| A | B |
|---|
| detritus | fallen dead leaves and other dead plant and animal material (litter on soil surface) |
| detrivores | litter feeders |
| transformers | special group of decomposers which break down large organic molecules into smaller molecules small enough to be absorbed by plant roots |
| herbivores | eats plants |
| omnivores | eat both plants and animals |
| carnivores | eats animals |
| decomposers | break down and feed on dead organic material |
| potassium | the nutrient that is the most limiting factor for crop and other plant growth |
| limiting factor | a factor such as food, space, water, shelter, disease, hunting which influences the life of any animal |
| groundwater | water that inflitrates the soil and is stored in slowly flowing and slowly renewed underground reservoirs called aquifers |
| surface runoff | a term used to describe when soil is infiltrated to full capacity and excess water, from rain, snowmelt, or other sources flow over the land |
| aquifers | underground water reservoirs |
| carbon dioxide | a by-product of respiration. This molecule is also used by plants in the production of sugars by photosynthesis |
| oxygen | a by-product of photosynthesis and is used by plants and animals for respiration |
| actinomycete | filamentous bacteria which form associations with nonleguminous plants and fix atmosperic nitrogen |
| nitrogen (N2) | 78% of the Earth's atmosphere |
| cyanobacteria | blue-green algae |
| colloid | soil particle |
| soil genesis | the study of the factors and processes of soil formation |
| soil forming factors | parent material, climate, relief, biota, time/exposure |
| relief | topography |
| biota | living organisms |
| soil horizons | distinct layers of soil |
| soil profile | the combination of the layers in sequence |
| parent material | the material underlying the soil from which, in most cases, the soil develops |
| mineral | a naturally occurring, inorganic crystalline material with definite physical properties and a unique chemical composition |
| igneous rock | "born of fire" (volcanic origin) |
| lava | molten material which flows onto the surface |
| magma | molten material which remains beneath the surface |
| sedimentary rock | formed from deposition of sediments or small rocks or remains of organisms |
| sedimentation | the deposition of sediments |
| erosion | the process of moving the products of weathering from one place to another |
| basalt | extrusive igneous rock |
| extrusive | rocks formed from lava |
| intrusive | rocks formed from magma |
| rock | complex mineral aggregates |
