keys to - philippine rice research institute

Iloilo iii

®

SIMPLIFIED SOIL SERIES Keys to

ILOILO

iv Simplified to Key Soil Series

This project was funded by the Knowledge Management and Promotion Program (KMP) and Open Academy for Philippine Agriculture (OpAPA) of PhilRice®.

Philippine Rice Research InstituteCopyright © 2008

Iloilo v

Table of Contents Foreword................................................. vii

The Simplified Key to Soil Series............ 1

Guide to Soil Series Identification........... 2

Soil Color Groups.................................... 5

Black/Dark Brown............................ 6

Strong Brown/Brownish Yellow........ 9

Yellowish Brown/Grayish Yellow....... 12

Soil Profile Pictures................................. 15

Soil Properties that affect crop growth.... 20

Soil Productivity....................................... 23

Crop Suitability Analysis.......................... 25

Soil Management Recommendations..... 31

Soil Taxonomic Classification.................. 41

Appendices:

Steps in Identifying Soil Series................ 49

Soil Sampling................................... 50

Color Determination......................... 51

Texture Determination...................... 52

pH Determination............................. 53

The PalayCheck System......................... 54

References.............................................. 56

vi Simplified to Key Soil Series

Iloilo vii

ForewordThis guidebook on “Simplified Keys to Soil Series Identification” was developed to make the field identification of soils easier.

Soil identification is an important component in rice farming. When the soil is properly analyzed and identified, the risks of incompatible management recommendations will be lessened and selection of knowledge and technologies to apply will be efficient. And that is why we have this Simplified Keys to Soil Series for Iloilo.

This is a good guide for effective nutrient management, which is one of the components of the PalayCheck System, a dynamic rice crop management system that presents easy-to-follow practices to achieve respective Key Checks and improve crop yield and input use efficiency.

It features the different color, texture, pH, coarse fragments, and mottles of the most common soils in Iloilo and contains four simple steps in identifying the soil series right in the field. It also includes the soil productivity index, soil properties that affect crop growth, soil taxonomic classification, crop suitability analysis, and soil management recommendations.

viii Simplified to Key Soil Series

The concept of simplified keys to soil series was first used in Thailand. In the Philippines, the project “Simplification of the Philippine Soil Series for Rice and Corn” started in 2005 under the Nutrient Management Support System (NuMaSS) to provide management recommendations for soils identified in the field.

We thank the farmers, agricultural technologists, and municipal and provincial agricultural officers for helping us validate the soil series, and for their comments and suggestions during the pre-evaluation of this guidebook. We also acknowledge the Bureau of Soils and Water Management (BSWM) for providing the secondary data of the soils.

We hope that this publication can help you identify suitable crops in your area, learn the limitations of your soils for crop production, and subsequently know the corresponding management recommendations.

LEOCADIO S. SEBASTIAN PhilRice Executive Director

Iloilo 1

The Simplified Key to Soil Series

“Simplified Key to Soil Series Identification” is a tool/guide in identifying soil series in the field following simple steps, for the use of researchers, agricultural technologists, extension workers, and other stakeholders of the rice industry, including farmers. Using this guidebook, identification of soils will be more accurate reducing the risks of incompatible management and technology recommendations. Transfer of technology will also be made more easy and efficient.

This guidebook is easy-to-use. It involves only five basic soil properties (color, texture, pH, coarse fragments, and mottles) at 30-50 cm soil depth and four simple steps in identifying the soil series right in the field. Once the soil is identified, suitable crops can be selected, and crop productivity ratings, soil properties that limit production, and soil management recommendations can be determined. Since same soil series behave similarly, the soil management technology in one area can be applied in other areas with the same soil identity.

Ten soil series found in Iloilo (Alimodian, Bantog, Barotac, Faraon, Guimaras, Luisiana, San Rafael, Sara, Sta. Rita, and Umingan) are included in this guidebook.

2 Simplified to Key Soil Series

Guide to Soil Series Identification

1. Choose a vacant area in your field and dig up to 50 cm depth from the surface (see page 50).

2. Get bulk soil sample (500 g) from between 30 cm and 50 cm depth.

3. Compare the soil sample with the color chart in the guidebook (see page 51).

Iloilo 3

4. Take a half handful of the same soil and check its texture by wetting the soil sample (neither too wet, nor too dry) (see page 52).

5. Take one spoonful of the same soil sample and put it in a test tube. Add 7 drops of reagent; shake gently, and compare with pH chart (see page 53).

Lateritic nodules

Manganese concretions Quartz

6. Take note of the presence or absence of coarse fragments such as limestone, rock fragments, lateritic nodules, manganese/Mn (black) and iron/Fe (red) concretions, sand materials, and other observable properties of the soil taken from soil surface up to 50 cm depth.


7. Take note also of other observable soil properties such as polished surface (cutans/slickensides), softness, hardness, stickiness, etc.

8. Use the Simplified Keys to Soil Series Book and compare all soil properties starting from the color until the soil name is identified.

slickensides / polished soil surfaces

Iloilo 5

Black/Dark Brown(go to page 6)

Strong Brown/Brownish Yellow(go to page 9)

Yellowish Brown/Grayish Yellow(go to page 12)

SoilColor Groups


Texture

Clay page 7

Black/Dark Brown

Iloilo 7

Black/Dark Brown

Sta. Rita (Srt)

Coarse Fragments none

pH 7.0-7.5

Others mottles (yellowish brown)

Faraon (Frn)

Coarse Fragments limestone fragments

pH 7.0-7.6

Others none

Texture: Clay

go to page 16

go to page 16


Bantog (Btg)


pH 7.2-7.6

Othersiron (brownish gray) and manganese (black) mottles

Texture: Clay

go to page 16

Iloilo 9

Texture

Clay page 10

Sandy Clay Loam page 12

Strong Brown/Brownish Yellow


Strong Brown/Brownish Yellow

San Rafael (Srf)

Coarse Fragments faint quartz

pH 4.5-5.8

Others none

Guimaras (Gmr)

Coarse Fragments gravels (black, white, yellow)

pH 6.0-6.8

Others none

Texture: Clay

go to page 17

go to page 17

Iloilo 11

Luisiana (Lsn)


pH 4.5-5.2

Others mottles (strong brown color)

