Nutrient Management

Key Check 5: Sufficient nutrients

from tillering to early

panicle initiation and

flowering

Part 1: Understanding the PalayCheck System

Nutrients are what plants need to

grow and become productive.

Proper nutrient management

improves crop growth and yield.

Rice plants grow and respond

better to fertilizer when there is

more sunlight.

Of all nutrient elements, rice

plants need more of the following

macronutrients: N, P, K, Zn, S

Nutrient facts

Climate

Indigenous

nutrient supply

Soil

Organic fert

Crop residues

Irrigation water

Inorganic

fertilizer

N-P-K

Nutrient inputs as fertilizers fill

the gap between crop need and

indigenous supply.

Why do rice plants need fertilizers?

Sufficient nutrients from

tillering to early panicle initiation (EPI) and flowering

ensures good and uniform growth,

panicle development, and

attainment of yield potential

nutrients are

needed to

produce many

tillers, panicles

and filled

grains for uniform

maturity

increased

yield from

many tillers

and panicles

more

panicles,

more

grains

Assessment of Key Check 5

urea

WS = 1 bag/ha

urea urea

DS = 1.5 bag/ha

Applied N fertilizer at

tillering to EPI and

flowering if leaf color

chart (LCC) reading

is below 4 for

transplanted and

below 3 for direct

wet-seeded rice.

Assessment of Key Check 5

For transplanted rice Achieved at least 300 panicles/m2

at flowering stage.

Randomly select 10 hills in a

diagonal line across the field and

count the panicles. Compute the

number of panicles/m2.

Panicles/m2 = Total number of panicles

10 hills

x Number of hills/m2

Assessment of Key Check 5

For direct wet-seeded rice Achieved at least 350 panicles/m2 at

flowering stage.

Use a 0.5 m x 0.5 m quadrat (0.25 m2).

Randomly select 3 sampling sites at least 1 m

from the levee and in a diagonal line across the

field. Count the panicles from each quadrat and

get the average. Compute for the number of

panicles/m2 .

No. of panicles/m2 = Ave. number of panicles

0.25 m2 hills

HOW TO ACHIEVE

Key Check 5?

HOW TO ACHIEVE

KEY CHECK 5?

Know and manage the nutrient requirement of your

crop based on the available information and

nutrient assessment and decision-support tools.

Minus-One Element

Technique

Leaf Color Chart

Nutrient Omission Plot

A pot experiment to determine the

nutrients deficient in the soil.

Minus-One Element Technique

Leaf Color Chart

A tool to visually assess the nitrogen

status of rice crops.

A means to assess indigenous nutrient

supply to serve as basis of fertilizer

recommendation.

Nutrient Omission Plot

a computer-based

decision tool

software providing

field-specific nutrient

management

guidelines for rice

Nutrient Manager for Rice

Consider this!

Aside from nutrient deficiency, consider

mineral toxicity in deciding on the nutrients

to apply.

Toxicity can occur when

minerals exist in a form that

becomes harmful to plants.

Worms (parasites) live in

every person’s intestines,

no matter how clean and

healthy a person is.

IRON TOXICITY

Iron is naturally present in the soil and plants need iron.

But iron can be harmful in permanently-flooded fields.

WHAT TO DO? Use intermittent irrigation and avoid

continuous flooding in poorly-drained soils, balance fertilizers

and perform dry tillage after harvest to increase iron oxidation

during the fallow period.

tiny brown spots on

the lower leaves

starting from the tip

or orange-yellow to

brown leaves

IRRI

HOW TO ACHIEVE

KEY CHECK 5?

Know and manage the nutrient requirement of your

crop based on the available information, nutrient

assessment and decision-support tools.

Knowing right kind, amount, and

timing of fertilizer application.

The right KAT!

• giving the right nutrients increases cost efficiency and attainment of yield target

Right kind

• too much nutrients may increase pest damage

• lack of nutrients may lead to slower growth of seedlings, fewer number of tillers, and lighter grain weight

Right amount

• wrong timing of fertilizer application increases input cost and decreases efficiency in nutrient uptake

Right timing

Right KAT!

Deficiency symptoms: Stunted, yellowish plants. Older leaves or whole plants are yellowish green.

NITROGEN

Kind NITROGEN

Nitrogen (N) promotes rapid growth for:

•increased plant height and number of tillers

•increased leaf size

•spikelet number per panicle

•percentage filled spikelets in each panicle

•grain protein content

Amount NITROGEN

Too much N particularly between panicle initiation and flowering makes the plant prone to lodging and pests.

Excessive N application is costly.

Use results of LCC and Nutrient Manager as basis in properly determining the amount of N to apply.

