Workshop: 4R Nutrient Stewardship Principles and Practices · Workshop: 4R Nutrient Stewardship Principles and Practices Dr. Terry L. Roberts, President Dr. Munir Rusan, Consulting

Workshop: 4R Nutrient Stewardship Principles and

Practices

Dr. Terry L. Roberts, President Dr. Munir Rusan, Consulting Director, Middle East

Dr. Kaushik Majumdar, Vice President, Asia, Africa, and the Middle East

Workshop purpose: to provide an overview of 4R

nutrient stewardship and its supporting scientific

principles

Outline:

1. Review the scientific principles of 4Rs

based on IPNI’s 4R manual (Terry

Roberts)

2. 4R fertigation for efficient nutrient

management in irrigated agriculture

(Munir Rusan)

3. Nutrient Expert® fertilizer decision

support tool to support 4R fertilizer

recommendations (Kaushik Majumdar)

The manual provides scientific principles of the 4Rs

Learning modules and

case studies are

included in the manual

…

Sustainable agriculture

Definition

Accommodating the growing demand for

production without compromising the natural

resources upon which agriculture depends.

• The concept of sustainability is multi-

dimensional … applies to social, economic,

and environmental dimensions simultaneously.

Click to edit Master title style

4R Nutrient Stewardship applying the

right nutrient source, at the right rate, right

time, and right place is an essential tool in

the development of sustainable agricultural

systems.

4R Nutrient Stewardship and

Sustainable Agriculture

• Implementation of 4R Nutrient

Stewardship can positively influence

the sustainability of agricultural

systems beyond the immediate

benefits of improved crop nutrition and

production.

Click to edit Master title styleThe 4R Nutrient Stewardship

Concept

4R Plant Nutrition Manual: Chapter 2

Source, Rate, Time, and Place describe any

nutrient application

Right means Sustainable

• Right source, rate,

time, and place

• Outcomes valued

by stakeholders

Examples of key scientific principles

The Four Rights (4Rs)

Source Rate Time Place

Key

Scientific

Principles

• Ensure

balanced

supply of

nutrients

• Suit soil

properties

• Assess

nutrient

supply from

all sources

• Assess plant

demand

• Assess

dynamics of

crop uptake

and soil supply

• Determine

timing of loss

risk

• Recognize

crop rooting

patterns

• Manage

spatial

variability

Examples of Practical Choices

• Ensure practices are in accord with principles

The Four Rights (4Rs)

Source Rate Time Place

Practical

Choices

• Commercial

fertilizer

• Livestock

manure

• Compost

• Crop residue

• Test soils for

nutrients

• Calculate

economics

• Balance crop

removal

• Pre-plant

• At planting

• At flowering

• At fruiting

• Broadcast

• Band/drill/inje

ct

• Variable-rate

application

Equal attention to all 4Rs

• Balance attention to all 4Rs

• Rate: easily overemphasized

• Source, Time, Place: often require major

changes and investments

The 4Rs interconnect

• with each other

• with local soil and climate factors

• with management of soils and crops

• other factors can limit productivity even

when levels of plant nutrients are

adequate

The 4Rs connect to the cropping system

• genetic yield

potential

• weeds

• insects

• diseases

• mycorrhizae

• soil texture &

structure

• drainage

• compaction

• salinity

• temperature

• precipitation

• solar radiation

• Soil water, air, and temperature influence nutrient

availability.

The 4Rs influence many performance indicators

• Social, Economic and Environmental performance

Net profit

Resource useefficiencies:

Energy, Labor,Nutrient, Water

Return on investment Yield

stability

Water &air quality

Farm income

Working conditions

Nutrientbalance

Nutrient loss

Yield

Quality

Soil erosion

Biodiversity

Ecosystem services

Affordable& accessible

food

• Influenced by crop

and soil management

as well

• Whole system

outcomes

Stakeholders have a say on

performance indicators

• Stakeholders define goals

• Indicators relate to goals

• Producers choose practices

Producers choose practices

• Practices selected to suit local site-specific

soil, weather, and crop conditions

• Conditions may change even on the day of

application

• Local decisions preferred

BMP adoption and evaluation – farm level

• Adaptive management

Farm Level

Producers,

Crop advisers

DECISION

Accept, revise, or reject

EVALUATION of OUTCOME

Cropping System

Sustainability Performance

LOCAL SITE

FACTORS

• Climate

• Policies

• Land Tenure

• Technologies

• Financing

• Prices

• Logistics

• Management

• Weather

• Soil

• Crop demand

• Potential losses

• Ecosystem

vulnerability

ACTION

Change in practice

• Logistics and science

Regional Level

Agronomic Scientists,

Agri-service Providers

DECISION SUPPORT based

on scientific principles

OUTPUT

Recommendation of right source,

rate, time, and place (BMPs)

Farm Level

Producers,

Crop advisers

DECISION



Cropping System


LOCAL SITE

FACTORS

• Climate

• Policies

• Land Tenure

• Technologies

• Financing

• Prices

• Logistics

• Management

• Weather

• Soil

• Crop demand


• Ecosystem

vulnerability

ACTION

Change in practice

BMP adoption and evaluation – regional level

Policy Level – Regulatory,

Infrastructure, Product Development

BMP adoption and evaluation – policy level

• Infrastructure and incentive

Regional Level

Agronomic Scientists,

Agri-service Providers

Farm Level

Producers,

Crop advisers

DECISION SUPPORT based

on scientific principles

OUTPUT

Recommendation of right source,

rate, time, and place (BMPs)

DECISION



Cropping System


LOCAL SITE

FACTORS

• Climate

• Policies

• Land Tenure

• Technologies

• Financing

• Prices

• Logistics

• Management

• Weather

• Soil

• Crop demand


• Ecosystem

vulnerability

ACTION

Change in practice

Sustainability indicators are long-

term

• Short-term efficiencies can lead to long-term

soil nutrient depletion

• Nutrient balance in context of inputs and

outputs

Source, Rate, Time, and Place

• Every application has all four

• Get all four right!

