NEGROS ORIENTAL
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
NEGROS ORIENTAL
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 Oriental ii
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
Brown/Yellowish Brown.......…………..... 11
Strong Brown/Red……...……................. 14
Soil Profile & Characteristics.......................... 15
Soil Productivity …………………………......... 30
Crop Suitability Analysis…….......................... 32
Soil Management Recommendations............ 39
Appendices……………………………….……. 47
Steps to Identify Soil Series…….......... 48
Soil Sampling....................................... 48
Color Determination............................. 49
Texture Determination.......................... 50
pH Determination................................. 51
The PalayCheck® System……………..…….. 52
Glossary………………………………………… 54
Soil Textural Classes………………..…. 56
References…………………………………….. 57
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 Oriental and contains four simple steps in identifying the soil series right in the field. It also includes the soil productivity index, soil properties that affect crop growth, soil taxonomic classification, crop suitability analysis, and soil management recommendations. 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 Oriental 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 fourteen (14) soil series in Negros Oriental, namely: Batuan, Bolinao, Dauin, Faraon, Guimbalaon, Isabela, La Castellana, Lugo, Mandawe, San Manuel, Siaton, Taal, Tupi, and Zam-boanguita.
The Simplified Keys to Soil Series
1 SIMPLIFIED KEYS TO SOIL SERIES
GUIDE TO SOIL SERIES IDENTIFICATION
Negros Oriental 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 48).
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 50).
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 49).
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 51).
7. Take note of other observable soil properties such as polished surfaces (cutans/slickensides), softness, hardness, stickiness, etc.
mottles slickenside
Negros Oriental 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
Isabela
Zamboangita
Siaton
Tupi
Mandawe
Dauin
Faraon
Gray/Bluish Gray (go to page 10)
Black/Grayish Brown (go to pages 7-9)
SOIL Color Groups
Bolinao
Lugo
Taal
San manuel
La Castellana
Guimbalaon
Batuan
Strong Brown/Red (go to page 14)
Brown/Yellowish Brown (go to pages 11-13)
Negros Oriental 6
SOIL Color Groups
Dauin (figure on page 18)
Coarse fragments Few gravels and stones
pH 6.0 – 6.5
Others Red and brown spot mottles; surface cracking during dry periods
Texture: Clay/Clay loam
Black/Grayish Brown
Faraon (figure on page 19)
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
7 SIMPLIFIED KEYS TO SOIL SERIES
Black/Grayish Brown
Mandawe (figure on page 24)
Coarse fragments Few soft powdery concretions
pH 5.0 – 8.0
Others
Gray streaks; gray/ black/ red coatings on pore spaces; compact; hard and cracks during dry periods
Texture: Clay/Clay loam
Negros Oriental 8
Siaton (figure on page 26)
Coarse fragments None but some weathered dark brown rocks are observed below 60-cm depth
pH 4.5 – 6.0
Others Few smooth and shiny surfaces (slickensides); slightly compact and sticky
Texture: Sand/ Sandy clay/ Sandy clay loam
Black/Grayish Brown
Tupi (figure on page 28)
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
9 SIMPLIFIED KEYS TO SOIL SERIES
Zamboanguita (figure on page 29)
Coarse fragments Red-orange nodules; soft weathered rocks
pH 5.0 – 6.5
Others
Dark greenish-gray spot mottles; shiny smooth surfaces; compact; very fine crystals
Texture: Clay/ Clay loam
Isabela (figure on page 21)
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
Gray/Bluish Gray
Negros Oriental 10
Brown/Yellowish Brown
Batuan (figure on page 16)
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 loam/Silty clay
Guimbalaon (figure on page 20)
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
11 SIMPLIFIED KEYS TO SOIL SERIES
Brown/Yellowish Brown
La Castellana (figure on page 22)
Coarse fragments
Soft powdery red concretions; granules, stones, and weathered rocks; large boulders on the surface (outcrops)
pH 4.5 – 6.0
Others Reddish brown, to gray spots (mottles)
Texture: Clay/Clay loam
Lugo (figure on page 23)
Coarse fragments None but limy consolidated shale can be observed below the profile
pH 4.5 – 5.5
Others
Brown to red spot mottles; white to grayish-white calcare-ous shale which can be crushed into powdery mass (below the profile); gritty feel
Texture: Clay/Silty clay/Silty clay loam
Negros Oriental 12
San Manuel (figure on page 25)
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
Taal (figure on page 27)
Coarse fragments Stones and gravels
pH 5.5 – 7.0
Others Fine quartz/crystals
Texture: Sand
13 SIMPLIFIED KEYS TO SOIL SERIES
Bolinao (figure on page 17)
Coarse fragments
Grayish-white pebbles and cobblestones; soft powdery black concretions; white hard limestone rock below the profile
pH 5.0 – 6.5
Others Grayish-brown spot mottles
Texture: Clay
Strong Brown/Red
Negros Oriental 14
15 SIMPLIFIED KEYS TO SOIL SERIES
SOIL Profile and Characteristics
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, 252.69 ha
Family: fine, isohyperthermic, Typic Ustifluvent
Soils derived from underlying calcareous shale 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% than slope; observed with a decrease in organic carbon in the underlying horizons, and shallow calcare-ous bedrock (fluv-). It is found in areas with pronounced wet and dry seasons (-ust, Ustic) . It has a mean annual soil tempera-ture higher than 22°C (isohyperthermic).
