other areas

that don’t.”

In the absence of aerial images, you

can tell a lot about corn’s N situation

simply by inspecting your elds.

“The appearance of the corn crop

is an excellent diagnostic tool,” says

Scharf. “Corn that is light green or

yellow-green is N-de cient nearly 100%

of the time in Missouri. However, corn

growing in waterlogged soil will be

N-de cient even if the N has not been

lost. This makes correct diagnosis more

dif cult. Sometimes this yellow corn will

green up when the soil dries out, and

no additional N is needed. By the time

you’ve been able to walk through the

eld for a week, the corn should look

substantially better if the N is still in the

soil. If not, a rescue N application is

called for.”

Several different sources of N can

be used for rescue applications. Corn

height and application method must be

considered when determining which N

source to use.

University of Missouri research agrono-

mist Kelly Nelson developed the Rescue

N Application Chart (shown above) based

on research by several agronomists.

Scharf says some people are

skeptical about recovering yield once

corn has been substantially stressed

by lack of N.

“My experience and research show

that corn has great capacity to use

rescue N to produce additional yield

until at least silking,” Nelson says.

“Research by others suggests that

this capacity extends at least a week

and probably usually two weeks past

silking.”

High-clearance applicators, which are

becoming increasingly common, enable

growers to dribble or inject liquid N

between the rows of tall corn.

Ryan Britt of Clifton Hills in north-

central Missouri applied rescue N for

several neighbors last year with the

Hagie applicator shown on the opening

page. Britt farms with his father, Randy,

and grandfather, Wayne.

Concerned about the risk of losing

preplant N, they switched to split appli-

cations of N in 2008. Last year, they

applied 60 pounds of N preplant then

sidedressed in June using N sensors to

adjust the rate on-the-go.

Nitrogen de ciency is evident on

lower leaves rst. Yellowing begins

at the tip of the leaf and proceeds

down the midrib.

The corn on the left received 40 pounds of rescue nitrogen (32%) while the row on the right did not. The extra N was applied 17 days before this photo was taken on July 16, 2005. The preplant rate was 120 pounds of NH3.

Reprinted from the May – June 2010 issue of Successful Farming magazine. © 2010 Meredith Corporation. All rights reserved.



Unlocking the Secrets

to Higher Yields

A N I N T E R V I E W W I T H F R E D B E L O W , P h . D .

U n i v e r s i t y o f I l l i n o i s a t U r b a n a - C h a m p a i g n


Table E.

Seven Wonders of the Corn Yield World

FACTOR BU/ACRE IMPACT

Weather 70+

Nitrogen 70

Hybrid Selection 50

Previous Crop 25

Plant Population 20

Tillage 15

Growth Regulators 10

Total = 260 bu/A*

* Represents the maximum yield level possible when each of these factors is optimized using standard crop management systems today and typical planting rates of 30,000 to 36,000 plants per acre.

World demand for food, feed, � ber and

fuel is increasing. Dr. Fred Below and

researchers at the University of Illinois—

Urbana-Champaign are assessing new

technologies and designing manage-

ment practices to unlock the secret to

higher yields. Here he shares details of

this effort.

You have spent your entire career

looking at corn physiology and factors

that impact yield. What are you focus-

ing on in your current research? There

are many new technologies available to

growers that are changing the face of

crop production and have the potential

to drive higher crop yields. For example,

today’s genetics are more tolerant of

the stresses of higher plant populations.

Corn rootworm (CRW) protection now

gives us a larger, more intact root system

so the corn plant can absorb nutrients

more ef� ciently. Fungicides protect

plants from yield-robbing diseases to

maintain plant health longer.

In our research, we’ve seen bene� cial

synergies from combining these manage-

ment tools. To move to the 300-bushel

level and beyond, we have to identify

the most ef� cient ways of combining

Table D.

Interaction of Technologies/Practices on Corn YieldUniversity of Illinois and The Mosaic Company

TRADITIONAL PROGRAM*

ENHANCED PROGRAM**

208 BU /ACRE 274 BU /ACRE

TECHNOLOGY/PRACTICEADDED TO TRADITIONAL PROGRAM OR REMOVED FROM ENHANCED PROGRAM

YIELD INCREASE ATTRIBUTED TO INDIVIDUAL PRACTICE

BU /ACRE

Additional P, S, Zn (MicroEssentials® SZ™) 7 18

Additional sidedress N 16 24

Higher plant population –15 14

Fungicide application –4 12

Genetics – CRW-resistant (triple-stack) 8 27

* Traditional program — Typical university recommendations without any enhanced inputs** Enhanced program — Typical university recommendations plus all enhanced inputs

these tools. In that effort, our research

is contrasting standard management

practices and planting populations with

a high-yield management approach

that pushes CRW-resistant hybrids

to 45,000 plants per acre, planted in

7½-inch twin rows on a 30-inch center.

It also incorporates 100 pounds of extra

sidedress N as a controlled-release

source as well as 100 pounds of P2O5

as MicroEssentials,® even though the

soil test suggested no additional P

was necessary.

As part of your high-management

system, you have ranked seven factors

that impact corn yield, and you refer

to them as the “Seven Wonders.”

Why are they important to success in

high-yield management systems? The

Seven Wonders are weather, nitrogen,

hybrid selection, previous crop, tillage,

plant population and a “catchall” I call

growth regulators that is represented by

the plant-health or performance aspect

of fungicides.

However, before we can uncover the

full potential of the Seven Wonders, there

are base prerequisites that must be

met. They are proper drainage, P and K

levels based on higher yield goals and soil

test values, plus effective weed control.

Your research shows that nitrogen

management has the second-biggest

impact on yield, right behind weather,

but what does your current research

suggest about the importance of man-

aging for P and K levels? There is no

doubt in my mind that to achieve high

yields, you have to meet base fertil-

ity levels in order to get the rest of the

Seven Wonders to reach their greatest

potential. Nitrogen, the Second Wonder,

is a major driver in corn yields, but we

are seeing that a balanced nutrition

approach is critical to helping nitrogen

achieve its full value, particularly toward

the 300-bushel level. We are seeing a

lot more cases impacted by the classic

law of the minimum. If the limiting nutri-

ent is P, K, S or Zn, that one de� ciency

can prevent the corn from getting the

full value of nitrogen applied. This is why

balanced fertility is an important man-

agement component of the high-yield

system I am evaluating.