• Completely interconnected

• 4R Nutrient Stewardship emphasizes impact on

outcomes

Click to edit Master title styleScientific Principles Supporting

RIGHT SOURCE


Scientific principles for Right Source

• Consider rate, time, and place of application

• Supply nutrients in plant-available form

• Suit soil physical and chemical properties

• Recognize synergisms among nutrient elements and

sources

• Recognize blend compatibility

• Recognize benefits and sensitivities to associated

elements

Primary &

Secondary

Macronutrients

Each plant nutrient has specific

and irreplaceable functions

• Of the 17 essential

plant nutrients, 14

of them are

supplied from the

soil

• Micronutrients are

just as important as

macronutrients, but

the amount required

is very smallValues are relative

concentrationsMicro-

nutrients

Most soils do not contain the appropriate balance of

nutrients for unrestricted plant growth

• Plants require a balance of all

the essential nutrients for

yield and quality

• Most soils are low in at least

one essential nutrient;

preventing plants from

reaching their potential

• Appropriate fertilizer

applications overcome these

limitations

Nutrients need to be in plant-available forms

for uptake

• Nutrients are only taken

up by roots when

dissolved in water

• Insoluble nutrients are

not immediately useful

for plant nutrition

Once in the plant, the nutrient source is no

longer important

• Plant roots primarily

take up inorganic

nutrients

• The source of nutrient

is not a factor for plant

nutrition

• For example, nitrate is

the same from fertilizer,

manure, or soil organic

matter

There is no one “right source” for every soil

and crop condition

• Each crop, soil, and farmer has different needs and

objectives …for example:

Farmer issues:

Fertilizer availability?

Product price?

Application equipment?

Environmental concerns?

Soil and Crop issues:

Ammonia loss from broadcast

urea?

Gaseous loss of nitrate from

wet soil?

Runoff of P from applications

on the soil surface?

Healthy plants need a sufficient supply of

every essential nutrient for maximum yield

and quality

• Avoid focusing only on the macronutrients, although they

are required in largest quantity

• An adequate supply required, but nutrient availability

must also match peak periods of plant demand

• Correct other soil conditions that may limit nutrient

uptake, such as acidity, compaction, or salinity

How to select the Right source?

• First determine what nutrients

are needed to achieve the

production goals

• Identify potential nutrient

limitations with soil and plant

analysis

• Nutrient omission plots may be

useful where laboratory testing

is not available

Phosphate sources

MAP (NH4H2PO4) or

DAP (NH4) 2HPO4)

Both fertilizers contain

identical elements, but have

very different properties

Consider the accompanying nutrients in the

fertilizer - two examples

Potassium sources

KCl, K2SO4, K2SO42MgSO4,

KNO3, K2S2O3

All contain soluble potassium,

but the accompanying

nutrient changes the

properties

Importance of balanced plant nutrition

• It is insufficient to focus on

each nutrient in isolation

• All nutrients must function

together for yield and quality

goals

• If one essential nutrient is

limiting growth, then none of

the other nutrients will be

efficiently utilized (see

Learning Module 3.5-1).

• Whenever any fertilizer source is added to soil, it will impact the behavior of other nutrients

– Ammonium can enhance phosphorus availability

– Excess potassium can restrict magnesium uptake

– High phosphate concentration can impair zinc uptake

– Limestone additions can improve phosphorus and molybdenum solubility, but decrease copper, iron, manganese, and zinc

Nutrient interactions


RIGHT RATE


Scientific principles for Right Rate

• Consider source, time, and place of application

• Assess plant nutrient demand

• Assess soil nutrient supply

• Assess all available nutrient sources

• Predict fertilizer use efficiency

• Consider soil resource impacts

• Consider economics

Nutrient demand is related to yield target

• Setting realistic yield targets

• Potential yield

• Maximum attainable yield

• Attainable yield in an average season

• 10% above 3 to 5-year average yield

• Yield goal is not yield limit

Mechanisms influencing soil supply

• Mineralization/immobilization

• Adsorption/desorption

• Precipitation/dissolution

• Reduction/oxidation

• Root interception, mass flow, diffusion

Factors affecting nutrient

availability

N P K S Ca and

Mg

Micros

Soil pH x x x x x x

Moisture x x x x x x

Temperature x x x x x x

Aeration x x x x x x

Soil organic matter x x x x x

Amount of clay x x x x x x

Type of clay x x x x

Crop residues x x x x x x

Soil compaction x x

Nutrient status of soil x x x

Other nutrients x x x x

Crop type x x x x

Cation exchange capacity (CEC) x x x

% CEC saturation x

Ways of assessing soil nutrient supply

• Soil test is the best tool

to assess indigenous

nutrient supplying

capacity of soils

• Nutrient omission plot

studies can also be

used in absence of soil

testing facility

Consider all available nutrient sources

Adjust rates of externally applied nutrients for:

• Native soil supply

• Organic manure

• Irrigation water

• Crop residues

• Biological N fixation

Fertilizer use efficiency

• Plants cannot utilize 100% of the externally

applied nutrients due to inherent sinks and

loss mechanisms

• Fixation by inorganic and organic soil

components

• Microbial immobilization

• Leaching

• Volatilization

FUE can be estimated by several ways

• Agronomic efficiency (AE) = (Y - Y0)/F

• Recovery efficiency (RE) = (U - U0)/F

• From nutrient omission plot data, with known AE or RE

F = (Y - Y0)/AE or F = (U - U0)/RE

• 4R Nutrient Stewardship raises both yields and FUE

Consider Soil Resource Impacts

Nutrient application rates that optimize plant growth:

• Contribute more C to the soil as crop residues

• Build up soil organic C

• Improve soil structure

• Improve soil water and nutrient holding capacity

• Maintain optimum soil test levels (P and K)

Rate estimation is governed by soil test

• Apply less than the crop removal when soil

test is high and vice versa

• For P and K fixing soils, apply additional

amounts to compensate for fixation

• Test soils every 3 to 5 years to ensure that

nutrients are maintained at sufficient level

Soil resource impact on right rate


RIGHT TIME


To assist in rate determination, the

manual provides tables of:

• Nutrient uptake for selected crops

• Dry matter and nutrient composition of

manure

• Annual N fixation by legumes

• Nutrient removal for selected crops

Principles supporting Right Time

• Consider source, rate, and place of application

• Assess timing of plant uptake

• Assess dynamics of soil nutrient supply

• Recognize dynamics of soil nutrient loss

• Evaluate logistics of field operations

Iowa S. Univ., 2008

Crop uptake dynamics and fertilizer timing

Example: Corn

• Most crop nutrient uptake

and dry matter

accumulation follows S

shaped or sigmoid

patterns

Crop uptake

dynamics and

fertilizer timing …continued

Rice

Bertsch, 2005

Wheat - most N should be applied

before the jointing stage, but some

applied late-season during heading

may increase grain protein

Cotton - majority of N and K taken up

after first flower; in some cases foliar

application after this point can improve

yield and/or quality

Timing by growth stage may be beneficial in

some crops

Assessing dynamics of soil nutrient

supply

• Most soils can supply at least some of the

nutrient requirements of a crop

• Soils with low nutrient holding capacity

require more emphasis on critical

application timing

Right Time

depends on

dynamics of

the nutrient

cycle

Soil testing and application timing

• Soil test level is a helpful tool in assessment

of soil nutrient supply

• Provides some idea of the probability of

response to fertilizer application

• At lower soil test levels, application timing is

more critical

• Higher soil test levels allow more flexibility

in timing


supply

Questions to ask/keep in mind

• Are there issues with immobilization or other

processes that might disrupt nutrient supply?