00 cm
30
50
80
Negros Oriental 16
Bolinao
Soil Type: Clay Area: 679.70 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 sat-uration, less than 60% (Dystr-), and a surface horizon high in organic carbon (Umbric). It is found in areas with pronounced wet and dry seasons (-ust, Ustic). It has a mean annual soil tem-perature higher than 22°C (isohyperthermic).
00 cm
13
35
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 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
Ap
Bt
BC
17 SIMPLIFIED KEYS TO SOIL SERIES
Soil Fertility Indicators
Inherent fertility Moderate to high
Soil pH Slightly acid (6.0 – 6.5)
Organic matter Moderate
Phosphorus (P) High
Potassium (K) Moderate
Nutrient retention (CEC)
Moderate
Base saturation High
Salinity hazard Low
Dauin
Physical Soil Qualities
Relief Level
Water retention High
Drainage Poor
Permeability Slow to moderate
Workability/tilth Hard to moderate
Stoniness None
Root depth Shallow Deep (0.5 m)
Erosion None
Flooding Seasonal
Soil Type: Clay/Sandy loam Area: 419.88 ha
Family: isohyperthermic, Typic Argiaquoll
Soils developed from older alluvial deposits. A fine-textured soil with less than 65% clay. It is dark-colored with high organic mat-ter content and high base status (-oll, Mollisol) and exhibits accumulation of clay in the subsoil (Argi-, Argillic). Alluvial de-posit over a once marshland hence partly decayed organic mat-ter is found below the profile. This soil is saturated with water for repeated periods (-aqu) of time. The mean annual soil temper-ature is higher than 22°C (isohyperthermic).
00 cm
15
28
43
Negros Oriental 18
58
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 Area: 120,604.66 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 usually found in areas with pronounced wet and dry seasons (-ust, Ustic) and mean annual temperature higher than 22°C (isohyperthermic).
00 cm
9
25
A
Bw
BC
19 SIMPLIFIED KEYS TO SOIL SERIES
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
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 & pebbles
Root depth Shallow (0.5 m)
Erosion Severe
Soil Type: Gravelly loam Area: 3,290.81 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, and 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 incipi-ent development stage toward mature soil, but has not yet fully developed its diagnostic 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 rivers.
00 cm
15
39
69
74
Ap
Bw
Bt1
Bt2
Bt3
Negros Oriental 20
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 Area: 9,320.25 ha
Family: Fine, smectitic (ca.), isohyperthermic, Aquic Hapludalf
Soils formed from alluvial deposits and are 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 hori-zons (-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 mois-ture for crop growth. The mean annual soil temperature is higher than 22°C (isohyperthermic).
00 cm
20
57
84
Apg
ABg
Bg
BCg
21 SIMPLIFIED KEYS TO SOIL SERIES
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
Soil Type: Clay/Clay loam Area: 18,143.78 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 incipi-ent development stage toward mature soil but has not yet fully devel-oped its diagnostic horizons. It has a subsurface horizon that is coarse-textured with less than 10% clay and consists of weatherable miner-als. The mean annual soil temperature is higher than 22°C (isohyperthermic).
00 cm
8
19
67
Ap
AC
C
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
Negros Oriental 22
78
Soil Fertility Indicators
Inherent fertility Moderate to high
Soil pH Slightly acid (5.0 – 6.5)
Organic matter Moderate
Phosphorus (P) Low
Potassium (K) Moderate
Nutrient retention (CEC)
Very high
Base saturation High
Salinity hazard Low
Lugo
Physical Soil Qualities
Relief Rolling to hilly
Water retention Moderate
Drainage Good
Permeability Rapid
Workability/tilth Hard to moderate
Stoniness None
Root depth Moderate (0.5 m)
Erosion Severe
Flooding None
Soil Type: Clay Area: 804.84 ha
Family: fine-clayey, montmorillonitic, isohyperthermic, Inceptic Hapludalf
Soils developed from calcareous shale. It is fine-textured with less than 60% clay composed mostly of minerals which have shrink-and-swell capacity (montmorillonitic). 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 horizo-nation (hapl-). 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. It has a mean annual soil temperature higher than 22°C (isohyperthermic).
