Soil Organisms and Ecology: Roles, Functions, and Interactions, Study notes of Agricultural engineering

Download Soil Organisms and Ecology: Roles, Functions, and Interactions and more Study notes Agricultural engineering in PDF only on Docsity! Introduction to Soils in the Environment Page 1 SOS 3022 Study Guide – Summer 2001 Chapter 10 - Organisms and ecology of the soil 1. Appreciate the significant role of soil organisms play in our ecosystem by degrading or decomposing organic materials or wastes. 2. Understand the differences between herbivores and detritivores, anaerobic and aerobic soil organisms, and autotrophic and hetertrophic soil organisms. 3. Have a "feel" for the relative numbers and biomass of bacteria, actinomycetes, fungi, algae and other soil organisms in surface soils (Table 10.1). 4. Be familiar with different methods to quantify soil organisms: numbers, biomass and metabolic activities (CO2 evolution). 5. Be familiar with the relative microbial activities in soils under grassland and forest (broadleaf and coniferous). 6. Be familiar with the quantity of earthworm casts produced in soils and their beneficial effects on soil properties (Table 10.3). 7. Understand the importance of plants roots to soil organisms and note the general relation of root biomass to above-ground biomass for higher plants. 8. Understand concept of rhizosphere, the difference between rhizosphere and bulk soils, and the significance of rhizodeposition from plant roots. 9. Be familiar with the functions of algae in soils and types of soils you are most likely to find algae. 10. Understand the definition and role of mycorrhizae (a symbiotic association between plant roots and fungi), and their ability to enhance nutrient supply, especially immobile nutrients like P, to plants. 11. Be familiar with the role of soil bacteria in nitrogen oxidation (nitrification), sulfur oxidation and nitrogen fixation in soils.