Earth Science: Learning Competencies PDF

EARTH SCIENCE LEARNING COMPETENCIES: ✓ Recognize what soil is and why it is importance resource ✓ Identify human activities such as farming, construction of structures, and waste disposal,...

EARTH SCIENCE LEARNING COMPETENCIES: ✓ Recognize what soil is and why it is importance resource ✓ Identify human activities such as farming, construction of structures, and waste disposal, that affect the quality and quantity of soil ✓ Describe how people generate different types of waste as they usevarious materials and resource ✓ Explain how different types of waste affect people’s health and theenvironment ✓ Appreciate the importance of conserving and protecting the soilfor future generations After going through this module, you are expected to answer the key questions: o How is soil formed and what are the factors that affect its characteristics? o What human activities are dependent on the use of soil and how do these activities affect soil quality? o How do human activities affect the environment? 1|  Do you remember playing with the soil when you were a kid? It is undeniable that digging, planting, building castles, and making mud pies out of soil is so much fun. Most of the time, people use the term dirt and soil interchangeably. This is why most parents usually inhibit their child from playing with soil. However, these two words are so different. Dirt is what makes something dirty. Therefore, you are not playing with dirt but you get dirty when playing with the soil. The soil’s function goes beyond this context. Soil is a medium for plant growth, a habitat for various organisms, a filter which helps clean the water, and many more. As a whole, soil is so much different from the simple dirt that you may be picturing. 2|  Module 4: SOIL AND MAN The Pedosphere Soil is an essential component of Earth; it forms the pedosphere. “Pedosphere” is derived from the Greek words pedon which means “soil” and sfaira which means “sphere.” Soil is unconsolidated regolith modified over time by water, air, and organic material. This is the layer that supports the growth of plants The Component of Soil 3|  Soil Science Soil science or the study of soil is concerned with soil characteriza tion, classification, mapping, physical, chemical, hydrologic, minera logical analysis, soil assessment, and evaluation. Soil science has two divisions—edaphology and pedology. Edaphology Edaphology comes from the Greek word “edaphos,” which means ground. Therefore, it is the study of soil as a habitat for living organisms. This division is concerned with how soil influences organisms especially plants. Pedology Pedology comes from the Greek word “pedon,” which means soil. This division involves the study of soil as a geologic entity, meaning, its formation, classification, chemistry, and morphology. 4| Soil Formation As shown in picture below, the process of soil formation involves four main steps. The first step is rock disintegration. The forces of wind, rain, freezing and thawing water, volcanoes, and earthquakes all work together to slowly break down rocks into smaller particles that will eventually create soil. The second step is also termed as the early stage of soil. In this stage, simple organisms thrive such as lichens. These lichens are especially important because of their ability to trap water, silt, and dust in the soil. Furthermore, when they die, they increase the amount of organic matter in the soil. In the third step, the soil slowly develops. It can now support plants with roots. The final step is where the soil is developed to support thick vegetation. Factors that affect soil formation: 1. Parent material – the source of regolith. Parent material undergoes physical and chemical changes during the process of soil formation. When the resulting soil is found in the same place as the parent material, it is called residual soil. When the source of material is coming from unconsolidated 5|  deposits transported by different media, the soil formed is called transported soil. 2. Climate- It determines how temperature and moisture vary and determines the intensity of the weathering processes. 3. Topography- Slope and aspect affect the moisture and temperature of soil. Steep slopes facing the sun are warmer. Steep soils may be eroded and lose their topsoil as they form. 4. Biological factors- Plants, animals, microorganisms, and humans affect soil formation. Animals and microorganisms mix soils and formburrows and pores. Plant roots open channels in the soils. Different types of roots have different effects on soils. Grass roots are fibrous near the soil surface and easily decompose, adding organic matter. Taproots open pathways through deeper layers. Microorganisms affect chemical exchanges between roots and soil. Humans can mix the soil so extensively that the soil material is again considered parentmaterial. 