NEGROS OCCIDENTAL
i SIMPLIFIED KEYS TO SOIL SERIES
This guidebook belongs to:
Name: _____________________________
Address: ___________________________
Contact number: ____________________
Philippine Rice Research Institute Maligaya, Science City of Muñoz, Nueva Ecija
Copyright © 2014
Authors
Managing Editor / Layout Artist
Rodolfo V. Bermudez, Jr
Editorial Adviser
Eufemio T. Rasco, Jr
PhilRice®
Wilfredo B. Collado Rona T. Dollentas Jovino L. De Dios Reynilda M. Monteza Judith Carla P. Dela Torre Jesiree Elena Ann D. Bibar UP Los Baños Rodrigo B. Badayos Armando E. Soliman
This guidebook was funded by the project “Identification, Biophysical Characterization and Mapping of the Rice Areas of the Philippines” of PhilRice
® (ISD -002-001).
Negros Occidental ii
NEGROS OCCIDENTAL
TABLE OF CONTENTS
Foreword……………………………………….. iv
The Simplified Keys to Soil Series………..…. 1
Guide to Soil Series Identification.................. 2
Soil Color Groups........................................... 5
Black/Grayish Brown ............................. 7
Gray/Bluish Gray ...……..……................ 10
Strong Brown/Red.............……………..... 11
Brown/Yellowish Brown..….................... 12
Olive Brown/Gray................................... 16
Soil Profile & Characteristics.......................... 17
Soil Productivity …………………………......... 36
Crop Suitability Analysis…….......................... 38
Soil Management Recommendations............ 45
Appendices……………………………….……. 55
Steps to Identify Soil Series…….......... 56
Soil Sampling....................................... 56
Color Determination............................. 57
Texture Determination.......................... 58
pH Determination................................. 59
The PalayCheck® System……………..…….. 60
Glossary………………………………………… 62
Soil Textural Classes…………………... 64
References…………………………………….. 65
iii SIMPLIFIED KEYS TO SOIL SERIES
FOREWORD
EUFEMIO T. RASCO, JR Executive Director
This guidebook on “Simplified Keys to Soil Series” was developed for easier field identification of soils.
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.
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 colors, textures, pH, and other observable properties of the most common soils of Negros Occidental and contains four simple steps in identifying the soil series right in the field. It also includes the soil productivi-ty index, soil properties that affect crop growth, soil taxonomic classification, crop suitability analysis, and soil management recommendations. The concept of simplified keys to soil series was first used in Thailand. In the Philippines, the pro-ject “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 munici-pal and provincial agriculturists for helping us validate the soil series. We also acknowledge the Bureau of Soils and Water Management (BSWM) for providing the secondary data of the soils used in this guidebook.
Negros Occidental iv
The “Simplified Keys to Soil Series” is a tool to identify soil series in the field following simple steps for the use of farmers, extension workers, agricultural technologists, researchers, and other stakeholders. Using this guidebook, identification of soil will be more accurate reducing the risk of incompatible management and technology recommendations. Selection of knowledge and technologies could also be easy and efficient with the identification of soil series. For instance, because some soil series behave similarly, the management practices and technology suitable in known soil names are expected to be adaptable in the same soil series of a different region.
This guidebook is easy to use. Using only five basic soil properties (color, texture, pH, coarse fragments, and mottles) at 30-50cm soil depth and following the simple steps provided, the soil series in the field could be identified. Once the soil is known, a compilation of thematic information related to the use of soils especially in crop production such as selection of suitable crops, crop productivity ratings, soil properties that limit production, and soil management recommendations can be determined.
This guidebook includes 18 soil series in Negros Occidental, namely: Bago, Bantay, Batuan, Bolinao, Cadiz, Faraon, Guimbalaon, Isabela, La Castellana, Luisiana, Manapla, Obando, Pulupandan, Silay, San Manuel, Tupi, Umingan, and Victorias.
The Simplified Keys to Soil Series
1 SIMPLIFIED KEYS TO SOIL SERIES
GUIDE TO SOIL SERIES IDENTIFICATION
Negros Occidental 2
2. From a vacant area of your identified site, dig a pit or use an auger to get the soil samples needed.
3. Soil samples should be taken from a recommended soil depth to make sure that the condition and structure of the soil is well-preserved and free from any kind of cultivation (see page 56).
1. Conduct preliminary interview on the historical background of your sampling site. Gather information on cultivation practices, natural
occurrences such as flood, erosion, and human activities that affect the condition and structure of the soil. Check whether the soil was disturbed or scraped.
3 SIMPLIFIED KEYS TO SOIL SERIES
5. Identify the texture of the soil. Texture is a unique property used as qualitative classifi-cation tool to deter-mine classes of soil (see page 58).
4. Know the color of the soil. Color is one of the most important physical properties of the soil as indicative to series recognition. Each soil series has its distinct inher-ent color which makes it dif-ferent from the other series (see page 57).
6. Determine the soil pH. The measure of acidity or alkalinity in soils is known as soil pH. This measure-ment corresponds to spe-cific soil series (see page 59).
7. Take note of other observable soil properties such as polished surfaces (cutans/slickensides), softness, hardness, stickiness, etc.
mottles slickenside
Negros Occidental 4
8. Take note of the presence or absence of coarse fragments such as limestone, rock fragments, lateritic nodules, black manganese (Mn) and red iron (Fe) concretions, sand materials, and other observable properties of the soil taken from surfaces up to 50-cm depth.
Lateritic nodules
Manganese/iron concretions
Quartz
9. Use the Simplified Keys to Soil Series Guidebook and com-pare all soil properties starting from the color until the soil name is identified.
5 SIMPLIFIED KEYS TO SOIL SERIES
SOIL Color Groups Black/Grayish Brown (go to pages 7-9)
Obando Isabela
Gray/Bluish Gray (go to page 10)
Cadiz
Silay
Faraon
Bago
Tupi
Luisiana Bolinao
Strong Brown/Red (go to page 11)
Negros Occidental 6
SOIL Color Groups Brown/Yellowish Brown (go to pages 12-15)
Bantay
Victorias
San manuel
Guimbalaon
Umingan
La Castellana
Batuan
Manapla Pulupandan
Olive Brown/Gray (go to page 16)
7 SIMPLIFIED KEYS TO SOIL SERIES
Bago (figure on page 18)
Coarse fragments Soft powdery grayish-brown concretions
pH 6.5-7.5
Others Brown spot mottles; shiny smooth surfaces (slickensides); massive
Texture: Clay
Black/Grayish Brown
Cadiz (figure on page 22)
Coarse fragments
Brown nodules, pebbles, and compacted reddish gravel “igang”; red/dark brown soft powdery black concretions
pH 6.0-7.0
Others Reddish specks; red/dark brown spot mottles
Texture: Clay/Clay loam
Negros Occidental 8
Faraon (figure on page 23)
Coarse fragments Limestone (grayish-white rock)
pH 7.0- 8.0
Others Grayish to white porous cor-alline limestone rock, which is soft and easily broken
Texture: Clay
Black/Grayish Brown
Silay (figure on page 31)
Coarse fragments None
pH 4.0-6.0
Others Yellowish-brown spot mottles; hard compact gray “bakias” below the profile
Texture: Silt loam
9 SIMPLIFIED KEYS TO SOIL SERIES
Black/Grayish Brown
Tupi (figure on page 33)
Coarse fragments
Porous volcanic pebbles, stones, and gravels (breccia); stones and boulders below the profile; big black boulders on the surface (outcrops)
pH 5.5-6.5
Others Brown spot mottles
Texture: Sand
Gray/Bluish Gray
Negros Occidental 10
Isabela (figure on page 25)
Coarse fragments None
pH 5.5-7.5
Others
Red/black/gray spot mottles; shiny smooth surfaces; compact; very plastic and sticky when wet, hard to compact when dry
Texture: Heavy clay
Obando (figure on page 29)
Coarse fragments Quartz/crystals; broken marine shells
pH 7.0-8.0
Others Gray-brown spot mottles
Texture: Sand
11 SIMPLIFIED KEYS TO SOIL SERIES
Bolinao (figure on page 21)
Coarse fragments
Grayish-white pebbles (limestone) and cobblestones; soft powdery black concre-tions; white hard limestone rock below the profile
pH 5.0-6.5
Others Grayish-brown spot mottles
Texture: Clay
Strong Brown/Red
Luisiana (figure on page 27)
Coarse fragments None
pH 4.5-5.5
Others Red specks and black spot mottles
Texture: Clay
Negros Occidental 12
Bantay (figure on page 19)
Coarse fragments Soft weathered shale
pH 5.0-6.0
Others Shale (easily crushed powdery mass) below the profile
Texture: Clay
Brown/Yellowish Brown
Guimbalaon (figure on page 24)
Coarse fragments
Reddish and angular gravels at the surface; soft powdery- red and black fragments; weathered andesite and basalts; partially weathered rock outcrops in some places
pH 5.0-6.5
Others Black and red spot mottles
Texture: Clay
Brown/Yellowish Brown
13 SIMPLIFIED KEYS TO SOIL SERIES
Batuan (figure on page 20)
Coarse fragments
Soft weathered yellowish and white shale fragments; yellowish-brown calcareous sandstone below the profile
pH 4.5-5.0
Others None
Texture: Clay/Silty clay/Silty clay loam
La Castellana (figure on page 26)
Coarse fragments
Soft powdery red concretions; granules, stones, and weathered rock fragments; large boulders on the surface (outcrops)
pH 4.5-6.0
Others Reddish-brown and gray spot mottles
Texture: Clay/Clay loam
Negros Occidental 14
San Manuel (figure on page 32)
Coarse fragments None
pH 6.5-7.5
Others
Brick red streaks; brown and gray spot mottles; gray shiny surfaces (clay skins); slightly compact
Texture: Silt loam/ Clay loam/Loam
Brown/Yellowish Brown
Umingan (figure on page 34)
Coarse fragments River-washed stones and gravels
pH 5.5-7.0
Others None
Texture: Clay loam/Loam/Sandy loam
Brown/Yellowish Brown
15 SIMPLIFIED KEYS TO SOIL SERIES
Victorias (figure on page 35)
Coarse fragments Dark-brown fragments turning into black powdery mass when crushed
pH 4.5-6.0
Others Gray spot mottles; shiny smooth surfaces; massive
Texture: Silty clay/Sand
Negros Occidental 16
Manapla (figure on page 28)
Coarse fragments Reddish-yellow soft rock fragments; brown rounded pebbles
pH 4.0-5.0
Others
Grass-like quartz; red and gray spot mottles; dark red streaks; smooth and shiny surfaces (slickensides)
Texture: Clay loam
Olive Brown/Gray
Pulupandan (figure on page 30)
Coarse fragments Moderately compact broken marine shells “kagaykay”
pH 6.0-7.0
Others Gray and brown spot mottles
Texture: Sand
17 SIMPLIFIED KEYS TO SOIL SERIES
SOIL Profile and Characteristics
Soil Fertility Indicators
Inherent fertility Moderate to high
Soil pH Slightly acid to neutral (6.0-7.5)
Organic matter Moderate
Phosphorus (P) High
Potassium (K) Low
Nutrient retention (CEC)
Moderate
Base saturation High
Salinity hazard None
Bago
Physical Soil Qualities
Relief Flat to rolling
Water retention Moderate to high
Drainage Poor
Permeability Very slow
Workability/tilth Hard
Stoniness None
Root depth Deep (>1 m)
Erosion None
Flooding Seasonal
Soil Type: Fine sandy loam/Loam/Sandy clay loam Area: 15,000.46 ha
Family: Fine, isohyperthermic, Vertic Argiudolls
Soils developed from older alluvial deposits. It has fine-textured soil with less than 65% clay. It is a dark-colored soil with high organic matter content and high base status (-oll, Mollisol) and exhibits accumulation of clay in the subsoil (Argi-, Argillic); found in areas with well-distributed rainfall (-ud-, Udic). Surface crack-ing greater than 5-mm wide is observed (vertic). It has a mean annual soil temperature higher than 22°C (isohyperthermic).