Dr. Below’s Five Management Factors for a High-Yield Corn System

1Fertility – 100 lbs of P2O5 as MicroEssentials® SZ™ even though the soil test suggested no additional P was necessary.

2Nitrogen – 100 lbs of extra N as a controlled-release source for a total of 280 lbs of nitrogen

3Hybrid Selection – Triple-stack hybrid, locally adapted for speci� c environment

4 Population – 45,000 plants/acre planted in 7.5-inch diamond-patterned twin rows

5 Fungicide – Single application of a well-timed fungicide

Photo courtesy of Cargill.



duction ChallengesPrairie Pothole Poi Pothole Poses Production Ch

M A N A G E M E N T P R O F I L E

possibility our soils also need supple-

mental sulfur, we’ve been evaluating

MicroEssentials® SZ.™ We’ve seen good

yield response in strip trials.” In his

2009 comparison, the corn receiving

MicroEssentials produced 10.9 bu /acre

more than the untreated check and

6.8 bu /acre more than that which

received MAP.

Nitrogen management also is a signi� -

cant challenge, according to Friest. “We

monitor our N use very carefully. We’ve

seen evidence of signi� cant leaching of N

from fall-applied manure, so management

of this resource must be done carefully.”

He continues, “We’re not only looking for

economic bene� t to our fertility practices,

but also environmental bene� ts. We need

to be good environmental stewards, and

if we can maintain productivity with less

nitrogen, everyone wins.”

Encouraged by a program from ISA to

cut N use, Friest has decreased N applica-

tion by 25 to 30 percent, or 50 lbs /acre,

and now applies around 150 pounds when

targeting 200-bushel yields on corn

following corn. He prefers to apply N in

the spring to reduce the opportunity of

leaching and has seen yield advantages

to sidedressing in June with 50 lbs /acre.

Friest fully expects nutrient manage-

ment to remain high on his list of factors

to evaluate and closely control.

“We have a lot of good tools in our

arsenal. We just need to continue working

to see what � ts best,” he concludes.

20/20 AirForce is a trademark of Precision Planting, Inc.

mulch-till compared to moldboard plowing

and no-till.

As one of the original On-Farm Network

participants, he fully utilizes this manage-

ment tool to evaluate the yield bene� t of new

products and crop production practices.

“There are certain requirements partici-

pants must meet, but we can test anything

we’d like as long as there are three

replicated strips across the � eld,” Friest

explains. “Through the years, I’ve looked at

hog manure, fungicides, soil insecticides,

tillage, different plant populations and

various fertilizers. With all the new traits

available in seed, we are always looking at

new hybrids to see what will work best.”

MOISTURE COMPLICATES

NUTRIENT MANAGEMENT

Nutrient management is one of Friest’s

greatest challenges.

“We’ve been working very hard on

nutrient management over the last six

or seven years, and something is always

changing. It is frustrating,” he says.

For example, Friest has seen a

signi� cant drop in his normally high P soil

test levels, which he attributes to nutrient

draw-down from 200 bu /acre corn yields.

He also has found the use of phytase in

swine feeds has lowered P available from

manure, which is a source of N, P and K

for a portion of his acres.

He explains, “We know hog manure

now will not provide enough P to meet crop

removal rates of P for both corn and the

following soybean crop, so � elds receiving

hog manure also receive supplemental P to

provide a base of 120 lbs /acre for our 200

bu /acre yield goal.”

Friest adds, “To meet P needs and the

While most farmers are anxiously awaiting

long-promised drought-tolerant corn hybrids,

Denny Friest would welcome moisture-

tolerant hybrids on his north-central Iowa

farm. Too much moisture is often the

biggest challenge of farming the dense,

poorly drained Clarion-Nicolette-Webster

soils, which are typical of North America’s

vast Prairie Pothole region.

“It’s hard to complain about too much

moisture, but Mother Nature almost always

gives us more than what we’d like to have,”

relates Friest. “Our soil here is heavy, dense

and prone to ponding. I lose far more yield

to too much moisture than to not enough.

Moisture creates issues from planting

through the production season.” He has

installed 4-inch tile every 70 feet in several

� elds. Though tiling is not a total solution

to improving crop performance, it has

decreased yield variability across � elds.

TILLAGE IS A “MUST DO”

Friest also has learned getting the crop off

to a good start requires managing fall crop

residue using a disk ripper to help soils

warm up and dry out the following spring.

The goal of this mulch-till approach is to

open up the soil but leave 70 percent of the

corn residue on the soil surface. His planter

is equipped with trash whippers to manage

the remaining residue and further warm

the seedbed. A 20/20 AirForce™ system on

the planter is used to optimize seed-to-soil

contact for better germination.

Mulch tillage has proved particularly

essential to maintain yields in corn

following corn. Replicated strip trials

conducted through Friest’s participation

in the Iowa Soybean Association’s On-Farm

Network veri� ed the advantages of

Denny Friest

Garden City, Iowa

Participant, Iowa Soybean Association

On-Farm Network

• Corn

• Soybeans

• Swine farrow-to-� nish



• The roles of other essential nutrients

such as sulfur, magnesium and zinc

in increasing crop yield and quality

• Why new insect-resistant, multi-

trait hybrids may bene� t from a new

approach to fertility

• How to identify yield-robbing nutrient

de� ciencies through visual analysis

• How to identify “hidden de� ciencies”

not visible to the eye

Visit www.Back-to-Basics.net

Order or bookmark

these valuable tools

and online resources:

“Ef� cient Fertilizer Use” manual. This

comprehensive guide to proper fertilizer

uses, soil pH, soil sampling and much

more is FREE! Order the CD-ROM, or

access the chapters online.

Legendary billionaire Warren Buffett has

inspired legions of followers worldwide

to heed his homespun moneymaking

advice: Invest in what you know.

Over a lifetime of investments,

including the 40-acre farm he purchased

in the 10th grade, Buffet demonstrated

that when investors have an intimate

knowledge about a topic, they naturally

spot more opportunities. The same

is true for farmers who gain deeper

knowledge of crop inputs, like fertilizer.

