This guide on “Simplified Keys to Soil Series” is designed for easier field identification of soils. It lists the different colors, textures, pH, and other observable properties of Antique's most common soils and provides four simple steps for identifying the soil ranges in the field. In the Philippines, the “Simplification of the Philippine Soil Series for Rice and Corn” project was initiated in 2005 under the Nutrient Management Support System (NuMASS) to provide management recommendations for field-identified soils.
We thank the farmers, agricultural technologists and municipal and provincial agricultural experts who helped us validate the soil series. The "Simplified Keys to Soil Range" is a tool for identifying soil ranges in the field by following simple steps for the use of farmers, extension workers, agricultural technologists, researchers and other stakeholders. Selection of knowledge and technology can also be easy and efficient in identifying soil ranges.
Using only five basic soil properties (colour, texture, pH, coarse fragments and stains) at a depth of 30-50 cm and following the simple steps given, the soil series can be identified in the field. This guide covers the 6 series of land in the province of Antique, namely: Alimodian, Magcalon, Patnongon, San Manuel, Sta. Each soil series has its own special color, which makes it different from other series (see page 27).
Use the book in the Simplified Keys to Soil series and compare all soil properties, starting with color, until you find the soil name.
Yellowish-Brown
Black/ Grayish-Brown
Soil Fertility Indicators Inherent Fertility Low to Moderate Soil pH Acid Organic Matter Low to Moderate Phosphorus (P) Low to Moderate Potassium (K) Low to Moderate Nutrient Retention. An old soil showing illuvial accumulation of clay in the subsoil from the underlying horizons and retaining a high base status (-alf, Alfisol), with a high amount of calcium in the subsoil (lime). It is found in areas with pronounced wet and dry seasons (-ust-, Ustic) with an average annual soil temperature higher than 22°C (isohyperthermic).
Drainage Poor to moderate Permeability Slow to moderate Workability/soil preparation Moderate Stonyness Occasional Root depth Shallow (0.5 m) Erosion Moderate. Soil type: : Sandy clay loam Area: 4,808 ha Family: Clayey skeletal, isohyperthermic, Aquic Eutrudepts A clayey soil with coarse fragments (skeletal). This soil is in the early stages of development towards a mature soil (-epts, Inceptisol) and has a high base saturation of at least 50% (Eutr-).
It is saturated with water for repeated periods of time (aquic), is found in areas with well-distributed precipitation (-ud-, Udic) and has an average annual soil temperature higher than 22°C (isohyperthermic). Organic matter Moderate to high Phosphorus (P) Moderate to high Potassium (K) Moderate to high nutrient retention. It is fine textured with 35 – 60% clay dominated by minerals with high shrinkage and swelling capacity (smectitic) creating wide cracks on the surface.
Therefore, it is subject to floods (fluvents), which receive annual deposits of alluvial soil from rivers. It is in initial development towards mature soil (-ept, Inceptisol) but has not yet fully developed its diagnostic horizons (Hapl-). It is found in areas with distinct wet and dry seasons (-ust, Ustic Moisture Mode) and an annual soil temperature above 22°C (isohyperthermic).
It is also a synthesis of conditions of soil fertility, water control, plant species, tillage, pest control and physical environment (Bainroth, 1978: Badayos, 1990). In economic terms, it is a measure of the quantity of inputs of factors of production required to correct land constraint(s) to achieve a certain level of production. For example, the maximum potential yield in the dry season is 8 tonnes/hectare, and the inherent and potential productivity ratings for Alimodian ranges are 0.67 and 0.80 respectively.
CROP
APPENDIX 1. STEPS TO IDENTIFY SOIL SERIES
The soil surface is not a good source of samples as it is always disturbed and processed. Soil color is an indirect measure of other characteristics such as drainage, aeration and organic matter content. If dry, determine the wet color by adding plenty of water to the soil sample.
Compare the color of the toe pattern with the group of toe colors found in the manual.
APPENDIX 2. THE PALAYCHECK ® SYSTEM
Glossary
Salinity - The salinity or dissolved salt content (such as sodium chloride, magnesium and calcium sulfate, and bicarbonates) in the soil. Soil drainage – refers to the frequency and duration of periods of soil saturation. Soil Family - A group of soils within a subgroup with similar physical and chemical properties that affect their response to management and manipulation for use.
Soil profile – includes the collection of all genetic horizons, natural organic layers at the surface, and parent material or other subsoil layers that influence soil genesis and behavior. Soil series - a group of soils with similar profiles developed from similar parent materials under comparable climatic and vegetative conditions. Soil taxonomy - hierarchies of classes that allow one to understand the relationships between soils and also between soils and the factors responsible for their character.
Soil texture- refers to the relative proportions of the different 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 water retention – the ability of soil to retain water to provide a continuous supply of water to plants between periods of recharge (infiltration) to enable their continued growth and survival.
The width (average or average width and maximum width) of cracks on the surface is given in centimeters. Tuff - A rock composed of finer types of volcanic detritus, usually fused together by heat. Workability/workability – ease of working the soil in terms of its structure, texture, presence of coarse fragments and relief.
We thank the Bureau of Soils and Water Management (BSWM) for the secondary data for the soil types used in this guide.