Negros Occidental 18
00 cm
28
43
88
Apg1
Apg2
Btg1
Btg2
Bantay
Soil Type: Clay loam Area: 57,567.00 ha
Family: Fine loamy, isohyperthermic, Typic Eutropepts
Soils developed from shale. It has a fine loamy texture with more than 15% fine sand annual soil, including gravels and 18 – 35% clay. It is a typical representative of the great group Eutropepts: a young soil in its incipient development stage toward mature soil (-ept, Inceptisol) and has a base saturation of more than 50% (eutr-).The mean temperature is higher than 22°C (isohyperthermic).
Physical Soil Qualities
Relief Gently sloping to undulating
Water retention High
Drainage Good
Permeability Slow to moderate
Workability/tilth Hard to moderate
Stoniness None
Root depth Shallow (0.3 m)
Erosion Moderate
Flooding None
Soil Fertility Indicators
Inherent fertility Moderate to high
Soil pH Slightly acid (5.0-6.0)
Organic matter Moderate
Phosphorus (P) High
Potassium (K) Low
Nutrient retention (CEC) High
Base saturation High
Salinity hazard Low
19 SIMPLIFIED KEYS TO SOIL SERIES
00 cm
17
28
54
Ap
AC
Cr
R
Soil Fertility Indicators
Inherent fertility Low to moderate
Soil pH Acidic (4.5-5.0)
Organic matter Moderate
Phosphorus (P) Low
Potassium (K) Moderate
Nutrient retention (CEC)
Moderate
Base saturation Moderate
Salinity hazard None
Batuan
Physical Soil Qualities
Relief Undulating to rolling
Water retention High
Drainage Moderate
Permeability Slow to moderate
Workability/tilth Easy
Stoniness Common (>35%)
Root depth Shallow (0.4 m)
Erosion Moderate
Flooding None
Soil Type: Clay Area: 5,077.17 ha
Family: Fine, isohyperthermic, Typic Ustifluvent
Soils derived from underlying calcareous shales and sandstones. It is fine-textured with more than 35% clay. It is a typical (typic) representative of the great group Ustifluvent: a young soil (-ent, Entisol), with less 25% slope; observed with a decrease in organic carbon in the underlying horizons, and shallow calcareous bedrock (fluv-). It is found in areas with pronounced wet and dry seasons (-ust, Ustic) . It has a mean annual soil temperature higher than 22°C (isohyperthermic).
Negros Occidental 20
00 cm
30
50
80
Soil Fertility Indicators
Inherent fertility Moderate to high
Soil pH Slightly acid (5.0-6.5)
Organic matter Moderate
Phosphorus (P) High
Potassium (K) Low
Nutrient retention (CEC)
High
Base saturation Moderate
Salinity hazard None
Bolinao
Physical Soil Qualities
Relief Undulating to mountainous
Water retention High
Drainage Moderate
Permeability Moderate
Workability/tilth Hard
Stoniness Common (15%)
Root depth Shallow (0.4 m)
Erosion Moderate
Soil Type: Clay Area: 6,462.41 ha
Family: Very fine, isohyperthermic, Humic Dystrustept
A very fine-textured soil with more than 65% clay developed from hard coralline limestone rock. It is a young soil in its incipient development stage toward mature soil, which diagnostic horizons are not fully developed (-ept, Inceptisol) . It has a low base saturation, less than 60% (Dystr-) and a surface horizon that is high in organic carbon (Umbric). It is found in areas with pro-nounced wet and dry seasons (-ust, Ustic). It has a mean annual soil temperature higher than 22°C (isohyperthermic).
21 SIMPLIFIED KEYS TO SOIL SERIES
00 cm
13
35
Ap
Bt
BC
Soil Fertility Indicators
Inherent fertility Low to moderate
Soil pH Slightly acid to neutral (6.0-7.0)
Organic matter Low
Phosphorus (P) Low
Potassium (K) Low
Nutrient retention (CEC)
Moderate
Base saturation Moderate
Salinity hazard Low
Cadiz
Physical Soil Qualities
Relief Flat to undulating
Water retention High
Drainage Poor
Permeability Slow
Workability/tilth Hard (due to gravels)
Stoniness Abundant (>35%)
Root depth Very shallow (0.25 m)
Erosion None
Flooding Moderate to severe
Soil Type: Gravelly loam Area: 3,243.32 ha
Family:
Soils developed from older alluvial deposits.
Negros Occidental 22
00 cm
10
30
51
Ap
Ag
Bt
BC
Soil Fertility Indicators
Inherent fertility High
Soil pH Neutral to slightly alkaline (6.5-8.0)
Organic matter Moderate
Phosphorus (P) Moderate
Potassium (K) Moderate
Nutrient retention (CEC)
High
Base saturation High
Salinity hazard None
Faraon
Physical Soil Qualities
Relief Rolling to hilly
Water retention High
Drainage Moderate to good
Permeability Slow to moderate
Workability/tilth Moderate
Stoniness Common to many
Root depth Shallow (0.3m)
Erosion Moderate to severe
Flooding None
Soil Type: Clay/Sandy loam Area: 141,009.23 ha
Family: Fine, isohyperthermic, Lithic Haplustolls
A calcareous fine-textured soil with less than 65% clay, developed from the weathering of the soft and porous coralline limestones which are usually grayish but become orange to dark yellowish gray upon weather-ing. It is dark-colored, with high organic matter content (-oll) and high base status. It exhibits minimum complexity in its horizonation (Hapl-). Limestone fragments are found in the shallow horizon (lithic). It is usu-ally found in areas with pronounced wet and dry seasons (-ust, Ustic); has mean annual temperature higher than 22°C (isohyperthermic).
23 SIMPLIFIED KEYS TO SOIL SERIES
00 cm
9
25
A
Bw
BC
Soil Fertility Indicators
Inherent fertility Low
Soil pH Slightly acid
(5.0-6.5)
Organic matter Moderate
Phosphorus (P) Low (highly fixed)
Potassium (K) Low (highly fixed)
Nutrient retention (CEC)
Moderate
Base saturation Low to moderate
Salinity hazard None
Guimbalaon
Soil Type: Clay/fine sandy loam/Loam/Gravelly loam Area: 123,829 ha
Family: Fine, loamy, skeletal, mixed, isohyperthermic, Andic Haplustept
Soils formed from older alluvium, which are country rocks and washed out materials from the upper slopes that have developed into brown or dark brown soils. It has a fine, loamy texture with more than 15% fine sand, 18 – 35% clay, and 35% or more rock fragments (skeletal). It is a young soil in its incipient development stage toward mature soil but has not yet fully developed its diag-nostic horizons (-ept, inceptisol). It exhibits minimum complexity in its horizonation (hapl-). This soil has significant amounts of amorphous minerals and Al-OH complexes (andic). It is found in areas with pronounced wet and dry seasons (-ust, Ustic), and has a mean annual temperature higher than 22°C (isohyperthermic). This soil is traversed by numerous deep gullies and
Physical Soil Qualities
Relief Rolling to hilly
Water retention Low to moderate
Drainage Moderate to good
Permeability Moderate to rapid
Workability/tilth Moderate to easy
Stoniness Outcrops and pebbles
Root depth Shallow (0.5 m)
Erosion Severe
Negros Occidental 24
00 cm
15
39
69
74
Ap
Bw
Bt1
Bt2
Bt3
00 cm
20
30
50
Soil Fertility Indicators
Inherent fertility High
Soil pH Neutral (7.0-7.5)
Organic matter Moderate
Phosphorus (P) High
Potassium (K) High
Nutrient retention (CEC)
High
Base saturation High
Salinity hazard Low
Isabela
Physical Soil Qualities
Relief Level
Water retention Very high
Drainage Poor to moderate
Permeability Slow
Workability/tilth Hard to moderate
Stoniness None
Root depth Deep (>1 m)
Erosion None
Flooding Seasonal river flooding
Soil Type: Clay/Sandy loam Area: 28,787.30 ha
Family: Fine, smectitic (ca.), isohyperthermic, Aquic Hapludalf
Soil formed from alluvial deposits and is well-traversed by big rivers. It is fine-textured with less than 60% composed mostly of minerals which have shrink-and-swell capacity (smectitic). It is an old soil with high base status and an alluvial accumulation of clay in the subsoil horizons from underlying horizons (-alf, Alfisol), and exhibits minimum complexity in its horizonation (hapl-). It is saturated with water for repeated periods of time (aquic). It is found in areas with humid climate that have well-distributed rainfall (-ud, udic) with 7 months wet and 3 months dry, thus have an adequate supply of moisture for crop growth. The mean annual soil temperature is higher than 22°C (isohyperthermic).
25 SIMPLIFIED KEYS TO SOIL SERIES
110
00 cm
20
57
84
Apg
ABg
Bg
BCg
Soil Fertility Indicators
Inherent fertility Low to moderate
Soil pH Acidic (5.0-5.5)
Organic matter Moderate
Phosphorus (P) Low (fixed)
Potassium (K) Moderate
Nutrient retention (CEC)
Moderate
Base saturation Moderate
Salinity hazard None
La Castellana
Physical Soil Qualities
Relief Rolling to hilly
Water retention Low
Drainage Good to excessive
Permeability Moderate to rapid
Workability/tilth Easy (without outcrops)
Stoniness Boulder outcrops
Root depth Shallow (0.5 m)
Erosion Severe
Flooding None
Soil Type: Clay loam Area: 12,780.04 ha
Family: Clayey-skeletal, kaolinitic, isohyperthermic, Oxic Dystropepts
Soils developed from andesites and basalts, and partly from volcanic tuff, breccia, and other igneous rocks. This soil has 35% or more rock fragments (clayey-skeletal) composed mainly of non expanding 1:1 kaolinite minerals. It is an inceptisol (-ept), a young soil in its incipient development stage toward mature soil but has not yet fully developed its diagnostic horizons. It has a subsurface horizon that is coarse-textured with less than 10% clay and consists of weatherable minerals. The mean annual soil temperature is higher than 22°C (isohyperthermic).