Texture: Clay

go to page 18

Barotac (Btc)

Coarse Fragments pebbles/red gravels

pH 4.9-6.6

Others manganese and iron concretions/coatings

go to page 18


Sara (Sra)


pH 6.2-7.0

Othersmottles(dull brown and black spots)

Texture: Sandy Clay Loam

go to page 17

Iloilo 13

Yellowish Brown/Grayish Yellow

Texture

Silt Loam page 14

Clay page 14


Umingan (Umn)

Coarse Fragments gravels and stones

pH 5.8-6.7

Others none

Texture: Silt Loam

go to page 19

Alimodian (Ald)


pH 5.4-6.9

Others tubulans(greenish gray)

Texture: Clay

go to page 19

Yellowish Brown/Grayish Yellow

Iloilo 15

SoilProfile Pictures


Bantog (Btg)page 21

Faraon (Frn)page 22

Sta Rita (Srt)page 21

Apg

Ag

Bt1

Bt2

Apg

Ag

Bt1

Bt2

00 cm

13

56

116+

Ap

Bwg1

Bwg2

Bwg3

Bwg4

Ap

Bwg1

Bwg2

Bwg3

Bwg4

00 cm

18

24

42

69

117+

A

Bw

BC

A

Bw

BC

00 cm

09

25

35

Iloilo 17

Sara (Sra)page 21

Guimaras (Gmr)page 22

San Rafael (Srf)page 22

Ap1

AP2

Bg1

Bg2

Bg3

BC

Ap1

AP2

Bg1

Bg2

Bg3

BC

00 cm

13

23

38

66

80+

Guimaras (Gmr) p

Ap

AB

Bw1

Bw2

BC1

BC2

Guimaras (Gmr) p Guimaras (Gmr) p

Ap

AB

Bw1

Bw2

BC1

BC2

00 cm

05

33

63

92

122

140+

San Rafael (Srf) p

Ap

AB

Bt1

Bt2

BC

San Rafael (Srf) p San Rafael (Srf) p

Ap

AB

Bt1

Bt2

BC

00 cm

09

23

49

72

100+


Luisiana (Lsn) page 22

Barotac (Btc)page 21

Ap

AB

Bt1

Bt2

Bt3

BC

Ap

AB

Bt1

Bt2

Bt3

BC

Barotac (Btc) p

Ap

BA

Btc1

Btc2

BC1

BC2

Barotac (Btc) p Barotac (Btc) p

Ap

BA

Btc1

Btc2

BC1

BC2

00 cm

20

35

60

89

130+

00 cm

12

27

42

59

90

110+

Iloilo 19

Ap

AB

BW1

BW2

BC

Ap

AB

BW1

BW2

BC

Alimodian (Ald) p23

Ap

AB

Bt1

Bt2

Bt3

BC

Alimodian (Ald) p23Alimodian (Ald) p23

Ap

AB

Bt1

Bt2

Bt3

BC

Umingan (Umn)page 22

Alimodian (Ald)page 21

Ap

AB

BW1

BW2

BC

Ap

AB

BW1

BW2

BC

Alimodian (Ald) p23

Ap

AB

Bt1

Bt2

Bt3

BC

Alimodian (Ald) p23Alimodian (Ald) p23

Ap

AB

Bt1

Bt2

Bt3

BC

00 cm

23

52

91

108+

00 cm

14

55

88

120+


Properties of Different Soil Seriesthat affectthe growthof crops

Iloilo 21

Table 1. Properties of Different Soil Series that Affect the Growth of Crops.

Soil Qualities in Relation to Crop Production

Lowland Soils Upland Soils

Bantog Sara Sta. Rita Alimo-dian Barotac

Soil pH 6.5-7.6 5.5-6.0 6.5-7.2 5.5-6.5 4.9-6.5

N Level medium low low low low

P Level high medium medium medium medium

K Level low medium medium low low

Soil Texture clay, clay loam silty clay clay clay loam

to clay clay

Drainage wellmod-erately well

poor to moder-ately well

mod-erately well

well

Permeabi-lity

slow to very slow

slow to very slow

slow to very slow

moderate-ly slow

moderate to slow

Rock Frag-ments none none none none

rock frag-ments, pebbles and gravels

Effective Soil Depth

deep (150cm)

deep (150cm)

deep (100-150cm)

deep (100-150cm)

moderate-ly deep to deep (60-150cm)

Flooding Hazard

sea-sonal none none none none

Topography flatflat to gently rolling

flatflat to undulat-ing

rolling to steep

Inherent Fertility high moderate

to high high moderate to high

low to moderate


Table 1. (continuation)


Upland Soils

Faraon Guima-ras Luisiana San

RafaelUmi-ngan

Soil pH 7.5-8.0 6.0-7.0 4.5-5.5 4.5-5.0 5.8-6.7


P Level high medium low medium low

K Level low low low low medium

Soil Texture clay loamy very fine clay

loamy to clayey

silty clay loam

Drainage well well well well well

Perme-ability

very slow to slow

mode-rate moderate mode-

ratemoder-ate

Rock Fragments

lime-stone

rock frag-ments none

rock frag-ments

gravels


shallow (<50 cm)

deep (100-150 cm)

deep (100-150 cm)

deep (90-120 cm)

deep (150 cm)

Flooding Hazard none none none none sea-

sonal

Topo-graphy

undu-lating, rolling to hilly

rolling to steep

rolling to steep

flat to undulat-ing

gently sloping

Inherent Fertility high moderate low low mode-

rate

Iloilo 23


Upland Soils

Faraon Guima-ras Luisiana San

RafaelUmi-ngan

Soil pH 7.5-8.0 6.0-7.0 4.5-5.5 4.5-5.0 5.8-6.7


P Level high medium low medium low

K Level low low low low medium

Soil Texture clay loamy very fine clay

loamy to clayey

silty clay loam

Drainage well well well well well

Perme-ability

very slow to slow

mode-rate moderate mode-

ratemoder-ate

Rock Fragments

lime-stone

rock frag-ments none

rock frag-ments

gravels


shallow (<50 cm)

deep (100-150 cm)

deep (100-150 cm)

deep (90-120 cm)

deep (150 cm)

Flooding Hazard none none none none sea-

sonal

Topo-graphy

undu-lating, rolling to hilly

rolling to steep

rolling to steep

flat to undulat-ing

gently sloping

Inherent Fertility high moderate low low mode-

rate

SoilProductivitySoil productivity is that quality of a soil that summarizes its potential in producing plants or sequences of plants under defined sets of management practices; it is also a synthesis of condition of soil fertility, water control, plant species, soil tilth, pest control and physical environment (Bainroth, 1978: Badayos, 1990). In economic terms, it is a measure of amount of inputs of production factors required to correct soil limitation(s) in order to attain a certain level of production. It is expressed as the average crop yield under defined sets of management classes (Badayos, 1990).

