iv Simplif ied Keys TO 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
Nueva Ecija v
Table of Contents Foreword................................................. vii
The Simplified Keys to Soil Series.......... 1
Guide to Soil Series Identification........... 2
Soil Color Groups.................................... 5
Gray/Yellowish Gray......................... 6
Dark Grayish Brown......................... 9
Dark Yellowish Brown...................... 12
Soil Profile Pictures................................. 17
Soil Properties that affect crop growth.... 22
Soil Productivity....................................... 25
Crop Suitability Analysis.......................... 27
Soil Management Recommendations..... 31
Soil Taxonomic Classification.................. 41
Appendices..............................................49
Steps in Identifying Soil Series......... 50
Soil Sampling............................. 50
Color Determination................... 51
Texture Determination................ 52
pH Determination....................... 53
The PalayCheck System.................. 54
References.............................................. 56
Nueva Ecija vii
Foreword
This 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 Nueva Ecija.
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.
The guidebook features the different color, texture, pH, coarse fragments, and mottles of the most common soils in Nueva Ecija and contains four simple steps in identifying the soil series right in the field. We also included the soil productivity index, soil properties that affect crop growth, soil taxonomic classification, crop suitability analysis, and soil management recommendations.
viii Simplif ied Keys TO 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
Nueva Ecija 1
The Simplified Keys to Soil Series
“Simplified Keys to Soil Series” is a tool/guide in identifying soil series in the field following simple steps, for the use of researchers, agricultural technologists, extension workers, farmers, and other stakeholders of the rice industry. Using this guidebook, identification of soils will be more accurate, thus, 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 30-50cm 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 Nueva Ecija (Annam, Bantog, Maligaya, Prensa, Quingua, San Fabian, San Manuel, Sibul, Umingan, and Zaragosa) are included in this guidebook.
2 Simplif ied Keys TO 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).
Nueva Ecija 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.
4 Simplif ied Keys TO Soil Series
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
Nueva Ecija 5
Gray/Yellowish Gray (go to page 6)
Dark Grayish Brown (go to page 9)
Dark Yellowish Brown (go to page 12)
SoilColor Groups
Nueva Ecija 7
Maligaya (Mlg)
Coarse Fragments none
pH 6.8-7.2
OthersFe (brown) and Mn (black) concretions; slickensides
Zaragosa (Zg)
Coarse Fragments none
pH 6.8-7.4
OthersFe (dark greenish gray) and Mn (black) concretions
Texture: Clay
go to page 18
go to page 18
Gray/Yellowish Gray
8 Simplif ied Keys TO Soil Series
Prensa (Pr)
Coarse Fragments gravels
pH 6.5-7.2
OthersFe (yellowish brown) and Mn (black) mottles; slickensides
Texture: Clay Loam
go to page 18
Gray/Yellowish Gray
10 Simplif ied Keys TO Soil Series
Dark Grayish Brown
San Manuel (Snm)
Coarse Fragments none
pH 6.7-7.4
Othersmottles (red spots); cutans (clay skins)
go to page 19
Texture: Clay Loam
Nueva Ecija 11
Texture: Clay
Dark Grayish Brown
San Fabian (Sfn)
Coarse Fragments gravels
pH 6.5-7.0
Others compacted
go to page 19
go to page 19
Bantog (Btg)
Coarse Fragments none
pH 7.2-7.6