Negros Occidental 26
00 cm
8
19
78
Ap
AC
C
67
Soil Fertility Indicators
Inherent fertility Low to moderate
Soil pH Acidic (4.0-5.5)
Organic matter Moderate
Phosphorus (P) Moderate
Potassium (K) Low
Nutrient retention (CEC)
Moderate
Base saturation Low
Salinity hazard None
Luisiana
Physical Soil Qualities
Relief Rolling to mountainous
Water retention Moderate to high
Drainage Good
Permeability Moderate
Workability/tilth Moderate
Stoniness None
Root depth Very deep (>2 m)
Erosion Moderate to severe
Flooding None
Soil Type: Clay Area: 23,766.43 ha
Family: Very fine, kaolinitic, isohyperthermic, Ustic Palehumult
A very deep (pale), fine-textured soil having clay content of high-er than 60% dominated by kaolinite minerals, developed from highly weathered volcanic basaltic rock materials. It is a highly leached old soil with accumulation of clay in the lower horizon and low base status (-ult, Ultisol). It is found in highlands (hum-) with pronounced wet and dry seasons (ustic) and a mean annual soil temperature higher than 22°C (isohyperthermic).
27 SIMPLIFIED KEYS TO SOIL SERIES
00 cm
20
35
89
Ap
AB
Bt1
Bt2
Soil Fertility Indicators
Inherent fertility Low to moderate
Soil pH Acidic (4.5-5.5)
Organic matter Moderate
Phosphorus (P) Low
Potassium (K) Low
Nutrient retention (CEC)
Moderate
Base saturation Low
Salinity hazard None
Manapla
Physical Soil Qualities
Relief Rolling
Water retention High
Drainage Good
Permeability Moderate
Workability/tilth Hard
Stoniness 5% stones and boulders
Root depth Moderate (0.6 m)
Erosion Severe
Flooding None
Soil Type: Loam Area: 27,971.59 ha
Family: Very fine, isohyperthermic, Typic Hapludalfs
Soils developed from basalt rocks. It has a very fine texture with more than 65% clay. It is a typical (typic) representative of the great group Hapludalfs, an old soil which has a high base status and an illuvial accumulation of clay in the subsoil horizons from underlying horizons (-alf, Alfisol); exhibits minimum complexity in its hori-zonation (hapl-); and found in areas of humid climate that have well distributed rainfall and have enough rain in summer (-ud, Udic), thus have adequate moisture for crop growth. The mean annual tempera-ture is higher than 22°C (isohyperthermic).
Negros Occidental 28
00 cm
28
38
72
Ap1
Ap2
Bg
BC1
93 BC2
Soil Fertility Indicators
Inherent fertility Low
Soil pH Slightly acid to slightly alkaline (5.5-8.0)
Organic matter Very low
Phosphorus (P) Low
Potassium (K) Low
Nutrient retention (CEC)
Low to moderate
Base saturation High
Salinity hazard Moderate
Obando
Soil Type: Sand Area: 1,240.67 ha
Family: Coarse loamy over sandy, mixed, isohyperthermic Typic Eutropepts
A calcareous soil developed from accumulated materials of sea wave actions and hence sand particles consist chiefly of quartz and mixed with broken marine shells. It has a coarse loamy texture with more than 15% fine sand including rock fragments and less than 18% clay. It is a typical (typic) representative of the great group Eutropepts, an Inceptisol (-ept) in incipient development stage toward mature soil but the diag-nostic horizons are not yet fully developed. This soil has high base satu-ration of more than 50% (eutr-) . The mean annual soil temperature is higher than 22°C (isohyperthermic).
Physical Soil Qualities
Relief Coastal plain
Water retention Low
Drainage Good
Permeability Moderate to rapid
Workability/tilth Easy
Stoniness None
Root depth Deep (1 m)
Flooding Frequent shallow flooding by rain and run-off water
29 SIMPLIFIED KEYS TO SOIL SERIES
00 cm
17
Ap
C1
C2
C3
Soil Fertility Indicators
Inherent fertility Low to moderate
Soil pH Slightly acid
(5.5-6.5)
Organic matter Moderate
Phosphorus (P) Low
Potassium (K) Low
Nutrient retention (CEC) Moderate
Base saturation Low
Salinity hazard None
Pulupandan
Soil Type: Sandy loam Area: 368.29 ha
Family: Mixed, isohyperthermic, Typic Tropopsamments
Composed of different minerals (mixed). It is a typical (typic) rep-resentative of the great group Tropopsamments: a young soil (-ents, Entisol) with a coarser texture (psamm-) consisting of less than 35% rock fragments. It is found in humid areas (trop-) with mean annual temperature higher than 22°C (isohyperthermic).
Physical Soil Qualities
Relief Beach ridges
Water retention Low
Drainage Excessive
Permeability Rapid
Workability/tilth Easy
Stoniness Cagaycay at 20 cm
Root depth Moderate (0.5 m)
Erosion None
Flooding None
Negros Occidental 30
33
63
00 cm
17
Ap
C1
C2
Soil Fertility Indicators
Inherent fertility Low to medium
Soil pH Acidic (4.5-6.0)
Organic matter Low
Phosphorus (P) High
Potassium (K) Low to moderate
Nutrient retention (CEC) Low
Base saturation Moderate
Salinity hazard Low
Silay
Soil Type: Fine Sandy loam/ Loam/Clay Area: 66,333.08 ha
Family: Fine, loamy, mixed, isohyperthermic, Aquic Tropudalfs
A fine loamy-textured soil with more than 15% fine sand including gravels and 18 – 35% clay composed of different minerals (mixed). It is an Alfisol (-alf), an old soil which has high base status and an illuvial accumulation of clay in the subsoil horizons from underlying horizons. It is saturated with water for sometime in a year (aquic). It is commonly found in areas with a mean annual temperature higher than 22°C (isohyperthermic) and humid climates that have well- distributed rainfall (-ud, Udic) thus have adequate supply of water for crop growth.
Physical Soil Qualities
Relief Level
Water retention Moderate
Drainage Poor to moderate
Permeability Slow to moderate
Workability/tilth Easy
Stoniness None
Root depth Moderate (0.8 m)
Erosion None
Flooding None
31 SIMPLIFIED KEYS TO SOIL SERIES
00 cm
25
43
82
Ap
Bx
Bw
BC
A
Soil Fertility Indicators
Inherent fertility High
Soil pH Neutral (6.5-7.0)
Organic matter Moderate
Phosphorus (P) High
Potassium (K) Moderate
Nutrient retention (CEC)
Moderate to high
Base saturation Very high
Salinity hazard Low
San Manuel
Soil Type: Loam/Fine Sandy loam Area: 16,294.70 ha
Family: Fine loamy, mixed, isohyperthermic, Fluventic Eutropepts
A non-calcareous soil formed in recent water-deposited sediments, mainly in flood plains. As such, these soils are subject to frequent flooding (Fluv-) and therefore stratified (fluventic). It is a young soil in its incipient development stage toward a mature soil (-epts, Incepti-sol) with high base saturation greater than 50% (Eutr-). It is a fine loamy-textured soil with more than 15% fine sand and moderate amount of clay (18 – 35%) composed of different clay minerals. It is found in areas with pronounced wet and dry seasons (-ust, Ustic) and a mean annual soil temperature higher than 22°C (isohyperthermic).
Physical Soil Qualities
Relief Level to slightly undulating
Water retention Moderate
Drainage Good
Permeability Moderate to rapid
Workability/tilth Easy
Stoniness None
Root depth Deep (>1 m)
Erosion None
Flooding Seasonal by river water
Negros Occidental 32
00 cm
6
36
69
Ap1
Ap2
Bw1
90
Bw2
Bw3
Soil Fertility Indicators
Inherent fertility Low to moderate
Soil pH Acidic (4.5-6.5)
Organic matter Moderate
Phosphorus (P) High
Potassium (K) Low
Nutrient retention (CEC) Low
Base saturation Very low
Salinity hazard None
Tupi
Soil Type: Silt loam/Fine Sandy loam Area: 40,555.22 ha
Family: Medial/ cindery, isohyperthermic Umbric Vintradepts
Soil developed from underlying residual material of partially weathered andesitic rocks. It is coarse-textured having more than 60% volcanic ash, cinders, and pumice fragments (medial) and less than 35% rock fragments (cindery). It is in the incipient development stage toward a mature soil but has not yet fully devel-oped its diagnostic horizons (-ept, Inceptisol). It has a dark-colored surface soil composed of coarse-fragments of less than 30 cm in diameter, have high organ-ic carbon (0.6 %) and less than 50% base saturation (Umbric). It is commonly found in humid climates that have well-distributed rainfall, 7 months wet and 2 months dry. The mean annual soil temperature is higher than 22°C (isohyperthermic). This soil is traversed by intermittent rivers and creeks.
Physical Soil Qualities
Relief Undulating to rolling
Water retention Low
Drainage Moderate to good
Permeability Moderate to rapid
Workability/tilth Easy
Stoniness Common at 0.3 m
Root depth Shallow (<0.5 m)
Erosion Moderate to severe
Flooding None
00 cm
18
49
69
C2
C3
33 SIMPLIFIED KEYS TO SOIL SERIES
Soil Fertility Indicators
Inherent fertility Moderate
Soil pH Slightly acid (5.5-6.0)
Organic matter Moderate
Phosphorus (P) High
Potassium (K) Moderate
Nutrient retention (CEC) Moderate to high
Base saturation Very high
Salinity hazard Low
Umingan
Soil Type: Clay loam Area: 262.80 ha
Family: Loamy skeletal, mixed (ca.), isohyperthermic, Fluventic Haplustept
A loamy-textured soil with many gravels and pebbles (skeletal)
occurring along the banks of rivers. Hence, is subject to flooding (fluventic) receiving yearly depositions of alluvial soil materi-
als from rivers. It is in the incipient development stage toward a mature soil (-ept, Inceptisol) but has not yet fully developed its diagnostic horizons (Hapl-). It is found in areas with pronounced wet and dry seasons (-ust, Ustic Moisture Regime) and annual soil temperature of higher than 22°C (isohyperthermic).