• Does the soil have the potential to

compromise availability of added nutrients

over time? (e.g., P in highly acid or alkaline

soils)


loss

• Losses of N and P have the most potential for

environmental impact

• Mechanisms of loss for N and P are very

different

• P normally lost through runoff, making

placement important in avoidance

Nitrogen can be lost through pathways such as

• Leaching

• Denitrification

• Runoff

Where there is high potential for N loss during the season,

timing is especially important

Nitrogen loss potential and timing

Nitrate-N in soils

• N occurs in several forms in soils, one of them is nitrate

• Most nitrate in soils is produced from the process of

nitrification

• Nitrification is the biologically driven conversion of

ammonium-N to nitrate-N

Nitrate-N in soils

• Nitrate is subject to loss through leaching and

denitrification, particularly in wetter environments

• Nitrate may accumulate in soils in arid

environments where leaching potential is low

– Soil testing for nitrate with deep (60 cm or

2 ft.) samples is useful in accounting for all

available N in more arid environments

Fall application of N for spring

planted crops

Spring application is best, but fall application

can be an option

– Should be done after soil temperature is <50°F (10°C)

– Inhibitor technology can be useful

Parameter (mean of 15 years,

1987-2001)

Time of N Application

Fall Fall +

N-Serve

Spring

Yield (bu/A) 144 153 156

Economic return over fall applied

N ($/A/yr)

-- 28 48

Flow-weighted NO3-N (mg/L) in

tile drainage water

14.1 12.2 12

N recovery in grain (%) 38 46 47

Fall application of N for spring planted crops:

An example

Randall, 2008

Logistics of field operations affect

timing decisions

• Application timing decisions are governed

by practicality

• As farm size has increased, logistics of

planting and input timing have changed

• Fall input, where reasonable, can save

valuable time in the spring

• P and K by nature lend themselves to early

application, but precautions should be taken

with fall N application

• Where logistics demand a single, one-time application,

EE fertilizer technologies may be useful

• These technologies include:

– Slow and controlled release fertilizer

– Nitrification and urease inhibitors

Enhanced efficiency fertilizer technology

may ease timing pressure


Right Place


Principles supporting Right Place

• Consider source, rate, and time of application

• Consider where plant roots are growing

• Consider soil chemical reactions

• Suit the goals of the tillage system

• Manage spatial variability

Examples of differences in root architecture

Weaver, 1926

Root plasticity

Drew, 1975

-0.10

0.00

0.10

0.20

0.30

0.40

0.50

0.0 0.1 0.2 0.3 0.4 0.5

Influx,

mill

ionth

of a m

illig

ram

of P

per

mete

r of

maiz

e r

oot

length

per

day

Solution concentration,milligrams of P per liter

Maximum influx

Influx as it approaches

the maximum

Nutrient uptake by plant roots

Barber, 1984

Nutrient uptake rate changes during the season

From Mengel and Barber, 1974

0.0

0.5

1.0

1.5

2.0

2.5

0.0

0.1

0.2

0.3

0.4

0 25 50 75 100

mgK

perm

ofro

otp

erd

aymgPpermofrootperday

Plantage,days

Phosphorus

Potassium

Nutrient placement options

• Broadcast

• Banded

• Point injected

• Combinations



Soil and Root Reactions to Band

Placement

Key effects of banding:

• Concentration of nutrients

• Higher localized soil solution concentrations

• Faster diffusion rates

• Root proliferation (N and P)

Higher rates:

• Extend the volume of

fertilized soil

• Bring fertilizer granules

or droplets closer

• Increase the longevity of

fertilized soil

Application rate affects fertilized soil volume

Placement affects fertilized soil volume

Broadcasting nutrients over time (conservation tillage)

Banding nutrients in the same location over time

Banding nutrients in different locations over time

Increasing time

Early season crop needs

Banded nutrients near

the seed:

• Are in close proximity

to a limited root

system

• Provide concentrated

supplies when influx

rates are highest

• Increase the rate of

nutrient diffusion to

roots

Factors to consider for seed-placed fertilizer

Adjust rates for:

• Seed sensitivity

• Fertilizer salt index

• Width of seed furrow

• Soil texture

• Soil moisture

• Amount of tolerable

stand loss

• Runoff losses

• Losses accompanying soil

erosion

• Gaseous losses of N

Reducing nutrient losses with banding

Sub-surface banding keeps nutrient concentrations

lower at the soil surface reducing:

Starter fertilizer: NH4+ and P should be placed together

Miller and Ohlrogge, 1958

400 800 1200 1600 2000

20

40

60

0

0

20-40 lb P2O5/A

20-40 lb P2O5/A + 10 lb N/A, mixed

20-40 lb P2O5/A + 10 lb N/A, separate

Pe

rce

nt o

f th

e p

lan

t P

co

min

g fro

m th

e b

an

d

Phosphate added to bulk soil, lb P2O5/A

147 900+ 900+34

Soil test P, ppm

54 204

Foliar fertilization

• Nutrients in the gaseous state

enter the leaves through the

stomata

• Nutrients in solution enter the

leaves through small pores in

the epidermis of the plant leaf

• Foliar fertilization creates small,

localized supplies of nutrients

that have a short duration

• Effective when soil supplies are

limited

Foliar with adjuvant

• Plants with thicker cuticle layers

• Runoff of fertilizer from leaves

• Washing off of fertilizer by rain

• Drying of liquid fertilizer on the

leaf

• Limited translocation of some

nutrients within the plant

• Leaf damage

Limitations of foliar fertilization

Factors limiting the effectiveness of foliar fertilization:

“Right place” goes beyond place within the soil to place within

the landscape

Managing spatial variability

Example:

P Index helps

target areas

where P

applications

need to be

reduced … or

sub-surface

placement

should be

utilized.

Sharpley, Gburek, USDA-ARS, Beegle, Penn State, University Park, PA

P lossvulnerability

Low (clear)

Medium

High

4R Fertigation for efficient nutrient management in irrigated agriculture

Dr. Munir Rusan, Consulting Director, Middle East

Outline

• What is fertigation?

• Why fertigation is necessary for arid & semiarid region?

• Advantages of fertigation

• 4R Fertigation:

Selecting right Source of both nutrients & irrigation water, IW

Selecting right Rate of both nutrients & IW application

Selecting right Time of both nutrients & IW application

Selecting right Place of both nutrients & IW application

• Conclusion

4Rs can be applied to any cropping

systems including:

rainfed agriculture, and irrigated

agriculture,

open or protected agriculture,

hydroponic or soilless culture

Fertigation

None of these cropping systems can be

perfectly sustainable, but the adoption

of the 4R is the way to optimize

sustainability.