To help farmers learn about crop

nutrition to gain con� dence in their

fertilizer decisions, The Mosaic

Company developed the free educa-

tional soil fertility resources found at

www.Back-to-Basics.net. At this

educational website, farmers can learn:

• When and why N-P-K applications

alone are not always enough to

optimize yields

B R U S H U P O N S O I L F E R T I L I T Y B A S I C S

Let www.Back-to-Basics.net be Your Guide

Regional agronomic updates. Click

on your region of the interactive map

to receive timely updates on local crop,

soil and weather conditions, along with

nutrient management tips, from the

expert staff at the IPNI.

Crop nutrient de� ciency photo library.

Nutrient de� ciencies in crops reduce

yields, grain/forage quality and pro� ts to

the farmer. Browse this image gallery for

help to identify various nutrient de� ciency

symptoms for 19 different crops.

After you visit www.Back-to-Basics.net

to brush up on soil fertility basics, contact

your local fertilizer dealer for help to

formulate the balanced soil fertility

pro gram needed to optimize your crop

production investment. The more you

know about nutrient needs of your

crops, and the needs of your soil, the

greater your opportunities to increase

yields and pro� ts.



CROP NUTRIENT UPTAKE lb/A

Crop Yield (A) N P205 K20 Mg S

Alfalfa* 8 ton 408 96 392 43 43

10 ton 510 120 490 54 54

Barley 120 bu. 166 67 182 17 23

Canola 60 bu. 180 90 150 37 30

Corn 150 bu. 135 57 41 14 12

Stalks 68 24 165 21 11

Total 203 81 206 35 23

200 bu. 180 76 54 18 16

Stalks 90 32 220 46 14

Total 270 108 274 64 30

250 bu. 225 95 68 23 20

Stalks 112 40 275 58 18

Total 337 135 343 81 38

Corn Silage 30 ton 291 93 219 60 33

Cotton (lint /seed) 1,500 lbs. 100 44 59 20 17

Stalks 140 28 151 12 19

Total 240 72 210 32 36

Fescue 3.5 ton 130 42 189 13 20

Oats 100 bu. 73 27 18 4 7

Straw 29 15 89 10 10

Total 102 42 107 14 17

Potatoes/ Tubers 500 cwt. 160 60 275 15 15

Plants 100 25 150 20 10

Total 260 85 425 35 25

Rice 7,000 lb. 112 60 168 14 12

Ryegrass 5 ton 215 86 215 40 60

Sorghum (grain) 175 bu. 116 68 47 11 11

Soybeans* (grain) 70 bu. 266 59 91 15 13

Stover 77 17 70 15 12

Total 343 76 161 30 25

Sun� ower 1.5 ton 151 45 110 21 18

Wheat 80-bu. Grain 120 48 27 12 8

Straw 56 13 96 8 11

Total 176 61 123 20 19

©2010. The Mosaic Company. All rights reserved. MicroEssentials is a registered trademark of The Mosaic Company. MES-0168

* Legumes derive most of the N from symbiotic N fi xation.

Source: IPNI and Mosaic

Visit Back-to-Basics.net for information on additional crops.


soil testing to determine fertility needs

of speci� c � elds and guide fertilizer

and manure application needed for

sustainable crop yields.

Figure 4.

2010 median soil levels and

change from 2005

PHOSPHORUS LEVELS*

SD 13-1

NE 18-4

IA 21-4

MO 15-3

IN 24-5

MI 38

-11

MN 17-1 WI

23-16

IL 24

-12

OH 23-2

17-1

KS 17-4

ON

37-10

KY

POTASSIUM LEVELS**

SD 245

-23

NE 320

-44

IA 161

-11

MO

149

-1

IN

130

-14

MI

131

-18

MN

160

+4 WI

133

+8

IL

181

+3

OH

145

-23

99

-35

KS 272

-22

ON

131

+3KY

* Median Bray P1 equivalent, ppmSoil samples, millions: 2005=2.0; 2010=3.0

** Median ammonium acetate K equivalent, ppmSoil samples, millions: 2005=2.0; 2010=2.8

are indeed falling in most of the Corn Belt.

The two maps show median soil

P and K levels (50 percent of samples

are above and below these levels) for

the Corn Belt states and Ontario. The

lower numbers in the maps are the

changes from 2005.

Phosphorus declined in all areas, with

Wisconsin and the Northeast showing

the largest drops. Soil P levels in the

Western states were lower initially, so

the 3 or 4 ppm reductions seen from

the summary are important to note.

Preliminary data indicates the P level

decline for Illinois is large.

Soil K relative changes were smaller

in comparison and less consistent.

Nine of the 13 areas showed reduc-

tions or virtually no change, and four

showed small increases. All three of

the western-most states showed large

drops in soil K because of highly nega-

tive nutrient balances, but their median

levels are still well above critical levels.

The northeast states and Ontario also

saw large reductions in soil K.

The takeaway is that crops have been

removing more P and K from many of

the soils of the Corn Belt than those

soils have been receiving as fertilizer

or manure, and the result is declining

soil fertility. The wide range of soil test

results reinforces the importance of

The status of soil fertility levels is an

indicator of the sustainability of farming.

Every � ve years, the staff of IPNI

and cooperating private and public

laboratories across the United States

and Canada summarize soil test levels

for phosphorus (P) and potassium (K)

as well as pH to get an inventory of soil

fertility levels across North America.

With decreased fertilizer use in

2009 and the long-term trend of crops

removing soil nutrients faster than

they’re being replenished, many are

interested in the 2010 summary.

Tests confirm that soil test

levels for P and K are falling

in most of the Corn Belt.

First, the good news from this

summary process is that there has

been a substantial increase in use of

soil testing since 2005; soil testing has

grown at an average of about 300,000

samples per year over the last � ve years.

We estimate that about 5.5 million

samples were collected in North

America for the 2010 crop compared

to about four million for the 2005 crop.

This is one of the highest growth rates in

soil testing ever in North America.

Unfortunately, the results of these tests

con� rm that soil test levels for P and K

The Direction of Soil Fertility in the Corn Belt

B Y P A U L E . F I X E N , P h . D .

I n t e r n a t i o n a l P l a n t N u t r i t i o n I n s t i t u t e



- Alfalfa removes approximately

6 pounds S per acre per ton pro-

duced. A 40 bu /acre wheat yield will

remove about 5 pounds S per acre.

• Sulfur is mobile in the soil.