Physical Soil Qualities
Relief Level to slightly undulating
Water retention Low
Drainage Good to excessive
Permeability Moderate
Workability/tilth Moderate to easy
Stoniness Abundant at 0.6 m
Root depth Moderate (0.6 m)
Erosion None
Flooding Seasonal by river water
Negros Occidental 34
00 cm
16
27
70
Ap1
Ap2
Bw1
Bw2
99
C
Soil Fertility Indicators
Inherent fertility Low
Soil pH Acidic (4.0-5.0)
Organic matter Moderate
Phosphorus (P) Low
Potassium (K) Low
Nutrient retention (CEC) Moderate
Base saturation Low
Salinity hazard Low
Soil Type: Clay loam Area: 415.50 ha
Family: Fine, montmorillonitic, isohyperthermic, Vertic Hapludults
Soil developed from older alluvial deposits; consists of almost compacted fine sandy loam. It is a fine-textured soil with less than 65% clay composed of shrink-and-swell clays (montmorillonitic). It is an old soil (-ult, Ultisol) of which has undergone extensive leach-ing of bases but which profile exhibits minimum complexity in its hori-zonation (hapl-). Surface cracking greater than 5-mm wide is ob-served (vertic). It is found in areas with well-distributed rainfall (-ud, Udic), thus have adequate moisture for crop growth. It has a mean annual soil temperature of higher than 22°C (isohyperthermic).
Physical Soil Qualities
Relief Flat to gently rolling
Water retention Very low
Drainage Poor to moderate
Permeability Moderate
Workability/tilth Moderate
Stoniness None
Root depth Moderate
Erosion Moderate to severe
Flooding None
35 SIMPLIFIED KEYS TO SOIL SERIES
Victorias
00 cm 5
27
76
Ap
BCg
AB
Bg
SOIL productivity Soil productivity is the quality that summarizes soil potential in producing plants or sequences of plants under defined sets of management practices. It is also a synthesis of conditions of soil fertility, water control, plant species, soil tilth, pest control and phys-ical environment (Bainroth, 1978: Badayos, 1990). In economic terms, it is a measure of the amount of in-puts of production factors required to correct soil limi-tation(s) to attain a certain level of production. It is expressed as average crop yield under defined sets of management classes (Badayos, 1990). Soil productivity index is used for making compari-sons among soils; categorized into inherent and potential. Inherent productivity is the natural capacity of the soil to produce a given yield while the potential refers to its capacity to produce yield after correctible soil constraints had been remedied. In economics, the predicted inherent yield is calculated by multiply-ing the inherent index by the maximum potential yield (MPY) of rice; predicted maximum possible yield is computed by multiplying the potential index by the MPY. For instance, MPY in the dry season is 8 tons/ha., and inherent and potential productivity ratings for Bago series are 0.65 and 0.95, respectively. The pre-dicted inherent and potential yields of rice in Bago soils are then 5.20 and 7.60 tons/ha.
Negros Occidental 36
Soil Series Inherent
Productivity Potential
Productivity
Bago 0.65 0.95
Bantay 0.65 0.95
Batuan 0.61 0.66
Bolinao 0.65 0.82
Cadiz - -
Faraon 0.62 0.72
Guimbalaon 0.29 0.49
Isabela 0.80 0.95
La Castellana 0.39 0.74
Luisiana 0.23 0.43
Manapla 0.67 0.74
Obando 0.55 0.83
Pulupandan 0.52 0.77
Silay 0.64 0.74
San Manuel 0.75 0.85
Tupi 0.67 0.87
Umingan 0.61 0.71
Victorias 0.47 0.72
Table 1. Soil productivity index for rice.
37 SIMPLIFIED KEYS TO SOIL SERIES
CROP Suitability Analysis
Negros Occidental 38
Soil suitability classification refers to the use of a piece of land on a sustainable basis based on physical and chem-ical properties and environmental factors. It is the ultimate aim of soil survey and may come up through a good judg-ment and thorough evaluation of soil properties and quali-ties such as depth, texture, slope, drainage, erosion, flood-ing, and fertility. Based on these soil properties, the suita-bility of a certain tract of land for crop production can be determined. Suitability ratings denote qualitative analysis of the potential of the soil to grow different crops. They imply what crop(s) would give the highest benefit in terms of productivity and profitability from a given soil type, indicat-ed by S1 as the most suitable down to S3 as marginally suitable. The symbol N implies that the crop is either cur-rently not suitable (N1) where the effect of limitation is so severe as greatly to reduce the yield or to require costly inputs, or permanently not suitable (N2) where the limita-tions cannot be corrected permanently. Crop suitability analysis also provides information on soil properties that limit the production of specified crop(s). When using a parametric system, the soil index can be equated into percentages shown below. It means that you can attain 75% of the potential crop yield when the soil index is highly suitable; less than 25% of the potential yield when the soil index is not suitable. S1: soil index >75 S3: soil index 25-50 S2: soil index 50-75 N: soil index <25
Su
itab
ilit
y R
ati
ng
s:
Lim
itati
on
s d
ue t
o:
S1 -
H
ighly
suitable
t -
Topog
raph
y;
slo
pe
S2 -
M
od
era
tely
suitable
w
-
Dra
inag
e; floo
din
g
S3 -
M
arg
inally
suita
ble
s -
T
extu
re; coa
rse f
ragm
ents
; soil
dep
th
N1 -
C
urr
en
tly n
ot suita
ble
f -
Soil
fert
ility
N2 -
P
erm
an
ently n
ot suita
ble
c -
C
limate
Ta
ble
2a. T
he c
rop s
uitab
ility
ra
ting
s f
or
diffe
rent s
oil
se
ries o
f N
egro
s O
ccid
en
tal.
39 SIMPLIFIED KEYS TO SOIL SERIES
So
il S
eri
es
Ric
e Irr
igate
d
Lo
wla
nd
R
ice R
ain
fed
U
pla
nd
R
ice R
ain
fed
L
ow
lan
d
Ban
an
a
Maiz
e
Ma
ng
o
On
ion
P
ap
aya
Bag
o
S3
sf
S3
wsf
N1
sw
f S
3w
sf
S3
wf
S3
wsf
N2w
f N
2w
f
Banta
y
S3
twsf
S3
sw
f S
3w
sf
S3
sf
S3
s
S3
s
S3
fws
S2
sf
Batu
an
N
2sf
S3
s
N1
sw
f S
3sf
S3
sf
S3
sf
S3
sf
N2fs
w
Bolin
ao
N
2ts
f S
3stf
S2
stf
S3
sft
S3
stf
S3
sft
S3
fst
S2
sft
Cadiz
N
2sf
S3
wsf
N2
sw
f N
2w
sf
N2w
sf
S3
wsf
N2w
sf
S3
wsf
Fara
on
N
2stw
f S
3st
S3
sw
tf
S3
stf
S3
stf
S3
st
S3
st
S3
sw
t
Negros Occidental 40
Ta
ble
2a. (c
ontin
uatio
n)
So
il S
eri
es
Ric
e I
rrig
ate
d
Lo
wla
nd
R
ice R
ain
fed
U
pla
nd
R
ice
Ra
infe
d
Lo
wla
nd
B
an
an
a
Maiz
e
Man
go
O
nio
n
Pap
aya
Guim
bala
on
N
2stw
f S
3st
N1sw
tf
S3
sft
S3
sft
S3
sft
S3
sft
S3
sft
w
Isabela
S
2sf
S3
wsf
S2
wsf
S3
sw
f S
3w
s
S3
ws
N1w
f N
1w
f
La C
aste
llan
a
N2ts
wf
S3
twsf
S3
twsf
S3
tsf
S3
tsf
S3
tsf
S3
twsf
S3
tsf
Luis
iana
N
2tw
sf
S3
tfw
S
3ft
w
N1
tf
S3
ft
S3
ft
S3
ftw
N
1ft
Mana
pla
N
2tw
sf
S3
fws
N1sfw
S
3fs
t S
3fs
S
3fs
t S
3fw
t N
1fs
t
Oband
o
N2sfw
S
3w
sf
N1sw
f N
1sw
f S
3w
sf
S3
wsf
N1w
sf
N1w
sf
41 SIMPLIFIED KEYS TO SOIL SERIES
Ta
ble
2a. T
he c
rop s
uitab
ility
ra
ting
s f
or
diffe
rent s
oil
se
ries o
f N
egro
s O
ccid
en
tal (
co
ntin
ua
tion).
Su
itab
ilit
y R
ati
ng
s:
Lim
itati
on
s d
ue t
o:
S1 -
H
ighly
suitable
t -
Topog
raph
y;
slo
pe
S2 -
M
od
era
tely
suitable
w
-
Dra
inag
e; floo
din
g
S3 -
M
arg
inally
suita
ble
s -
T
extu
re; coa
rse f
ragm
ents
; soil
dep
th
N1 -
C
urr
en
tly n
ot suita
ble
f -
Soil
fert
ility
N2 -
P
erm
an
ently n
ot suita
ble
c -
C
limate
So
il S
eri
es
R
ice Irr
igate
d
Lo
wla
nd
R
ice R
ain
fed
U
pla
nd
R
ice R
ain
fed
L
ow
lan
d
Ban
an
a
Maiz
e
Man
go
O
nio
n
Pap
aya
Pulu
pand
an
N
2w
sf
S2
sfw
S
3w
sf
S3
sf
N1w
sf
S2
sf
S3
fsw
S
2sf
Sila
y
S2
fs
S2
fs
N1
sw
f S
3f
S3
fs
S3
fs
S3
f S
3fw
San M
anue
l S
3tw
s
S3
wsf
N1wf
S3
wsf
S3
ws
S3
ws
N1w
f N
1w
f
Tupi
N1
sft
S3
sfw
t S
3fs
wt
S3
fst
S3
fst
S3
fst
S3
fst
S3
fsw
t
Um
ingan
N
2w
s
S3
wsf
S3
wsf
S3
fws
S3
wsf
S3
wsf
N1w
f N
1w
sf
Vic
tori
as
S3
ft
S3
f S
3fw
s
S3
fs
S3fs
S
3fs
S
3f
N1fsw
Negros Occidental 42
Ta
ble
2b. T
he c
rop s
uitab
ility
ra
ting
s f
or
diffe
rent s
oil
se
ries o
f N
egro
s O
ccid
en
tal.