5. Time- Time is also a component for the other factors to interact withthe soil. Over time, soils exhibit features that reflect the other forming factors. Soil formation processes are continuous. Recently depositedmaterial, such as the deposition from a flood, exhibits no featuresfrom soil development activities. The previous soil surface and underlying horizons become buried. The time clock resets for these soils. Terraces above the active floodplain, while similar to the floodplain, are older land surfaces and exhibit more developmentfeatures. Soil Texture Soil texture is defined as the relative proportion of the particle sizes in the soil-sand, silt, and clay. Soil is naturally composed of a mixture of these particles and proportion of which affects other soil properties such as soil porosity and water retention. The proportions of clay, silt, and sand are plotted in the soil textual triangle to determine its soil type base on particle size. 6|  Soil Profile A soil profile shows the sequence of soil horizons from the surface down to the underlying bedrock. It varies depending on climate, topography, rock type or parent materials, biological activity, and time. Soil scientists use the capital letters O,A,B,C, and E to identify the soil horizons. O (humus or organic), composed of loose or partly decayed organicmatter. This horizon is a habitat to many microorganisms such as bacteria, algae, and fungi. It may be thin, thick, or absent in some soils. A (topsoil) is composed of mineral matter mixed with somedark organic humus. 7| E (eluviated)some have this horizon, characterized minerals and leaching. The concentration of sand, silt particles of quartz or other resistant minerals remained. This is the zone of eluviation. Eluviation is the process of washing out of soil particles by the downward percolation of water. This downward percolation of water dissolves soluble components, which are carried to deeper zones, along with finer sediments. This process is called leaching. B (subsoil) is the accumulated clay and other nutrients from the layersabove it. This layer is often referred to as the zone of accumulation. C (substratum) is composed of partially altered parent material. It is characterized as partially altered bedrock. Parent material can be easily identified in this layer. Little or no sign of soil formation is evident in this layer. R use for hard bedrock, which is not soil. 8| 9|  Soil Taxonomy 1. Gelisols -frozen soils; found in the coldest regions on Earth 2. Histosols -organic wetland soils; high organic content and wet 3. Spondosols – cool temperate, acidic soils; sandy and acidic soils found in moist climates that often support dense forests 4. Andisols -volcanic ash soils; composed of volcanic ash 5. Oxisols -highly weathered tropical soils; very weathered and common in tropical climates 6. Ventisold – shrinking and swelling soils; clay like soils that shrink and swell 7. Aridisols – dryland soils; very dry soils in arid regions 8. Ultisols- weathered tropical and subtropical soils; weathered soils 9. Mollisols-grassland soils; deep and fertile soils 10. Alfisols-moderately weathered soil; moderately weathered productive soils found in temperate and humid regions 11. Inceptisols-slightly developed soils; slightly developed, young soils found on steep slopesand mountain ranges 12. Entisols -undeveloped soils; Newly formed soils found in steep rock lands The Philippines recognizes nine soil orders according to Bureau of Soils and Water Management (BSWM) which include alfisol, andisol, entisol, histosol, inceptisol, mollisol, oxisol, ultisol, and vertisol. 10 | 11 | 12 |  Soil and Soil Quality Soil is important in sustaining man’s existence and provides humans with the following services: 1. Arable land for agriculture – The word arable comes from Latin word arabilis which means “able to be plowed.” Arable lands refer to lands that are capable of producing crops or are suited for farming. These agricultural lands are distributed worldwide. The Philippines, as of 2003, has 5.7 million hectares and is 38th in rank among the countries worldwide. The United States ranks first with 174.45 million hectares. In contrast to arable lands, non-arable lands are those which are not suited for farming. 2. Regulating water and filtering potential pollutants 3. Nutrient cycling 4. Foundation and support 5. Mineral deposit -Soils are mined for their mineral content- whether it be iron, nickel, or aluminum. These soils are called Laterites. 13 | 14 |  How Human Activities Degrade Soil Quality The Food and Agriculture Organizations of the United Nations (UN FAO) define soil degradation as a change in the soil health status in a diminished capacity of the ecosystem to provide goods and services for its beneficiaries. Degraded soils cannot provide the goods and services required by its ecosystem. Soil degradation results in the loss of arable lands and drought and aridity. Degradation also takes away the soil’s ability to hold water which results in increased flooding. Polluted soil affects water quality as toxic substances in the soil are eventually discharged in waterways. Around 40% of soil used in agriculture worldwide are identified as degraded or seriously degraded. 