Soil Resources Earth Science Learning Objectives: describe soil and its types. identify human activities, such as farming, construction of structures, and waste disposal, that affect the quality and quantity of soil. realize the environment’s cleanliness by reducing waste products to prevent health problems that may occur in schools, homes, and communities by citing examples. participate actively in the discussion responding orally through recitation. by Today's lesson: Soil Sub Topics: Horizons Types of Soil Human Activities that affect the Quality and Quantity of Soil Introduction Soil is the outmost part of the earth’s crust on that we have a tendency to live, work and grow food crops. Soil provides all mineral nutrients, anchorage, and water required for the expansion and development of plants and animals. What is a Soil? Soil Soil is the thin layer of material covering the earth’s surface and is formed from the weathering of rocks. It is a mixture of minerals and partially decomposed organic matter that is divided into different layers based on a composition called horizons. Layers of Soil Mountain Plateau O Horizon Humus on the ground surface. Mostly non-decomposed plant litter can be found in forests. A Horizon • Topsoil, contains a lot of organic matter mixed with some minerals. • Rich in nutrient organic matter and biological activity. Typically, dark color. • Grasslands have the largest A horizon. • Zone of Leaching B Horizon • Zone of Accumulation • Made of small particles of minerals that form clay. • Clay-rich subsoil. This horizon is often less fertile than the topsoil but holds more moisture. It generally has a lighter color and less biological activity than the A horizon. C Horizon • Underlying weathered rock (from which the A and B horizons form). • Weathered bedrock (rotten rock). R Horizon • Bedrock (Parent material) from which the soil was formed. Types of Soil Chalk Sandy Silt Loamy Sandy • It consists of small particles of weathered rock. • One of the poorest types of soil for growing plants. • Is usually formed by the breakdown or fragmentation of rocks like granite, limestone and quartz. Silt • made up of rock and other mineral particles, which are smaller than sand and larger than clay. It is the smooth and fine quality of the soil that holds water better than sand. • The silt soil is more fertile compared to the other three types of soil. Therefore, it is also used in agricultural practices to improve soil fertility. Clay • Clay is the smallest particle among the other two types of soil. The particles are tightly packed together with each other with very little or no airspace. • This soil has very good water storage qualities. • Clay is the densest and heaviest type of soil which does not drain well or provide space for plant roots to flourish. Loamy • It is a combination of sand, silt, and clay. It has the ability to retain moisture and nutrients; hence, it is more suitable for farming. • Referred to as "agricultural soil”equilibrium of all three types of soil materials being sandy, clay, and silt and it also happens to have humus. • It also has higher calcium and pH levels Peat • Peat soil is high in organic matter and retains a large amount of moisture. • This type of soil is very rarely found in a garden and is often imported into a garden to provide an optimum soil base for planting. Chalk • Can be either light or heavy but always highly alkaline due to the calcium carbonate or lime within its structure. • As these soils are alkaline they will not support the growth of ericaceous plants that require acidic soils to grow. Human activities that leave the soil expose and speed up erosion Agricultural Depletion Overgrazing Animals Deforestation Development and Expansion • Recreational Activities • • • • Human activities that affect the Quality and Quantity of Soil Farming • Negative Effect of Farming • Tillage - All tillage operations, including aerations and sward lifting, cause direct damage to soil macrofauna to new predators. • Pesticides - These are diverse groups of chemicals used to control insects and other organisms harmful to cultivated plants and animals. Farming • Negative Effect of Farming • Veterinary Medicines • Direct application of antimicrobials and nematicides usually used as veterinary medicines to soil has been shown to have a negative impact on soil organisms. Farming • Positive Effect of Farming • Herbicides • Earthworms seem to benefit more from weedy conditions than other species groups but, in general where weeds don’t restrict crop growth or adversely affect forage quality, they should be considered as a positive benefit for soil health. Farming • Positive Effect of Farming • Organic Manures and other Organic Fertilizers • These materials provide inputs of organic matter thus providing a source of energy/food for many of the soil organisms. Therefore, when applied regularly, organic fertilizer inputs generally lead to an increase in the populations of all soil organisms. Farming • Positive Effect of Farming • Lime and Mineral Fertilizers • Provides stable optimum growing conditions, meets plant nutrient demand, and maintains a balanced nutrient budget. In general, lower rates of application are used in grassland than in cropping systems; however, intensive dairy pasture may receive high rates of nitrogen fertilizers. Farming • Positive Effect of Farming • Growing Plants • Plant growth is directly linked to soil organisms, it is the plant that provides energy through root growth and exudation in the soil during growth and the amount of quality of litter and residues turned to the soil. The action of roots is important for the development and stabilization of soil structure. Roots tend to compress soil in their vicinity changing pore size distribution. Farming • Positive Effect of Farming • Drainage and Irrigation • The main effect of irrigation and drainage on soil organisms and consequently on soil health is indirect. By regulating the seasonal effects of rainfall patterns, irrigations and/or drainage tend to stabilize the soil moisture regime away from extremes. Irrigation in dry seasons reduces the disturbance effect of soil drying and can increase the length of time during which soil organisms are active. Construction of Structures • Urban development activities can cause rapid soil degradation and sedimentation. Soil erosion and sedimentation from construction sites can be significant in quantity and in the impact on offsite resources such as streams. Construction of Structures • Erosion which produces sediment, is accelerated when soil is disturbed, left bare, and exposed to rainfall. Construction activities, such as grading and filling, reduce soil quality on construction sites. • Urban development activities can cause rapid soil