Su
itab
ilit
y R
ati
ng
s:
Lim
itati
on
s d
ue t
o:
S1 -
H
ighly
suitable
t -
Topog
raph
y;
slo
pe
S2 -
M
od
era
tely
suitable
w
-
Dra
inag
e; floo
din
g
S3 -
M
arg
inally
suita
ble
s -
T
extu
re; coa
rse f
ragm
ents
; soil
dep
th
N1 -
C
urr
en
tly n
ot suita
ble
f -
Soil
fert
ility
N2 -
P
erm
an
ently n
ot suita
ble
c -
C
limate
So
il S
eri
es
Pean
ut
So
rgh
um
S
ug
arc
an
e
Sw
eet
Po
tato
T
ob
acco
T
om
ato
W
ate
rme
lon
Bag
o
N2w
S
3w
S
3w
f S
3w
f N
2w
f S
3w
f S
3w
f
Banta
y
S3
ws
S2
ws
S3
wsf
S3
sf
S3
sf
N1sw
f N
2sw
f
Batu
an
S
3sf
S2
s
S3
sf
S3
sf
S3
sf
N1sf
N2sf
Bolin
ao
S
3sft
S2
tsf
S3
stw
f S
3sft
S3
sft
N1
sw
tf
N2
sfw
t
Cadiz
N
2w
s
S3
s
N2w
sf
N2w
sf
N2w
sf
N1sw
f N
2w
sf
Fara
on
S
3sw
t S
3ts
S
3sw
t S
3stf
S3
st
N1st
N2st
43 SIMPLIFIED KEYS TO SOIL SERIES
Ta
ble
2b. T
he c
rop s
uitab
ility
ra
ting
s f
or
diffe
rent s
oil
se
ries o
f N
egro
s O
ccid
en
tal (c
ontin
ua
tion
).
Su
itab
ilit
y R
ati
ng
s:
Lim
itati
on
s d
ue t
o:
S1 -
H
ighly
suitable
t -
Topog
raph
y;
slo
pe
S2 -
M
od
era
tely
suitable
w
-
Dra
inag
e; floo
din
g
S3 -
M
arg
inally
suita
ble
s -
T
extu
re; coa
rse f
ragm
ents
; soil
dep
th
N1 -
C
urr
en
tly n
ot suita
ble
f -
Soil
fert
ility
N2 -
P
erm
an
ently n
ot suita
ble
c -
C
limate
So
il S
eri
es
Pean
ut
So
rgh
um
S
ug
arc
an
e
Sw
eet
Po
tato
T
ob
acco
T
om
ato
W
ate
rme
lon
Guim
bala
on
S
3sfw
t S
3st
S3
sfw
t S
3sft
S2
sft
S3
sft
S3
sft
Isabela
N
1w
S
2w
S
3w
sf
S3
wf
N1w
f S
3w
f S
3w
f
La C
aste
llan
a
S3
twsf
S3
tsw
S
3ts
fw
S3
twsf
S3
tsf
S3
twsf
S3
twsf
Luis
iana
S
3ft
ws
S3
twf
S3
ftw
S
3ft
w
S3
fts
S3
tfw
N
1tf
w
Mana
pla
S
3fs
w
S2
wf
S3
ftw
s
S3
ftw
s
S3
fs
S3
fsw
t N
1fs
t
Oband
o
N1w
sf
S3
wsf
N1sw
S
3w
sf
N1w
f S
3w
f S
3w
fs
Negros Occidental 44
Ta
ble
2b. (c
ontin
uatio
n)
So
il S
eri
es
Pean
ut
So
rgh
um
S
ug
arc
an
e
Sw
eet
Po
tato
T
ob
acco
T
om
ato
W
ate
rme
lon
Pulu
pand
an
S
3sw
f S
2sfw
S
3fs
w
S3
fsw
S
2sf
S3
sw
f S
3sf
Sila
y
S3
fw
S1
S
3f
S3
f S
3fs
w
S3
fs
N1fs
San M
anue
l N
1w
S
2w
s
S3
wsf
S3
wf
N1w
f S
3w
f S
3w
f
Tupi
S3
fsw
t S
3fs
wt
S3
fsw
t S
3fs
t S
3fs
N
1sft
N2
sft
Um
ingan
N
1w
sf
S2
w
S3
fsw
S
3w
fs
N1w
sf
S3
wsf
S3
wsf
Vic
tori
as
S3
fs
S2
f S
3fs
S
3f
S3
fsw
S
3fs
N
1fs
SOIL Management recommendations
Soil management aims to protect the soil and en-hance its performance to increase farm profitability and preserve environmental quality. It is the combi-nation of soil factors to maximize crop production at the lowest possible cost while maintaining the soil’s productive state. It involves maintaining the soil in good physical condition and fertility status, and influencing the biological aspect of the soil to attain maximum benefits (Harpstead, et al. 1997).
Soil management recommendations suitable for each soil identified were enumerated in the succeeding pages. Soil factors such as slope, texture, and climate cannot be changed. However, control tillage, crop rotations, soil amendments, and other management choices can be done. Through these choices, the structure, biological activity, and chemical content of the soil can be altered and later on influence erosion rates, pest population, and nutri-ent availability and crop production.
45 SIMPLIFIED KEYS TO SOIL SERIES
Ta
ble
3.
Lim
ita
tion
s t
o c
rop p
rod
uctio
n a
nd r
ecom
me
nd
ed
ma
nag
em
ent s
tra
teg
ies fo
r d
iffe
rent
cro
ps w
hen
gro
wn
in a
g
ive
n s
oil
se
ries.
So
il
Seri
es
L
imit
ati
on
f
or
cro
p p
rod
ucti
on
So
il M
an
ag
em
en
t R
eco
mm
en
dati
on
s
Ric
e
Div
ers
ifie
d
cro
ps
R
oo
t cro
ps
T
ree/F
ore
st/
P
lan
tati
on
cro
ps
Bag
o
Cro
ps c
annot gro
w w
/o
dra
inage;
slo
wer
N
m
inera
lizatio
n; Z
n
deficie
ncy in r
ice;
K d
eficie
ncy; lo
w o
rganic
m
att
er;
lack o
f m
ois
ture
Suffic
ient
irrig
atio
n
supply
with
adequate
dra
in-
age;
OM
incorp
o-
ration;
gre
en
manurin
g;
K f
ert
ilizatio
n;
applic
atio
n o
f Z
nS
O42-
in
lo
wla
nd r
ice w
hen
deficie
ncy o
ccurs
OM
in
corp
ora
tio
n;
suffic
ient irrig
atio
n
supply
with
adequate
dra
inage;
gre
en m
anuring;
fert
ilizatio
n
Can b
e p
lante
d to
root
cro
ps
assurin
g a
good
dra
inage s
yste
m
and a
dequate
irrig
atio
n s
upply
; adequate
fert
iliza-
tio
n; O
M in
corp
o-
ratio
n
Fru
it tre
es s
uch a
s
mango a
nd b
anana;
coconut
Cro
pp
ing
Patt
ern
: lo
wla
nd
/up
lan
d r
ice
-div
ers
ifie
d c
rops; fr
uit t
rees
Banta
y
Acid
ic; shallo
w s
oil
limits
pro
ductivity o
f shallo
w-
roote
d c
rops; lo
w K
;
modera
te e
rosio
n
Lim
ing u
pla
nd r
ice;
adequate
fert
iliza-
tio
n; O
M a
dditio
n;
terr
acin
g
Lim
ing; adequate
fe
rtili
zation;
OM
additio
n o
r gre
en
manurin
g
Modera
tely
suited
to r
oot cro
ps;
ade-
quate
fert
ilizatio
n
Coconut; f
ruit t
rees
adapta
ble
to the a
rea
like b
anana
Cro
pp
ing
Patt
ern
: r
ice-r
ice/d
ivers
ifie
d c
rops
Negros Occidental 46
Ta
ble
3.
Lim
ita
tion
s t
o c
rop p
rod
uctio
n a
nd r
ecom
me
nd
ed
ma
nag
em
ent s
tra
teg
ies fo
r d
iffe
rent
cro
ps w
hen
gro
wn
in a
g
ive
n s
oil
se
ries (
co
ntin
ua
tion
).
So
il
Seri
es
L
imit
ati
on
f
or
cro
p p
rod
ucti
on
So
il M
an
ag
em
en
t R
eco
mm
en
dati
on
s
Ric
e
Div
ers
ifie
d
cro
ps
R
oo
t cro
ps
T
ree/F
ore
st/
P
lan
tati
on
cro
ps
Batu
an
P d
eficie
ncy; S
hallo
w s
oil
limits p
roductivity o
f shal-
low
roote
d c
rops; m
od-
era
te s
oil
ero
sio
n
hazard
; acid
ic
Adequate
and
bala
nced N
PK
fe
rtili
zatio
n;
terr
acin
g o
r
constr
uctio
n o
f bunds;
limin
g;
use o
f hig
h-
yie
ldin
g v
arie
tie
s
Conto
ur
terr
acin
g;
bala
nced N
PK
fert
ili-
zatio
n;
limin
g a
nd
additio
n o
f org
anic
m
att
er;
use o
f hig
h-
yie
ldin
g v
arieties
Pro
ductio
n c
an
be lim
ited d
ue
to s
hallo
w
ro
otin
g d
epth
of
the s
oil;
conto
ur
farm
ing/
terr
acin
g
Suitable
for
sugarc
ane
pro
ductio
n in a
reas w
ith
lesser
ero
sio
n hazard
; pla
nt
perm
anent cro
ps/
trees lik
e c
oconut
Cro
pp
ing
Patt
ern
: r
ice-d
ivers
ifie
d c
rops/r
oot cro
ps;
pla
nta
tio
n c
rops (
e.g
sugarc
ane)
Bolin
ao
Rolli
ng t
opogra
phy in
som
e
are
as w
hic
h c
auses r
isk o
f ero
sio
n; shallo
w r
ootin
g
depth
; lo
w a
vaila
ble
P a
nd
K
Suitable
for
rice
but
needs t
err
ac-
ing a
nd u
se o
f lim
esto
ne o
utc
rops
for
rein
forc
ing
dik
es/b
unds;
appli-
catio
n o
f phos-
phate
fert
ilizers
; upla
nd r
ice
Conto
ur
terr
acin
g;
pro
per
fert
ilizatio
n;
pro
per
tim
ing o
f
cultiv
atio
n a
nd
pla
ntin
g;
additio
n o
f org
anic
matt
er
and
anim
al m
anure
to
impro
ve s
oil
fert
ility
and a
pplic
atio
n o
f phosphate
fert
ilizers
Conto
ur
terr
ac-
ing;
use o
f cov-
er
cro
ps lik
e Ipil
-ip
il fo
r soil
rehabili
tatio
n
and s
ourc
e o
f fire
wood a
t th
e
sam
e tim
e;
additio
n o
f
org
anic
matt
er
Can b
e p
lante
d to fru
it
trees p
rovid
ed
with
pro
per
fert
ilizatio
n a
nd
use o
f lo
cally
adapte
d
tree s
pecie
s lik
e ip
il-ip
il
Cro
pp
ing
Patt
ern
: r
ice-r
ice; rice-d
ivers
ifie
d c
rops/v
egeta
ble
s/r
oot cro
ps
47 SIMPLIFIED KEYS TO SOIL SERIES
Ta
ble
3. (c
ontin
uatio
n)
So
il
Seri
es
L
imit
ati
on
f
or
cro
p p
rod
ucti
on
So
il M
an
ag
em
en
t R
eco
mm
en
da
tio
ns
Ric
e
Div
ers
ifie
d
cro
ps
R
oo
t cro
ps
T
ree/F
ore
st/
P
lan
tati
on
cro
ps
Cadiz
Low
fert
ility
; pre
sence o
f gra
vels
that im
pede t
illa
ge
opera
tio
ns; hard
com
pact
mass o
f burn
ed r
ock c
alle
d
igang t
hat im
pedes inte
rnal
dra
inage; m
odera
te to
severe
flo
odin
g
NP
K fert
ilizatio
n;
org
anic
matt
er
applic
atio
n t
o
impro
ve s
oil
fert
ility
; subsoili
ng
once e
very
5 o
r 6
years
to bre
ak
igang;
flo
od c
ontr
ol
syste
m o
r pla
nt
varie
tie
s that
are
flo
od-t
ole
rant
Fe
rtili
zatio
n;
org
anic
m
att
er
applic
atio
n to
impro
ve s
oil
fert
ility
; subsoili
ng e
very
5 o
r 6 y
ears
to b
reak
igang;
pla
ntin
g o
n
hig
h b
roadbeds o
r rid
ges
Fe
rtili
zatio
n;
org
anic
matt
er
applic
atio
n t
o
impro
ve s
oil
fert
ility
; subsoili
ng e
very
5 o
r 6 y
ears
to
bre
ak ig
ang;
pla
ntin
g o
n h
igh
bro
adbeds o
r rid
ges
Coconut
and o
ther
fruit
trees a
dapta
ble
to t
he
are
a
Cro
pp
ing
Patt
ern
: r
ice-r
ice/d
ivers
ifie
d c
rops
Fara
on
Pla
nts
ma
y s
uff
er
from
Fe
and Z
n d
eficie
ncy d
ue to
hig
h p
H; K
deficie
ncy;
shallo
w e
ffective s
oil
depth
lim
itin
g p
roductivity o
f
shallo
w r
oote
d c
rops;
rock
outc
rops a
re p
resent; h
illy
topogra
phy;
gro
win
g p
erio
d
is p
ossib
le o
nly
durin
g r
ain
y
season u
nle
ss irr
igate
d
Constr
uctio
n o
f bunds f
or
upla
nd
or
terr
acin
g;
applic
ation o
f Z
nS
O42 in
low
-la
nd r
ice if
deficie
ncy o
ccurs
Conto
ur
farm
ing;
shallo
w c
ultiv
atio
n;
fert
ilizatio
n;
adequate
irrigation s
yste
m;
min
imum
till
age to
lessen e
rosio
n r
ate
s
Modera
tely
suitable
to r
oot
cro
ps d
ue t
o
shallo
w r
ooting
depth
and p
res-
ence o
f out-
cro
ps; m
inim
um
tilla
ge to lessen
ero
sio
n r
ate
s
Suited for
fruit tre
es,
fore
st, a
nd o
ther
hard
wood t
rees e
.g.