23 SIMPLIFIED KEYS TO SOIL SERIES
00 cm
20
30
50
110
Soil Fertility Indicators
Inherent fertility High
Soil pH Slightly alkaline (7.5 – 8.0)
Organic matter Moderate
Phosphorus (P) High
Potassium (K) Low
Nutrient retention (CEC)
High
Base saturation High
Salinity hazard Low
Mandawe
Physical Soil Qualities
Relief Level
Water retention Good
Drainage Poor to moderate
Permeability Slow to moderate
Workability/tilth Hard to moderate
Stoniness Very few to none
Root depth Moderate (0.8 m)
Erosion None
Flooding Occasional
Soil Type: Clay Area: 325.09 ha
Family: fine silty, mixed, isohyperthermic Fluventic Eutropepts
A young soil (-ept, Inceptisol) developed from recent alluvial deposits of fine soil material from surrounding uplands with high base saturation greater than 50% (Eutr-). This soil is subject to frequent flooding (fluventic). It has fine silty texture (18 – 35% clay) consisting of mixed minerals. This soil is found in areas with pronounced wet and dry seasons (Ustic). It has a mean annual soil temperature higher than 22°C (isohyperthermic).
00 cm
10
29
56
85
Negros Oriental 24
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
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
Soil Type: Loam/Fine sandy loam Area: 12,347.27 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).
25 SIMPLIFIED KEYS TO SOIL SERIES
00 cm
6
36
69
Ap1
Ap2
Bw1
90
Bw2
Bw3
00 cm
18
38
56
100
Soil Fertility Indicators
Inherent fertility High
Soil pH Slightly acid (5.0 – 6.5)
Organic matter Moderate
Phosphorus (P) Moderate
Potassium (K) Moderate
Nutrient retention (CEC)
High
Base saturation High
Salinity hazard Low
Siaton
Physical Soil Qualities
Relief Nearly flat
Water retention Moderate
Drainage Good
Permeability Moderate
Workability/tilth Easy
Stoniness None
Root depth Deep (>1 m)
Erosion None
Flooding None
Soil Type: Sandy loam Area: 229.57 ha
Family: isohyperthermic, Typic Eutrudept
A non-calcareous alluvial soil whose materials originated from the surrounding uplands found along coastal areas. It is slightly elevated inland and also forms high bluff from the shorelines. It is a young soil in its incipient development stage toward a mature soil (-epts, Inceptisol) with high base saturation greater than 50% (Eutr-). It is commonly found in areas with a mean annual temperature higher than 22°C (isohyperthermic) and humid cli-mate that have well-distributed rainfall (-ud, Udic), thus have
adequate supply of water for crop growth.
Negros Oriental 26
Soil Fertility Indicators
Inherent fertility Low
Soil pH Slightly acid to neutral (6.5 – 7.0)
Organic matter Moderate
Phosphorus (P) Low
Potassium (K) Low
Nutrient retention (CEC) Low
Base saturation Low
Salinity hazard Low
Taal
Soil Type: Sandy loam Area: 10,177.13 ha
Family:
This is a water-laid volcanic soil. It has a mean annual soil tem-perature higher than 22°C (isohyperthermic).
Physical Soil Qualities
Relief Undulating to rolling
Water retention Low
Drainage Good to excessive
Permeability Rapid
Workability/tilth Easy
Stoniness Many (35%)
Root depth Deep (1.3 m)
Erosion Moderate
00 cm
27
45
65
27 SIMPLIFIED KEYS TO SOIL SERIES
110
120
130
Soil Fertility Indicators
Inherent fertility Low to moderate
Soil pH Acidic (4.5 – 6.5)
Organic matter Moderate
Phosphorus (P) Moderate to high
Potassium (K) Low
Nutrient retention (CEC) Low
Base saturation Very low
Salinity hazard None
Tupi
Soil Type: Silt loam/Fine sandy loam Area: 30,379.10 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 its 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, has high organic 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
Negros Oriental 28
Soil Fertility Indicators
Inherent fertility Moderate
Soil pH Slightly acid (5.0 – 6.0)
Organic matter Moderate
Phosphorus (P) Low
Potassium (K) Low
Nutrient retention (CEC) Moderate
Base saturation Moderate
Salinity hazard Low
Zamboanguita
Soil Type: Clay loam Area: 13,358.13 ha
Family: isohyperthermic, Typic Humaquept
Soils developed from basaltic rock. It is a young soil in its incipi-ent development stage toward mature soil but has not yet fully developed its diagnostic horizons (-ept, inceptisol). It is found in highlands (hum-) saturated with water for repeated periods of time (aquic). It has mean annual soil temperature higher than 22°C (isohyperthermic). This soil is bisected by numerous gullies and creeks.