Soil productivity index is used for making comparisons among soils; categorized into inherent and potential. The inherent productivity index is the natural capacity of the soil to produce a given yield; potential refers to the capability of the soil to produce yield after correctible soil constraints had been remedied. In economics, the predicted inherent yield is calculated by multiplying the inherent index by the maximum potential yield of rice; predicted maximum possible yield is computed by multiplying the potential index by the maximum poten-tial yield. For instance, the maximum potential yield in the dry season is 8 tons/hectare, and the inherent and potential productivity ratings for Sara soil is 0.75 and 0.83, respectively. Then, the predicted inherent and potential yields of rice in Sara soils are 6.0 and 6.6 tons/ha, respectively.


Table 2. The soil productivity index for rice.

Soil Series Inherent Productivity

Potential Productivity

Alimodian 0.67 0.80

Bantog 0.72 0.83

Barotac 0.62 0.77

Faraon 0.48 0.60

Guimaras 0.57 0.70

Luisiana 0.23 0.43

San Rafael 0.43 0.55

Sara 0.75 0.83

Sta. Rita 0.65 0.83

Umingan 0.61 0.71

Iloilo 25

CropSuitability Analysis


Soil suitability classification refers to the use of a piece of land on a sustainable basis, based on physical and chemical properties and environmental factors. It is the ultimate aim of soil survey and this may come up through good judgment and a thorough evaluation of soil properties and qualities like depth, texture, slope, drainage, erosion, flooding and fertility. Based from these properties, the suitability of a certain tract of land for crop production is determined.

Suitability ratings denote qualitative analysis of the potential of a certain soil to different crops. It implies what crop(s) would give the highest benefit in terms of productivity and profitability from a given soil type, indicated by S1 as the most suitable, S2 as moderately suitable and S3 as marginally suitable. The symbol N implies that the crop is either currently not suitable (N1) where the effect of limitation is so severe as greatly to reduce the yield and require costly inputs or permanently not suitable (N2) where the limitations cannot be corrected permanently. Crop suitability analysis also provides information on soil properties that limit the production of specified crop(s). The crop suitability analysis for the soils of Iloilo is shown on Table 3.

When using a parametric system, the soil index can be equated into percentage shown below. It means that you can attain 75% of the potential yield of the crop when the soil index is highly suitable (S1) while less than 25% of the potential yield when the soil index is not suitable (N).

S1: soil index >75 S3: soil index 25-50S2: soil index 50-75 N: soil index <25

Crop Suitability Analysis

Iloilo 27

Tabl

e 3.

Th

e cr

op s

uita

bilit

y an

alys

is o

f the

soi

ls o

f Ilo

ilo fo

r di

ffer

ent c

rops

.

Lim

itatio

ns d

ue to

:

t

- to

pogr

aphy

; slo

pe

w

-

drai

nage

; floo

ding

s -

text

ure;

coa

rse

fragm

ents

; soi

l dep

th

f -

soil

ferti

lity

c -

clim

ate

Suita

bilit

y ra

tings

:

S1 -

H

ighl

y su

itabl

e

S2 -

M

oder

atel

y su

itabl

e

S3 -

M

argi

nally

sui

tabl

e

N1

- C

urre

ntly

not

sui

tabl

e

N2

- Pe

rman

ently

not

sui

tabl

e

Soil

Serie

sSl

ope

Ran

geR

ice

Irrig

ated

Lo

wla

ndR

ice

Rai

nfed

Lo

wla

ndR

ice

Rai

nfed

U

plan

dM

aize

Alim

odia

nLe

vel t

o un

dula

ting,

sl

ight

ly ro

lling

to h

illyN

2tS2

tfS2

tfS2

c

Ban

tog

Leve

l to

near

ly le

vel

S1S2

fsS2

fsS2

sc B

arot

acR

ollin

g to

ste

epN

2tS2

tfsS2

tfsS2

tfsc

Far

aon

Und

ulat

ing,

rollin

g &

hilly

N2t

ws

S3tfs

S3tfs

S3tfc

Gui

mar

asR

ollin

g to

hilly

N2t

S3tfs

S3tfs

S2tfc

Lui

sian

aR

ollin

g to

hilly

to s

teep

N2t

fS3

tfsS3

tfN

1tfc

San

Raf

ael

Und

ulat

ing

to ro

lling

N2t

fS2

fwS3

tfsN

1fc

Sar

aLe

vel t

o ge

ntly

rollin

gS2

fS2

fsS2

fwS2

c S

ta. R

itaLe

vel t

o ne

arly

leve

lS2

tfwS3

fsS2

sS2

sc U

min

gan

Leve

l to

undu

latin

gS3

tfws

S3fs

S3fs

S2fs

c


Tabl

e 3.