citru
s, m
ango, ip
il, m
o-
lave,
coconut, e
tc.
Cro
pp
ing
Patt
ern
: lo
wla
nd
ric
e-lo
wla
nd r
ice/d
ivers
ifie
d c
rops/v
egeta
ble
s;
fruit tre
es
Negros Occidental 48
Ta
ble
3.
Lim
ita
tion
s t
o c
rop p
rod
uctio
n a
nd r
ecom
me
nd
ed
ma
nag
em
ent s
tra
teg
ies fo
r d
iffe
rent
cro
ps w
hen
gro
wn
in a
g
ive
n s
oil
se
ries (
co
ntin
ua
tion
).
So
il
Seri
es
L
imit
ati
on
f
or
cro
p p
rod
ucti
on
So
il M
an
ag
em
en
t R
eco
mm
en
da
tio
ns
Ric
e
Div
ers
ifie
d
cro
ps
R
oo
t cro
ps
T
ree/F
ore
st/
P
lan
tati
on
cro
ps
Guim
bala
on
Poor
nutr
ient re
tentio
n
(le
achin
g o
f bases);
acid
ic;
P a
nd K
deficie
ncy (
due to
fixatio
n);
pre
sence o
f
hard
pan;
low
mois
ture
; severe
ero
sio
n; pre
sence
of
rock o
utc
rops that
impede d
rain
age
OM
in
corp
ora
-tio
n; lim
ing;
suitable
for
rice
but
needs
terr
acin
g a
nd
use o
f outc
rops
for
rein
forc
ing
dik
es
Conto
ur
terr
acin
g/
farm
ing; ero
sio
n
pre
ventio
n a
nd w
ate
r contr
ol pra
ctices;
pro
per
fert
ilizatio
n;
OM
incorp
ora
tion;
limin
g; subsoili
ng t
o
bre
ak h
ard
pan
Lim
ing; pro
per
fert
ilizatio
n a
nd O
M
incorp
ora
tio
n;
conto
ur
terr
acin
g;
subsoili
ng t
o b
reak
hard
pan
Suited for
coconut,
cacao
Cro
pp
ing
Patt
ern
: u
pla
nd
ric
e-d
ivers
ifie
d c
rops/r
oot cro
ps; fr
uit t
rees
Isabela
Cro
ps c
annot gro
w w
/o
dra
inage;
slo
wer
N
m
inera
lizatio
n;
Zn
deficie
ncy in
ric
e; hig
h
P fix
atio
n;
severe
topsoil
shrinkin
g &
sw
elli
ng;
hard
to
till
; seasonal river
flo
odin
g
Applic
atio
n o
f Z
nS
O42-
in
low
land r
ice
when d
eficie
ncy
occurs
; N
and P
fe
rtili
zation;
build
dra
inage c
anals
and f
lood c
ontr
ol
syste
m
N a
nd P
fert
ilizatio
n;
build
dra
inage c
anals
; constr
uct
bro
ad b
eds,
rid
ges o
r fu
rrow
;
cultiv
ate
only
at
optim
um
mois
ture
conte
nt; c
over
cro
p-
pin
g
N a
nd P
fert
iliza-
tio
n;
build
dra
inage
canals
; cultiv
ate
only
at
optim
um
m
ois
ture
conte
nt;
not
suitable
for
nuts
; constr
uct
beds,
rid
ges o
r fu
rrow
Pla
nt
fruit t
rees
Cro
pp
ing
Patt
ern
: r
ice-r
ice; rice-d
ivers
ifie
d c
rops/r
oot cro
ps; fr
uit t
rees
49 SIMPLIFIED KEYS TO SOIL SERIES
Ta
ble
3. (c
ontin
uatio
n)
So
il
Seri
es
L
imit
ati
on
f
or
cro
p p
rod
ucti
on
So
il M
an
ag
em
en
t R
eco
mm
en
da
tio
ns
Ric
e
Div
ers
ifie
d
cro
ps
R
oo
t cro
ps
T
ree/F
ore
st/
P
lan
tati
on
cro
ps
La C
aste
llan
a
N &
P d
eficie
ncy; acid
ic;
severe
ero
sio
n that lo
ses
the m
ore
fert
ile t
opsoil
than
the s
ubsurf
ace s
oil;
pre
sence o
f bould
er
outc
rops t
hat
impede
tilla
ge; lo
w m
ois
ture
N &
P fert
ilizatio
n;
limin
g in
upla
nd;
adequate
ero
sio
n
contr
ol m
easure
s;
adequate
irr
igatio
n
N &
P fert
ilizatio
n;
limin
g; adequate
ero
sio
n c
ontr
ol
measure
s; conto
ur
farm
ing; str
ip
cro
ppin
g a
nd
cover-
cro
ppin
g;
adequate
irr
igatio
n
N &
P fert
iliza-
tio
n; lim
ing in
upla
nd r
ice &
oth
er
div
ers
ifie
d
cro
ps; adequate
ero
sio
n c
ontr
ol
measure
s;
ade-
quate
irr
igatio
n
Pla
nt perm
anent cro
ps
in h
igher
slo
pes; fr
uit
trees a
nd s
econdary
fo
rest
Cro
pp
ing
Patt
ern
: u
pla
nd
ric
e-d
ivers
ifie
d c
rops/
root cro
ps; perm
anent
cro
ps/
trees
Luis
iana
Low
K,
Ca,
Mg; very
acid
ic;
Fe
or
Al to
xic
ity;
low
nutr
ient
rete
ntio
n; ru
n-o
ff;
hill
y t
opogra
phy
Lim
ing u
pla
nd r
ice;
adequate
P a
nd K
fe
rtili
zatio
n;
pra
ctice
fallo
w p
erio
d a
nd
retu
rn b
ack s
tubble
s
in t
he fie
ld t
o
enhance n
utr
ient
rete
ntion o
r in
sta
ll vegeta
tio
n c
over;
OM
in
corp
ora
tio
n; early
pla
ntin
g
Conto
ur
farm
ing
and c
over-
cro
ppin
g;
adequate
fert
iliza-
tio
n; lim
ing;
OM
in
corp
ora
tio
n;
vegeta
tio
n c
over
or
fallo
win
g
Best suited f
or
root
cro
ps; O
M
incorp
ora
tio
n to
impro
ve f
ert
ility
; conto
ur
cro
p-
pin
g/t
err
acin
g
Pla
ntin
g o
f perm
anent
cro
ps a
nd t
rees t
o
resto
re s
oil
fert
ility
; pla
cin
g fert
ilizer
at th
e
zone o
f m
axim
um
root
activity o
f tr
ee c
rops
Cro
pp
ing
Patt
ern
: ri
ce-f
allo
w;
rice-d
ivers
ifie
d c
rops/r
oot cro
ps; fr
uit t
rees/fore
st
Negros Occidental 50
Ta
ble
3.
Lim
ita
tion
s t
o c
rop p
rod
uctio
n a
nd r
ecom
me
nd
ed
ma
nag
em
ent s
tra
teg
ies fo
r d
iffe
rent
cro
ps w
hen
gro
wn
in a
g
ive
n s
oil
se
ries (
co
ntin
ua
tion
).