Excessive rainfall or irrigation water

can move SO4-S through the soil,

particularly when soils are sandy.

Assessing the need for sulfur

As more signs of sulfur de ciency are

seen in crops, a growing number of

producers will wonder if they need to

supplement S. To identify where supple-

mental S will be bene cial, it’s important

to understand sulfur’s role as a plant

nutrient.

Identifying areas with S de ciency

often begins with organic matter

content of the soil. Fields with low

organic matter and long histories of

forage/silage production or continuous

corn systems with no manure additions

would be more likely to exhibit S de -

ciency. Some nutrient de ciencies can

be con rmed with a soil test, but with S

as with N, it is dif cult to get a reliable

assessment of available S from soil

chlorophyll production, which makes

the younger leaves of the plant appear

yellow, a symptom sometimes confused

with N de ciency.

Putting S out of balance

What has changed to bring about a

need for supplemental sulfur in crop

production?

• Decreased S deposition from rain/

air (Figure 5). Since the 1970 Clean

Air Act, emissions of sulfur dioxide

have decreased dramatically, resulting

in reduced deposition from rain/air.

• Changing fertilization practices.

A switch away from ammonium sul-

fate as a source of N and decreased

use of single super phosphate, which

contained some S, means we’re

adding less S to soils. Manure use

also has changed.

• Increased crop removal.

An increase in both grain and forage

yields results in more rapid depletion

of S from soils.

- A 180 bu /acre corn crop removes

about 14 pounds S per acre.

The rst occurrences of sulfur (S)

de ciency in corn were reported in the

1960s. At the time, sulfur de ciency

was virtually unheard of. Textbooks

devoted chapters to nitrogen (N), phos-

phorus (P) and potassium (K) and their

roles in crop production. Sulfur received

only short paragraphs.

To sustain optimum crop

yields, the S balance in soils

will need to be maintained

through supplemental S.

Today, the situation is quite different.

Since the late 1980s, university agrono-

mists from New York to Kansas,

Michigan to Alabama, have been

observing sulfur de ciency in crops and

advising growers on the importance of

supplemental sulfur. With this change,

S has become the fourth “essential”

nutrient. It is a com ponent of numer-

ous protein enzymes that regulate

photosynthesis and nitrogen xation.

In fact, when S is limiting, there is less


Changes Creating Need for Sulfur

B Y D E A N F A I R C H I L D



testing because of sulfur’s mobility in

the soil and the varying rates of S min-

eralization from crop residues. Tissue

testing is considered more reliable, and

comparing samples in the same � eld/

hybrid between poor and good areas

may be the best strategy.

Visual symptoms also are an indica-

tor, and plants with severe de� ciencies

have yellow or white streaks along the

leaf veins that may stretch the full length

of the newer, upper leaves. Probably

the most reliable way to know if a

sulfur application will result in a positive

re sponse is to apply some in strips to see

if a difference in yield can be measured.

Choosing a source of supplemental sulfur

Several products are available for cor-

recting or preventing a sulfur de� ciency.

When choosing a product, remember

that sulfur forms vary in their availability

for plant growth. Plants can readily take

up sulfate (SO4), so this form is preferred

for corn and small-grain production as it is

immediately available to developing roots,

helping plants get off to a faster start.

Elemental sulfur (S) must be oxidized

into SO4 by soil bacteria before plants

can take it up. This takes time and is

slowed by cool spring temperatures.

Elemental sulfur is more of a slow-

release fertilizer and can be used in a

soil maintenance program or by plants

later in the season. Choosing a fertilizer

source containing elemental sulfur also

helps ensure S is available to plants all

season long because it is not as mobile

as sulfate, which can move out of the

root zone when precipitation is high.

Sources of sulfur for plants

There are several fertilizers available

to supply S when it is needed. The

MicroEssentials® family of products

provides season-long availability of S by

providing both the elemental and sulfate

forms. K-Mag® fertilizer is virtually 100

percent water soluble and provides K,

Mg and S that are immediately available

to plants. Your local agronomist, crop

consultant or fertilizer dealer can help

you assess the right product to optimize

yields in your crop production program.

Table F.

Sulfur content of some common fertilizers

MATERIAL NAME S CONTENT (%)

Ammonium sulfate (21–0–0–24) 24

Ammonium thiosulfate (12–0–0–26) 26

K-Mag® (0–0–21.5) 22

MicroEssentials® S15™ (13–33–0–15S) 15 (7.5 sulfate; 7.5 elemental)

MicroEssentials SZ™ (12–40–0–10S-1Zn) 10 (5 sulfate, 5 elemental)

MicroEssentials S10™ (12–40–0–10S) 10 (5 sulfate, 5 elemental)

Potassium sulfate (0–0–50) 18

Sulfur deposited by precipitation in 1986 compared to 2008

Figure 5. When comparing these maps, it is apparent the 3 –12 pounds per acre of S deposited by precipitation in 2008 is not enough to replenish the amount of S removed by crops.

2008

1986

National Atmospheric Deposition Program/National Trends Network http://nadp.sws.uluc.edu



Some seek answers in the stars.

Others look to the sea.

We’re fi nding ours in the soil.

Science is a world of

pioneers. Especially the

science of soil. With

more than 40% of crop

yields dependent on

the soil’s fertility, we’re

developing the balanced

fertility strategies to drive

yields even higher. This

initiative has made us a

leader in conservation,

environmental steward-

ship and sustainability.

And kept us in tireless

pursuit of the next great

answer to help the world

grow the food it needs.

MosaicCo.com

©2010. The Mosaic Company. All rights reserved. Mosaic is a registered trademark of The Mosaic Company. MOSC-0072


h to Crop ProductionLittle Is “Typical” A“Typical” About Approach to Crop P


Kim Drackett

Randy Bales

Lewisville, Indiana

Fairholme Farms Inc.

• Continuous no-till

• Corn, soybeans

• Swine farrow-to-� nish

we have the data and have used this

approach for so many years, I believe we’ve

dramatically reduced the variability in our soil

test levels across each � eld, and as a result,

have reduced the probability that P, K or pH

will be the limiting factors to grain yield.