(c

onti

nuat

ion)

Lim

itatio

ns d

ue to

:

t

- to

pogr

aphy

; slo

pe

w

-

drai

nage

; floo

ding

s -

text

ure;

coa

rse

fragm

ents

; soi

l dep

th

f -

soil

ferti

lity

c -

clim

ate

Suita

bilit

y ra

tings

:

S1 -

H

ighl

y su

itabl

e

S2 -

M

oder

atel

y su

itabl

e

S3 -

M

argi

nally

sui

tabl

e

N1

- C

urre

ntly

not

sui

tabl

e

N2

- Pe

rman

ently

not

sui

tabl

e

Soil

Serie

sSl

ope

Ran

geB

eans

Tom

ato

Toba

cco

Suga

rcan

e

Alim

odia

nLe

vel t

o un

dula

ting,

slig

htly

rollin

g to

hilly

S3fc

S2fs

cS3

scS3

fc

Ban

tog

Leve

l to

near

ly le

vel

S3sc

S3w

scS3

scS3

sc

Bar

otac

Rol

ling

to s

teep

S3tfs

cS3

tfsc

S3tfs

cS3

tfsc

Far

aon

Und

ulat

ing,

rollin

g &

hilly

S3tfs

cN

2tsc

S3tfs

cS3

tfsc

Gui

mar

asR

ollin

g to

hilly

S3tc

S3tfs

cS3

tfcS3

tfc

Lui

sian

aR

ollin

g to

hilly

to s

teep

S3tfc

S3tfc

S3tfs

cS3

tfc

San

Raf

ael

Und

ulat

ing

to ro

lling

N1f

cN

1fc

N1f

cS3

fc

Sar

aLe

vel t

o ge

ntly

rollin

gS3

fwc

S2fw

cS3

fsc

S3fc

Sta

. Rita

Leve

l to

near

ly le

vel

S3sc

N2s

cS3

fsc

S3c

Um

inga

nLe

vel t

o un

dula

ting

S3fs

cN

2fsc

S3fs

cS3

fsc

Iloilo 29

Lim

itatio

ns d

ue to

:

t

- to

pogr

aphy

; slo

pe

w

-

drai

nage

; floo

ding

s -

text

ure;

coa

rse

fragm

ents

; soi

l dep

th

f -

soil

ferti

lity

c -

clim

ate

Suita

bilit

y ra

tings

:

S1 -

H

ighl

y su

itabl

e

S2 -

M

oder

atel

y su

itabl

e

S3 -

M

argi

nally

sui

tabl

e

N1

- C

urre

ntly

not

sui

tabl

e

N2

- Pe

rman

ently

not

sui

tabl

e

Soil

Serie

sSl

ope

Ran

geSw

eet

Pota

toC

assa

vaO

nion

Wat

erm

elon

Alim

odia

nLe

vel t

o un

dula

ting,

slig

htly

rollin

g to

hilly

S3fc

S2w

sN

2fsc

S2fs

Ban

tog

Leve

l to

near

ly le

vel

S3fs

cS3

ws

N2s

cS3

s

Bar

otac

Rol

ling

to s

teep

S3tfs

cS3

tfsN

2tfs

cS3

tfs

Far

aon

Und

ulat

ing,

rollin

g &

hilly

S3tfs

cN

2tfs

N2t

fsc

N2t

fs

Gui

mar

asR

ollin

g to

hilly

S3tfc

S2tf

N2t

fcS3

tf

Lui

sian

aR

ollin

g to

hilly

to s

teep

N1t

fcS2

tfN

2tfc

S3tfs

San

Raf

ael

Und

ulat

ing

to ro

lling

S3fc

S3f

N2f

cN

1f

Sar

aLe

vel t

o ge

ntly

rollin

gS3

fwc

S2fw

N2f

wc

S2fw

s

Sta

. Rita

Leve

l to

near

ly le

vel

S3fs

cS3

ws

S3sc

S3s

Um

inga

nLe

vel t

o un

dula

ting

S3sc

S2fs

S3fs

cS3

fs


Soil

Serie

sSl

ope

Ran

geB

anan

aPa

paya

Man

goC

ocon

ut

Alim

odia

nLe

vel t

o un

dula

ting,

slig

htly

ro

lling

to h

illyS2

fS2

fws

S2fs

S1

Ban

tog

Leve

l to

near

ly le

vel

S2fs

N2w

sS3

ws

S3s

Bar

otac

Rol

ling

to s

teep

S2tfs

S2tfs

S3tfs

S2tfs

Far

aon

Und

ulat

ing,

rollin

g &

hilly

S3tfs

S3tfs

N2t

fsS3

fs

Gui

mar

asR

ollin

g to

hilly

S3tf

S3tf

S3tf

S2tf

Lui

sian

aR

ollin

g to

hilly

to s

teep

S3tf

S3tfs

S3tfs

N1t

f

San

Raf

ael

Und

ulat

ing

to ro

lling

S2fs

N2f

S3f

S3f

Sar

aLe

vel t

o ge

ntly

rollin

gS2

fwS3

fws

S3fw

S2w

s

Sta

. Rita

Leve

l to

near

ly le

vel

S2fs

S3fw

sS3

ws

S3w

Um

inga

nLe

vel t

o un

dula

ting

S3fs

S3fs

S3fs

S2fs

Tabl

e 3.

(c

onti

nuat

ion)

Lim

itatio

ns d

ue to

:

t

- to

pogr

aphy

; slo

pe

w

-

drai

nage

; floo

ding

s -

text

ure;

coa

rse

fragm

ents

; soi

l dep

th

f -

soil

ferti

lity

c -

clim

ate

Suita

bilit

y ra

tings

:

S1 -

H

ighl

y su

itabl

e

S2 -

M

oder

atel

y su

itabl

e

S3 -

M

argi

nally

sui

tabl

e

N1

- C

urre

ntly

not

sui

tabl

e

N2

- Pe

rman

ently

not

sui

tabl

e

Iloilo 31

Soil ManagementRecommendations


The goal of soil management is to protect the soil and enhance its performance to increase farm profitably and preserve environmental quality. It is the combination of soil factors to maximize crop production at the lowest possible cost while leaving the soil in a productive state. It involves: maintaining the soil in good physical condition and its soil fertility status, and influencing the biological aspect of the soil so that maximum benefits result (Harpstead, et.al. 1997). Soil management recommendations suitable for each soil identified are enumerated in the succeeding pages (Table 4). In coming up with soil management recommendations, soil properties such as texture, mineralogy, moisture and temperature regimes, and climate were considered since these factors affect crop growth. These properties cannot be changed but controlled tillage, crop rotation, soil amendments, and other management choices can be done. Through these choices, the structure, biological activity, and chemical content of soils can be altered to influence erosion rates, pest population, nutrient availability, and crop production.

Soil Management Recommendations

Iloilo 33

Tabl

e 4.