1. Soil erosion 2.Soil compaction 3. Desertification 4. Intensive agriculture 5. Urbanization or the increasing population has led to the conversion of land to urban center 33% of global soil is moderately to highly degraded through erosion, salinization, compaction, acidification, chemical pollution, and nutrients depletion which hamper soil functions and limit food production. ❖ Human Activities Here are some human activities that leave the soil exposed and 15 | speed up erosion. We speed up erosion through the following actions. 1. Agricultural Depletion - Farming can degrade the topsoil and lead to an increase in erosion. To plant a field, a farmer must first till the soil, breaking it up and loosening it so the new plants can take root. Planting cover crops in the fall can help maintain the soil. In addition, rotating the crops planted can help return nutrients to the soil to prevent its degradation. 2. Overgrazing Animals - Grazing animals are animals that live on large areas of grassland. They wander over the area and eat grasses and shrubs. They can remove large amounts of the plant cover for an area. If too many animals graze the same land area, once the tips of grasses and shrubs have been eaten, they will use their hooves to pull plants out by their roots. 3. Deforestation - Deforestation is another practice that can greatly increase the rate of erosion in a region. One of the most important barriers to erosion is plant life, as long-lived trees and other species put down roots that literally help hold the soil together. 4. Mining operations are major contributors to erosion, especially on a local level. Many mining techniques involve shifting large amounts of earth, such as strip mining or mountaintop removal. 5. Development and Expansion - Urban and suburban development can also exacerbate erosion, especially if the developers ignore the natural state of the land. Construction of a building often begins by clearing the area of any plants or other natural defenses against soil erosion. In addition, some landscapers replace natural ground cover with plant species unsuited to the climate, and these plants may not be as effective at preventing erosion. 6. Recreational activities, like driving vehicles off-road or hiking - Humans also cause erosion through recreational activities, like hiking and riding off-road vehicles. An even greater amount of erosion occurs when people drive off-road vehicles over an area. The area eventually develops bare spots where no plants can grow. Erosion has become a serious problem in these areas. 16 |  Conservation of Soil Resource 1. Increasing soil organic matter 2. Keeping the soil covered and vegetated 3. Avoiding excessive tillage 4. Manage pests and nutrients efficiently 5. Promoting crop rotation 17 |  6. Reducing erosion and preventing soil compaction 18 |  Topic 3 Human Activities, Waste, and Waste Management Humans cope with the progressively rising living standards through industrialization, modernization, and innovation in technologies. Humans exert effort to improve the ways in transportation, food security processes in the form of agriculture, and harnessing energy sources to make living much more comfortable to the present and future generations. The drawback, however, is the inevitable 19 | production of immense amounts of waste, which are by-products of these developments. Some of these wastes are treated properly for proper disposal but most goes directly to the environment and accumulates. Excessive waste production is detrimental to human health and the environment. However, with proper waste management, and environment-friendly practices and policies, the harmful effects of these wastes can be minimized. This unit focuses on the classification of wastes, identification of its sources, and the proper waste disposal of commonly human generated wastes that could harm the environment. ❖ Waste Waste refers to any discarded or rejected material mainly from human activities and some other processes. In general, and for simplicity, waste can be classified as solid and liquid waste. Solid wastes, as their name implies, refers to wastes that are in solid form. Solid wastes are further subdivided as either putrescible or non- putrescible. Types of solid waste: 1. Municipal waste includes materials that people in a community no longer want because they are broken, spoiled, or no longer useful. 2. Agricultural waste is a common form of waste derived from farming and poultry. 3. Industrial solid waste comes from industrial sources other than mining. 20 |  4. Mining waste Liquid Wastes Liquid wastes are those that are in liquid form, freely flowing when transported or heated to 60°C and are not capable of being picked up by a spade or shovel. Method of Waste Disposal Waste may be disposed in a landfill, burned through incineration, converted into mulch or compost, or they could berecycled. 1. Landfill is the cheapest and the most convenient method. However, the threat of groundwater contamination reduces the use of this practice. Landfill Waste Management Landfill involves the dumping of waste in a designated area. This area resembles a pit lined with an impermeable clay layer designed to minimize infiltration through underlying soil layers. However, in cases where the leachates leak through the clay layers, they contaminate the groundwater and badly affect water quality, leading to adverse health effects in nearby communities. Furthermore, landfill sites contribute to increased methane and carbon dioxide levels in the atmosphere, which contribute to the rising global temperature. This is why landfill dumping, despite the significantly cheaper costs involved in processing, is not highly encouraged as a disposal method. 