“For optimum productivity, our goal is to

maintain phosphorus at 25 ppm and potas-

sium at 150 to 200 ppm, depending on

the cation exchange capacity (CEC). When

soil test data indicates nutrient levels need

to be brought up, we work on a four-year

build program for P, K and lime,” Drackett

adds. “Our typical process is to apply

these nutrients at a build rate, plus one

year’s removal for both corn and soybeans.

Application is done every other year, prior

to corn.” After four years, if things appear

to be going well, they switch to a mainte-

nance program, occasionally pulling a few

soil samples to con� rm their beliefs.

INVESTING RESOURCES WISELY

PAYS OFF

Drackett and Bales also plant on a

variable-rate basis, with plant population

ranging from 26,000 to 35,000 plants

per acre. This allows these farmers to

invest resources where they will produce

the most bushels. Nitrogen (N) for corn

on 150 high-management acres near the

swine operation is supplied using irriga-

tion water from the two-stage lagoon

system. And while all other acres typically

receive anhydrous ammonia as a sidedress

application, the fortuitous addition of a real-

time kinetics (RTK)-guidance auto-steering

system in early 2010 allowed application of

anhydrous preplant.

“We’ve experienced several years when

it has been wet in the month of June,

making it hard to get sidedressing done,”

says Bales, who oversees crop planning

and operations. “If we hadn’t been able

to apply N prior to planting, we probably

would have been dripping liquid N between

the rows with highboys.” Because the

farm has the equipment and labor to apply

anhydrous, Bales estimates the ability to

complete timely application plus the savings

on appli cation cost may have paid for their

investment in the RTK-guidance technology.

GETTING BETTER AT

EVERYTHING

Since 1981, Fairholme Farms has worked

with its crop consultants, Purdue University

and the University of Illinois, to complete

numerous on-farm trials. This has helped

them achieve a � ve-year average yield

of 165 bu /acre on corn and 59 bu /ac on

soybeans. While Drackett and Bales are

always game to try something new, they

like to have proof it works.

With their experience in crop production

and from what they’ve seen through previ-

ous on-farm research, the duo is convinced

reaching the industry’s 300-bushel yield

goal will require everything coming together.

“We are going to have to get better at

everything,” says Drackett. “We’ll need

more plants per acre, better soil tilth, more

balanced nutrition, and better hybrids and

varieties. On the nutrient side, we will need

to use fertilizer formulations as well as

technologies that provide nutrition through-

out the entire growing season. Finding what

works is why we’ve been doing on-farm

research so long and why we will continue

to do so.”

Both Kim Drackett and Randy Bales

describe 1,850-acre Fairholme Farms as

“a typical eastern Corn Belt operation,” but

their management approach is, and long

has been, anything but typical.

For example, the operation began

2.5-acre grid sampling in the 1950s. At the

time, they variable-rate-applied fertilizer by

simply driving a gear slower with the tractor

and fertilizer spreader in areas that needed

more nutrients.

Drackett then worked with other farmers

to form a local Maximum Economic Yield

group, and together the group enlisted

a local retailer to invest in variable-rate

application equipment. In 1992, the farm’s

� rst yield data was collected. In 1997, after

working with a crop consultant and Purdue

University to complete a statistical evalua-

tion of what size soil test grid captured the

variability in their soils, they switched to

sampling on a 1-acre grid.

VARIABLE-RATE PROGRAM BASED

ON CALCULATED SOIL TEST

Today, the operation soil-samples on

a 1-acre grid every six to eight years.

Fairholme Farms’ zone management–

based variable-rate crop nutrition program

is built using a beginning soil test and

a soil test value calculated between soil

tests by combining the base soil test with

nutrient applications and crop removal

rates from yield data. While sampling on a

1-acre grid is costly, the expense is spread

over more years, and the resulting nutrient

management process has helped eliminate

variability in soil test levels.

“So much of crop risk management is

reducing variability,” says Drackett. “Since




Managing P Soil Test Values

B Y G Y L E S W . R A N D A L L , P h . D .

U n v e r s i t y o f M i n n e s o t a — W a s e c a


P to be available in the soil.

Maintaining high STP values gives

growers the exibility to skip P fertiliza-

tion without sacri� cing yield. Moreover,

the risk of failing to maximize yield

in exceptional years is reduced by

maintaining STP at high levels. Less-

than-high STP values can easily be yield

limiting, resulting in potential yield being

left in the � eld. Finally, high STP gives

extra resource value to the land, provid-

ing better return on investment to both

the landowner and renter.

Visit www.Back-to-Basics.net for

more information on soil testing and

managing phosphorus.

Soil testing is the best tool farmers have

for determining and managing phos-

phorus (P) levels in their � elds. Testing

can con� rm increases in soil test phos-

phorus (STP) resulting from application

of P and also document how much

crop removal has decreased STP.

Unfortunately, in the last decade or

two, STP has declined in many areas

of the Corn Belt. The steady decline is

generally due to increasing yields, which

remove greater levels of P from the soil,

coupled with P application rates that

often have fallen below crop nutrient

removal rates (Table G). This trend is

particularly evident for rented land when

the renter chooses to mine P from the

soil rather than apply fertilizer or manure

P at a rate suf� cient to maintain STP at

an optimum level.

Building P soil test values

Since nutrients removed by the crop

need to be replaced by fertilizer or

manure P to maintain soil test P values,

farmers often ask, “How much phos-

phate will it take to raise my STP value

to the optimum level?” This is a dif� cult

question to answer as the amount of

P required depends on current and tar-

geted STP levels, subsoil P level, depth

of P2O5 incorporation and crop yields/

nutrient removal during the time frame

in which the STP is to be increased.

A common rule of thumb developed

by University of Illinois researchers

says 18 pounds P2O5 per acre will

increase Bray P1 by 1 ppm. In a 12-year

Minnesota study during the ’70s and

’80s, with corn yields averaging 150

bu /acre, Bray P1 STP was maintained

at 20 ppm with an annual 50-pounds-

P2O5-per-acre rate. STP increased 1

ppm per year when an additional 30

pounds P2O5 per acre were applied

annually. Thus, given the many variables

involved, annual soil testing is an excel-

lent way to monitor changes in STP for

each particular situation.

Recent research indicates high soil

test P values may be necessary for

economically successful corn and

soybean production. A three-year study

in Minnesota compared yields of corn

and soybeans grown on low P-testing

soil and very high P-testing soil. A

50-pounds-P2O5-per-acre rate was

Table G.