Others Fe (brownish gray) and Mn (black) mottles
12 Simplif ied Keys TO Soil Series
Dark Yellowish Brown
Texture
Loamy sand/Silt Loam page 13
Clay page 14
Clay Loam page 15
Silt Loam page 16
Nueva Ecija 13
Texture: Loamy Sand/Silt Loam
Dark Yellowish Brown
go to page 20
Quingua (Qga)
Coarse Fragments none
pH 6.8-7.6
OthersFe (yellowish brown) and Mn (black) mottles
14 Simplif ied Keys TO Soil Series
Texture: Clay
Dark Yellowish Brown
go to page 20
Sibul (Sbl)
Coarse Fragments none
pH 5.5-6.0
Others Fe (yellowish brown) mottles
Nueva Ecija 15
Texture: Clay Loam
Umingan (Umn)
Coarse Fragments gravels and stones
pH 5.8-6.7
Others none
Dark Yellowish Brown
go to page 21
16 Simplif ied Keys TO Soil Series
Texture: Silt Loam
Dark Yellowish Brown
go to page 21
Annam (Anm)
Coarse Fragments rock fragments
pH 5.5-6.0
Others mottles (brown spots)
18 Simplif ied Keys TO Soil Series
Zaragosa (Zg)page 24
Prensa (Pr)page 23
Maligaya (Mgl)page 23
Apg
ABg
Bg1
Bg2
Apg
ABg
Bg1
Bg2
Apg
AB
Bg1
Bg2
Apg
AB
Bg1
Bg2
Ap
Bcg
Btcg
BCcg
Cg
Ap
Bcg
Btcg
BCcg
Cg
00 cm
15
30
50
90
00 cm
25
52
110
00 cm
10
25
50
94
Nueva Ecija 19
San Manuel (Snm)page 23
Bantog (Btg)page 23
San Fabian (Sfn)page 24
Ap1
Ap2
Bw1
Bw2
Bw3
Ap1
Ap2
Bw1
Bw2
Bw3
Ap
Bwg1
Bwg2
Bwg3
Bwg4
Ap
Bwg1
Bwg2
Bwg3
Bwg4
05 cm
35
70
100
140
15 cm
40
70
110
00 cm
30
60
90
20 Simplif ied Keys TO Soil Series
Quingua (Qga) page 23
Sibul (Sbl)page 24
Ap
AB
Bw1
Bw2
Bw3
Bw4
Ap
AB
Bw1
Bw2
Bw3
Bw4
Ap
Bw1
Bw2
BC
Ap
Bw1
Bw2
BC
00 cm
30
60
100
125
00 cm
40
80
120
175
Nueva Ecija 21
Umingan (Umn)page 24
Annam (Anm)page 24
Ap
AB
BW1
BW2
BC
Ap
AB
BW1
BW2
BC
Ap
Bo1
Bo2
BC1
BC2
Ap
Bo1
Bo2
BC1
BC2
00 cm
25
50
75
100
00 cm
50
75
115
Nueva Ecija 23
Table 1. Properties of Different Soil Series that Affect the Growth of Crops.
Soil Qualities in Relation to Crop Production
Lowland Soils
Bantog Maligaya Prensa Quingua San Manuel
Soil pH 6.5-7.6 6.8-7.2 6.5-7.2 6.8-7.6 6.7-7.4
N Level medium low low low low
P Level high high medium medium low
K Level low low low medium medium
Soil Texture clay, clay loam
clay clay loam
clay to clay loam, silt loam
silt loam
Drainage well imper-fectly
mode-rately well
well well
Permeabi-lity
slow to very slow
slow to very slow
slow to very slow
mode-rately slow
modera-te to slow
Rock Frag-ments
none none none none none
Effective Soil Depth
deep (150cm)
deep (150cm)
deep (150cm)
deep (150cm)
deep (150cm)
Flooding Hazard
sea-sonal
none to seaso-nal
none seasonal sea-sonal
Topogra-phy
flat almost flat
undu-lating, rolling
almost flat
almost flat
Inherent Fertility
high high mode-rate
mode-rate
modera-te to high
24 Simplif ied Keys TO Soil Series
Soil Qualities in Relation to Crop Production
Upland Soils
Zara-gosa
Annam San Fabian
Sibul Umi-ngan
Soil pH 6.8-7.4 5.5-6.0 6.5-7.0 5.5-6.0 5.8-6.7
N Level low medium medium low low
P Level medium low high low low
K Level low low high low medium
Soil Texture clay silty clay loam to clay
clay loam clay silty clay loam
Drainage some-what poor
good well well well
Perme-ability
slow to very slow
mode-rate
moderate mode-rate
moder-ate
Rock Fragments
none rock frag-ments
gravels none gravels
Effective Soil Depth
deep (150cm)
mode-rately deep (<90 cm)
deep (100)
shallow deep
Flooding Hazard
sea-sonal
none none none sea-sonal
Topo-graphy
almost flat
undu-lating, rolling to steep
rolling to hilly with some level areas
roll-ing to steep
gently sloping
Inherent Fertility
high low to moder-ate
moderate moder-ate
mode-rate
Table 1. (continuation)
Nueva Ecija 25
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
26 Simplif ied Keys TO Soil Series
Table 2. The soil productivity index for rice.