Physical Soil Qualities
Relief Rolling to hilly
Water retention Low to moderate
Drainage Moderate to excessive
Permeability Moderate to rapid
Workability/tilth Easy without outcrops
Stoniness Boulder outcrops
Root depth Deep (1m)
Erosion Severe
Flooding None
00 cm
15
40
70
29 SIMPLIFIED KEYS TO SOIL SERIES
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 capaci-ty of the soil to produce a given yield; potential refers to its capacity 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 (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 Batuan series are 0.51 and 0.66, respectively. The predicted inherent and potential yields of rice in Batu-an soils are then 4.08 and 5.28 tons/ha.
Negros Oriental 30
Soil Series Inherent
Productivity Potential
Productivity
Batuan 0.51 0.66
Bolinao 0.65 0.82
Dauin 0.78 0.88
Faraon 0.48 0.60
Guimbalaon 0.29 0.49
Isabela 0.80 0.95
La Castellana 0.39 0.74
Lugo 0.50 0.62
Mandawe 0.70 0.98
San Manuel 0.75 0.95
Siaton 0.71 0.83
Taal - -
Tupi 0.67 0.87
Zamboanguita 0.53 0.75
Table 1. Soil productivity index for rice.
31 SIMPLIFIED KEYS TO SOIL SERIES
CROP Suitability Analysis
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
Negros Oriental 32
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
rie
nta
l.
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
Ma
ize
Ma
ng
o
On
ion
P
ap
aya
Batu
an
N
2scf
S3
s
N1
sw
f S
3fs
c
S3
sfc
S
3fs
c
N2cfs
N
1fs
w
Bolin
ao
N
2cts
f S
2ts
f S
2ts
f S
3fs
tc
S3
sctw
f S
3fs
tc
N2cts
f S
2fs
t
Dauin
S
2cs
S3
ws
S3
w
S3
sw
c
S3
wsc
S3
wsc
N2cw
s
N2w
s
Fara
on
N
2w
sfc
S
3ts
S
3tw
sf
S3
cts
f S
3stc
f S
3stc
N
2cts
S
3ts
w
Guim
bala
on
N
2ctw
sf
S3
tc
N1
stf
S3
sfc
t S
3sftc
S3
fstc
N
2cts
f S
3sfw
t
33 SIMPLIFIED KEYS TO SOIL SERIES
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 R
ain
fed
L
ow
lan
d
Ban
an
a
Ma
ize
Man
go
O
nio
n
Pa
pa
ya
Isabela
S
2cs
S3
wsf
S2
wsf
S3
cw
sf
S3
wcs
S3
wsc
N2cw
f N
2w
f
La C
aste
llan
a
N2
cw
sf
S3
fsw
t S
3tw
sf
S3
fstc
S
3fs
tc
S3
fstc
N
2cft
ws
S3
fst
Lugo
N
2tc
sw
f S
3tw
s
S3
tw
S3
cts
f S
3ts
c
S3
ftsc
N2ctw
f S
3tf
s
Mand
aw
e
S2
csf
S3
wf
S2
wf
S3
cfw
S
3w
cf
S3
wc
N2cw
f N
1w
f
San M
anue
l S
3w
tcs
S3
wsf
N1
sw
f S
3cw
f S
3w
sc
S3
wsc
N2cw
f N
1w
f
Negros Oriental 34
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
rie
nta
l (c
ontin
ua
tion
).
So
il S
eri
es
R
ice I
rrig
ate
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
Sia
ton
S
3w
fcs
S3
wsf
N1
sw
f S
3csf
S2
cs
S3
fsc
N2cw
f S
3f
Taal
N2
wstf
c
S2
twsf
S3
twsf
S3
cstf
S2
cts
f S
3fs
tc
N2ctw
sf
S3
fst
Tupi
N1
stf
c
S3
stw
f S
3tw
sf
S3
cfs
t S
3fs
tc
S3
fstc
N
2cts
f S
3fs
wt
Zam
boanguita
N
2tw
sfc
S
3tw
s
S3
twsf
S3
cts
f S
3cts
f S
3fs
tc
N2ctw
sf
S3
sft
35 SIMPLIFIED KEYS TO SOIL SERIES
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
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
rie
nta
l.