Calculate P and K Removal rates

To calculate phosphorus (P) and potassium (K) removal rates in corn grain and

soybean seed, multiply yield by estimated P and K removal constants.

CORN

P Removal Rate = corn yield bu. X .35 (P2O5 /bu. removal constant)

K Removal Rate = corn yield bu. X .25 (K2O/bu. removal constant)

SOYBEAN

P Removal Rate = soybean yield bu. X .85 (P2O5 /bu. removal constant)

K Removal Rate = soybean yield bu. X 1.3 (K2O/bu. removal constant)

Source: G. Randall, University of Minnesota

applied for corn each year followed by

no additional P for soybeans the next

year. All other inputs were similar across

both STP regimes.

Table H shows the economic penalty

(nearly $120 per acre per year) of low-

testing compared to very-high-testing

soils even when P fertilizer is applied.

This illustrates further that managing

soil phosphorus levels is critical as

farmers attempt to maximize the

return on their fertilizer dollar. Knowing

the soil test P status of soils is espe-

cially important on rented or recently

acquired acres. Simply said, high yields

require high P uptake, which requires

Table H.

Soil Test P Impact on Yield, Economic Return

LOW STP 7 PPM

VERY HIGH STP 25 PPM

YIELD DIFFERENCE

ECONOMIC BENEFIT PER

ACRE FOR VERY HIGH STP

P2O5 prior to corn 50 lbs /A 50 lbs /A

Corn yield 3-yr avg. 167 bu 193 bu 26 bu$117

($4.50/bu)

Soybean yield 3-yr avg. 39 bu 49 bu 10 bu$97.50

($9.75/bu)

Source: G. Randall, University of Minnesota



g to ChanceAn “Edge” That Ledge” That Leaves Nothing to Cha


Kriss Schroeder

Colby, Kansas

• Corn

• Wheat

• Sorghum

• Sun� ower

• Dryland, no-till, intensive management

from 0 to 6 inches and also 6 to 24 inches.

In years in which nutrient leaching is sus-

pected, N, Cl and S are evaluated at 24- to

48-inch depths.

NUTRIENT PLAN ADJUSTED, BALANCED EACH YEAR

Using a spreadsheet built following nutri-

ent recommendations from Kansas State

University, Schroeder develops a balanced

nutrient program for each � eld, each

year, adjusting the rates up or down a bit

depending on expectations for the growing

season. He stresses the importance of

formulating a program every year on every

� eld and balancing nutrition for his crops.

“If you’re taking vitamins, you don’t load

up on vitamin C and forget about vitamin

A, calcium and other nutrients,” he says.

“Plants are no different. If you load up one

nutrient and another nutrient is limiting,

that will limit your yields. I strive to make

sure nothing I can control limits my yields.”

At planting, granular fertilizer is applied

as a starter with the planter or drill. He uses

MicroEssentials® SZ™ as his source for P,

N, Zn, S and supplements it with additional

K as needed. Liquid nitrogen in the form

of UAN is streamed on in a band every

15 inches in the fall or winter after the

soil temperature drops below 50 degrees.

If moisture conditions are favorable for a

bumper crop, additional N is occasionally

applied in the spring.

Yields are proof Schroeder has found the

“edge” he needs for success. His whole-

farm averages for each crop are well above

average for the area.

year, he studies seed and fertilizer test

plots and does his own on-farm testing of

new genetics as well as other crop produc-

tion products.

“On-farm research is the fun part of

farming. There are a lot of differences

in soils, and something that might work

200 miles from here may not work here,”

he explains. “On-farm research is risk

management. Before you spend thousands

of dollars on something, you’d better know

it works.”

SOIL TESTING EVERY YEAR

Another risk-management tool Schroeder

employs is annual soil testing of every � eld.

While he has experimented with 2.5-acre

grid sampling, he currently samples every

8 to 10 acres and combines samples from

like soils within each � eld.

“Through the years, the greatest variabil-

ity we’ve seen from a nutrition standpoint

is due to mineralization of nutrients from

the previous crop’s residue,” Schroeder

explains. “Some years we have a fair

amount of rain and heat. That mineralizes a

lot of nutrients. If the following year is dry,

we may not have as much mineralization,

so we’ll need to apply more fertilizer.” He

estimates this variability can range from a

nearly insigni� cant amount to the crop’s

full requirement from the lowest to highest

years; therefore, he is not con� dent in

building a nutrient program based strictly

on estimated crop removal.

Levels of mobile nutrients, nitrogen (N),

chloride (Cl) and sulfur (S), also are hard to

predict without annual soil tests because of

leaching. Soil samples typically are pulled

In 1991, when Kriss Schroeder put away

his veterinary license and came home to

farm near Colby, Kan., he knew he’d need

an edge to make a living in the dryland-

cropping region.

Schroeder adopted an intensive manage-

ment program that took a 180-degree

approach to traditional summer-fallow

wheat production. By switching to continu-

ous no-till, he now raises a crop every year,

on every acre.

“Water is by far our number one limiting

factor to crop production. By switching to

no-till, I felt I would be able to conserve

enough moisture to grow a crop every

year,” relates Schroeder. “We do this by

keeping as much residue on the surface as

possible and not letting anything grow that

doesn’t produce income.”

With 70 percent of his acres in corn, he

follows a two- to three-year cycle of the

same crop, rather than rotating yearly. This

enhances weed control and reduces the

risk that can come from needing to drill

wheat immediately following the combine

in the fall.

Residue preservation involves stripper-

headers during wheat harvest and keeping

the header as high as possible during corn,

sorghum and sun£ ower harvest so more

residue stands longer. Stubble and stalks

are moisture-management assets providing

shade, snow-holding capacity and protec-

tion from drying winds. Weeds are killed

before they can steal moisture.

Beyond conserving moisture, the north-

west Kansas farmer believes good genetics

and a balanced soil fertility program are the

most important facets of his success. Each



Magnesium—Often Forgotten, but Most Essential

• Increasing rates of needed K fertil-

izers will put greater stress on Mg

absorption. This places more K ions

in the soil solution to compete with

Mg ions for uptake by plant roots.

• Root uptake dif� culties brought on

by soil acidity, by soil � ooding or

compaction, or by reduced-tillage

practices.