Soil Series Inherent Productivity
Potential Productivity
Annam 0.58 0.73
Bantog 0.81 0.91
Maligaya 0.83 0.93
Prensa 0.60 0.78
Quingua 0.68 0.78
San Fabian 0.60 0.70
San Manuel 0.75 0.85
Sibul 0.36 0.46
Umingan 0.61 0.71
Zaragosa 0.75 0.95
yield is computed by multiplying the potential index by the maximum potential yield. For instance, the maximum potential yield in the dry season is 8 tons/hectare, and the inherent and potential productivity ratings for Maligaya soil is 0.83 and 0.93, respectively. Then, the predicted inherent and potential yields of rice in Maligaya soils are 6.6 and 7.4 tons/ha, respectively.
28 Simplif ied Keys TO Soil Series
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 a 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 Nueva Ecija is shown on Table 3 (29-30).
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
Nueva Ecija 29
Tabl
e 3.
Th
e cr
op s
uita
bilit
y an
alys
is o
f the
soi
ls o
f Nue
va E
cija
for
diff
eren
t cro
ps.
Soil
Serie
sSl
ope
Ric
e Irr
igat
ed
Low
land
Ric
e R
ainf
ed
Upl
and
Ric
e R
ainf
ed
Low
land
Mai
zeSo
rghu
mO
nion
Anna
mun
dula
ting
to ro
lling
S2sf
S2cf
S2ct
sS1
S1S3
tfBa
ntog
leve
l to
near
ly le
vel
S1S2
cwS2
cS1
S1S1
Mal
igay
ale
vel t
o un
dula
ting
S2f
S2cf
S2cf
S2f
S2f
Nf
Pren
sage
ntly
slo
ping
S2sf
S2cf
S2cs
fS2
fS1
S3f
Qui
ngua
leve
l to
near
ly le
vel
S2f
S2cf
S2cf
S2f
S1S2
fSa
n Fa
bian
rollin
g to
hilly
S3f
S3f
S3w
S3f
S3f
S3f
San
Man
uel
leve
l to
near
ly le
vel
S3sf
S2cf
S3sf
S1S1
S1Si
bul
undu
latin
g, ro
lling
to s
teep
S2sf
N2t
N2t
S2f
N1t
Ntf
Um
inga
nle
vel t
o un
dula
ting
S2sf
S3f
S2sf
S2sf
S2sf
S2sf
Zara
gosa
leve
l to
near
ly le
vel
S3f
S3f
S3f
S3f
S2sf
S3f
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
30 Simplif ied Keys TO Soil Series
Limitations due to:
t -
topography; slope
w -
drainage; flooding
s -
texture; coarse fragments; soil depth
f -
soil fertility
c
- clim
ate
Suitability ratings:
S1 - H
ighly suitable
S2 - M
oderately suitable
S3 - M
arginally suitable
N1 -
Currently not suitable
N
2 - Perm
anently not suitable
Table 3. (continuation)
Soil SeriesSlope
TobaccoSw
eet Potato
Sugar-cane
PeanutW
ater M
elonM
ango
Annamundulating to rolling
S3tsS2f
S3tS3t
S3tS3t
Bantoglevel to nearly level
S3ws
S1S1
S1S2w
sS1
Maligaya
level to undulatingS3w
sfS2f
S2fS3f
S3wf
S2fPrensa
gently slopingS2f
S3fS3f
S2fS2f
S2fQ
uingualevel to nearly level
S2fS2f
S2fS2f
S2fS2f
San Fabianrolling to hilly
S3fS3f
S3fS2tsf
S3sfS3s
San Manuel
level to nearly levelS1
S1S1
S1S1
S1Sibul
undulating, rolling, to steepN
tS3f
Nt
Nt
Nt
Nt
Um
inganlevel to undulating
S2sfS2f
S2sfS2sf
S2sfS2sf
Zaragosalevel to nearly level
S3fS3f
S3fS3f
S3fS3f
32 Simplif ied Keys TO Soil Series
The goal of soil management is to protect 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, maintaining the 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 were enumerated in the succeeding pages (table 4). In making soil management recommendations, soil properties such as texture, mineralogy, moisture and temperature regimes, and climate were considered since these factors affect the crop growth. However, these properties cannot be changed but control tillage, crop rotations, soil amendments and other management choices can be done. Through these choices, the structure, biological activity, chemical content of soil can be altered and later on influence erosion rates, pest population, and nutrient availability and crop production.
