Earth Systems & Resources
Which of the following is not a physical property of soil?
Particle size
Permeability
pH
Aeration
How might overgrazing affect topsoil characteristics, directly influencing both productivity and environmental stability?
Increased soil erosion
Increased nitrogen fixation
Increased phosphate levels
Enhanced litter decomposition
What is the term used to describe the amount of water that soil can absorb given the effects of gravity upon the soil?
Permeability
Water-holding capacity
Aeration
Porosity
Which term refers to the nutrient levels of soil and to what extent it is able to support vegetation?
Permeability
Porosity
pH
Fertility
What is the term used to describe the ability of soil particles to attract cations?
Permeability
pH
Nutrient capacity
Cation exchange
What is the primary role of humus in the soil?
It binds soil particles into larger aggregates.
It increases soil fertility by adding organic matter.
It filters water to prevent pollutants from entering groundwater.
It aerates the soil by creating spaces for air pockets.
How would an excessive use of a single type of pesticide in an agricultural setting most likely affect soil biodiversity over time?
Increase diversity by creating new ecological niches.
Cause fluctuations in diversity without a clear trend.
Decrease diversity by eliminating pesticide-sensitive species.
Have no impact on diversity due to quick degradation.

How are we doing?
Give us your feedback and let us know how we can improve
Which soil particle is associated with the best water-holding capacity?
Clay
Silt
Sand
Loam
Given current climate predictions involving increased precipitation variability what comprehensive policy should be enacted in flood-prone agricultural areas to prevent nutrient runoff into local watersheds?
Widening rivers through mechanical means only during peak rainfall seasons
Incentivizing uninterrupted cropping systems that maximize ground cover year-round
Promoting riparian buffer zones composed of native vegetation along waterways
Constructing higher levees around farmlands regardless of riverbank ecosystems
Considering the ecological, economic, and social aspects of sustainable agriculture, which measure is most effective at preserving soil biodiversity while still maintaining crop yields?
Relying on genetically modified crops for pest resistance.
Utilizing heavy machinery for rapid planting and harvesting.
Applying broad-spectrum insecticides regularly on crops.
Introducing cover crops during off-season periods.