degradation and sedimentation Waste Disposal • Hazardous chemicals that get into the soil (contaminants) can harm plants when they take up the contamination through their roots. If humans eat plants and animals that have been in contact with such polluted soils, there can be a negative impact on their health. Contextualization /Localization: How do farmers manage to plant crops given they have different types of soil in their areas? Values Integration: Why do we need to reduce waste products to prevent health problems that may occur in schools, homes, and communities? As a Marist student. How can you reduce waste products to prevent health problems that may occur in schools, homes, and communities? Soil Conservation Earth Science Learning Objectives: identify methods for soil conservation and protection for future generations. recognize the soil as one of the resources that the farmers developed as the source of life and agriculture by citing examples. participate actively in the discussion by responding orally through recitation by using Zoom’s reaction button. Soil Conservation? Soil conservation contributes to sustainability and offers the following benefits: • Improves soil quality and productivity. Increased fertility improves crop yields, reduces the need for chemical fertilizers, and saves money. • Optimizes water infiltration. Better filtration increases water storage, preventing soil from drying out. • Provides food and shelter. Soil-producing vegetation provides nourishment to all types of animals and offers protection from the elements. Soil Conservation Methods Forest Protection The natural forest cover in many areas has decreased due to commercial activity. One of the purposes this cover provided was the protection of the soil. Businesses involved in building constructions can conserve by ensuring these areas are protected. Buffer Strips • Soil erosion is a large problem that is being battled around the country. This is particularly an issue where there are natural bodies of water. • Buffer strips come in handy for conservation efforts. They provide protection where stream banks exist. They can be created with grass, trees and shrubs. No till Farming • This process can work to enhance the soil’s composition. It is possible to do this work and still conserve the soil. No-till farming is an approach that allows crops to remain in place for a season. • This keeps the soil from being left bare and unprotected. Fewer Concrete Surfaces • The soil requires an adequate amount of water in order to function properly. Lots of concrete surfaces, especially in residential areas, make it difficult for water to get to the soil. • Using paving stones for patios and gardens work to protect the soil. They are also a tool to prevent soil erosion in specific areas. Plant Windbreaks Areas • Windbreaks are composed of shrubs, plants, and trees. They work in combination and serve a conservation purpose. These will work together to slow the force of wind over ground areas. This is a method that can also work to prevent erosion of soil. Terrace Planting • This type of planting is done by maximizing the topography of the land. It benefits from the way the rainwater flows naturally. This is a way to protect the soil from erosion. It is also a proven method to encourage growth from moist soil areas. Crop Rotation • The way you plant your crops can have an impact on the soil. Crop rotation is a process that works to conserve soil. It is accomplished by planting and growing a series of different crops in the same soil. Overall, this process prevents overgrowth of pathogens and a lack of fertility in the soil. Mulch • Mulch is one of the great conservation tools that protect the soil, and the majority of these are used simply to beautify lawns. Mulch works to prevent erosion from the wind. It is also a great product to help the soil to retain the water it needs. Dig Drainage Channels to Guide Water Run Off • Create channels where water might collect and around the edges of your property to redirect runoff water. Drainage channels reduce runoff and keep surges of water from carrying off soil or killing plants due to overwatering. Dams • Dams are important resources when it comes to soil conservation. These structures work to prevent soil erosion. This is especially important in areas where rivers exist. • Flooding of rivers has been the cause of many instances of soil erosion. Dams also offer additional protection. Maintain pH • The pH levels in the soil can be affected by a number of things. Pollutants and acids are just two examples in this category. Purchasing a soil tester is a good way to monitor your soil’s levels. This also allows you to learn what needs to be added to ensure healthy soil and conservation. Indigenous Crops • Farming is all about diversity, but indigenous crops are important. These are native crop options that enhance the soil. Planting these is a way to ensure conservation efforts. They should be planted even when diverse crops are being planted, as well. No Compacting • A simple conservation method that some gardeners and farmers apply is not to compact the soil. This is a protection method that is helpful. • You can do this by creating dedicated paths in your garden. This helps you not to walk on wet soil, causing it to be compacted. Importance of Soil Conservation Importance of Soil Conservation • The soil is literally the foundation of plant life • A tree will not be a tree without soil. While there are some plants that can live in water or air, most plants need to be rooted to the ground. It is the soil that provides nutrition to this plant life. It is through this vegetation that nourishes humankind and the animal kingdom. Plants are important resource of food and fuel and of wood and other by-products that make our other life functions possible. Importance of Soil Conservation • The soil additionally supports the animal kingdom. • Our agriculture also relies on soil, for its location and for other functions to be derived from its existence. It will be almost impossible to support the animal and human life without land. Biodiversity relies on soil at all times. Importance of Soil Conservation • The soil is necessary for water supply. • This is the magic of nature. The land is also necessary to ensure the quality of water we derive from our earth. Soil and water co-exist. • So do we and soil co-exist? Taking good care of our soil equates to taking care of our water supply. Contextualization /Localization: How do farmers develop our soil as a source of many agricultural products? Values Integration: Why do farmers need to conserve the soil as our resource? As a Marist student. How is soil one of our resources that are developed by farmers in the Philippines? Soil Resources Earth Science