Soil Management Recommendations
Nueva Ecija 33
Tabl
e 4.
Th
e so
il se
ries
of N
ueva
Eci
ja w
ith
thei
r lim
itat
ions
for
crop
pro
duct
ion
and
corr
e-sp
ondi
ng m
anag
emen
t rec
omm
enda
tion
s fo
r di
ffer
ent c
rops
.
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
Anna
mAl
umin
um
(Al)
and
Iron
(Fe)
Tox
icity
; ru
n-of
f; sl
opin
g to
pogr
aphy
poor
ly d
rain
ed s
oils
on
the
allu
vial
bas
in
are
mod
erat
ely
suita
ble
for p
addy
; fe
rtiliz
atio
n; m
aint
ain
prop
erly
the
padd
y di
kes
gree
n m
anur
ing:
lim
ing;
larg
e in
itial
app
licat
ion
of p
hosp
hate
fe
rtiliz
ers;
su
itabl
e fo
r di
vers
ified
cro
ps
limin
g; c
onto
ur
terra
cing
; buf
fer
strip
cro
ppin
g;
addi
tion
of
orga
nic
mat
ter
and
anim
al
man
ure
to
impr
ove
soil
ferti
lity
and
wat
er h
oldi
ng
capa
city
upla
nd a
nd h
illy
land
is w
ell-s
uite
d fo
r agr
ofor
est,
indu
stria
l cro
ps,
orch
ard
and
fore
st b
ut u
se
loca
lly a
dapt
ed
high
-yie
ldin
g va
rietie
s of
tree
cr
ops;
pra
ctic
e pr
oper
ferti
lizat
ion
Cro
ppin
g Pa
ttern
: ric
e-m
aize
/sor
ghum
/veg
etab
les/
root
cro
ps
34 Simplif ied Keys TO Soil Series
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
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
adeq
uate
dra
inag
e an
d irr
igat
ion
syst
em; a
pplic
atio
n of
org
anic
mat
ter
and
farm
man
ure
unsu
itabl
e un
der p
rese
nt
cond
ition
s bu
t w
ill be
com
e su
itabl
e if
prop
er m
anag
e-m
ent p
ract
ices
ar
e do
ne, l
ike
esta
blis
hmen
t of
adeq
uate
dra
in-
age
and
flood
co
ntro
l sys
tem
s;
use
of s
uita
ble
tree
spec
ies
and
prop
er
ferti
lizat
ion
Cro
ppin
g Pa
ttern
: ric
e-ric
e; ri
ce-d
iver
sifie
d cr
ops/
vege
tabl
es/ro
ot c
rops
Nueva Ecija 35
Mal
i-ga
yahe
avy
clay
: poo
r dr
aina
ge: h
igh
shrin
k an
d sw
ell c
apac
ity
upon
wet
ting
and
dryi
ng p
rodu
cing
wid
e cr
acks
in th
e so
il, h
ard
whe
n dr
y; v
ery
slow
pe
rmea
bilit
y
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
appl
icat
ion
of
ferti
lizer
s an
d or
gani
c m
atte
r; al
low
pro
per
drai
nage
sys
tem
in
the
field
to a
ddre
ss
the
heav
y cl
ay
text
ure
of th
is s
oil;
use
broa
dbed
s,
ridge
s an
d m
ulch
ing
esta
blis
hmen
t of
adeq
uate
dra
inag
e an
d irr
igat
ion
sys-
tem
; use
of t
he ri
ght
kind
and
am
ount
of
ferti
lizer
s in
clud
ing
thei
r met
hods
of
appl
icat
ion;
pro
per
timin
g of
cul
tivat
ion
and
plan
ting
prac
tice
prop
er ti
min
g of
cul
tivat
ion
and
plan
ting
due
to c
laye
y te
xtur
e
Cro
ppin
g Pa
ttern
: ric
e-ric
e; ri
ce-d
iver
sifie
d cr
ops/
vege
tabl
es/ro
ot c
rops
Pren
sadi
ssec
ted
phys
iogr
aphy
lim
its p
addy
fiel
d si
zean
d ex
cess
ele
vatio
ns
incr
ease
cos
t of e
xten
-si
ve g
ravi
ty ir
rigat
ion
inpu
ts; e
xces
s 2:
1 cl
ayca
uses
phy
sica
l lim
ita-
tions
for d
iver
sifie
d cr
ops;
slo
ping
to
pogr
aphy
requ
ires
cont
our l
