This manual on "Simplified Soil Series Keys" was developed to facilitate soil identification in the field. It contains the different colors, textures, pH and other notable characteristics of the most common soils of Zambales and contains four simple steps to identify the soil series right in the field. In the Philippines, the Nutrient Management Support System (NuMASS) project “Simplifying the Philippine Soil Series for Rice and Maize” was initiated in 2005 to provide management recommendations for soils identified in the field.
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. Use the simplified soil key series guide and compare all soil properties starting from color until the soil name is identified.
Gray
Strong/Reddish Brown
Brown
Dark Brown
Dark gray and brown spots; sticky and waxy when wet; cracking of the topsoil when it dries.
Olive Gray
Yellowish Red
Stonyness Outcrops of boulders/some weathered gravels below 0.2 m depth Root depth Deep (>1 m) Erosion Moderate to severe. Soil type: Sandy loam/clay Area: 19,711 ha Family: Fine clayey, kaolinitic, isohyperthermic, Typical Kandiustox This is a finely structured soil with a clay content of 35-60% and has an isohyperthermic temperature regime (>22°C). It is an Oxisol (-ox), an intensely weathered soil dominated by oxides of iron and aluminum resulting from repeated high precipitation and high temperatures (-ust).
It is a typical representative of the large group Kandiustox, which has low base saturation (kandi-). Soil type: Sandy loam/ fine sand Area: 39,837 Family: Sandy, mixed, isohyperthermic, Typical Ustipsam- A young soil with only a small development and soil properties largely determined by the parent material (-ent, Entisol). Soil Type: Clay Area: 57,721 ha Family: Fine, Mixed, Isohyperthermic, Kandic Paleustalf An ancient soil that has undergone extensive weathering with illuvial accumulation of clay in the subsoil horizon from the underlying horizon (-alf, Alfisol).
Soil type: Clay Area: 5,944 ha Family: Fine loamy, montmorillonitic, isohyperthermal, Typical Haplustalf An old soil that has undergone extensive weathering but has retained a high base status in its horizon (-alf, Alfisol) and that has minimal complexity in its horizon (hapl-). It is repeatedly saturated with water (aqu-) but not as wet as the typical, which means it is better aerated, usually because groundwater is deep or the saturation period is shorter (air). Soil type: Sandy clay loam Area: 12,038 ha Family: Loam skeleton, kaolinitic, isohyperthermal, Typical Kandiustalf An old soil that has undergone extensive weathering but has retained a high base status in its horizon (-alf, Alfisol) but has a low cation exchange capacity (candi-).
Family: Sandy, mixed, isohyperthermic, Typical Psamma- A young soil with only weak development and soil properties largely determined by the parent material (-ent, Entisol). Soil type: Silt loam Area: 7,767 ha Family: Fine, montmorillonitic, isohyperthermic, Typical Hap- An ancient soil that has undergone extensive weathering but has retained a high base status in its horizon (-alf, Alfisol) and that exhibits minimal complexity in its horizon (hapl-). It is also a synthesis of conditions for soil fertility, water management, plant species, soil, 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. The inherent productivity is the natural capacity of the land to produce a given yield while the potential refers to the capacity of the land to produce yield after correctable land constraints are removed.
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 it is dry, determine a moist color by adding plenty of water to the soil.
Compare the color of the soil sample with the soil color set 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, the natural organic layers on the surface and the parent material or other layers below the solum that influence the formation and behavior of the soil. Soil series - a group of soils with similar profiles, developed from similar parent materials under similar climatic and vegetative conditions. Soil taxonomy – hierarchies of classes that allow understanding the relationships between soils, but 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 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 of Soils and Water Management (BSWM) for the secondary soil data used in this manual.