N

P

K

FeN

P

K

Fe

N

P

K

Fe

N

P

K

Fe

• Fertigation is the application of soluble and compatible fertilizers through IW

• Can be practiced with any irrigation system.

• However, due water scarcity, it is practiced dominantly with pressurized irrigation systems; drip irrigation systems being the most efficient irrigation method

• Fertigation controls 4R components more precisely than other system

Rainfall is low and poorly distributed

Agric. production can be practiced only with irrigation

Water Resources are Limited

Cultivable Land are limited

Water & Soil Fertility are the Main 2 Limiting Factors of

Agriculture Production

These 2 factors can be simultaneously and best

managed with fertigation

Why Fertigation?

Fertigation for Arid and Semiarid Region is

not a choice but a mandatory & prerequisite:

• Horizontal expansion is limited- limited water & land resources

• Agric. Intensification - main approach to increase food:

• Ag. Intensification Intensive use of inputs, where fertilizer

use is considered the leading factor

• > 50% of World food production is attributed to fertilizers use

(FAO)

• Growing Environmental concern with Ag. Intensification

• Therefore, water and fertilizer should be managed

sustainably (that is be economically feasible, environmentally

and socially acceptable -Eco-intensification)

• This can be better achieved with fertigation

Under these conditions

(scarcity of water & cultivable land):

Current & Future Trends:

Due to scarcity of water resources:

• farmers are switching from surface to

pressurized irrigation

• drip is the common practice

Conventional Fertilization to Fertigation

Fertigation

Main Advantages:

• Precisely control source, rate, time and place of

application (4R)

• Increase the yield

• Improves both WUE & FUE, saving water &

fertilizers

• Reduces nutrients leaching below the root zone

• Save energy, time and cost

• Saline, shallow and with- slope soils can better

be cultivated

• others…

d

aba

bcc

0

2

4

6

8

10

12

14

16

18

20

N0 N1 N2 N3 NS

Squash yield, T/ha (Rate of N2-fertig = Rate of NS-soil application

0 65 131 197 128 kg/ha

N2

f

N2s

Fertigation of 65 kg N/ha performed better than

soil application of 128 kg N/ha

Rusan, Nutrient Cycling in Agroecosystem 67: 1-10, 2003

Research has proven superiority of fertigation

b

a

b

c

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

N1 fertigation N2 fertigation N3 fertigation Ns=N2 soil appl

WUE (kg/mm) by Squash with N fertigation vs soil application

• N fertigation:

– Enhances plant biomass and

– Increase density and depth of root,

– Resulting in higher evapo-transpriration (water consumption) and WUE


Nitrogen Utilization efficiency

Using Isotopic 15N Labelled Fertilizer

Fruit Shoot Fruit Shoot Total NUE

Trt Kg ha-1

N dff

%

N uptake dff

Kg N ha-1

N uptake dff

Kg N ha-1 %

N0 0

N1 66 35.0 c 39.8 c 24.1 c 7.4 b 31.5 c 47.9 a

N2 132 43.1 b 45.4 b 44.1 b 15.4 a 59.5 b 45.3 a

N3 198 50.0 a 49.7 a 46.3 a 17.6 a 63.9 a 32.4 b

NS 128 27.1 d 33.5 d 20.0 d 6.0 b 26.0 d 20.3 c

N Derived from N Fertilizer (% and Uptake) &

N Utilization Efficiency (NUE)

were more than double for fertigation vs soil application

• dff = Derived from fertilizer

• N1, N2, N3 = Fertigation trts & NS = Soil application trt

• N2 = NS


Trts N Rate FNUEp FNUEa RE PFP

kg ha-1 kg kg –1

N0 0 - - - -

N1 66 36.46 a 26.45 a 0.73 a 144.6 a

N2 132 23.61 b 16.91 b 0.72 a 75.97 b

N3 198 22.94 b 10.17 c 0.44 b 49.55 c

NS 128 21.98 b 9.42 c 0.43 b 40.33 c

* N1, N2, N3 = Fertigation trts & NS = Soil application trt

Physiological FNUE (FNUEp), kg kg -1 = (FWf - FWc) / (TNUPf – TNUPc)

Agronomical FNUE (FNUEa), kg kg -1 = (FWf - FWc) / NA

Recovery Efficiency (RE), kg kg -1 = (TNf - TNc) / NA

Partial Factor Productivity (PFP), kg kg -1= (FWf / NA)

FWf = fruit weight of fertilizer treatment

FWc = fruit weight of control treatment

TNUPf = total N uptake by fruit and shoot in fertilizer treatment

TNUPc = total N uptake by fruit and shoot in control treatment

NA = nutrient applied

Components of Nitrogen Utilization Efficiency


• Limited soil wet zone

• Shallow root depth

• Limited zone for fertilizer placement

• Higher depletion rate so requires higher frequency of application of W + F

• Higher interaction among nutrients

• Concentrated soil solution salinity High nutrients interaction

• Available concentration < Apparent due to higher ionic strength.

ai = Ƒ * ci ;

a = activity = availability;

C = concentration;

Ƒ = activity coefficient

DRIPPER

With Drip Irrigation:

Accumulation of

Salts & NO3

Irrigation Water

Leached Zone

Higher salts

and mobile

nutrients

Saturated ZoneH2PO4K

Ca

NH4

Fe

NO3

NO3

DRIPPER

Pattern of Accumulation of Nutrients & Salts

in the Irrigated Volume by a Dripper

• Under these conditions, I mean nutrient management in

such small and concentrated soil zone is very challenging.

• However, this can be achieved with fertigation thru

accurately controlling the Source, Rate, Time & Place of

Water + Fertilizer application

• That is by fertigation, we can Apply Water + Fertilizer

together using the

right source of F+W,

right rate of F+W,

right time of F+W

right place of F+W

Ensure 1. balanced

supply of nutrients, 2.

Solubility, and

Compatibility with

irrigation water

3. Suitability to soil

chemical and physical

properties

Example

of

scientific

principle

Example

of

practical

choices

Asses nutrient supply

from all sources and

plant demand,

Recognize irrigation

requirement and

frequency, soil texture

and growth stage

Asses dynamics of crop

uptake and soil supply

Determine timing of loss

risks

Recognize soil texture

and irrigation frequency

Soil moisture level and

climatic conditions

Recognize crop rooting

patterns, irrigation

method and soil

texture.