tivat
ion
esta
blis
hmen
t of
ade
quat
e dr
aina
ge
and
irrig
atio
n sy
stem
; pro
per
leve
ling,
co
nstru
ctio
n an
d m
ain-
tena
nce
of
padd
y di
kes
appl
icat
ion
of
ferti
lizer
s an
d or
gani
c m
atte
r; re
quire
s co
ntou
r cu
ltiva
tion;
use
gr
een
man
ures
and
m
ulch
es; p
rope
r tim
ing
of c
ultiv
atio
n an
d pl
antin
g
esta
blis
hmen
t of
adeq
uate
dra
inag
e an
d irr
igat
ion
syst
em; r
egul
ar
addi
tion
of o
rgan
ic
mat
ter a
nd a
nim
al
man
ure;
pro
per
timin
g of
cul
tivat
ion
and
plan
ting
prac
tice
prop
er ti
min
g of
cul
tivat
ion
and
plan
ting
due
to c
laye
y te
xtur
e
Cro
ppin
g Pa
ttern
: ric
e-ric
e; ri
ce-d
iver
sifie
d cr
ops/
vege
tabl
es/ro
ot c
rops
36 Simplif ied Keys TO Soil Series
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
Qui
n-gu
acl
imat
e,
seas
onal
flo
odin
g
suite
d fo
r pa
ddy
rice;
ap
plic
atio
n of
inor
gani
c fe
rtiliz
ers
to
mai
ntai
n th
e fe
rtilit
y of
the
soil
suite
d fo
r div
ersi
fied
crop
s;
cons
truct
ion
of a
dequ
ate
drai
nage
irrig
atio
n an
d flo
od
cont
rol s
yste
m; p
rope
r tim
ing
of
culti
vatio
n an
d pl
antin
g
suite
d fo
r roo
t cr
ops;
con
stru
ctio
n of
ade
quat
e dr
aina
ge ir
rigat
ion
and
flood
con
trol
syst
em; p
rope
r tim
ing
of c
ultiv
atio
n an
d pl
antin
g
suite
d fo
r tre
e cr
ops;
co
nstru
ctio
n of
ade
quat
e dr
aina
ge
irrig
atio
n an
d flo
od c
ontro
l sy
stem
Cro
ppin
g Pa
ttern
: ric
e-ric
e; ri
ce-d
iver
sifie
d cr
ops/
vege
tabl
es/ro
ot c
rops
San
Fa
bian
durin
g th
e dr
y se
ason
, th
e un
plow
ed
soil
is
com
pact
and
ha
rd, a
nd
crac
ks in
to
big
clod
s;
not s
uita
ble
for i
rriga
ted
low
land
rice
pr
oduc
tion
due
to
irrig
atio
n pr
oble
m;
prac
tice
cont
our f
arm
ing;
co
nser
vatio
n til
lage
suc
h as
m
ulch
ing
and
grou
ndco
ver h
elp
cons
erve
moi
stur
e; m
inim
ize
runo
ff an
d co
ntro
l ero
sion
; pr
actic
e gr
een
man
urin
g to
impr
ove
soil
ferti
lity
and
stru
ctur
e; s
uite
d fo
r veg
etab
les
subs
oilin
g; a
dditi
on
of o
rgan
ic m
atte
r an
d an
imal
man
ure
to im
prov
e so
il fe
rtilit
y an
d w
ater
ho
ldin
g ca
paci
ty
subs
oilin
g;
cove
r cro
ppin
g w
ith le
gum
es;
use
of lo
cally
ad
apte
d
high
-yie
ldin
g va
rietie
s of
tree
cr
ops
Nueva Ecija 37
San
Fabi
an
(con
ti-nu
ed)
slop
ing
topo
grap
hy;
irrig
atio
n pr
oble
ms
suite
d fo
r ra
infe
d ric
e a
nd o
ther
cas
h cr
ops
but a
pply
fe
rtiliz
ers
and
orga
nic
mat
ter
Cro
ppin
g Pa
ttern
: up
land
rice
-div
ersi
fied
crop
s/ve
geta
bles
/root
cro
ps; d
iver
sifie
d cr
ops/
vege
tabl
es/ro
ot c
rops
- div
ersi
fied;
cro
ps/v
eget
able
s/ro
ot c
rops
San
Man
uel
exce
ssiv
ely
wet
and
an
nual
flo
odin
g fo
r sho
rt pe
riods
and
ex
cess
ive
drou
ghtin
ess
from
Mar
ch
to M
ay; l
ow
phos
phor
us
cont
ent
appl
icat
ion
of p
hosp
hate
fe
rtiliz
ers;
su
ited
for
padd
y ric
e du
ring
wet
se
ason
and
w
ith a
