This guide on "Simplified Keys to Soil Series" has been developed for easier field identification of soils. It contains the different colors, textures, pH and other observable characteristics of the most common soils of Capiz and includes four simple steps to identify the soil range right in the field. We thank the farmers, agricultural technologists and municipal and provincial agricultural experts who helped us validate the soil series.
"Simplified Keys to Soil Series" is a tool to identify soil series in the field by following simple steps for use by farmers, extension workers, agricultural technologists, researchers and other stakeholders. Selection of knowledge and technologies could also be easy and effective with identification of soil series. Using only five basic soil characteristics (color, texture, pH, coarse fragments and patches) at 30-50 cm soil depth and following the simple steps, the soil series in the field could be identified.
This guidebook covers the 10 soil series in the provinces of Capiz, namely: Alimodian, Bantog, Faraon, Luisiana, Maligaya, San Manuel, Sapian, Sara, San Rafael and Sta. Use the Simplified Keys to Soil Series book and compare all soil properties starting from the color until the soil name is identified.
Texture: Clay/Clay loam
Yellowish/Strong Brown
Texture: Clay/Silt loam
Texture: Clay
Black/Grayish Brown
Hard powdery black concretions; some weathered stone chips and gravel (brown, gray and red); outcrops of black basaltic rocks/boulders. Brick red stripes; brown and gray spots; gray shiny surfaces (clay skins); slightly compact.
Texture: Silty clay loam/Clay loam/Loam
Soil Fertility Indicators Natural Fertility Low to Medium Soil pH Acidity Organic Matter Low to Medium Phosphorus (P) Low to Medium Potassium (K) Low to Medium Nutrient Retention. It is found in areas with pronounced wet and dry seasons (-ust-, Ustic) with an average annual soil temperature higher than 22°C (isohyperthermic). Organic matter Moderate to high Phosphorus (P) Moderate to high Potassium (K) Low to moderate nutrient retention.
It is saturated with water repeatedly (-aqu) but is well aerated because either the groundwater is deep or the period of saturation is shorter (Aeric). It is dark in color with a high content of organic matter (-oll) and a high base status. It is usually found in areas with pronounced wet and dry seasons (-ust, Ustic) and average annual temperature higher than 22°C (isohyperthermic).
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 an average annual soil temperature higher than 22°C (isohyperthermic). It is an old soil that has undergone extensive leaching of base and accumulation of clay in the subsoil (-ult, Ultisol).
It is found in areas with well-distributed rainfall (-ud, Udic), average annual soil temperature above 22°C (isohyperthermic). These soils are repeatedly saturated with water (- aqu-, aquic) and have an annual soil temperature above 22 °C (isohyperthermic). Drainage Good permeability Moderate Cultivation/cultivation Easy stony Gravelly Root depth Deep (0.9 m) Erosion Flash floods None.
It is a young land with only slight development; properties are largely determined by the parent material (Entisol, -ent). 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 a high shrinkage and swelling capacity (smectites) which create wide cracks on the surface;.
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.
Soil Series Inherent
Productivity Potential Productivity
CROP
APPENDIX 1. STEPS TO IDENTIFY SOIL SERIES
The soil surface is not a good source for the samples as it is always disturbed and cultivated. Soil color is an indirect measure of other properties such as drainage, aeration and organic matter content. If dry, perform a wet color determination by adding ample water to the soil sample.
Compare the color of the soil sample with the soil color group in the manual. Place a ball of soil between your thumb and index finger, gently push the soil with the thumb and pinch it up into a ribbon. Allow the ribbon to emerge and extend over the index finger, breaking under its own weight.
Make sure that the color of the solution on the ground matches the corresponding color chart of the pH indicator dye used.
APPENDIX 2. THE PALAYCHECK ® SYSTEM
Glossary
Salinity – the salinity or level of dissolved salts (such as sodium chloride, magnesium and calcium sulphates and bicarbonates) in the soil. Soil drainage – refers to the frequency and duration of periods of saturation in the soil. Soil family – a group of soils within a subgroup with similar physical and chemical properties that influence their responses to management and manipulation for use.
Soil profile - includes a collection of all genetic horizons, natural organic layers on the surface, and parent material or other layers below the salt that influence the formation and behavior of the soil. Soil Series - A group of soils with similar profiles that have developed from similar parent materials under comparable climatic and vegetation conditions. Soil taxonomy - a hierarchy of classes that allows understanding 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. In concrete terms, it refers to the proportions of clay, silt and sand with a diameter of less than 2 millimeters. Soil water retention – the ability of the soil to retain water to provide a continued water supply to plants between periods of recharge (infiltration) to enable their continued growth and survival.
The width (average, or average width and maximum width) of the cracks on the surface is indicated in centimeters. Tuff – a rock made up of the finer types of volcanic debris usually fused together by heat. Workability/slope – the ease of working the soil in relation to the structure, texture, presence of coarse fragments and relief.
We thank the Bureau for Land and Water Management (BSWM) for the secondary data of the soils used in this guide.