So
il S
eri
es
P
ean
ut
So
rgh
um
S
ug
arc
an
e
Sw
eet
Po
tato
T
ob
acco
T
om
ato
W
ate
rme
lon
Batu
an
S
3fs
c
S3
cs
S3
scf
S3
sfc
S
3fs
c
N1sfc
N
2sfc
Bolin
ao
S
3sftc
S2
cts
f S
3ctw
sf
S3
sfw
tc
S3
sftc
N1scfw
t N
2sctw
f
Dauin
N
1w
sc
S3
wcs
S3
wsc
S3
wsc
N1w
cs
S3
wcs
N1w
cs
Fara
on
S
3stw
c
S3
tcs
S3
sw
tc
S3
stfc
S3
stc
N
1stc
N
2stc
Guim
bala
on
S
3fs
wtc
S
3stc
S
3fs
twc
S3
sftc
S2
fstc
S
3sctf
S3
scft
Negros Oriental 36
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
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
rie
nta
l (c
ontin
ua
tion
).
So
il S
eri
es
P
ean
ut
So
rgh
um
S
ug
arc
an
e
Sw
eet
Po
tato
T
ob
acco
T
om
ato
W
ate
rme
lon
Isabela
N
1w
c
S2
cw
S
3w
sfc
S
3w
fc
N1w
fc
S3
wcf
S3
wcf
La C
aste
llan
a
S3
fsw
tc
S3
stc
wf
S3
fstw
c
S3
fsw
tc
S3
fstc
S
3sftcw
S
3fs
tcs
Lugo
S
3sw
tc
S3
tcw
s
S3
twsc
S3
twsfc
S
3tc
s
S3
cstfw
S
3cts
wf
Mand
aw
e
N1w
sfc
S
2cw
S
3fw
c
S3
fwc
N1w
fc
S3
cw
f S
3fw
c
San M
anue
l N
1w
c
S2
cw
s
S3
fwsc
S3
wfc
N
1w
fc
S3
cw
f S
3cw
f
37 SIMPLIFIED KEYS TO SOIL SERIES
Ta
ble
2b. (c
ontin
uatio
n)
So
il S
eri
es
P
ean
ut
So
rgh
um
S
ug
arc
an
e
Sw
eet
Po
tato
T
ob
acco
T
om
ato
W
ate
rmelo
n
Sia
ton
S3
fwc
S2
cw
s
S3
fwsc
S3
fwc
S3
fc
S3
cfw
S
3fc
Taal
S
3sw
tc
S2
ctw
sf
S3
fsw
tc
S3
fsw
tc
S2
fsc
S3
ctw
sf
S3
cts
f
Tupi
S
3fs
wtc
S
3fs
wtc
S
3fs
tc
S3
fstc
S
3fs
c
N1sfc
t N
2sft
c
Zam
boanguita
S
3fs
wtc
S
3stc
w
S2
fsw
tc
S2
cts
f S
2stc
S
3ctw
sf
S3
ctfs
Negros Oriental 38
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 com-bination 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.