dequ
ate
irrig
atio
n du
ring
dry
seas
on
cons
truct
ion
of a
dequ
ate
drai
nage
, irri
gatio
n an
d flo
od
cont
rol s
yste
m d
ue to
sea
sona
l flo
odin
g ha
zard
and
hig
h se
ason
al w
ater
tabl
e; u
se
broa
dbed
s, a
nd ri
dges
; sui
ted
for d
iver
sifie
d cr
ops
such
as
corn
, veg
etab
les,
and
wat
er
mel
on
esta
blis
hmen
t of
adeq
uate
dra
inag
e an
d irr
igat
ion
syst
em; r
egul
ar
addi
tion
of o
rgan
ic
mat
ter a
nd a
nim
al
man
ure
to im
prov
e so
il fe
rtilit
y
adeq
uate
dra
in-
age
and
irrig
a-tio
n sy
stem
; co
ver c
ropp
ing
with
legu
mes
; pr
oper
ferti
liza-
tion,
tim
ing
of
culti
vatio
n an
d pl
antin
g; u
se o
f lo
cally
ada
pted
hi
gh-y
ield
ing
varie
ties
is
reco
mm
ende
d to
impr
ove
the
grow
th a
nd y
ield
of
tree
cro
psC
ropp
ing
Patte
rn:
rice-
rice;
rice
-div
ersi
fied
crop
s/ve
geta
bles
/root
cro
ps
38 Simplif ied Keys TO Soil Series
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
Sibu
lsh
allo
w s
oil;
undu
latin
g to
st
eep
topo
grap
hy;
som
etim
es
pres
ence
of
limes
tone
frag
men
t at
the
top
soil
not s
uite
d fo
r irri
gate
d lo
wla
nd
prod
uctio
n be
caus
e of
irr
igat
ion
cons
train
ts;
leve
ling
and
terra
cing
appl
icat
ion
of fe
rtiliz
er
and
orga
nic
mat
ter;
prac
tice
cont
our f
arm
ing;
co
nser
vatio
n til
lage
suc
h as
m
ulch
ing
and
grou
ndco
ver
help
con
serv
e m
oist
ure,
sl
ow ru
noff,
min
imiz
e an
d co
ntro
l ero
sion
; mul
chin
g us
ing
orga
nic
mat
eria
ls
help
sus
tain
soi
l fer
tility
; su
ited
to a
ny c
ash
or
dive
rsifi
ed c
rops
cont
our t
erra
cing
; bu
ffer s
trip
crop
ping
; pro
per
ferti
lizat
ion;
pr
oper
tim
ing
of
culti
vatio
n an
d pl
antin
g; li
min
g;
addi
tion
of o
rgan
ic
mat
ter a
nd
anim
al m
anur
e to
impr
ove
soil
ferti
lity
and
wat
er
hold
ing
capa
city
fruit
trees
, ag
rofo
rest
and
in
dust
rial t
ree
spec
ies
are
reco
mm
ende
d in
ro
lling
to s
teep
to
pogr
aphy
; co
ntou
r ter
raci
ng,
tilla
ge a
nd
plan
ting;
cov
er
crop
ping
with
le
gum
es; u
se o
f lo
cally
ada
pted
hi
gh-y
ield
ing
varie
ties
of tr
ee
crop
s C
ropp
ing
Patte
rn:
upla
nd ri
ce-d
iver
sifie
d cr
ops/
vege
tabl
es/ro
ot c
rops
Nueva Ecija 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 st
ones
and
gra
vel,
the
soils
tend
to
be
drou
ghty
; oc
curre
nce
of
flood
s du
ring
and
afte
r hea
vy ra
ins
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
el
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
grav
el a
t the
lo
wer
sub
soil
may
ca
use
the
low
er
yiel
d of
root
cro
ps
clea
ring
of la
rge
grav
el a
nd ro
ck
outc
rops
Cro
ppin
g Pa
ttern
: ric
e-di
vers
ified
cro
ps/v
eget
able
s/ro
ot c
rops
Zara
-go
sase
ason
al fl
oodi
ng
haza
rds
and
high
se
ason
al w
ater
ta
ble;
ext
rem
e cl
imat
ic li
mita
tion;
so
me
depo
sitio
nal
prob
lem
suite
d fo
r lo
wla
nd ri
ce
prod
uctio
n du
ring
dry
seas
on
appl