Timing NITROGEN

Use the LCC every 7 days from 14 DAT or 21 DAS until early flowering. If 14-14-14-12S is applied at 14 DAT or 21 DAS, LCC reading starts at 21 DAT or 28 DAS.

Determine right time of N application by using LCC. If more than 5 out of 10 leaves are below 4, apply 1.5 bags urea or 3.5 bags 21-0-0-24S during WS.

(Use ammonium sulfate instead of urea if plant shows sulfur deficiency or if sulfur-containing fertilizer is not used.)

Organic

(Basal)

Timing

NITROGEN

Deficiency symptoms:

Stunted dark green plants with narrow, short, very erect leaves and greatly reduced tillering.

PHOSPHORUS

Kind

Phosphorus (P) promotes tillering, root development, early flowering, and ripening.

Lack in phosphorus causes thin stems and retarded development. The number of leaves, panicles, and grains per panicle are also reduced.

PHOSPHORUS

Amount PHOSPHORUS

Use results of MOET test and Nutrient Manager as basis in properly determining the amount of P to apply.

Organic

Timing

PHOSPHORUS

(Basal)

POTASSIUM

Deficiency symptoms: Dark green plants with yellowish brown leaf margins or dark brown necrotic spots first appear on the tip of older leaves.

Kind POTASSIUM

Potassium (K) improves root

growth and plant vigor and helps

prevent lodging. It also enhances

crop resistance to pests and

diseases.

K deficiency is often not detected

because its symptoms do not

appear until the later growth stages

and are not as easy to recognize

as that of N deficiency.

Amount POTASSIUM

Use results of MOET test and Nutrient Manager as basis in properly determining the amount of K to apply.

Organic fert

(Basal)

Timing

POTASSIUM

Deficiency symptoms: Dusty brown spots on upper leaves of stunted plants appearing 2-4 weeks after transplanting

ZINC

Kind ZINC

Zinc (Zn) promotes good seedling and overall growth

of plants.

Zn deficiency problem

must be corrected to

attain high yields. In Zn-

deficient soils, NPK

fertilizers alone cannot

provide good yield

unless Zn deficiency is

corrected.

Amount

Apply 25 kg zinc sulfate per ha at 14 DAT once

a year during DS.

Use results of MOET test and Nutrient

Manager as basis in properly determining the

amount of Zn to apply.

ZINC

Organic

Timing

14 DAT

ZnSO4

ZINC

Deficiency symptoms: yellowing of young leaves, reduced no. of tillers, fewer and shorter panicles, reduced no. of spikelets per panicle, and delayed maturity

SULFUR

Kind SULFUR

Sulfur (S)

promotes uniform

growth and

maturity.

Amount SULFUR

The amount of sulfur in 14-14-14-12S (12% sulfur) as

recommended to treat P and K deficiencies is adequate

to correct usual sulfur deficiency.

Use results of MOET test and

Nutrient Manager as basis in

properly determining the amount

of S to apply.

Timing SULFUR

Use 14-14-14-12S as basal or

topdress 21-0-0-25S

(ammonium sulfate) instead of

urea.

Use 3.5 bags ammonium

sulfate/ha in the dry season

and 2 bags ammonium

sulfate/ha in the wet season.

Timing

SULFUR

Organic

K

A

T

Know the right KIND of nutrients your plant needs. Use nutrient assessment and decision-support tools to guide you in determining the right fertilizer to use.

Know the right AMOUNT of fertilizer to apply. Too much or too little is not good.

Know the right TIMING of fertilizer application to increase efficiency in input cost and nutrient uptake.

In summary…

INPUTS

• Right kind of fertilizer used

• Right amount of fertilizer applied

• Right timing of fertilizer application

OUTPUTS

• Sufficient nutrients during tillering to early panicle initiation and flowering

OUTCOME

• Good yield

Let’s review!

Nitrogen Phosphorus Potassium Zinc Sulfur

Matching game

N def P def K def S def Zn def Fe toxicity

N def

P def K def

S def

Zn def

Fe toxicity

Nutrient Management

Key Check 5: Sufficient nutrients

from tillering to early

panicle initiation and

flowering

CREDITS

Instructional presentation designer:

Ms. Ev Parac

Sources of technical content/reviewers of presentation:

Mr. Wilfredo Collado; Mr. Efren Laureles, IRRI;

Mrs. Constancia Mangao and Mrs. Pelagia Orpia, BSWM

Note:

Adapted from powerpoint presentations developed by:

Mr. Salvador Yabes; Engr. Eugenio Castro, IRRI; Dr.

Manny Regalado

You may use, remix, tweak, For more information, visit:

& build upon this presentation

non-commercially. However, always

use with acknowledgment.

Unless otherwise stated, the names

listed are PhilRice staffers.

Produced in 2011. Text: 0920-911-1398