Th

e so

il se

ries

of I

loilo

wit

h th

eir

limit

atio

ns fo

r cr

op p

rodu

ctio

n an

d co

rres

pond

ing

man

agem

ent r

ecom

men

dati

ons

for

diff

eren

t cro

ps.

Soil

Serie

s Li

mita

tions

for c

rop

prod

uctio

n

Soil

Man

agem

ent R

ecom

men

datio

ns

Ric

eD

iver

sifie

d cr

ops

Roo

t cro

pTr

ee/F

ores

t/Pl

anta

tion

crop

Alim

odia

nhe

avy

clay

su

bsoi

l tha

t can

im

pede

inte

rnal

dr

aina

ge

and

root

de

velo

pmen

t; to

pogr

aphy

; lo

w fe

rtilit

y

ferti

lizat

ion;

see

d be

d co

nfigu

ratio

n;

terra

cing

orga

nic

mat

ter

inco

rpor

atio

n;

limin

g; m

inim

um

tilla

ge; d

eep

plow

ing;

m

ulch

ing;

sui

ted

to c

orn

deep

plo

win

g;

appl

icat

ion

of

ferti

lizer

plan

t cov

er

crop

s, tr

ees

and

legu

mes

to

rest

ore

ferti

lity

and

min

imiz

e er

osio

n; p

ut u

p di

kes

of s

tone

s ac

ross

the

slop

e

Cro

ppin

g Pa

ttern

: ric

e-m

aize

/sor

ghum

/veg

etab

les/

root

cro

ps


Soil

Serie

s Li

mita

tions

for c

rop

prod

uctio

n

Soil

Man

agem

ent R

ecom

men

datio

ns

Ric

eD

iver

sifie

d cr

ops

Roo

t cro

pTr

ee/F

ores

t/Pl

anta

tion

crop

Bant

ogpo

or d

rain

age;

hig

h sh

rink

and

swel

l ca

paci

ty u

pon

wet

ting

and

dryi

ng p

rodu

cing

w

ide

crac

ks in

the

soil,

har

d w

hen

dry;

se

ason

al fl

oodi

ng

in lo

w a

reas

; slo

w

perm

eabi

lity;

irrig

atio

n w

ater

prac

tice

shal

low

cu

ltiva

tion

whe

n so

il m

oist

ure

is a

t opt

imum

; su

ited

for

irrig

ated

and

ra

infe

d pa

ddy

rice;

mai

ntai

n pr

oper

ly th

e pa

ddy

dike

s

cons

truct

ion

of

adeq

uate

dra

inag

e irr

igat

ion

and

flood

co

ntro

l sys

tem

due

to

sea

sona

l floo

ding

ha

zard

in lo

w a

reas

; us

e of

bro

adbe

ds,

ridge

s or

furro

ws

and

mul

chin

g;

appl

icat

ion

of

orga

nic

mat

ter a

nd

farm

man

ure

esta

blis

hmen

t of

ade

quat

e dr

aina

ge a

nd

irrig

atio

n sy

stem

; ap

plic

atio

n of

or

gani

c m

atte

r an

d fa

rm m

anur

e

unsu

itabl

e un

der p

rese

nt

cond

ition

but

be

com

e su

it-ab

le if

pro

per

man

agem

ent

prac

tices

like

es

tabl

ishm

ent o

f ad

equa

te d

rain

-ag

e an

d flo

od

cont

rol s

yste

ms;

us

e of

sui

tabl

e tre

e sp

ecie

s an

d pr

oper

fe

rtiliz

atio

n

Cro

ppin

g Pa

ttern

: ric

e-ric

e; ri

ce-d

iver

sifie

d cr

ops/

vege

tabl

es/ro

ot c

rops

;

rice-

mun

go/to

bacc

o/co

rn

Tabl

e 4.

(c

onti

nuat

ion)

Iloilo 35

Baro

tac

iron

and

alum

inum

to

xici

ty; a

cidi

c; lo

w

ferti

lity

stat

us; d

ifficu

lt to

man

age;

run-

off;

grav

els

are

pres

ent i

n al

l hor

izon

; top

ogra

phy

appl

icat

ion

of p

hosp

hate

fe

rtiliz

ers;

di

kes

cons

truct

ion

limin

g; a

pplic

atio

n of

fres

hly

deco

mpo

sed

orga

nic

mat

ter

not s

uita

ble

for r

oot

crop

s du

e to

gra

vels

plan

t cov

er

crop

s, tr

ees

and

legu

mes

to

rest

ore

ferti

lity

and

min

imiz

e er

osio

n; u

se

of lo

cally

ad

apte

d tre

e va

rietie

sC

ropp

ing

Patte

rn:

upla

nd ri

ce-c

orn;

div

ersi

fied

crop

s-di

vers

ified

cro

ps; t

rees

Fara

onsh

allo

w s

oil d

epth

lim

iting

pro

duct

ivity

to

shal

low

root

ed c

rops

; ou

tcro

ps p

rese

nt;

topo

grap

hy

cons

truct

ion

of

bund

sco

ntou

r far

min

g;

shal

low

cul

tivat

ion;

fe

rtiliz

atio

n

not s

uita

ble

for r

oot

crop

s du

e to

out

crop

s pr

esen

t

suite

d fo

r fru

it, fo

rest

an

d ot

her

hard

woo

d tre

es e

.g.

citru

s,

man

go, i

pil,

mol

ave,

co

conu

t etc

.