icat
ion
of p
hosp
hate
fe
rtiliz
ers
and
orga
nic
mat
ter;
artifi
cial
irrig
atio
n an
d dr
aina
ge re
quire
d du
e to
sea
sona
l floo
ding
haz
ard
and
high
sea
sona
l wat
er
tabl
e; a
llow
pro
per d
rain
age
syst
em; g
row
floo
d-to
lera
nt
crop
s du
ring
wet
sea
son
esta
blis
hmen
t of
ade
quat
e dr
aina
ge a
nd
irrig
atio
n sy
stem
adeq
uate
dr
aina
ge a
nd
irrig
atio
n sy
stem
; pl
ant fl
ood-
tole
rant
cr
ops
Cro
ppin
g Pa
ttern
: ric
e-di
vers
ified
cro
ps/v
eget
able
s/ro
ot c
rops
42 Simplif ied Keys TO Soil Series
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 43-48). These features/properties influence crop growth and serve as basis for transferability of soil management technology.
Nueva Ecija 43
Table 5. Soil taxonomic classification of each soil series in Nueva Ecija with interpretation.
Soil Series
Taxonomic Classification
Interpretation
Annam Fine loamy, mixed (ca.), isohyperthermic TYPIC EUTRUSTOX
This soil has fine-loamy 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 Eutrustox which means it has high base saturation (eutr-).
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.
44 Simplif ied Keys TO Soil Series
Soil Series
Taxonomic Classification
Interpretation
Mali-gaya
Fine, smectitic, isohyperthermic, TYPIC CALCIAQUERT
This is a fine loamy-textured soil with high clay content of 35-60% 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 a typical (typic) representative of the great group Calciaquerts which means it is saturated with water for repeated periods of time (aqu-) manifested by its grayish color with or without mottles. This soil has high calcium (calci-) saturation in its subsoil horizons.
Prensa Fine, mixed, isohyperthermic, VERTIC EPIAQUALF
This is a fine-textured soil containing a large amount of clay (35-60%) and has isohyperthermic temperature regime (>22°C). It is an Alfisol (-alf), i.e. there is illuvial accumulation on clay in the subsoil horizons from the underlying horizons. It is saturated with water for repeated periods of time (aqu-) manifested by its grayish color with or without mottles. It is a representative of the great group Epiaqualfs that has vertic properties, i.e. it is dominated by clays that shrink and swell producing wide cracks and slickensides due to repeated wetting and drying.
Nueva Ecija 45
Soil Series
Taxonomic Classification
Interpretation
Quin-gua
Fine silty, isohyper-thermic, FLUVA-QUENTIC EPIAQUOLL
Fine loamy-textured soil with moderate amount of clay (18-35%) and isohyperthermic temperature regime (>22°C). It is Mollisol (-oll) or dark-colored, fertile soils with high base saturation and natural to medium acid pH. It is saturated with water for repeated periods of time (aqu-) due to river flooding (fluvaquentic) manifested by its grayish color with or without mottles.