Manage spatial

variability

Solid fertilizer

Liquid fertilizer

Suspension fertilizer

Single vs compound

fertilizers

Salt index of fertilizer

Quality of IW

Test soils for nutr.

Calculate economics

Balance crop removal

Test and calibrate

fertigation head

Pre-plant

At planting

At flowering

At fruiting

Continuously

Every other irrig.

Fertigate with

surface irrigation

Fertigate with

subsurface irrigation

Fertigate with drip,

sprinkler or surface

irrigation methods

Source Time PlaceRateIrrigation Pipe

4R Fertigation

To select the right nutrient source for fertigation consider the following:

• Determine soil nutrients levels to recognize deficient nutrients

• Recognize impact of accompanying ions on environment &

public health

• Recognize the feasibility, accessibility and affordability of the

source applied and its impact on the income of the farmer

• Source must supply all nutrients needed in a balanced way to

prevent any negative or antagonistic interactions among

nutrients

avoid accumulation of certain nutrients

avoid depletion of certain nutrients

• Source must be water soluble - most important factors for

fertigation, especially when preparing fertilizer solutions from dry

fertilizers

Right source of nutrients for fertigation

To select the R1 for fertigation consider the following:

• Source should be suitable for soil chemical and physical

properties to

Ensure maximum crop recovery efficiency and

Minimize losses of nutrients through leaching, fixation,

volatilization

Effect on soil pH, EC, structure .. others

• Source must be in the right combination with the Rate, Time and

Place

• Source should have low salt

Right source of nutrients for fertigation

Compatibility

1. Between fertilizers and other fertilizersa. Interaction among fertilizers in the stock solution

b. Solubility products of different fertilizers

2. Between fertilizers and Irrigation watera. Hard water

b. pH

c. HCO3

d. Temperature

3. Between fertilizers and irrigation methodsa. Boron

b. Chloride

Source must be compatible with other

fertilizers and Irrigation water

Interactions and compatibility among fertilizers

• Actual solubility of individual fertilizer in the fertilizer stock

solution is less than the theoretical one

• Solubility products of various fertilizers can react with each

others and form precipitates, leading to clogging problems and

reduce the actual nutrients concentration. For example:

• Calcium nitrate with any sulfates = formation of CaSO4 precipitate

• Ca(NO3)2 + (NH4)2SO4 CaSO4 + …..

• Calcium nitrate with any phosphates = formation of Ca phosphate

precipitate Ca(NO3)2 + NH4H2PO4 CaHPO4 + …..

• Magnesium nitrate with MAP/DAP = formation of Mg phosphate

precipitate

– Mg(NO3)2 + NH4H2PO4 MgHPO4 + …..

• Ammonium sulfate with KCl or KNO3 = formation of K2SO4 precipitate

SO4(NH4)2 + KCl or KNO3 K2SO4 + …..

• Phosphorus with iron = formation of iron phosphates precipitate

– Fe + NH4H2PO4 FeHPO4 + …..

Assuming a grower wants to prepare stock solution

from following fertilizers:

• KNO3, Ca(NO3)2, MAP, MgSO4, cationic micronutrients and acid:

• Ca(NO3)2 is not compatible with MAP or with cationic micronutrients

• MgSO4 is not compatible with Ca(NO3)2 and micronutrients.

• Acid should be in a separate tank for pH adjustment.

• Therefore 3 tanks are needed to prepare 3 different solutions to avoid

incompatibility limitation. That is:

• Tank A: MAP and magnesium sulfate

• Tank B: Potassium nitrate, calcium nitrate and micronutrients

• Tank C: Acid.

Tank B:

KNO3

Ca(NO3)2

Micronutrients

Tank A:

MAP

MgSO4

Tank C:

Acid

_ NH4 NO3

UREA (NH4)2 SO4

(NH4)2 HPO4

KCl K2SO4 KNO3 Ca (NO3)2

NH4 NO3

_ _ _ _ _ _ _ _

UREA

OK _ _ _ _ _ _ _

(NH4)2 SO4

OK OK _ _ _ _ _ _

(NH4)2 HPO4

OK OK OK _ _ _ _ _

KCl

OK OK X OK _ _ _ _

K2SO4

OK OK OK OK OK _ _ _

KNO3

OK OK X OK OK OK _ _

Ca

(NO3)2

OK OK X X OK X OK _

Fertilizers Mixing

Kind of metal Ca(NO3)2

(NH4)2SO4

NH4NO3

UreaPhos.

AcidDAP

Galvanized iron 2 4 4 1 4 1

Sheet aluminum No 1 1 No 2 2

Stainless steel No No No No 1 No

Bronze 1 3 3 No 2 4

Brass 1 2 3 No 2 4

No = none

1 = slight

2 = moderate

3 = considerable

4 = severe

CorrosivitySource should not be corrosive to the equipment used

fertilizers should be flushed from irrigation system after fertilization

Cooling effect

• Recognize effect of temperature on solubility of fertilizers used

• Most dry fertilizers (such as KCl, Urea) absorb heat from the water

upon dissolution (endothermic reaction):

The temperature of the solution is lowered

Total solubility of the fertilizer decreases

• Dilution of phosphoric acid generate heat (exothermic reaction):

The temperature of the solution is increased

Therefore it should be added before the addition of urea or

KCl, which have an endothermic reaction

Right Source of irrigation water (Water

Quality Parameters):

Hard waters:

– high content of Ca and Mg (> 50 ppm),

– bicarbonates (> 150 ppm)

– and alkaline pH (> 7.5)

• Ca+Mg (from water) will precipitates with phosphate & sulfate from

fertilizers

• Ca forms lime scale (calcium carbonate precipitate):

CO32- + Ca2+

CaCO3 (at pH > 7.5)

• It is recommended:

– Use fertilizers with acid reaction (for P; phosphoric acid, MAP)

– Periodically inject acid into the irrigation system to dissolve

precipitates and unclog the drippers

– Add Ca & Mg fertilizers according to their level in the irrigation water

Right source of irrigation water (Water Quality Parameters):

A. Ammonia is a common N source used in fertigation

• If NH3 is injected into hard water (rich in Ca, Mg), may lead to:

Increase pH of the solution (NH3 + H2O = NH4+ + OH-)

Precipitate Ca and Mg as CaCO3 and Mg CO3

Clog the emitters, filters, pipes

For example:

– IW with EC=0.2 dS/m and 10 mg/l of Ca+Mg, can safely tolerate an

NH3 N concentration of 30 g/L (30000 ppm)

– While IW with EC=0.8 dS/m and 30 mg/l of Ca+Mg can only tolerate

an NH3-N concentration of 1 g/L (1000 ppm)

– While IW with EC=2.5 dS/m and 200 mg/l of Ca+Mg can only tolerate

an NH3-N concentration of 0.25 g/L (250ppm).