39 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
Batu
an
P d
eficie
ncy; shallo
w s
oil
limitin
g p
roductivity o
f shal-
low
-roote
d c
rops; m
odera
te
soil
ero
sio
n h
azard
; acid
ic
Adequate
and
bala
nced N
PK
fe
rtili
zatio
n;
terr
acin
g o
r
constr
uction o
f bunds;
limin
g;
use
of
hig
h-y
ield
ing
varie
tie
s
Conto
ur
terr
acin
g;
bala
nced N
PK
fe
rtili
zatio
n;
limin
g
and a
dditio
n o
f or-
ganic
matt
er;
use o
f hig
h-y
ield
ing
varie
tie
s
Pro
ductio
n c
an b
e
limited d
ue to
shallo
w r
ootin
g
depth
of th
e s
oil;
conto
ur
farm
ing/
terr
acin
g
Suitable
for
sugarc
ane
pro
ductio
n for
are
as
with le
sser
ero
sio
n
hazard
; pla
nt
perm
anent cro
ps/tre
es
like c
oconut
Cro
pp
ing
Patt
ern
: r
ice-d
ivers
ifie
d c
rops/r
oot cro
ps;p
lanta
tio
n c
rops (
e.g
. sugar-
cane)
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
te
rracin
g a
nd u
se
of
lime
sto
ne
outc
rops f
or
rein
forc
ing d
ikes/
bunds;
applic
atio
n
of
phosphate
fe
rtili
zers
; upla
nd
rice
Conto
ur
terr
acin
g;
pro
per
fert
ilizatio
n;
pro
per
tim
ing o
f cultiv
atio
n a
nd
pla
nting;
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
acin
g;
use o
f cover
cro
ps
like Ipil-
ipil
for
so
il re
habili
tatio
n a
nd
sourc
e o
f fire
wood
at
the s
am
e tim
e;
additio
n o
f org
anic
m
att
er
Cro
pp
ing
Patt
ern
: r
ice-r
ice; rice-d
ivers
ifie
d c
rops/v
egeta
ble
s/r
oot cro
ps
Negros Oriental 40
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
Dauin
Shallo
w w
ate
r ta
ble
(<
1m
) th
us p
oor
dra
inage;
satu
rate
d w
ith w
ate
r fo
r re
peate
d p
erio
ds o
f tim
e
Constr
uctio
n o
f dra
inage a
nd f
lood
contr
ol syste
m;
Constr
uctio
n o
f
dra
inage a
nd f
lood
contr
ol syste
m;
use o
f hig
h b
road b
eds,
ridges
Constr
uctio
n o
f dra
inage a
nd
flo
od c
ontr
ol
syste
m; use o
f hig
h b
road
beds,
ridges
Modera
tely
suited for
fruit tre
es e
.g. m
ango
and b
anana
Cro
pp
ing
Patt
ern
: r
ice-r
ice; rice-d
ivers
ifie
d c
rops
Fa
raon
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; ro
ck
outc
rops a
re p
resent; h
illy
topogra
phy;
gro
win
g p
erio
d
is possib
le o
nly
durin
g
rain
y s
eason u
nle
ss
irrig
ate
d
Constr
uctio
n o
f bunds f
or
upla
nd
or
terr
acin
g;
applic
atio
n o
f Z
nS
O4
2 i
n lo
wla
nd
rice if
deficie
ncy
occurs
Conto
ur
farm
ing;
shallo
w c
ultiv
atio
n;
fert
ilizatio
n;
adequate
irrig
atio
n s
yste
m;
min
imum
till
age to
lessen e
rosio
n r
ate
s
Modera
tely
suitable
for
root
cro
ps d
ue t
o
shallo
w r
ootin
g
depth
and
pre
sence o
f outc
rops;
min
imum
till
age
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,
mola
ve, coconut,
etc
.
Cro
pp
ing
Patt
ern
:
low
lan
d r
ice
-lo
wla
nd r
ice/d
ivers
ifie
d c
rops/v
egeta
ble
s; fr
uit tre
es
41 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
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 o
f ro
ck o
utc
rops that im
pede
dra
inage
OM
in
corp
ora
tio
n;
limin
g; S
uitable
for
rice b
ut needs
terr
acin
g a
nd u
se
of
outc
rops f
or
rein
forc
ing d
ikes
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
ilization;
OM
in
corp
ora
tio
n;
limin
g; subsoili
ng t
o
bre
ak h
ard
pan
Lim
ing; pro
per
fert
ilizatio
n a
nd
OM
in
corp
ora
-tio
n; conto
ur
terr
acin
g;
subsoili
ng t
o
bre
ak h
ard
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; Z
n
deficie
ncy in r
ice;
hig
h P
fixatio
n;
severe
topsoil
shrin
kin
g &
sw
elli
ng;
hard
to
till
; seasonal river
flo
odin
g
Applic
atio
n o
f Z
nS
O4
2- i
n lo
wla
nd
rice w
hen
deficie
ncy o
ccurs
; N
and P
fert
iliza-
tio
n;
build
dra
inage
canals
and flo
od
contr
ol syste
m
N a
nd P
fert
ilizatio
n;
build
dra