San Fabian
Fine loamy, mixed (ca.), isohyper-thermic, TYPIC CALCIQUERT
Fine loamy-textured soil with high clay content of 35-60% and 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 a typical (typic) representative of the great group Calciaquerts. It is saturated with water for repeated periods of time (aqu-) manifested by its grayish color with or without mottles. This soil also has high calcium (calci-) saturation in its subsoil horizons.
46 Simplif ied Keys TO Soil Series
Soil Series
Taxonomic Classification
Interpretation
San Manuel
Fine loamy, smectitic (ca.), isohyper-thermic, FLUVA-QUENTIC EPIAQUEPT
Fine loamy-textured soil with moderate amount of clay (18-35%) and isohyperthermic temperature regime (>22°C). It is an Inceptisol (-ept), i.e. it is in the incipient development toward mature soil, but has not yet fully developed its diagnostic horizons. It is saturated with water for repeated periods of time (aqu-)due to river flooding (fluvaquentic) manifested by its grayish color with or without mottles.
Sibul Fine to very fine, isohy-perthermic, TYPIC EUTRUDEPT
Fine to very fine-textured soil containing >60% clay and has isohyperthermic temperature regime (>22°C). It is an Inceptisol (-ept), i.e. it is in the incipient development toward mature soil, but has not yet fully developed its diagnostic horizons. It is a typical (typic) representative of the great group Eutrudepts which has high base saturation (eutr-)occurring in areas with well distributed rainfall (-ud).
Nueva Ecija 47
Soil Series
Taxonomic Classification
Interpretation
Umingan Loamy skeletal, mixed (ca.), isohyper-thermic, 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 has 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).
Zaragosa Fine,smectitic (ca.), isohyperther-mic, VERTIC EPIAQUEPT
Fine-textured soil with moderate amount of clay (18-35%) and isohyperthermic temperature regime (>22°C). It is an Inceptisol (-ept), i.e. it is in the incipient development toward mature soil, but has not yet fully developed its diagnostic horizons.
48 Simplif ied Keys TO Soil Series
Zaragosa(continued)
Fine,smectitic (ca.), isohyperther-mic, VERTIC EPIAQUEPT
It is saturated with water for repeated periods of time (aqu-) manifested by its grayish color with or without mottles. This is a representative of the great group Epiaquepts vertic properties, i.e. it is dominated by clays that shrink and swell producing wide cracks and slickensides due to repeated wetting and drying.
50 Simplif ied Keys TO Soil Series
Choose a vacant area in your field. Using a spade/auger, dig up to 50cm from the soil surface.
Depth of soil is important. The surface/top soil is not a good basis since it is always cultivated.
1 Soil sampling
Get bulk soil sample (½ kilo) from a 30-50cm depth; place it in a container (plastic/pail). This sample will be used for soil series identification.
APPENDIX 1. STEPS TO IDENTIFY SOIL SERIES
Nueva Ecija 51
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. Gray indicates a fairly con-stant water-saturated condition. Bright brown and red colors are in-dicative of good aeration and drainage.
Get an ample amount of soil from the sample. The soil should be moist (neither too wet, nor too dry).
Compare the color of the soil sample with the color chart in the guidebook. Take note of the classifica-tion of the soil color.
Nueva Ecija 53
pH Determination (UPLB procedure)4Get 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.
54 Simplif ied Keys TO Soil Series
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.
Nueva Ecija 55
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.
56 Simplif ied Keys TO Soil Series
Badayos, R. B. 1990. Lowland rice soils in the Philippines, their characteristics and classification in relation to productivity. Inaugural 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 Nueva Ecija 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
Nueva Ecija 57
Subject Matter Specialists
PhilRice Wilfredo B. Collado
Mary Rose O. Obico Rona T. Dollentas Jesiree Elena Ann P. Dela Torre Jovino L. De Dios Leo C. Javier Eduardo Jimmy P. Quilang, Jr., PhD
UP Los Baños Rodrigo B. Badayos, PhD Armando E. Soliman
Managing Editor/Layout Artist Hazel V. Antonio
Editor Constante T. Briones Editorial Advisers Leocadio S. Sebastian, PhD Madonna C. Casimero, PhD Ronan G. Zagado