Study Guide for Chapters 3.5 and 12: Nutrient Cycles, Soil, and Food Resources

Study Guide for Chapters 3.5 and 12: Nutrient Cycles, Soil, and Food Resources

Chapter 3

• Know the major reservoirs on Earth: Atmosphere, Lithosphere (especially soils), Hydrosphere (especially oceans), Biosphere.
• Be able to explain the following processes in the water cycle: transpiration, evaporation, precipitation, condensation, infiltration, percolation, runoff, groundwater, and aquifer.
• Be able to define the basic processes of the carbon, nitrogen, phosphorus and sulfur cycles.

Know for all cycles:

• Why the nutrient is importantfor living organisms; what forms it takes; what the major reservoirs are (sources and sinks), what the processes are that transform the nutrient and move it from one reservoir to another; how the nutrient gets into the food chain,the role of microbes (bacteria) in the N and S cycles, and how humans are influencing the cycle. Review the cycle diagrams in the book, the handout of the flow diagrams for each cycle, and the Nutrient Cycle synthesis key (online). Be able to draw the cycles if assigned to one.

In particular:

• Carbon cycle: includingphotosynthesis (carbon fixation) and respiration, combustion of fossil fuels, the role of the ocean, and the formation of limestone (CaCO3).
• Nitrogen cycle: Understand the role of bacteria in nitrogen fixing, nitrification, and denitrification. Knowthat nitrogen-fixing bacteria found in the soil and on root nodules of certain plants (legumes) convert atmospheric N2 into nitrogen compounds in the soil. Know that the Haber-Bosch process is a method to produce synthetic nitrogen fertilizer.
• Sulfur Cycle: Know how it can lead to acid rain when sulfur dioxide (SO2) enters the atmosphere through combustion of fossil fuels, smelting of metal ores (refining process), or eruption of volcanoes.
• Phosphorous cycle: know there is no atmospheric component

Chapter 12: Soil

• Know what makes up a soil: major and minor sources. Know the different soil horizons
• Know the categories of inorganic soil components by particle size (sand, silt and clay). Be able to interpret a soil texture triangle. Know how the relative concentration of these different size particles affects the soil’s porosity, permeability, and water/nutrient –holding capacity. Understand the importance of each of these factors.
• Be able to define loam and humus.
• Know why pH is important
• Know the causes of soil erosion and degradation, and be able to describe the consequences of effects on the soil of each one: conventional tillage, overgrazing, deforestation, damage from wind and water, excessive irrigation(salinization and waterlogging)
• Know what desertification is, and why it is more common in arid areas.
• Know the advantages and disadvantages to using fertilizers to replenish soil.
• Be able to explain strategies to reduce soil erosion in agriculture, including conservation tillage farming (no till farming), terracing, contour farming, strip cropping, alley cropping techniques, wind breaks, organic fertilizer, crop rotation, and irrigation techniques that reduce water usage.

Chapter 12: Food and Pest management

• Know the effects of malnutrition/under-nutrition, and that this is most prevalent in underdeveloped nations.
• Know the components to food security (i.e. access, availability, and utilization), and major threats to food security
• Know what over-nutrition is.
• Know what the Green revolution was and how it affected food production and soil use. Be able to describe some of the agriculture advances in the Green Revolution and know when this increase in agricultural output began.
• Know what industrialized agriculture is, including monocultures and plantation agriculture, vs. traditional agriculture. Know where these types of agriculture tend to take place.
• Know which continents are net food producers (food exporters), and which continents have a food deficit (food importers)
• Be able to define Genetically Modified Organism (GMO) and the alternate terms for this biotechnology (transgenic organism, recombinant organism or genetically engineered organism). Know that it involves inserting genes from other species into crop species. Know why it is done.
• Understand how GMO’s have been developed along with herbicides such as glyphosate (Roundup). Understand the development of Roundup-resistant weeds. Know the pros and cons to Glyphosate (Roundup)
• Know the advantages and disadvantages to using GMO’s.
• Know about the history of DDT and the role that Rachel Carson played in exposing the dangers of DDT
• Understand how pesticides bioaccumulate in organisms and biomagnify up the food chain. Know the potential connection to the decline of bee colonies.
• Know that alderin (DDT replacement) was also found to be too harmful and was banned.
• Know the difference between a broad spectrum pesticide and a narrow spectrum pesticide.
• Know the advantages and disadvantages to using pesticides.
• Know what the FIFRA and the Food Quality Protection Acts are, and which government agencies oversee them.
• Be able to define Integrated Pest Management (IPM). Be able to describe pest reduction strategies besides pesticides: pheromone traps, crop rotation, pest predators.
• Know the issues with industrialized meat production, including large use of water and grain, poor treatment of animals, animal waste runoff, potential health effects of using growth hormones and antibiotics
• Know what aquaculture is, and what the advantages and disadvantages are of using aquaculture.