inage c
anals
; constr
uct
bro
ad b
eds,
ridges; cultiv
ate
only
at
optim
um
mois
ture
conte
nt; c
over
cro
ppin
g
N a
nd P
fert
iliza-
tio
n;
build
dra
in-
age c
anals
; cultiv
ate
only
at
optim
um
mois
-tu
re c
onte
nt; n
ot
suitable
for
nuts
; constr
uct
beds,
rid
ges
Pla
nt fr
uit 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
Negros Oriental 42
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
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 t
he s
ubsurf
ace s
oil;
pre
sence o
f bould
er
outc
rops t
hat
impede till
-age;
low
mois
ture
N a
nd P
fert
iliza-
tio
n; lim
ing in
upla
nd;
adequate
ero
sio
n c
ontr
ol
measure
s;
adequate
irr
iga-
tio
n
N &
P fert
ilizatio
n;
limin
g; adequate
ero
sio
n c
ontr
ol
measure
s; conto
ur
farm
ing; str
ip c
roppin
g
and c
over-
cro
ppin
g;
adequate
irr
igatio
n
N &
P fert
ilizatio
n;
limin
g in
upla
nd
rice a
nd o
ther
div
ers
ifie
d c
rops;
adequate
ero
sio
n
contr
ol m
easure
s;
adequate
irr
igation
Pla
nt perm
anent
cro
ps in
hig
her
slo
pes; fr
uit t
rees a
nd
secondary
fore
st
Cro
pp
ing
Patt
ern
: u
pla
nd
ric
e-d
ivers
ifie
d c
rops/
root cro
ps; perm
anent
cro
ps/
trees
Lugo
P d
eficie
ncy; scanty
wate
r supply
fro
m r
ivers
; difficult
to till
due t
o form
atio
n o
f hard
clo
ds; severe
soil
ero
sio
n t
hat
deple
tes the
more
fert
ile t
opsoil
P f
ert
ilizatio
n;
adequate
irrig
atio
n;
OM
in
corp
ora
tio
n to
impro
ve t
ilth;
terr
acin
g
P f
ert
ilizatio
n;
adequate
irr
igatio
n;
OM
in
corp
ora
tio
n to
impro
ve t
ilth; ero
sio
n
pre
vention m
easure
s
e.g
. conto
ur
terr
acin
g/
farm
ing
Slig
htly s
uitable
due t
o form
atio
n o
f hard
clo
ds t
hat
may im
pede
gro
wth
of
root
cro
ps; pro
per
tilla
ge a
nd O
M
incorp
ora
tio
n; ade-
quate
fert
ilizatio
n
Pla
ntin
g o
f perm
anent
cro
ps a
nd t
rees t
o
resto
re s
oil
fert
ility
Cro
pp
ing
Patt
ern
:
rice-d
ivers
ifie
d c
rops/
root cro
ps
43 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 c
rop
s
Ro
ot
cro
ps
T
ree/F
ore
st/
P
lan
tati
on
cro
ps
Mand
aw
e
Fre
quent
flo
odin
g
Adequate
flo
od
contr
ol syste
ms;
pla
nt
flo
od-
tole
rant
varie
ties
or
cro
ps
Adequate
flo
od c
ontr
ol
and d
rain
age s
yste
ms;
Use o
f hig
h b
road b
eds,
rid
ges
Adequate
flo
od
contr
ol syste
ms;
use o
f hig
h
bro
ad b
eds,
ridges
Fru
it tre
es
Cro
pp
ing
Patt
ern
: r
ice-r
ice; rice-d
ivers
ifie
d c
rops
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
manuring
Constr
uctio
n o
f adequate
dra
inage,
irrig
atio
n, and
flo
od c
ontr
ol syste
ms d
ue
to s
easonal flo
od h
azard
and h
igh s
easonal w
ate
r ta
ble
; use b
road b
eds
and r
idges; suited for
div
ers
ifie
d c
rops s
uch a
s
corn
, vegeta
ble
s, and
wate
rmelo
n d
urin
g d
ry
season 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
and irr
igatio
n s
yste
m;
cover
cro
ppin
g w
ith
legum
es; pro
per
fe
rtili
zatio
n, tim
ing o
f cultiv
atio
n a
nd
pla
ntin
g;
use o
f lo
cally
adapte
d h
igh-y
ield
ing
varieties is
recom
mended to
impro
ve t
he g
row
th
and y
ield
of tr
ee c
rops
Cro
pp
ing
Patt
ern
: ri
ce-r
ice; rice-v
egeta
ble
s/r
oot cro
ps
Negros Oriental 44
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
Sia
ton
Only
has m
inim
um
limitatio
n; slig
htly c
om
pact
Split
applic
atio
n o
f fe
rtili
zers
;
adequate
irr
igatio
n
or
pla
nt
early-
m
atu
ring v
arieties
Adequate
irr
igatio
n;
fert
ilizatio
n;
OM
additio
n
Adequate
irr
iga-
tio
n; fe
rtili
zatio
n;
OM
additio
n
Suited for
coconut
and
banana
Cro
pp
ing
Patt
ern
: r
ice-r
ice; rice-d
ivers
ifie
d c
rops/r
oot cro
ps
Taal
Very
lo
w in
fert
ility
; ra
pid
le
achin
g o
f bases,
hence
K,
Ca, &
Mg d
eficie
ncy c
an