21 |  The so-called Smokey Mountain, which was once located in Tondo, Manila, is a known example of a landfill site here in the Philippines. It started out as an unplanned landfill in the 1950s. In the 1980s, its population climbed to over 30,000 with people living off scraps and wastes dumped in the landfill. The landfill was eventually closed in the 1990s. 2. Incineration involves burning in a controlled manner using an incinerator. Later used to generate electricity. Incineration Incineration uses combustion or burning of wastes to recover energy and reduce the number of wastes going to disposal. During incineration, waste materials are converted to gases, particles, and heat which are later used to generate electricity. However, combustion-based processes such as incineration can emit harmful pollutants such as heavy metals, dioxins, and furans into the air, land, and water, causing harm to the environment and human health. This is why despite its potential for energy recovery, incineration as a waste disposal method is highly discouraged in many countries including the Philippines, and it continues to be a 22 |  major subject of environmental debates globally. 3. Mulch and compost method is one of the simplest methods to dispose of waste at homes. Composting is the method of allowing the natural process of decomposition to transform organic materials into humus-like material called compost. 4. Composting Composting is a natural process of recycling decomposed organic materials into rich fertile soils known as composts. Thus, composting is known to contribute to the optimum growth and development of plants. This activity also increases plant’s resistance to pests, therefore lessening the need for the treatment of pesticides. In the process, organic materials and minerals, normally in the form of food wastes, are combined. This compost pile will be decomposed by natural 23 |  bacteria with the presence of oxygen and then produces the finished compost together with other byproducts, such as water, heat, and carbon dioxide. 5. Source reduction refers to the method of designing, manufacturing, purchasing, using, and reusing materials so that the amount of waste or its toxicity is reduced. 6. Recycling is the method of collecting throwaway materials and turning them into useful products. Recycling Recycling involves the recovery and reprocessing of materials from products after they have been used by consumers. Usually, waste ends up having different uses after it has been recycled. Among the most common types of wastes recycled are solid household wastes, such as paper, plastics, and glass. 24 |  ❖ Waste Management 1. Reducing the waste at the source involves buying durable products that can be used for a long time and refraining from buying disposable products that lead to more waste. 2. Reuse and recycle solid waste to serve another purpose. 3. Treatment of waste minimizes its effects on the environment. Waste management in homes, schools, communities, and industries can be done using the waste management hierarchy ofoptions. 25 | Legislation on Waste Management The ever-growing problem of excessive waste production and pollution called for policies to be implemented by government agencies and numerous environmental organizations. In the Philippines, most waste management practices are governed by the Republic Act 9003 known as the Ecological Solid Waste Management Act of 2000, which basically aims to protect the 26 | public’s health and the environment through proper waste disposal and environment-friendly methods of utilizing our resources. Since its implementation, government offices, as well as those in the private sectors, have conducted various programs towards a greener and cleaner country. Numerous local government units passed ordinances banning the use of plastics and foams, which clogged waterways and drainage systems resulting in flooding and water pollution. Shopping mall giants, such as Shoemart and Ayala Malls, promoted the three R’s (Reduce, Reuse, Recycle) through their ecobag programs and nationwide recycling fairs. Segregation was also strongly enforced through “no segregation, no collection” campaigns The RA 9003 also mandated the establishment of materials recovery facilities (MRFs) in individual or clusters of barangays, schools, malls, and other establishments. These MRFs receive, sort, and process compostable and recyclable materials. Dump sites were closed and were replaced with sanitary landfills whose impermeable linings prevent leachates from polluting ground and surface waters. Olivar III, J, et.al. (2016). Exploring Life Through Science , Quezon City: Phonix Publishing House, Inc.. Refran, J, et.al. (2016). Earth Science. Quezon City : Vibal Group Inc., https://www.earth-science-teaching-guide?from_action=save 27 |