• Greater removal of Mg from the

� eld occurs due to increasing yields

and multiple cropping. (Nutrient

uptake values for individual crops

are presented on page 12.)

Higher crop yield and quality

Magnesium’s contributions to yield

and quality are both crop and site

speci� c. Scientists in Minnesota, for

example, pay special attention to the

Mg status of forage crops to help avoid

an Mg shortage in the diet of ruminant

animals. Magnesium’s contributions to

crop quality are seldom visible since

it works behind the scenes regulating

enzyme systems, producing sugars or

helping with other vital crop activities.

University specialists in the Southeast

United States point out that a shortage

of Mg is most likely for high-yield crops

growing on acidic, sandy soils of the

Coastal Plain.

Vegetable crops are often responsive

to fertilizer Mg. For example, Mg

improved the protein content of potatoes

and reduced internal discoloration while

increasing � rmness. Color disorders in

tomatoes were reduced by balancing

Mg and K in the fertilization program.

Yield response has been noted for

different crops growing on low-testing

soils: 1) Mg increased potato yield from

6.7 to 8.7 tons per acre in Michigan;

2) 50 lbs/acre of Mg increased tomato

yield from 16.5 to 20.3 tons/acre; and

3) Mg increased corn grain yield at three

locations on low-Mg coastal plain soils.

To learn more about the role of

magnesium in crop production,

visit www.Back-to-Basics.net.

Without photosynthesis, plant life would

not exist. And without magnesium (Mg),

there would be no photosynthesis.

Plants could not produce our food, and

hunger would become our number one

concern.

Often the “forgotten nutrient,” Mg is

the most essential of the 17 nutrients

needed for plant growth. It is a vital

team player working with other nutri-

ents and is essential for top-pro� t crop

production.

Contributions to plant growth

As the central ion in the chlorophyll

molecule, Mg is essential for photosyn-

thesis. It works with phosphorus (P) to

transfer energy needed within the plant

for growth, and it works with nitrogen

(N), sulfur (S) and potassium (K) to build

quality protein. Seed formation requires

both Mg and P.

Crop and soil needs for Mg are science based

Soil tests are the most reliable way

to determine Mg availability from soil

reserves. The soil’s Mg status should

be updated whenever pH, P and K

levels are checked. Remember, crop

response to fertilizer Mg occurs most

often on acidic, low-exchange-capacity

soils that are low in organic matter and

soil test Mg.

Plant analysis can help to detect a

shortage of Mg. Sample the whole plant

at the seedling stage for corn, small

grains or soybeans. As plants approach

their reproductive stage, speci� c leaves

become a better measure of the Mg

status. For many crops, a rule of thumb

is to sample the youngest fully mature

leaves. If possible, collect a soil sample

at the same time and from the same

area of the plant sample.

Increasing yields will require higher Mg levels

• Higher plant populations per acre will

require more nutrients to meet growth

needs.

Time-proven source of Mg

Crop advisors often address the need

for Mg by incorporating potassium

magnesium sulfate (K-Mag®) into a

balanced fertilization program. Also

known as langbeinite or double sulfate

of potash, K-Mag is sourced from ore

beds deep beneath the earth’s surface.

Langbeinite, an evaporite mineral, is

one of the most soluble salts in the

ocean. As a result, K-Mag is virtually

100 percent water soluble and the Mg,

K and S it provides are immediately

available to crops.

B Y N O B L E U N D E R W O O D

I P N I — R e t i r e d

A g r i - Te c h S e r v i c e s L L C , P r e s i d e n t




Understanding Zinc De� ciency

B Y D A N F R O E H L I C H , P h . D .



lower soil temperature and higher soil

moisture level. These conditions put

stress on a small root system, making

it dif� cult to uptake required Zn, as

well as P and Mg.

• Low organic matter. Zinc availability

also has been linked to soil organic

matter content. The soil test for Zn

usually increases as the soil organic

matter content increases. So, Zn

de� ciency symptoms will usually

appear � rst on eroded portions of the

landscape where the organic matter

content is low.

• Early crop-planting windows.

Corn and certain vegetables are

being seeded earlier in the spring,

when soils are cool and moist. This

compounds the stress on seed-

lings caused by reduced tillage, and

makes a readily available supply of Zn

and other nutrients even more impor-

tant to ensure early plant growth.

• Soils testing low in Zn and high

in P. Soil-test each � eld to help

identify where crops will respond to

Zn. Fields that test low in Zn and high

in soil pH and P need attention � rst.

University scientists report that a low

Zn level, teamed with a high soil pH,

can increase crop uptake of P to an

excessive level. A shortage of Zn

severely impairs the plant’s ability to

regulate P accumulation. This triggers

excess uptake of P and the develop-

ment of Zn de� ciency symptoms.

Getting ready for next year’s crops starts now

Soil and plant analysis labs provide

guidelines for sampling � elds, evaluating

crop need for Zn and determining the

amount of fertilizer Zn needed to correct

a de� ciency.

Soil-sample � elds carefully, and

analyze the lab reports on a � eld-by-

� eld, crop-by-crop basis with your

agronomic advisor. Remember, a Zn

de� ciency is often not visible at the high-

yield level. Thus, soil and plant analysis

are key detection tools. Knowing the

other conditions that create resis-

tance to root uptake of Zn will help to

determine when Zn should become a

member of the balanced nutrient team.

To learn more about zinc, visit

www.Back-to-Basics.net.

Zinc (Zn) has been put to work on farms

for decades. Fencing wire and nails are

galvanized with zinc to prevent rust.

Metal buckets are coated with zinc to

last longer. However, zinc’s most impor-

tant job is in the � eld, as one of the 17

essential elements in plant growth.

Zinc de� ciency is growing in the

Midwest, and it is more likely to occur

in corn than soybean � elds. This is

due in part to earlier planting of corn in

cool and moist soil. Also, more residue

resulting from conservation tillage and

higher grain yields places added stress

on seedlings to absorb Zn from soil.

Zinc is heavily involved in enzyme

systems that regulate the early growth

stages, and is vital for fruit, seed and

root system development, photosynthe-

sis, formation of plant growth regulators

and crop stress protection. In addition,

Zn is a team player with nitrogen (N),

phosphorus (P) and potassium (K).

