Notes for Second Test

Notes for Second Test - Environmental Notes-Soil and Food...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Environmental Notes-Soil and Food Production Land Use: o Land in use: about 21% (grazed: 10%, cultivated: 11%) o “Potential” Cropland: 28% o Not Usable: 51% Top soil : soil concerned about o Critical o Rich and vital to environment o Comprised of: Detritus (dead decaying material), Mineral Particles, and Detritus Feeders Soil : page 198 o Different textures (sandy, clay, etc.) o Concerned about the mixture of the different materials (clay with clay loam and sandy clay, etc.)-percentage of each that makes up the overall soil o Loam: organic portion, richest, best for growing crops/workability o Determine by feel and sight o Concerned about: workability, pH, water and nutrient holding capacity o Acidity of soil-affects plants ability to absorb nutrients (sometimes have to add lime to soil-sweetens the soil) o If you add more loam to the soil, then everything gets better (workability, water capacity, etc.) Different Layers in Soil : see handout o Called horizons o O Horizon Surface Litter, freshly fallen leaves/organic debris o A Horizon Topsoil, partially decomposed organic material (humus), most critical o E Horizon Zone of Leaching, dissolved/suspended materials move downward o B Horizon Subsoil, accumulation of iron, aluminum, humic compounds
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
o C Horizon Parent Material, partially broken down, layer before bedrock o R Bedrock, impenetrable layer Capillarity and evaporation cause materials to rise, moves up, some pressure that can occur o Recharge area o Force of groundwater moving can actually push water up o Critical for plant growth Soil is an ecosystem (see chart on back of handout) o Most active area upper area, A Horizon, the topsoil o Rock particles, humus, fungi, bacteria, worms, insects, roots o Thickness varies in different types of biomes, not the same everywhere Soil Characteristics: o Grasslands: Rich thick layer of soil, deep dark layers of the topsoil o Deserts: Very little organic material, weak mix, lots of mineral material, topsoil is not very rich Water=limiting factor in desert for plant growth If put water in desert soil: grows crops very well Develop agriculturally productive area in desert areas through irrigation Problem: leaches down, soil becomes too salty, plant can’t absorb the nutrients, etc. anymore salinization o Deciduous Forest: Relatively thick layer, but not real real thick If you dig down, can find the A Horizon-less than a foot down Roots are where the nutrients are, so they stay where the topsoil is (only 1-2 ft)
Background image of page 2
o Tropical Forest: Acidic humus, iron, clay Not a rich layer of topsoil Because of greenhouse-like conditions growth of fungi, grow into roots of trees and deliver nutrients directly into the tree; no accumulation Not conducive to agriculture o Coniferous Forest: Has some accumulation Acidic Soil not the same everywhere (country to country, even within country) o See “Soil Types” handout
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/07/2008 for the course EESC 101 taught by Professor Bass during the Fall '07 term at Mary Washington.

Page1 / 12

Notes for Second Test - Environmental Notes-Soil and Food...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online