Cro

ppin

g Pa

ttern

: ric

e-ric

e; ri

ce-d

iver

sifie

d cr

ops/

vege

tabl

es/ro

ot c

rops


Soil

Serie

s Li

mita

tion

for c

rop

prod

uctio

n

Soil

Man

agem

ent R

ecom

men

datio

ns

Ric

eD

iver

sifie

d cr

ops

Roo

t cro

pTr

ee/F

ores

t/Pl

anta

tion

crop

Gui

ma-

ras

topo

grap

hy;

low

CEC

; ru

n-of

f

appl

icat

ion

of fe

rtiliz

ers

to in

crea

se

yiel

d;

cons

truct

ion

of b

unds

; te

rraci

ng

orga

nic

mat

ter i

ncor

pora

tion;

pr

actic

e co

ver c

ropp

ing,

gre

en

man

urin

g an

d lim

ing;

pla

nt w

ith

legu

mes

to lo

w n

utrie

nt le

vels

; te

rraci

ng

suite

d fo

r ca

mot

esu

ited

for

coco

nut a

nd

fruit

trees

; pla

nt

loca

lly a

dapt

ed

varie

ties;

te

rraci

ng

Cro

ppin

g Pa

ttern

: co

conu

t/fru

it tre

es-d

iver

sifie

d cr

ops/

root

cro

ps

up

land

rice

- div

ersi

fied

crop

s/ ro

ot c

rops

Luis

i-an

ahi

ghly

leac

h-ed

; ver

y ac

id-

ic; i

ron

and

alum

inum

to

xici

ty; l

ow

base

sat

ura-

tion

and

low

C

EC; r

un-o

ff;

topo

grap

hy

limin

g;

ferti

lizer

ap

plic

atio

n;

best

sui

ted

for r

ice

prac

tice

cont

our f

arm

ing,

stri

p cr

oppi

ng a

nd c

over

cro

ppin

g;

appl

icat

ion

of fe

rtiliz

er

suite

d fo

r roo

t cr

ops

suite

d fo

r pe

rman

ent

crop

s an

d tre

es

to re

stor

e th

e fe

rtilit

y of

the

soil

Cro

ppin

g Pa

ttern

: up

land

rice

-div

ersi

fied

crop

s/ro

ot c

rops

; fru

it tre

es/fo

rest

tree

s

Tabl

e 4.

(c

onti

nuat

ion)

Iloilo 37

Soil

Serie

s Li

mita

tion

for c

rop

prod

uctio

n

Soil

Man

agem

ent R

ecom

men

datio

ns

Ric

eD

iver

sifie

d cr

ops

Roo

t cro

pTr

ee/F

ores

t/Pl

anta

tion

crop

Gui

ma-

ras

topo

grap

hy;

low

CEC

; ru

n-of

f

appl

icat

ion

of fe

rtiliz

ers

to in

crea

se

yiel

d;

cons

truct

ion

of b

unds

; te

rraci

ng

orga

nic

mat

ter i

ncor

pora

tion;

pr

actic

e co

ver c

ropp

ing,

gre

en

man

urin

g an

d lim

ing;

pla

nt w

ith

legu

mes

to lo

w n

utrie

nt le

vels

; te

rraci

ng

suite

d fo

r ca

mot

esu

ited

for

coco

nut a

nd

fruit

trees

; pla

nt

loca

lly a

dapt

ed

varie

ties;

te

rraci

ng

Cro

ppin

g Pa

ttern

: co

conu

t/fru

it tre

es-d

iver

sifie

d cr

ops/

root

cro

ps

up

land

rice

- div

ersi

fied

crop

s/ ro

ot c

rops

Luis

i-an

ahi

ghly

leac

h-ed

; ver

y ac

id-

ic; i

ron

and

alum

inum

to

xici

ty; l

ow

base

sat

ura-

tion

and

low

C

EC; r

un-o

ff;

topo

grap

hy

limin

g;

ferti

lizer

ap

plic

atio

n;

best

sui

ted

for r

ice

prac

tice

cont

our f

arm

ing,

stri

p cr

oppi

ng a

nd c

over

cro

ppin

g;

appl

icat

ion

of fe

rtiliz

er

suite

d fo

r roo

t cr

ops

suite

d fo

r pe

rman

ent

crop

s an

d tre

es

to re

stor

e th

e fe

rtilit

y of

the

soil

Cro

ppin

g Pa

ttern

: up

land

rice

-div

ersi

fied

crop

s/ro

ot c

rops

; fru

it tre

es/fo

rest

tree

s

San

Raf

ael

iron

and

alum

inum

to

xici

ty;

acid

ic; v

ery

low

nat

ive

ferti

lity;

ru

n-of

f; to

pogr

aphy

appl

icat

ion

of fe

rtiliz

er;

cons

truct

ion

of b

unds

limin

g; fe

rtiliz

atio

n; o

rgan

ic

mat

ter i

ncor

pora

tion;

mul

chin

g;

inte

rcro

ppin

g; m

ultip

le

crop

ping

; ter

raci

ng

suite

d fo

r roo

t cr

ops

suita

ble

for

fore

st tr

ees;

pl

ant l

ocal

ly

adap

ted

varie

ties

Cro

ppin

g Pa

ttern

: up

land

rice

-root

cro

ps/ d

iver

sifie

d cr

ops;

fore

st tr

ees

Sara

soil

hard

enin

g ca

usin

g su

rface

cr

acki

ng

and

diffi

culty

in

tilla

ge;

acid

ic; l

ack

of ir

rigat

ion

need

s lim

ing;

fe

rtiliz

atio

n of

com

plet

e fe

rtiliz

er;

cons

truct

ion

of ir

rigat

ion

syst

em

limin

g; ti

min

g of

land

pr

epar

atio

n; s

ub-s

oilin

gno

t sui

ted

for r

oot

crop

ssu

itabl

e fo

r tre

es; p

lant

to

acid

tole

rant

cr

ops

e.g.

le-

gum

es, c

ocon

ut

Cro

ppin

g Pa

ttern

: ric

e-ric

e; ri

ce-d

iver

sifie

d cr

ops/

vege

tabl

es/ro

ot c

rops


Soil

Serie

s Li

mita

tion

for c

rop

prod

uctio

n

Soil

Man

agem

ent R

ecom

men

datio

ns

Ric

eD

iver

sifie

d cr

ops

Roo

t cro

pTr

ee/F

ores

t/Pl

anta

tion

crop

Sta.

R

itaso

il ha

rden

ing

caus

ing

surfa

ce

crac

king

and

di

fficu

lty in

tilla

ge

phos

phat

e fe

rtiliz

atio

n;

best

sui

ted

for r

ice

orga

nic

mat

ter

inco

rpor

atio

n; c

over

cro

ps;

mul

chin

g; c

onst

ruct

ion

of b

road

beds

, rid

ges

and

furro

ws;

sui

ted

for

suga

rcan

e

not s

uite

d du

e to

text

ure

cons

train

ts

suita

ble

for t

rees

; pl

ant l

ocal

ly

adap

ted

varie

ties

Cro

ppin

g Pa

ttern

: ric

e-di

vers

ified

cro

ps; c

orn/

suga

rcan

e-co

rn/s

ugar

cane

; ric

e-co

rn/m

ungo

/legu

mes

; coc

onut

s

Tabl

e 4.