However, Zn is required in very small

amounts compared to N or K. Only

about a half-pound of Zn is needed per

acre for high-yield (180 bu/acre) corn

production. Sixty-bushel wheat needs

about 0.28 pound of Zn per acre. Yet,

lack of Zn can limit plant growth, just

like N or K, if the soil is de� cient or crop

uptake is restricted.

Give plants a good start

Crops need readily available Zn,

especially when plants are young and

growing vigorously. Zn does not move

in the soil, so the small seedling’s root

system may have dif� culty � nding and

taking up Zn reserves. Zinc availability

and uptake also can be limited by other

environmental and crop management

practices, including:

• Liming to reduce soil acidity.

Availability of Zn to plants declines as

soil pH increases. Zinc is usually more

available as soil pH moves to the acid

side of 7.0. Be alert for a Zn shortage

for sensitive crops growing on soils

with pH 6.0 or higher.

• Low soil temperature. The solubility

or availability of Zn in soil is affected

by soil temperature, and solubility

decreases as soil temperature drops.

• Reduced-tillage systems. Crop

residues on the soil surface at plant-

ing time shade the soil, resulting in a

The photo above illustrates symptoms

of zinc de� ciency in corn.



Grain-based biofuels have both pas-

sionate proponents and opponents,

but political support for these programs

looks solid, particularly if energy prices

trend up as predicted this decade

and grain and oilseed prices remain at

moderate levels due to expected yield

increases. For example, corn used for

ethanol production in the United States

is projected to increase to more than

135 million tonnes, or about 5.4 billion

bushels, in order to meet blending man-

dates by the middle of this decade.

Given this positive demand outlook,

the challenge for farmers around

the world is to produce another

500 million tonnes of grains and

oilseeds per year by the end of

the decade—equal to another U.S.

harvest—and to boost global produc-

tion by more than 70 percent by the

middle of this century. Farmers will

need to harvest record area and reap

ever-increasing yields in order for grain

and oilseed supplies to keep pace with

accelerating demand.

Put another way, the horse race

between grain and oilseed supply and

demand looks like a nearly dead heat.

Supply will inch ahead and stocks will

grow when harvests exceed trend as was

the case in 2008 and 2009. Demand

Global demand for the leading grain

and oilseed crops is projected to

increase from about 2.6 billion tonnes

today to 3.1 billion tonnes in 2020 and

to more than 4.5 billion tonnes in 2050.

In fact, demand growth has accelerated

despite the Great Recession and linger-

ing fears about the global economy.

Demand has increased at a 2.2 percent

per-year clip during the last � ve years

compared to a 1.8 percent per-year pace

during the � rst half of the last decade.

Grain and oilseed demand is fueled

by three key drivers: 1) steady popula-

tion growth, 2) increases in income and

the upgrading of diets by a swelling

middle class, especially in the populous

and rapidly developing countries of

Asia, and 3) the expansion of grain-

based biofuels production, particularly

the exponential growth of corn-based

ethanol output in the United States.

All of these demand drivers look

positive. Global population is projected

to increase from 6.7 billion today to

7.6 billion by the end of the decade

and to more than 9.0 billion by 2050.

Global population currently increases

about 75 million people per year—the

equivalent of adding another Ethiopia to

the world each year.

Based on IHS Global Insight fore-

casts, global GDP per capita in 2005

dollars is projected to increase from the

Great Recession low of $7,200 to more

than $9,300 in 2020 and to about

$18,700 by 2050. Statistics show

people spend a large percentage of

the increase in income on protein-rich

and more grain-intensive foods such

as meat, eggs and dairy products as

they move from low to moderate levels

of income.

will inch ahead and stocks will fall

when harvests fall below trend growth

as is the case this year. Never theless,

farmers and crop input suppliers

will need to whip the supply horse

in order for it to keep pace with the

demand horse. That is exactly what

futures prices for most agricultural

commodities are signaling today for the

next several crop years: Keep whipping

the supply horse by planting record

area and harvesting record yields year

after year.

Yet, as highlighted throughout this

supplement, achieving the next genera-

tion of yields will require a complete

bundle of high-technology inputs—

including not only promising new seed

varieties but also more sophisticated

crop nutrient products and practices.

For example, feeding 45,000 corn plants

per acre will require innovative products

that uniformly deliver suf� cient amounts

of primary as well as secondary nutri-

ents and micronutrients. This also likely

will necessitate more precise placement

or even multiple applications. One thing

we can say with certainty: Meeting

future demand will require � nding the

most synergistic combination of innova-

tive production technologies with which

to drive tomorrow’s high-yield systems.

The Production ChallengeB Y M I K E R A H M , P h . D .




With every new generation, population continues to grow. This means we need more food.

Today’s farmers are leading the way to meet the increasing food demands of the future.

MicroEssentials® is the next generation of fertilizer designed to meet the needs of your

advanced farming operation. Demand more;

demand MicroEssentials. For more infor mation,

go to MicroEssentials.com.

© 2010, The Mosaic Company. All rights reserved. MicroEssentials is a registered trademark of The Mosaic Company. MES-0169

The next generation of fertilizer

for the next generation of farming.

Every MicroEssentials

granule contains nitrogen,

phosphorus and sulfur. This

ensures uniform distribution

and better nutrient uptake.


Are You Ready

for Higher Yields?

Achieving the next generation of yields will require a complete

package of high-technology inputs, new management practices

and crop fertility. Review the checklist below to see if your crop

production program is ready for the higher yields needed to meet

future demand for food, feed, � ber and fuel.

I have a fertility plan for every � eld. Page 20

I have made management changes to ensure I’m optimizing

the return on my investment in seed. Page 8

I agree the triple-stack hybrids I’m planting yield more and need

a higher level of fertility to ful� ll their yield potential. Page 2

My fertilizer application rates have increased as my yields

increase. Page 2

I have a regular, systematic plan to soil-test every � eld on my

farm to make sure soil nutrient levels have not decreased

below critical levels. Page 13

I am experimenting with higher plant populations on my farm.

Page 8

In the past three years, I have seen corn plants on my farm

showing pale striping of the leaves. Page 22

Sulfur is a nutrient that may be needed on my farm. Page 14

For more information, turn to the page

listed after each statement, visit

www.Back-to-Basics.net

This information produced and presented by The Mosaic Company.


Balanced Crop Nutrition

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