• Possible solutions:

– Add inhibitors to "Hard water" as sodium hexametaphosphate or

ammonium polyphosphate to sequester Ca+Mg & decrease

precipitation

– Neutralize the pH with acids

Anionic composition of the irrigation water (mainly,

bicarbonate, sulfate, chloride and boron):

B. Anionic composition of the irrigation water (mainly, bicarbonate,

sulfate, chloride and boron):

1. Bicarbonate anions:

a. Increases pH of the solution

b. Decreases actual solubility of fertilizers

c. Enhances precipitation of Ca and Mg

d. Stimulates salting out fertilizer solution

e. Inactivates Fe and Zn in plant tissues

2. Chloride & sulfate anions tend to increase salinity

3. Sulfate anions enhance precipitation of Ca, Mg and Fe (SO4)

Anionic composition of the irrigation water (mainly,

bicarbonate, sulfate, chloride and boron):

C. pH of the irrigation water:

1. Indicator of precipitation and clogging problems

2. Indicator of relative conc. of ions (Na, HCO3, HMs etc)

3. Solubility of fertilizer is lower with higher pH

D. Total Suspended Solids (TSS), Turbidity:

Solid particles may:

1. Act as a nucleus for precipitation in solution

2. Clog the dripper, and precipitate in the irrigation lines.

3. Clog soil pores and affect water permeability in the soil

Therefore, whenever IW contain high TSS, filters must be used to remove the

sediments.

Right Rate of nutrients application for fertigation:

It important to apply the right rate of nutrient application to:

• Make sure the crop is receiving the required amount of

nutrients, but avoiding excess

• Avoid application of excess fertilizer at one time that may

cause:

Salt damage – fertigation deals with concentrated solution

Unnecessary fertilizer cost

Reduce profitability

Adverse impacts on natural resources (water, soil, air)

Nutrients accumulation in agricultural products above acceptable levels

Right Rate of nutrients application for fertigation:

The following should be considered to determine and select the

right rate:

• Recognize the attainable yield, target yield or yield goal of the

crop, considering the specific field where the crop is grown

• Recognize the nutrient requirement, or removal for the crop yield

• Recognize the water and irrigation requirements of the crop

• Recognize the right irrigation scheduling of the crop

• Recognize the pattern of nutrient uptake by the crop

- The uptake rate of the primary essential nutrients follows the rate of

biomass accumulation

• Assess available nutrients from all sources (soil, water, manure

and others)

Where;

NR = nutrient requirement of the crop, kg/ha

NS = nutrients from the soil, kg/ha

NO = nutrients from organic fertilizer, kg/ha

MW = nutrients from irrigation water, kg/ha

FUE = fertilizer use efficiency in %

𝑹𝑨𝑻𝑬 𝒐𝒇 𝑵 =𝑵𝑹− 𝑵𝑺 + 𝑵𝑾+𝑵𝑶 ∗ 𝟏𝟎𝟎

𝑭𝑼𝑬

Rate of nutrient application from mineral

fertilizers (RATE):

Right Time of nutrients application for fertigation:

Pattern of nutrient uptake:

• For example,

• The uptake of N and K is initially slow, followed by a rapid

increase during the flowering stage. K uptake peaks during

fruit development.

• The uptake rate of P and secondary nutrients (Ca and Mg) is

relatively constant during the growing season for the tomato

crop.


The following considerations are necessary for selecting the

right time of nutrient application:

• Consider the source, rate and placement being used

• Method of irrigation (the most important factor)

• Type and geometry of the root system

• Consider the dynamics of the nutrient in the soil (mineralization,

precipitation, adsorption, etc)

• Consider the dynamics of the nutrient uptake by the crop

• Consider the potential losses of the nutrient from the soil

(leaching, volatilization, fixation, immobilization)

• Movement mechanism of nutrient in soil (mass

flow/diffusion/contact exch.)


Soil physical and chemical properties (texture, water holding

capacity, nutrient buffer capacity, pH, CEC):

In fine texture,

• injecting fertilizer in the middle of the irrigation cycle resulted in better

distribution than when injected in at the beginning or at the end of

irrigation.

• Injecting at the beginning resulted in nutrient leaching from the root

zone while injection at the end did not completely flush the fertilizer

from the system, and thus did not reach the roots.

In coarse textured soil where leaching potential is high,

• injecting mobile nutrient such as nitrate fertilizers during the last third

period was better and prevented nitrate leaching. For immobile

nutrients injection at the beginning of irrigation would give a more

uniform distribution.

Right fertigation scheduling - right rate

and right time:

• Fertigation scheduling is the process of determining the right

rate and right time of IW+F application

• In fertigation, the right rate and time are closely linked and

follow the rate and time of irrigation water application.

• Therefore, over-irrigation or under-irrigation will lead to over-

fertilization or under-fertilization.

• It can be based on either direct soil water measurement, plant

moisture measurement or by using climatic data.


and right time:

• Selecting the right fertigation scheduling is mainly important

under salinity

• A higher frequency of fertigation, that is an application of low

rate but more frequent, is recommended under saline condition

to avoid an accumulation of salts in the root zone.

• The lower the frequency of fertigation,

the higher the concentration of the fertigation solution,

the higher the salinity level of the fertilizer solution

the higher the accumulation of salts in the root zone

the higher the leaching of mobile nutrients

the higher the precipitation and adsorption of the immobile nutrients

the lower the fertilizer use efficiency


and right time:

Right fertigation scheduling - right rate and

right time:

Right Place of nutrients application for

fertigation:

• Proper placement of fertilizer has several benefits such as:

enhancing fertilizer use efficiency,

reducing losses,

enhancing seed germination and emergence,

improving plant establishment,

• Proper placement of fertilizer should be selected in

combination with the right source, rate and time of application.

• With fertigation, applied fertilizers are placed close to the

roots, therefore, application of higher than recommended rates

might induce a fertilizer-burn and potentially inhibit root

growth.

Right Place of nutrients application for

fertigation:

The right placement of nutrient application depends on several

factors including:

• mobility of the nutrient applied,

• soil characteristics,

• form of fertilizer and

• the developmental pattern of plant roots.

• proper placement of fertilizer should maximize the

probability of being intercepted by the roots, maximize

nutrient uptake and minimize nutrient losses.