occur;
pre
sence o
f m
any
sto
nes/g
ravels
; m
odera
te
ero
sio
n
NP
K fert
ilizatio
n;
adequate
dra
inage
syste
m; org
anic
m
att
er
incorp
ora
-tion; cro
p r
ota
tion
with legum
es/
gre
en m
anurin
g o
r cover
cro
ppin
g
NP
K fert
ilizatio
n;
adequate
dra
inage
syste
m; org
anic
matter
incorp
ora
tio
n; cro
p
rota
tion w
ith legum
es/
gre
en m
anuring o
r cover
cro
ppin
g
Adequate
fert
ilizatio
n;
terr
acin
g; cover
cro
ppin
g
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 ipil-
ipi
Cro
pp
ing
Patt
ern
: r
ice-r
ice; rice-d
ivers
ifie
d c
rops/r
oot cro
ps
45 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
Tupi
Low
fert
ility
; acid
ic;
K d
eficie
ncy; severe
ero
sio
n r
em
ovin
g the m
ore
fe
rtile
topsoil
Lim
ing u
pla
nd;
adequate
ero
sio
n
contr
ol m
easure
s;
adequate
fert
iliza-
tio
n
Lim
ing; im
ple
me
nt
ero
sio
n c
ontr
ol
measure
s e
.g.
conto
ur/
terr
acin
g;
OM
additio
n a
nd
adequate
fert
iliza-
tio
n; cover
cro
p-
pin
g/g
reen m
anur-
ing
Imple
ment
ero
sio
n c
ontr
ol
measure
s e
.g.
conto
ur/
terr
acin
g;
adequate
fert
ilization
Fru
it tre
es a
nd s
econd
gro
wth
fore
st;
modera
tely
suitable
fo
r banana, sugar-
cane,
and m
ango
Cro
pp
ing
Patt
ern
: u
pla
nd
ric
e-d
ivers
ifie
d c
rops/; r
oot cro
ps; fr
uit t
rees/s
econd
gro
wth
fore
st
Za
mboanguita
Soil
easily
drie
d u
p d
urin
g
sum
mer;
pre
sence o
f ro
ck
outc
rops t
hat
imp
ede
tilla
ge; lo
w P
& K
; severe
ero
sio
n h
azard
causin
g
gulli
es form
atio
n
Upla
nd r
ice;
adequate
irr
igatio
n
syste
m; te
rracin
g/
constr
uctio
n o
f bunds
Ensure
cover
cro
ps; conto
ur
farm
ing o
r
terr
acin
g;
irrigation s
yste
m;
PK
fert
ilization
Ensure
cover
cro
ps; conto
ur
farm
ing o
r
terr
acin
g;
constr
uct
irriga-
tion s
yste
m;
fert
ilizers
applic
a-
tio
n
Perm
anent cro
ps; fr
uit
trees lik
e m
ango,
banana,
etc
.; g
row
ing
of
gra
sses o
n
uncultiv
ate
d a
reas to
lessen s
oil
ero
sio
n
Cro
pp
ing
Patt
ern
: u
pla
nd
ric
e-d
ivers
ifie
d c
rops (
vegeta
ble
s);
perm
anent
cro
ps/
fruit tre
es
Negros Oriental 46
Appendices
47 SIMPLIFIED KEYS TO SOIL SERIES
APPENDIX 1. STEPS TO IDENTIFY SOIL SERIES
1 Soil sampling
Negros Oriental 48
Choose a vacant area in your field. Use a spade or soil auger to dig up to 50 centimeters from the soil surface.
The depth of the soil is important. The soil surface is not a good source of the samples since it is always disturbed and cultivated.
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
49 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 Oriental 50
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
51 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 Oriental 52
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.
53 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 Oriental 54
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 stone larger than a pebble and smaller 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.
55 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 Oriental 56
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 Oriental Province. Department of Agricul-
ture 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.
57 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:
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For published material, contact:
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Readers are encouraged to quote the content of this
guidebook with acknowledgement. Suggested citation:
PhilRice, “Simplified Keys to Soil Series of Negros
Oriental”. Soil Series Guidebook ISBN 978-971-9081-91-3:
57p., 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