So
il
Seri
es
L
imit
ati
on
f
or
cro
p p
rod
ucti
on
So
il M
an
ag
em
en
t R
eco
mm
en
dati
on
s
Ric
e
Div
ers
ifie
d
cro
ps
R
oo
t cro
ps
T
ree/F
ore
st/
P
lan
tati
on
cro
ps
Mana
pla
P &
K d
eficie
ncy;
acid
ic;
pre
sence o
f pebble
s t
hat
dam
age r
oot; d
eple
tio
n o
f th
e t
op s
oil
due to s
evere
ero
sio
n
P &
K f
ert
ilizatio
n;
limin
g u
pla
nd r
ice;
adequate
ero
sio
n
contr
ol m
easure
s
like terr
acin
g
P &
K f
ert
ilizatio
n;
limin
g; adequate
ero
sio
n c
ontr
ol
measure
s (
e.g
.
conto
ur
cro
ppin
g/
terr
acin
g)
P &
K f
ert
iliza-
tio
n; lim
ing;
adequate
ero
sio
n c
ontr
ol
measure
s (
e.g
. conto
ur
cro
p-
pin
g/t
err
acin
g)
Coconut
and o
ther
adapta
ble
fru
it t
rees
Cro
pp
ing
Patt
ern
: r
ice-d
ivers
ifie
d c
rops/r
oot cro
ps
Oband
o
Calc
are
ous; P
& K
defi-
cie
ncy; shallo
w s
oil;
lack o
f m
ois
ture
for
shallo
w-r
oote
d
cro
ps d
ue t
o lo
w w
ate
r hold
ing c
apacity ; fre
quent
shallo
w f
loodin
g fro
m
rain
fall
and r
un-o
ff
Suitable
for
rice
durin
g w
et
season
but
needs a
mple
am
ount
of fe
rtili
z-
ers
to a
ddre
ss t
he
fert
ility
pro
ble
m;
phosphoru
s a
nd
OM
applic
atio
n;
adequate
irr
igatio
n
supply
Applic
atio
n o
f org
anic
m
att
er
to im
pro
ve s
oil
str
uctu
re; pra
ctice
tim
ing o
f pla
ntin
g;
deep p
low
ing;
phosphoru
s a
pplic
a-
tion; flood c
ontr
ol
measure
s (
use b
road-
beds o
r rid
ges)
Suitable
for
root
cro
ps d
ue t
o
sandy t
extu
re;
use o
f bro
ad
beds,
rid
ges o
r fu
rrow
s;
ade-
quate
irr
igation
Coconut
and o
ther
adapta
ble
fru
it t
rees
Cro
pp
ing
Patt
ern
:
rice-r
ice;
rice-d
ivers
ifie
d c
rops/r
ootc
rops
51 SIMPLIFIED KEYS TO SOIL SERIES
Ta
ble
3. (c
ontin
uatio
n)
So
il
Seri
es
L
imit
ati
on
f
or
cro
p p
rod
ucti
on
So
il M
an
ag
em
en
t R
eco
mm
en
da
tio
ns
Ric
e
Div
ers
ifie
d
cro
ps
R
oo
t cro
ps
T
ree/F
ore
st/
P
lan
tati
on
cro
ps
Pulu
pand
an
Calc
are
ous; P
& K
deficie
ncy;
easily
dra
ined
soil;
beach r
idges r
elie
f
P &
K f
ert
ilizatio
n;
adequate
irr
igatio
n
supply
P &
K f
ert
ilizatio
n;
adequate
irr
igatio
n
supply
P &
K f
ert
iliza-
tio
n;
adequate
irrig
atio
n
supply
Best suited f
or
coconut
Cro
pp
ing
Patt
ern
: r
ice-r
ice/d
ivers
ifie
d c
rops
Sila
y
Low
fert
ility
& a
cid
ic;
perc
ola
tio
n is im
peded d
ue
to p
resence o
f bakia
s
beneath
the s
urf
ace
N &
K fert
ilizatio
n;
org
anic
matt
er
incor-
pora
tio
n e
.g. plo
win
g
under
of
cro
p r
esi-
dues &
gre
en m
a-
nurin
g;
cro
p r
ota
tio
n
with le
gum
es; lim
ing
in u
pla
nd;
deep
plo
win
g;
build
ade-
quate
irr
igatio
n a
nd
pro
vis
ion o
f dra
inage
canals
N &
K fert
ilizatio
n;
org
anic
matt
er
in-
corp
ora
tio
n e
.g.
plo
win
g u
nder
of
cro
p r
esid
ues &
gre
en m
anurin
g;
limin
g; deep p
low
-in
g;
build
ade-
quate
irr
igatio
n a
nd
pro
vis
ion o
f dra
in-
age c
anals
Adequate
fe
rtili
zatio
n;
OM
in
corp
ora
-tio
n; lim
ing;
adequate
irrig
atio
n a
nd
pro
vis
ion o
f
dra
inage c
a-
nals
Suited for
sugarc
ane
pro
ductio
n
Cro
pp
ing
Patt
ern
: r
ice-r
ice/d
ivers
ifie
d c
rops; pla
nta
tio
n c
rops
Negros Occidental 52
Ta
ble
3.
Lim
ita
tion
s t
o c
rop p
rod
uctio
n a
nd r
ecom
me
nd
ed
ma
nag
em
ent s
tra
teg
ies fo
r d
iffe
rent
cro
ps w
hen
gro
wn
in a
g
ive
n s
oil
se
ries (
co
ntin
ua
tion
).
So
il
Seri
es
L
imit
ati
on
f
or
cro
p p
rod
ucti
on
So
il M
an
ag
em
en
t R
eco
mm
en
da
tio
ns
Ric
e
Div
ers
ifie
d c
rop
s
Ro
ot
cro
ps
T
ree/F
ore
st/
P
lan
tati
on
cro
ps
San M
anue
l
Excessiv
ely
wet
and
annual flo
odin
g for
short
perio
ds a
nd e
xcessiv
e
dro
ught
durin
g d
ry s
eason;
low
OM
Suited for
paddy
rice d
urin
g w
et
season a
nd w
ith
adequate
irr
iga-
tio
n d
urin
g d
ry
season; O
M
additio
n t
hru
anim
al or
gre
en
manurin
g
Adequate
dra
inage,
irrig
atio
n,
and f
lood
contr
ol syste
ms d
ue t
o
seasonal flo
od h
azard
and h
igh s
easonal
wate
r ta
ble
; use b
road
beds a
nd r
idges; suited
for
div
ers
ifie
d c
rops
such a
s c
orn
, vegeta
-ble
s a
nd w
ate
rmelo
n
durin
g d
ry s
eason w
ith
supple
menta
l irrig
atio
n
Esta
blis
hm
ent
of
adequate
dra
inage a
nd
irrig
atio
n
syste
m; re
gula
r additio
n o
f org
anic
matt
er
and a
nim
al
manure
to
impro
ve s
oil
fert
ility
Adequate
dra
inage a
nd
irrig
atio
n s
yste
m; cover
cro
ppin
g w
ith le
gum
es;
pro
per
fert
ilizatio
n,
tim
ing o
f cultiv
atio
n a
nd
pla
nting;
use o
f lo
cally
adapte
d h
igh-y
ield
ing
varie
tie
s to im
pro
ve t
he
gro
wth
and y
ield
of tr
ee
cro
ps
Cro
pp
ing
Patt
ern
: ri
ce-r
ice; rice-v
egeta
ble
s/r
oot cro
ps
Tupi
Low
fert
ility
; acid
ic;
K d
eficie
ncy;
severe
ero
sio
n r
em
ovin
g
the m
ore
fert
ile t
opsoil
Lim
ing u
pla
nd;
adequate
ero
sio
n
contr
ol m
easure
s;
adequate
fert
ilizatio
n
Lim
ing; im
ple
me
nt
ero
-sio
n c
ontr
ol m
easure
s
e.g
. conto
ur/
terr
acin
g;
OM
additio
n a
nd
adequate
fert
ilizatio
n;
cover
cro
ppin
g/g
reen
manurin
g
Imple
ment
ero
sio
n c
ontr
ol
measure
s e
.g.
conto
ur/
terr
acin
g;
adequate
fert
ili-
zatio
n
Fru
it tre
es a
nd s
econd
gro
wth
fore
st;
modera
tely
suitable
for
banana,
sugarc
ane,
and m
ango
Cro
pp
ing
Patt
ern
: u
pla
nd
ric
e-d
ivers
ifie
d c
rops/r
oot cro
ps;
f
ruit tre
es/s
econd g
row
th f
ore
st
53 SIMPLIFIED KEYS TO SOIL SERIES
Negros Occidental 54
Ta
ble
3. (c
ontin
uatio
n)
So
il
Seri
es
L
imit
ati
on
f
or
cro
p p
rod
ucti
on
So
il M
an
ag
em
en
t R
eco
mm
en
da
tio
ns
Ric
e
Div
ers
ifie
d
cro
ps
R
oo
t cro
ps
T
ree/F
ore
st/
P
lan
tati
on
cro
ps
Um
ingan
Rela
tively
lo
w f
ert
ility
;
pre
sence o
f gra
vels
and
sto
nes in t
he s
ubsoil
that
dam
age r
oots
; excessiv
e
dow
nw
ard
movem
ent of
wate
r, h
ence t
ends to b
e
dro
ughty
; seasonal
flo
odin
g e
specia
lly a
fter
heavy r
ain
s
Applic
atio
n o
f fe
rtili
z-
er;
cle
arin
g o
f la
rge
gra
vels
and r
ock;
adequate
irr
igatio
n
supply
Constr
uctio
n o
f adequate
irr
igatio
n
and f
lood c
ontr
ol
syste
m; applic
atio
n
of
fert
ilizer
and
org
anic
matt
er;
suited f
or
div
ers
ifie
d
cro
ps; use o
f bro
ad-
beds a
nd r
idges
Gra
velly
sub-
soil
ma
y c
ause
low
er
yie
ld o
f ro
ot
cro
ps;
adequate
irrigation a
nd
flood c
ontr
ol
syste
m; use o
f bro
adbeds a
nd
rid
ges
Esta
blis
hm
ent of
flo
od c
ontr
ol a
nd
irrig
atio
n s
yste
ms;
pro
per
fert
ilizatio
n
Cro
pp
ing
Patt
ern
: r
ice-r
ice; rice-d
ivers
ifie
d c
rops/v
egeta
ble
s
Vic
tori
as
P &
K d
eficie
ncy;
low
fert
ility
; acid
ic;
hard
im
peded d
rain
age; severe
ero
sio
n
Adequate
P &
K
fert
ilizatio
n;
OM
applic
atio
n;
limin
g;
pro
vis
ion o
f dra
inage
canals
and s
uffic
ient
irrig
atio
n s
upply
Lim
ing, pla
nt
acid
-to
lera
nt cro
ps;
adequate
fert
iliza-
tion; conto
ur
farm
ing o
r cover
cro
ppin
g
Lim
ing;
adequate
fe
rtili
zatio
n;
terr
acin
g/
conto
ur
cro
p-
pin
g;
pro
vis
ion
of
dra
inage
canals
Suited for
sugarc
ane
pro
ductio
n; oth
er
adapta
ble
fru
it t
rees
like c
oconut, m
ango,
banana,
etc
.
