Exam 3: Biofuels/Biochar

What is biochar? What two factors strongly affect the composition of the resulting biochar?

Biochar is a name for charcoal when it is used for particular purposes, especially as a soil amendment
Pyrolysis conditions, feedstock material

What are two potential benefits and one limitation of biochar use as a soil amendment?

Enhance plant growth by various means, increase microbial numbers and activity, alter microbial community structure

Why are biofuels considered to be more carbon neutral than fossil fuels?

The carbon in biofuels is derived from recent carbon fixation by plants and so its considered to be renewable (carbon neutral) in the sense that carbon dioxide produced by its combustion does not come from fossil sources but rather from the atmosphere.

What are four types of biofuels that were covered? What is one potential negative consequence for soil health of growing biofuels instead of food? (can be choose to be specific to a type of
biofuel or all)

Starch-based ethanol, cellulosic ethanol, biodiesel, stover and biomass crops
Depletion of soil nutrients