Factors affecting the selection of the right

place of nutrient application:

• Method of irrigation (the most important factor)

• Consider the type, geometry and distribution of the root system

• Soil properties (texture, water holding capacity, nutrient buffer capacity,

pH, CEC)

• Planting spacing

• Consider the source, rate and time of application

• Consider dynamics of soil nutrients (mineralization, precipitation,

adsorption)

• Consider potential losses of nutrient (leaching, volatilization, fixation,

erosion)

• Consider mechanism of movement: mass flow, diffusion, contact

exchange

• Since drip irrigation results in a small and limited wet soil volume where

the active crop roots will be distributed, depletion rate is higher thus F+W

must be added more frequently and within the wet soil zone



• In sandy soils, over irrigation can lead to leaching of mobile

nutrients below the root zone leaving them positionally not

available

• In clay soils nutrients distribution is mainly affected by their

mobility in the soil, their potential of being adsorbed or

precipitated in the soil

• For example, positively charges nutrients (NH4 & K) tend to be retained

at the soil surface

• On the other hand, negatively charged nutrients (NO3 & Cl) tend to

move freely in the soil and follow the movement of the irrigation water.

• Some negatively charged nutrients are immobile (phosphate). They

precipitate with Ca and Mg in basic soil and with Al and Fe in acid soil

• Consider the type of interaction between nutrients. For example, co-

placement of N and P has a synergistic effect while P and Zn has a

antagonistic effect



• Method of of fertigation (fertilizer injection) is a big factor

affecting placement

• The most common fertilizers injection systems are:

By-Pass system

Venture system

Pumping system

WATER WATER &

FERTILIZER

FERTILIZER

0

10

20

30

40

50

60

0 2 4 6

Co

nc

Time

Fertilizer Injection

Systems:

A. Fertilizer Tank (By-Pass

injection system)

This system maintains proportional

mixing ratio using two mixing

mechanisms:

Operational principle:

• Fraction of IW of main line is by-

passing thru valve to fertilizer

tank to dissolve fertilizer. Then

fertilizer solution is injected back

to the main irrigation line

Advantages:

• Simple & Inexpensive

Disadvantages:

• Concentration not constant

• Can not be automated

B. Direct Injection of Fertilizers into Irrigation Line

This system maintains proportional mixing ratio using two mixing mechanisms:

Venturi setup (Pressure difference):

Operational principle: The constriction in the devise accelerates water flow

and creates suction effect that pumps fertilizer solution into IW line

Advantages:

• Relatively inexpensive

• Fair control of fertilizer concentration

Disadvantages:

• High head loss

• Relatively low discharge rate

Water inlet

Fertilizer

tank

Venturi

injector

Main line

Booster

pump

Injection

point

0

20

40

60

80

0 2 4 6

Co

nc

Time

Fertilizer Injection Systems:

C. Hydraulic fertilizer injection pumps

Operational principle: Water-powered pump (derive its operation energy

from irrigation line pressure) draws fertilizer stock solution from the tank and

inject it into the irrigation system. Water or electrically-powered.

Advantages:

• No head loss

• Flexible discharge rates, including high rates

• Constant concentration and good control over it

Disadvantages: Relatively expensive & Need skilled personnel

0

10

20

30

40

50

60

0 2 4 6

Co

nc

Time

Fertilizer Injection Systems:

Conclusion

• Adopting the 4Rs principles in fertigation

provide a powerful tools for efficient and

sustainable nutrient management under

irrigated agriculture

Nutrient Expert® Fertilizer Decision Support Tool

Dr. Kaushik Majumdar, Vice President, Asia, Africa, and the Middle East

Drivers of Nutrient Expert® Development

• Inappropriate fertilizer use is a growing challenge

– Average cereal yields at 50-60% of potential yield

– Reduced fertilizer response

– Nutrient Mining

– Environmental Impacts

• Average crop N recovery estimated at 33-50%

• Need for large scale extension of improved nutrient

management to quickly provide many farmers with a

science-based fertilizer guideline tailored to their

specific field, crop, season and resource endowment

for sustainably improving cereal productivity

The Nutrient Expert decision support tool

• Nutrient Expert is a computer-based decision support tool for

crop advisers. It uses the principles of site-specific nutrient

management (SSNM).

• SSNM aims to supply a crop’s nutrient requirements tailored

to a specific field or growing environment.

– accounts for indigenous nutrient sources

– applies fertilizer at optimal rates and at critical growth stages

4Rs (right source, right rate, right time, right place)

Estimating plant nutrient requirements

Total amount of nutrient needed to achieve a yield target is• estimated from the relationship between grain yield and balanced

uptake of nutrients at harvest as defined by the QUEFTS model (Janssen et al. 1990)

YPD

YPA

YKD

YKA

YND

YNA

YN YP YK

Source: Setiyono et al. 2010

Nutrient uptake requirements for cereals as

predicted using QUEFTS

Crop Reciprocal internal efficiency (kg nutrient/1000 kg grain)

N P K

Rice1 14.6 2.7 15.9

Maize2 18.0 2.56 17.4

Wheat3 22.3 4.0 20.0

1 Buresh et al. 2010. Plant and Soil 335: 35–642 Setiyono et al. 2010. Field Crops Research 118 (2): 158–1683 IPNI data (Several Publications)

Estimating fertilizer nutrient requirementsThe SSNM approach

1. Identify a yield target (i.e. attainable

yield)– Depends on climate, variety, and season

– Yield achieved with best management

practices where nutrients were not limiting

– Indicates the total amount of nutrients that

must be taken up by the crop

2. Estimate indigenous nutrient supply– Can be determined through use of nutrient

omission plots: 0N (PK), 0P (NK), 0K (NP)

– Yield in nutrient omission plot indicates amount

of nutrient from indigenous sources

• e.g. N-limited yield reflects indigenous N

supply

3. Estimate amount of nutrient to be

supplied as fertilizer– The difference between the total crop demand

(attainable yield) and indigenous supply

(nutrient-limited yield) will provide an estimate

of the amount of nutrient to be supplied as

fertilizer

Attainable

yield

Yield without

N fertilizerIndigenous N supply

N from fertilizer

5 t

10 t

Yield potential

What is the Knowledge Requirement

• Minimum dataset

– Attainable Yield

– Nutrient Uptake Requirement

– Soil Nutrient Supplying Capacity

– Crop Uptake Pattern

• Further refinement

– Previous crop history

• What crop

• What yield

• How much nutrient was applied

• Still further refinement

– Genotypes

– Tillage

– Residue Management

– Nutrient Input from other sources (Irrigation water etc.)