Cro
pp
ing
Patt
ern
: r
ice-r
ice/d
ivers
ifie
d c
rops/r
oot cro
ps; coconut/fr
uit tre
es
Appendices
55 SIMPLIFIED KEYS TO SOIL SERIES
APPENDIX 1. STEPS TO IDENTIFY SOIL SERIES
1 Soil sampling
Negros Occidental 56
Choose a vacant area in your field. Use a spade or soil auger to dig up to 50 centimeters from the soil surface.
Depth of the soil is im-portant. The surface/top soil is not a good basis since it is always culti-
vated.
Get a bulk of soil (0.5 kilogram) from 30 to 50 centimeter-depth and place it in a container. This sample will be used in soil series identifica-tion.
2 Soil color determination
57 SIMPLIFIED KEYS TO SOIL SERIES
Soil color is an indirect 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 constant water-saturated condition. Bright brown and red colors are indic-ative of good aeration and drainage.
Get an ample amount of soil from the sample. Note that the soil surface should be freshly exposed and not pressed. Rec-ord the moisture condition (dry, wet, or moist). If dry, have a moist color determination by adding ample amount of water to the soil.
Compare the color of the soil sample with the color chart in the guidebook. Take note of the classifica-tion of the color.
3 Texture determination
Negros Occidental 58
N
N N
Y Y Y
N
N
N
N
N
N
Y
Y
Y
Y
Y
Y
Y
Y
Y
Take a half handful of the same soil sample. Add water (not too wet). Soil is at proper consistency when moldable, like moist putty.
Add dry soil to absorb water.
Does soil remain in a ball when squeezed?
Is soil too dry? Is soil too wet? Sand
Place ball of soil between thumb and forefinger, gently pushing the soil with the thumb, squeezing it upward into a ribbon. Form a ribbon of uniform thickness and width. Allow the ribbon to emerge and extend over the forefinger, breaking under its own weight.
Does soil form a ribbon? Loamy sand
Does soil make a weak ribbon less than 1 inch long before breaking?
Does soil make a medium ribbon 1 to 2 inches long before breaking?
Does soil make a strong ribbon 2 inches or longer before breaking?
Excessively wet a small pinch of soil in palm of hand and rub with forefinger.
Does soil feel very gritty?
Does soil feel very smooth?
Neither grittiness nor smoothness predominates
Sandy loam
Loam
Silt loam
Does soil feel very gritty?
Does soil feel very smooth?
Neither grittiness nor smoothness predominates
Clay loam
Sandy clay loam
Silty clay loam
Does soil feel very gritty?
Does soil feel very smooth?
Neither grittiness nor smoothness predominates
Sandy clay
Clay
Silty clay
Y
Y
Y
N N
4 pH determination (UPLB) procedure
59 SIMPLIFIED KEYS TO SOIL SERIES
Get soil sample from 30 to 50 centimeter -depth. Fill the test tube with soil sample up to the scratch mark.
Add seven drops of CPR (chloropenol red). Mix by gently swirling the test tube.
If pH is six or greater, repeat the steps using BTB (bromthymol blue). If soil pH is five or less, repeat the steps using BCG (bromcresol green).
Match the color of the solution on top of the soil with the corre-sponding color chart of the pH indicator dye used.
APPENDIX 2. THE PALAYCHECK® SYSTEM
Negros Occidental 60
The PalayCheck® System is a rice integrated crop management that combines the tech-nologies and learning processes to identify strengths and weaknesses of current crop management practices, make improvements in the next sea-son to increase grain yield, input-use efficiency, and profit with environmental concerns. The PalayCheck® System describes the crop man-agement practices (input) to achieve the following Key Checks (output):
1) Used high-quality seeds of a recommended variety.
2) No high and low soil spots after final level-ing.
3) Practiced synchronous planting after a fallow period.
61 SIMPLIFIED KEYS TO SOIL SERIES
4) Sufficient number of healthy seedlings.
5) Sufficient nutrients at tillering to early panicle initiation and flowering.
6) Avoided excessive water or drought stress that could affect the growth and yield of the crop.
7) No significant yield loss
due to pests.
8) Cut and threshed the crop at the right time.
Glossary
Negros Occidental 62
Base saturation – the amount of positively charged ions (Ca, Mg, K, and Na), excluding hydrogen and aluminum ions, that are ab-sorbed on the surface of soil particles, and measured and reported as a percentage.
Boulder – rocks with grain size of usually no less than 256 mm (10 inches) diameter.
Clay skins – clay coatings on ped or pore surfaces. Coarse fragments – significant proportions of fragments coarser than
very coarse sand and less than 10 inches, if rounded, or 15 inches along the longer axis, if flat. They influence the nutri-ent status, water movement, use and management of the soil. They also reflect the origin and stage of development of the soil.
Cobblestone – naturally rounded stones larger than a pebble and small-er than a boulder.
Concretions – cemented bodies similar to nodules, except for the pres-ence of visible, concentric layers of material around a point, line, or plane.
Cutans – modification of the soil texture, or soil structure, at natural surfaces (particle, pore, or ped) in soil materials due to illuviation. Cutans are oriented deposits which can be composed of any of the component substances of the soil material.
Gravels – composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments.
Inherent fertility – the natural ability of the soil to supply plant nutrients. Mottles– appearance of uneven spots with spherical or irregular shape.
The color differs from the soil matrix color. Nodules – cemented bodies of various shapes that can be removed as
discrete units from soil. Nutrient retention – referred to as Cation Exchange Capacity (CEC) or
the maximum quantity of total cations, of any class, that a soil is capable of holding, at a given pH value, available for exchange with the soil solution.
Pebble – small usually rounded stone especially when worn by the action of water.
Permeability – property of the soil to transmit water and air. It affects irrigation, and leaching of salts and fertilizers.
Quartz – a mineral consisting of silicon dioxide occurring in colorless and transparent or colored hexagonal crystals or in crystalline masses.
Relief – refers to the elevation or inequality of the land surface consid-ered collectively.
Rock – naturally occurring solid aggregates of one or more minerals or mineraloids.
Rooting depth – the ability of the plant’s roots to penetrate through the soil. It can be limited by soil compaction, absence of nutrients, waterlogged layer or cemented layers.
63 SIMPLIFIED KEYS TO SOIL SERIES
Salinity – the saltiness or dissolved salt content (such as sodium chlo-ride, magnesium and calcium sulfates, and bicarbonates) in soil.
Slickenside – polished and grooved surface produced by one mass sliding past another.
Soil compaction – described according to its nature, continuity, struc-ture, agent, and degree. Compacted material has a firm or stronger consistence when moist and a close packing of parti-cles.
Soil drainage –refers to the frequency and duration of periods of satura-tion in the soil.
Soil family – a group of soils within a subgroup having similar physical and chemical properties that affect their responses to manage-ment and manipulation for use.
Soil pH –measure of acidity and basicity of soils. It affects availability or release of soil nutrients.
Soil profile – includes the collection of all the genetic horizons, the natu-ral organic layers on the surface, and the parent material or other layers beneath the solum that influence the genesis and behavior of the soil.
Soil series – a group of soils with similar profiles developed from similar parent materials under comparable climatic and vegetational conditions.
Soil taxonomy – hierarchies of classes that permit one to understand the relationships between soils and also between soils and the factors responsible for their character. A systematic distinguish-ing, ordering, and naming of type groups within a subject field.
Soil texture- refers to the relative proportions of the various size groups of individual soil grains in a mass of soil. Specifically, it refers to the proportions of clay, silt, and sand below 2 millimeters in diameter.
Soil type – the lowest category in classification systems. It is distin-guished within series on the basis of texture, a single character-istic.
Soil water retention – the ability of soil to retain water to provide an ongoing supply of water to plants between periods of replenish-ment (infiltration) to allow their continued growth and survival.
Stoniness – the relative proportion of stones over 10 inches in diameter or on the soil.
Surface cracking – develops in shrink–swell clay-rich soils after they dry out. The width (average, or average width and maximum width) of the cracks at the surface is indicated in centimeters. The average distance between cracks may also be indicated in cen-timeters.
Tuff – a rock composed of the finer kinds of volcanic detritus usually
fused together by heat.
Workability/tilth – the ease of cultivating the soil with regard to its struc-ture, texture, presence of coarse fragments, and relief.
Negros Occidental 64
Soil textural classes
Sand (S) - gritty Silt (Si) - smooth and floury Clay (C) - sticky Loam (L) - equal proportion of S, Si and C Sandy loam (SL) - presence of S, Si and C; but grittiness predominates Loamy sand (LS) - distinctively gritty with slight smoothness and sticki-
ness Silt loam (SiL) - presence of S, Si and C; but smoothness predominates Clay loam (CL) - presence of S, Si and C; but stickiness predominates Sandy clay loam (SCL) - presence of S, Si, and C; but more sticky and
gritty feel Silty clay loam (SiCL) - presence of S, Si and C; but more of sticky and
floury feel Sandy clay (SC) - sticky with slight grittiness Silty clay (SiC) - sticky with slight smoothness
References
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. Hampstead, M.I., TJ Sauer, and WF Bennet. 1997. Soil Science
Simplified. 3rd Edition. Iowa State University Press, Ames Iowa 500014.
“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 the Trop-ics.” August 4-10, 2003. Bangkok, Thailand.
Soil Survey of Negros Occidental Province. Department of Agri-
culture 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.
Keys to Soil Taxonomy. US Department of Agriculture 10th
Edition. 2006. Soil Survey Staff, Natural Resource Conservation Service, US Department of Agriculture.
Soil Taxonomy: A Basic System of Soil Classification for Making
and Interpreting Soil Surveys. Soil Survey Staff, Soil Conservation Service, US Department of Agriculture.
Sys, I.C., et al. Land Evaluation Part III: Crop Requirements.
Agricultural Publications. N°7, 1993.
65 SIMPLIFIED KEYS TO SOIL SERIES
For more information, write, visit, or call:
Agronomy, Soils, and Plant Physiology Division or
Information Systems Division
Philippine Rice Research Institute
Maligaya, Science City of Muñoz, 3119 Nueva Ecija
Tel. No. (044) 456-0285; -0113; -0651 local 217,
215, 212, 233
or text:
The PhilRice Text Center - (0920) 911-1398
For published material, contact:
Development Communication Division or
Business Development Division
Tel. No. (044) 456-0285; -0113; -0651 local 511,
509, 520
Readers are encouraged to quote the content of this
guidebook with acknowledgement. Suggested citation:
PhilRice, “Simplified Keys to Soil Series of Negros
Occidental”. Soil Series Guidebook ISBN 978-971-9081-
90-6: 65p., October 2014.
We thank the Bureau of Soils and Water Manage-ment (BSWM) for the secondary data of the soils used in this guidebook.
ISBN