Скачать с ютуб Soil | Class 7 Science | Types of Soil | Online Classes | Session 3 - Swiflearn в хорошем качестве

Soil | Class 7 Science | Types of Soil | Online Classes | Session 3 - Swiflearn

Soil | Soil Class 7 | Soil Class 7 Science | Science Class 7 | Class 7 Science | Online Class 7 | Science Online Class | Online Science Class | Science Online Tuition | Online Classes | FREE Online Classes | Swiflearn Online Classes | Swiflearn Online | Swiflearn This is session 3 of the Chapter: Soil from Class 7 Science. In this Session, Trisika Mam will Introduce you the the Chapter: Soil Class 7 and will take you through the following topics: 00:00 - Introduction 10:17 - Absorption of water by soil 14:25 - Absorption of water by different soil 14:40 - Texture of soil 18:44 - Air content 25:15 - Soil erosion 27:45 - Overgrazing To Download FREE Revision Notes for this Chapter, Visit: https://swiflearn.com/revision-notes/... 🔸Now you can visit Swiflearn YouTube Channel to attend the LIVE classes that will cover your entire syllabus. 🔸SwifLearn is India's best platform for LIVE face-to-face online tuitions. Access to India's best teachers from the comfort of your homes. Maximum 6 students in a single batch. Deep individual engagement and attention are given to each student. #LIVEClass7​ #Class7Science 🔸SwifLearn provides LIVE ONLINE Face-to-Face Tuitions for Classes 1 to 10. 🔸Book a Free Trial Class; Visit our website: https://www.swiflearn.com​ Visit our Facebook page:   / ​   Visit our Instagram page:   / swiflearn   Visit our Linkedin page:   / swif.  . Download our App : https://play.google.com/store/apps/de... ------------------------------------------------------------------------- Soil Life on earth is highly dependent upon soil. It is important in the sense that it provides anchorage and supplies water and minerals to the plant Layers of the soil include:  Humus  water  clay  sand  gravel Climatic factors effecting soil include  Temperature  Light  Humidity  Rainfall  Wind Humus is the rotting dead matter in soil Weathering is the breakdown of rocks to form soil by wind, water and climate Plastic is a non-biodegradable substance which  Degrades soil quality  Kills microorganisms  Causes soil pollution  Demanded by many people to be banned Soil Profile Soil profile - A vertical section through the different layers of soil is called soil profile. These layers are the horizons. Soil profile consists of A horizon  Uppermost horizon and is also called top soil  Rich in humus and minerals which gives it a dark colour  Soft, porous, and high water retention capacity  Provide nutrients to growing plants and shelter to many living organisms B horizon  It is the middle layer Short Notes Class 7 Science Soil https://www.swiflearn.com/  It contains less humus and more minerals  More hard and compact layer C horizon  It consists of lumps of rocks  It has cracks and crevices Bedrock  The lowest layer  Hard and difficult to dig in  Soil is the mixture of humus and rock particles  The soil microflora also important for determining the quality soil Types of soil The 3 types of soil based on particle proportion include Sandy soil  great proportion of big particles  Light, well aerated and usually dry Clayey soil  great proportion of fine particles  Big, less aerated but hold more water Loamy soil  same proportion of big and fine particles  mixture of sand, clay and silt  contains humus and is the best soil for growing plants  Right amount of water retention capacity Silt occurs as a deposit in riverbeds and its particle size is between that of sand and clay. The cultivation of different crops is dependent of different soils.  Wheat, gram, paddy – clayey and loamy soil  Cotton – sandy loam soil Percolation of soil Percolation of soil - The process in which water passes down slowly through the sol Soil moisture – The water retained by soil. Water retention capacity of soil is an important factor various crop cultivation. Short Notes Class 7 Science Soil https://www.swiflearn.com/ Percolation rate is measured in ml/min is given by (Amt. of water in ml/ percolation rate in min) Percolation rate of water will vary with the type of soil – highest in sandy soil and lowest in clayey soil Soil erosion Soil erosion - The removal of soil surface by wind, water or ice  Areas devoid of vegetation has loose soil which is blown away by wind  Most affected areas include deserts and bare lands  It can be prevented by forestation