(c

onti

nuat

ion)

Iloilo 39

Um

i-ng

anpr

esen

ce o

f gr

avel

ly o

r sto

ny

laye

r at t

he lo

wer

su

bsoi

l. D

ue to

th

is la

yer o

f sto

nes

and

grav

els,

th

e so

ils te

nd

to b

e dr

ough

ty;

occu

rrenc

e of

flo

ods

durin

g an

d af

ter h

eavy

rain

s

appl

icat

ion

of fe

rtiliz

er;

suite

d fo

r pa

ddy

rice

and

othe

r cr

ops;

cl

earin

g of

la

rge

grav

els

and

rock

ou

tcro

ps

cons

truct

ion

of a

dequ

ate

drai

nage

irrig

atio

n an

d flo

od c

ontro

l sys

tem

; ap

plic

atio

n of

ferti

lizer

and

or

gani

c m

atte

r; su

ited

for

dive

rsifi

ed c

rops

; adj

ust t

he

crop

ping

sea

son

grav

els

at th

e lo

wer

sub

soil

may

cau

se th

e lo

wer

yie

ld o

f ro

ot c

rops

clea

ring

of la

rge

grav

els

and

rock

ou

tcro

ps; s

uita

ble

for t

rees

suc

h as

co

conu

t, at

is e

tc

Cro

ppin

g Pa

ttern

:ric

e-di

vers

ified

cro

ps/v

eget

able

s/ro

ot c

rops

; div

ersi

fied

crop

s/ro

ot c

rops

- div

ersi

fied

crop

s/ro

ot c

rops

Iloilo 41

Soil TaxonomicClassification


Soil Taxonomic ClassificationSoil taxonomy is a system of naming, describing, and categorizing soils. It helps us to understand how soils had formed, changed, and their effects on crops and natural resource management. It uses a specific nomenclature that both classifies the soil and gives a distinctive name to the individual soil. Names are constructed from the formative elements (generally originating from Greek and Latin) which are used in specific combinations to provide a highly descriptive name to a specific soil type.

Scientists have developed different systems of soil classification to group soils of similar properties in one class, allowing them to exchange information on soils found in different areas. In the classification scheme, characteristics and information about the soil become more specific as one continues from order, sub-order, great group, sub-group, family, to series level. For this purpose, the USDA Soil Taxonomic Classification scheme was employed for technical use of researchers and students. Soil Taxonomic Classification that implies the general features of a given soil indicating its texture, mineralogy, moisture and temperature regimes, diagnostic horizons, and soil order is presented in Table 5 (pages 43-47). These features/properties influence crop growth and serve as basis for transferability of soil management technology.

Iloilo 43

Soil Series

Taxonomic Classification

Interpretation

Ali-modian

Fine, smectitic (ca.), isohyperthermic, CALCIC HAPLUSTALFS

This is a fine-textured soil with large amount of clay (35-60%) and isohyperthermic temperature regime (>22°C). It is an Alfisol (alf), i.e. there is illuvial accumulation of clay in the subsoil horizons from the underlying horizons. It has minimum complexity in its soil horizonation (hapl-) found in areas with pronounced wet and dry seasons (-ust). It is a member of the great group Haplustalfs with high percentage of calcium saturation in the subsoil (calcic).

Bantog Very fine, mixed, isohyperthermic, AERIC CALCIAQUERT

This is a very fine-textured soil with high clay content of >60% and has isohyperthermic temperature regime (>22°C). It is a Vertisol(-ert), dominated by shrink-swell clays that cause deep wide cracks, slickensides, very sticky when wet and compact when dry. It is saturated with water repeatedly (aqu-) but not as wet as the typical, i.e. it is better aerated, usually because either groundwater is deep or the period of saturation is shorter (aeric). This soil also has high calcium saturation (calci-) in its subsoil horizons.

Table 5. Soil taxonomic classification of each soil series in Iloilo with interpretation.


Soil Series

Taxonomic Classification Interpretation

Barotac Fine, kaolinitic (ca.), isohyperthermic, TYPIC KANDIUSTOX

This soil has fine texture and isohyperthermic temperature regime (>22°C). It is an Oxisol (-ox), which is an intensely weathered soil predominated by oxides from iron and aluminum due to repeated high precipitation and high temperature (-ust). It is a typical (typic) representative of the great group Kandiustox. It has low cation exchange capacity (CEC) (kandi-), thus has low fertility status.

Faraon Fine, isohyperthermic, LITHIC HAPLUSTOLLS

Fine-textured soil (35-60% clay content) and has isohyperthermic temperature regime (>22°C). It is a Mollisol (-oll) - dark-colored, fertile soils with high base saturation and neutral to medium acid pH. It has minimum complexity in its soil horizonation (hapl-) found in areas with pronounced wet and dry seasons (-ust). It is a representative of the great group Haplustolls with lithic contact, specifically, it is a shallow soil with hard coralline limestone bedrock at 35cm depth.


Iloilo 45

Soil Series


Gui-maras

Fine loamy, mixed (ca.), isohyperther-mic, OXIC HAPLUS-TEPTS

This is a fine-loamy-textured soil with isohyperthermic temperature regime (>22°C). It is an Inceptisol (-ept), i.e. it is in the incipient development toward mature soil, but have not yet fully developed its diagnostic horizons. It has minimum complexity in its soil horizonation (hapl-) found in areas with pronounced wet and dry seasons (-ust) and a representative of the great group Haplustepts which has low CEC (oxic).

Luisi-ana

Very fine, kaolinitic (ca.), isohyperther-mic, USTIC PALEHUMULT

This is a very fine-textured soil with high clay content of >60% and has isohyperthermic temperature regime (>22°C). It is an Ultisol (-ult) which is a highly leached soil that has clay illuviation and low base saturation. It is a very deep (pale-) soil found in highlands (hum-) with pronounced wet and dry seasons (ustic).



