AGRI331: Quiz 13

The major productivity costs associated with soil erosion is (Applying Prin. Sust. Farming)

loss of nutrients

Environmentally friendly chemical fertilizers include: (Applying Prin. Sust. Farming)

mono-ammonium phosphate

The conversion of ammonium to nitrate is a process referred to as: (N Sources & Transformations)

nitrification

Refer to the following graph which shows phenotypic changes for three unrelated species that occur in different parts of the world. Species 2 evolves into new species 3 and species 4 evolves into new species 5. Which of the following illustrates directional selection?

species 4 only

In diverse farm systems, severe pest outbreaks are rare for two reasons: (Applying Prin. Sust. Farming) 1). Higher natural enemy populations persist in diverse mixtures 2). Pest insects usually feed on one type of plant and thus have fewer opportunities to feed, move around, and breed in diverse mixtures. 3). More animal manure is present in diverse mixtures which have allelopathic effects 4). Enhanced organic matter in diverse mixtures increase fungal pathogens on pest species

1 and 2

The carbon to nitrogen (C:N)ratio of microorganisms is (N Sources & Transformations)

20:1

In the Figure 3, what do R, S, T, U, and V refer to, respectively? (Applying Prin. Sust. Farming)

R= nutrient uptake, S = on farm consumption, T = manure, U = leaching losses, and V = erosion losses

Which is the correct sequence of how nitrogen is passed through its cycle? (N Sources & Transformations)

Fixation, nitrate formation, denitrification

Considering the N cycle, which of the following is nitrate not subject to? (N Sources & Transformations)

Volatilization.

The process of denitrification requires (N Sources & Transformations)

all of the above*

On the farm, energy capture is enhanced by __________ and _________________. (Applying Prin. Sust. Farming)

maximizing leaf area and efficient cycling stored energy through the food chain

Which is one of the primary roles of nitrogen in plant growth? (N Sources & Transformations)

building proteins

Transformation of organic N to ammonium in soils is termed (N Sources & Transformations)

mineralization

Keeping the soil covered with a skin of dead plant material, does the following, EXCEPT (Applying Prin. Sust. Farming)

decreases water penetration

An effective water cycle include all the following, EXCEPT (Applying Prin. Sust. Farming)

high soil surface evaporation

A student placed 20 tobacco seeds of the same species on moist paper towels in each of two petri dishes. Dish A was wrapped completely in an opaque cover to exclude all light. Dish B was not wrapped. The dishes were placed equidistant from a light source set to a cycle of 14 hours of light and 10 hours of dark. All other conditions were the same for both dishes. The dishes were examined after 7 days, and the opaque cover was permanently removed from dish A. Both dishes were returned to the light and examined again at 14 days. The following data were obtained. Additional observations were made on day 21, and no yellow-leaved seedlings were found alive in either dish. This is most likely because

yellow-leaved seedlings were unable to convert light energy to chemical energy