* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Soil Notes PowerPoint
Survey
Document related concepts
Soil horizon wikipedia , lookup
Soil erosion wikipedia , lookup
Soil respiration wikipedia , lookup
Plant nutrition wikipedia , lookup
Crop rotation wikipedia , lookup
Terra preta wikipedia , lookup
Surface runoff wikipedia , lookup
Canadian system of soil classification wikipedia , lookup
Soil compaction (agriculture) wikipedia , lookup
No-till farming wikipedia , lookup
Soil food web wikipedia , lookup
Soil salinity control wikipedia , lookup
Soil microbiology wikipedia , lookup
Transcript
The unknown ecosystem What is soil? What is it made of? Where do we get if from? What is your “definition” of soil The number of organisms in one shovelful of soil The number of humans on earth More in one shovelful than all the humans that have ever lived on earth Many don’t even have names yet A Recipe for Soil Start with minerals Add organic materials (humus) Water Air It takes 100 to 100,000 years to form one meter of soil Soil forms by weathering and decomposition. Faster in warmer climates Why? Mineral (weathered rock) = 45% Air = 25% Water = 25% Organic matter (humus) = 5% Dark organic matter from decomposed plants and animals Provides nutrients for crops Soil organisms feed on it Absorbs and holds water 1000 fit on the head of a pin. Divide to reproduce every 20 minutes. Arachnids No eyes (it’s dark in the soil) Eat only fungus Also called round worms Only 1 mm long Some eat bacteria, some eat detritus, some eat fungus Live 3 to 6 years Eat detritus, also swallow soil Add bacteria back to soil https://www.youtub e.com/watch?v=Vu Hznslr8aI https://www.youtub e.com/watch?v=YF8 OJt_pujc https://www.youtub e.com/watch?v=cjV 2WP0wkvo The texture is caused by the size of the soil particles Sand – Between 0.06-2.0 mm in size Sandy soil drains quickly so roots can penetrate. Too much sand in a soil does not hold enough water and nutrients for most plants. Does not shrink or swell so it makes a good foundation for buildings. Silt – Between .002-.05mm in size. Silt allows for air to circulate but still retains some water. Silty soils do not usually hold enough water for most plants. Clay - < .002 mm in size. Water clings to tiny particles holding larger soil particles together forming clumps called aggregates. Aggregates like gravel provide drainage channels for water. Water will not drain in soils with a lot of clay. Clay is easily compacted, crushing air and water pore space. Plants root cannot penetrate through dense clay soils. Clay is a poor material to build on because it swells with water. Loam is soil with a mixture of sand, silt and clay. It is the best type of soil for most crops