Soil Series


San Rafael

Fine, smectitic (ca.), isohy-perthermic, TYPIC PA-LEUSTULTS

This is a fine-textured soil with high clay content of >60% and has isohyperthermic temperature regime (>22°C). It is an Ultisol (-ult) which is a highly leached soil that has clay illuviation and low base saturation. This is a typical (typic) representative of the great groups Paleustults which is very deep (pale-) occurring in areas with pronounced wet and dry seasons (ust-).

Sara Fine, smectitic (ca.), isohy-perthermic, TYPIC EPI-AQUEPT

It is a fine-textured soil (35-60% clay content) and has isohyperthermic temperature regime (>22°C). It is an Inceptisol (-ept), i.e. it is in the incipient development toward mature soil, but have not yet fully developed its diagnostic horizons. It is a typical (typic) representative of the great group Epiaquepts. It is saturated with water for repeated periods of time (aqu-) manifested by its grayish color with or without mottles.


Iloilo 47

Soil Series


Sta. Rita

Fine, smectitic (ca.), isohyper-thermic, TYPIC EPIAQUEPT

It is a fine-textured soil (35-60% clay content) and has isohyperthermic temperature regime (>22°C). It is an Inceptisol (-ept), i.e. it is in the incipient development toward mature soil, but have not yet fully developed its diagnostic horizons. It is a typical (typic) representative of the great group Epiaquepts. It is saturated with water for repeated periods of time (aqu-) manifested by its grayish color with or without mottles.

Umin-gan

Loamy skel-etal, mixed (ca.), isohy-perthermic, FLUVENTIC HAPLUSTEPT

Loamy skeletal-textured soil with many gravels and pebbles present and isohyperthermic temperature regime (>22°C). It is an Inceptisol (-ept), i.e. it is in the incipient development toward mature soil, but have not yet fully developed its diagnostic horizons. This soil has minimum complexity in its soil horizonation (hapl-) found in areas with pronounced wet and dry seasons (-ust). It is a representative of the great group Haplustepts which is subject to seasonal river flooding (fluventic).


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Appendices


Choose a vacant area in your field. Using a spade/auger, dig up to 50cm from the soil surface.

Depth of soil is impor-tant. The surface/top soil is not a good basis since it is always culti-vated.

Get bulk soil sample (½ kilo) from 30-50cm depth; place it in a container (plastic/pail). This sample will be used for soil series identification.

1 Soil sampling

APPENDIX 1. STEPS TO IDENTIFY SOIL SERIES

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2 Soil color determination

Soil color is an indi-rect measure of other characteristics such as drainage, aeration, and organic matter content. Black-colored soils may indicate high fertility and productivity.

Get an ample amount of soil from the sample. The soil should be moist (neither too wet, nor too dry).

Gray indicates a fairly constant water-saturated condition. Bright brown and red colors are indicative of good aeration and drainage.

Compare the color of the soil sample with the color chart in the guidebook. Take note of the classifica-tion of the soil color.


3 Texture determination

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Get soil sample from a 30-50cm depth. Fill the test tube with soil sample up to the scratch mark.

Add 7 drops of CPR (chlorphenol red). Mix by gently swirling the test tube.

If soil pH is 6 or greater, repeat the steps using BTB (brom thymol blue).

If the soil pH is 5 or less, repeat the steps using BCG (brom cresol green).

Match the color of the solution on top of the soil with the corresponding color chart of the pH indicator dye used.

pH Determination (UPLB procedure)4


APPENDIX 2. THE PALAYCHECK SYSTEM

The Palaycheck System is a rice integrated crop management that combines the technologies and learning processes to identify strengths and weaknesses of current crop management practices, make improvements in the next season to increase grain yield, input use efficiency, and profit with environmental concerns.

The PalayCheck System describes the crop management practices (input) to achieve the following Key Checks (output):

1) Used certified seeds of a recommended variety.

2) No high and low soil spots after final leveling.

3) Practiced synchronous planting after a fallow period.

4) Sufficient number of healthy seedlings.

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5) Sufficient nutrients at tillering to early panicle initiation, and flowering.

6) Avoided excessive water or drought stress that could affect the growth and the yield of the crop.

7) No significant yield loss due to pests.

8) Cut and threshed the crop at the right time.


Badayos, R. B. 1990. Lowland rice soils in the Philippines, their characteristics and classification in relation to productivity. Inaugaral Professorial Lecture. SEARCA, UPLB.

Beinroth, F. H. 1978. Some fundamentals of soil classification. In: Soil-resource data for agricultural development. Ed. Leslie D. Swindale. Hawaii Ag. Expt. Sra., College of Trop. Agric., University of Hawaii. p.12-19.

MI Harpstead, TJ Sauer, and WF Bennet. 1997. Soil Science Simplified. 3rd Edition. Iowa State University Press, Ames Iowa 50014.

“Simplified Keys to Soil Series (29 Soil Series for Maize Production), Lop Buri Province” The International Training Workshop on “Applying Information Technology for Site-Specific Agriculture in Small Farms of Tropics.” August 4-10, 2003. Bangkok, Thailand.

Soil Survey of Iloilo Province. Department of Agriculture and Natural Resources, Bureau of Soils, Manila, Philippines. Bureau of Printing Manila.

Soil Survey Manual. US Department of Agricultural Handbook No. 18. August 1951.Soil Survey Staff, Bureau of Plant and Industry, Soils, and Agricultural Engineering. Agricultural Research Administration, US Department of Agriculture.

References

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Subject Matter Specialists

PhilRice®Wilfredo B. ColladoJesiree Elena Ann P. Dela TorreMary Rose O. ObicoRona T. DollentasConstancio A. Asis, Jr, PhDJovino L. De DiosEvelyn F. JavierLeo C. JavierEduardo Jimmy P. Quilang, PhDMadonna C. Casimero, PhD

UP Los BañosRodrigo B. Badayos, PhDArmando E. Soliman

Provincial Agriculture Office of IloiloIldefonso Toledo, PhDEly SandigAurea DelicanaMerlie Camarino

Managing Editor/Layout Artist Erik-Ray Matthew S. Palomar Editorial Advisers Leocadio S. Sebastian, PhD Ronan G. Zagado

keys to - philippine rice research institute

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