Nutrient Expert: Simplifies implementation of

SSNM

Site &

farming

information

Nutrient

Expert DSS

Fertilizer

recommendation

Farmer Crop adviser

Farmer

Nutrient Expert provides SSNM-based fertilizer

guidelines for a location using site information that can

be easily provided by a farmer or crop adviser

Decision rulesAlgorithm

Agronomic database:

multiple locations, diverse conditions

Nutrient Expert: development process

Data

collection

Model

development

Field

validation

Version 1

for release

Agronomic

database:

multiple locations,

diverse conditions

• Attainable yield

• Yield response

to N, P, K

• Fertilizer use

efficiency (AE,

RE)

• Nutrient uptake

• Data analyses

• Consultation

meetings

• Algorithm

development

• Programming

• On farm field

testing: NE, FP,

other fertilizer

practices

• Model adjustment

(as needed)

Site-specific nutrient management, QUEFTS model

software.ipni.net

Nutrient Expert is developed through collaboration

with local experts and stakeholders

• Collaboration with target users and

stakeholders through consultation

meetings

– Collection of locally-available

agronomic data and information

– Field testing, evaluation, and

refinement of the software

– Building confidence in the concept with

collaborators

• Tailored to

location-specific

conditions

• Consistent with:

- right source

- right rate

- right time

- right place

Integration

of organics

Right

time

Right source Right

rate

Nutrient Expert recommendation:

NE provides options for resource-

constrained farmers

Nutrient Expert® improved maize yield and

profit

Parameter Unit Effect of NE (NE – FFP)

India Indonesia Philippines

(n = 412) (n = 26) (n = 190)

Grain yield t/ha +1.27 *** +0.92 *** +1.10 ***

Fertilizer N kg/ha –6 ns –12 ns +3 ns

Fertilizer P2O5 kg/ha –16 *** –5 ns +18 ***

Fertilizer K2O kg/ha +22 *** +15 *** +18 ***

Fertilizer cost USD/ha –1 ns +16 ns +37 ***

Gross profit USD/ha +256 *** +234 *** +267 ***

Current situation: farmers’ yield < attainable yield

Field Performance of Nutrient Expert in China

(2010-13)

Parameter Unit Wheat (n = 290) Maize (n = 541)

FP NE Soil test FP NE Soil test

Grain yield t/ha 7.9 8.0 8.3 9.9 10.2 10.3

N kg/ha 271 162 237 230 158 202

P2O5 kg/ha 118 82 105 62 56 57

K2O kg/ha 50 74 73 47 68 75

Fert. cost USD/ha 357 267 344 272 234 274

Gross profit USD/ha 2282 2417 2459 2902 3031 3006

REN % 17.5 30.2 22.5 18.5 29.1 23

AEN kg/kg 5.2 8.6 6.3 7.8 11.8 10

Current situation: farmers’ yield ≈ attainable yield

REN: apparent recovery efficiency of N (increase in N uptake/applied N)

AEN: agronomic efficiency of N (kg yield increase/kg applied N)

Nutrient Expert for Rice Improved N Use

Efficiency

0

5

10

15

20

25

30

AE

_N

(kg/k

g)

NE FP

OPTS

0

10

20

30

40

50

60

RE

_N

(%

)

NE FP

OPTS

0

10

20

30

40

50

60

70

80

PF

P_N

(kg/k

g)

NE FP

OPTS

Compared with the FP and OPTS treatments, NE increased AE 23.6% and 15.6%, RE 12.2 and 8.4 percentage points, and PFP 9.1% and 7.5%, for N fertilizer, respectively.

Grain yield of wheat (t/ha, 13.5% MC)

Morocco: Cropping season 2014-2015

Grain yield 2015 (t/ha)

Durum Wheat Bread Wheat

Regions Province (n) SSNM** FFPSSNM -

FFP

SSNM*

*FFP

SSNM

- FFP

Abda Safi 10 4.71 4.43 +0.30 5.28 4.54 +0.74

ChaouiaSettat 5 3.95 2.31 +1.74 3.75 2.45 +1.31

Berrechid 5 4.99 3.35 +0.89 3.75 2.86 +0.88

Fez Sefrou 10 5.61 3.94 +1.86 5.36 4.20 +1.16

Tadla Fquih bensaleh 10 8.05 6.73 +1.33 7.89 6.86 +1.43

*Highest yield obtained for durum wheat in the 2014-15 field trial

** Recommendation using Nutrient Expert for Wheat (Morocco)

Nutrient Expert® reduced GHG emission in

wheat with increased yield and profit

Source: Sapkota et al. 2014, Field Crops Res. 155: 233-244

Northwest India: 2010-12

Farm Type 1 [Moderate-resourced commercial maize grower]

Farm Type 2 [‘Exclusive cultivators’ with large holding and large family]

Farm Type 3 [Low-yielding new maize growers]

Farm Type 4 [Moderately resourced family farms]

Farm Type 5 [Traditional maize grower]

Farm type 6 [Resource-rich commercial ‘seed producers’]

-$2

-$5

+$10

+$5

-$8

-$1642%

47%

73%

37%

55%

64%

Recommendation based on Farmer Resources

The best scalable ICT solution for improving rural livelihood

Global Program of Nutrient Expert: Current

Status

Maize

Cassava

Maize

Maize

Maize,

Cassava

Maize, Wheat, Rice, Soybean

Maize, Wheat, Rice

Cotton, Soybean

Wheat

Black: Field-validated model. Available at software.ipni.net

Blue: Beta version under field validation

Red: Initial stage of model development

Kenya, Zimbabwe:

Maize

Nutrient Expert Delivery Progress

Region Crop MS Access Web App for Android Web App for PC

Windows Andriod gadgets Win/Mac

China Hy Maize ✓ ✓

Wheat ✓

Rice ✓

Soybean ✓

S Asia Hy Maize ✓ ✓ ✓

Wheat ✓ ✓ ✓

Rice

SE Asia Hy Maize ✓ ✓ ✓

SSAfrica Hy Maize

N Africa Wheat ✗

- In development/field validation

Target: All current NE tools in web platform by the end of 2017

Nutrient Expert app – for Android mobile gadgets

Tablet Smart phone

The app can work offline – it does not require Internet to generate a

recommendation

Who are our clients

Stakeholders with direct interest in Nutrient Management

• National Soil Health Card Program, Govt. of India

• Indian Council of Agricultural Research

– IIMR, IIWBR,IIRR, IIFSR, ATARI

• State Agricultural Universities

• State Departments of Agriculture

• CIMMYT

• CGIAR-CCAFS Climate Smart village Program

• Member Companies and other Fertilizer Industry

• Self-Help Groups & Farmer Cooperative Societies

Stakeholders with indirect interest in Nutrient Management

• Seed Companies

• ITC (Tobacco major and Commodity Company)

• Tata Consultancy Services (Software Major)

• NGOs

Thank You!www.gpca.org.ae

Workshop: 4R Nutrient Stewardship Principles and Practices · Workshop: 4R Nutrient Stewardship Principles and Practices Dr. Terry L. Roberts, President Dr. Munir Rusan, Consulting

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