Question 1

For most soils, even if they test "high" in a nutrient such as potassium or nitrogen, it is necessary to apply at least as much of each nutrient as is removed in the harvest, if the soil is not to eventually become infertile and unproductive.

Accepted Answer

The answer of For most soils, even if they test...

Question 2

Many years of research have confirmed that the quadratic (parabolic curve) model is the best method of making fertilizer recommendations based on response curves, especially if environmental quality is a high priority.

Accepted Answer

The best method for making fertilizer recommendations based on response curves can vary depending on the specific crop, soil conditions, and environmental considerations. While the quadratic (parabolic curve) model is commonly used, other models like linear, exponential, and others may better fit certain situations. The choice of model depends on the response of the crop to fertilizer in specific conditions, and no single model is universally the best across all scenarios.

Question 3

Soil test interpretations have been developed so that for most fields testing "high" in a nutrient, addition of that nutrient will not increase yield enough to more than pay for the cost of applying the nutrient.

Accepted Answer

This is generally true for most fields and nutrients, although there may be some exceptions depending on the specific crop, soil type and yield goals.

Question 4

The primary means to avoid non-point source nitrogen and phosphorus pollution in agricultural watersheds is to avoid applications that bring the available supply of these nutrients in soils to amounts higher that can be used by crop plants.

Accepted Answer

This statement is true because excessive levels of nitrogen and phosphorus in soils can lead to runoff and leaching into nearby water sources, causing eutrophication and harmful algal blooms. By managing nutrient applications carefully, farmers can ensure that only the necessary amount of nutrients are being used by crops, reducing the risk of pollution.

Question 5

For most plants the relationship between plant tissue concentration of a nutrient and the dry matter production of the plant is linear until toxicity begins to have an effect.

Accepted Answer

The relationship between plant tissue concentration of a nutrient and the dry matter production of the plant typically follows a curve, not a linear pattern. Initially, as nutrient concentration increases, dry matter production increases up to an optimum level. Beyond this optimum, further increases in nutrient concentration can lead to toxicity, reducing dry matter production. This relationship is often depicted as a sigmoid curve, illustrating initial deficiency, optimal range, and toxicity.

Question 6

To enable the most consistent and appropriate interpretations, all soil samples submitted to a particular soil test lab should be taken from the same soil depth, regardless of differences in the type of tillage used or plants grown.

Accepted Answer

The answer of To enable the most consistent and appropriate...

Question 7

Soil test interpretations have been developed so that for most fields testing "low" in a nutrient, addition of that nutrient will increase yield enough to more than pay for the cost of applying the fertilizer.

Accepted Answer

Soil testing allows farmers to determine which nutrients their soil is lacking, and the results are interpreted to determine the appropriate amount of fertilizer to add. Generally, if a nutrient is determined to be "low" and fertilizer is added to address that deficiency, the resulting increase in yield will be greater than the cost of the fertilizer application.

Question 8

Integrated nutrient management seeks to apply, as fertilizer, enough of each nutrient to replace that removed from the soil by plant uptake.

Accepted Answer

The answer of Integrated nutrient management seeks to apply, as...

Question 9

Routine soil testing on a regular basis allows landowners to monitor most changes in soil quality.

Accepted Answer

The answer of Routine soil testing on a regular basis...

Question 10

Based on the data given in the Table, if the revegetation site were limed and fertilized with nitrogen, would you also recommend the addition of P fertilizer to improve tree growth?
A) no
B) yes
C) no basis to judge
Average height of 10 trees planted on reclaimed, mined-over land.
Growth factor added Nothing added 100 kg/ha N 50 kg/ha P 2 cm / wk water
No lime 56 45 63 50
Lime added 85 170 84 80
True or False Questions
(Write T or F after each question.)

Accepted Answer

The answer of Based on the data given in the...

Question 11

Consider the data in the accompanying Table giving the average height of 10 trees planted in order to revegetate a disturbed soil. What was the most limiting factor for tree growth on this soil?
A) water
B) soil pH
C) nitrogen
D) phosphorus

Accepted Answer

The most limiting factor for tree growth on this soil appears to be soil pH, as indicated by the wide variation in tree height (from 1.5 to 6 meters) despite all other factors (water, nitrogen, phosphorus) being kept constant. Soil pH outside of the optimal range can limit nutrient availability and uptake, which can in turn limit plant growth.

Question 12

Buffer strips are usually a last-resort mechanism of pollution control because of their expense and unfavorable side-effects.

Accepted Answer

Buffer strips are commonly used and considered a best management practice for controlling agricultural runoff and reducing pollution. They are cost-effective and have positive side-effects such as improving soil health and enhancing wildlife habitat.

Question 13

The cost of fertilizer is the main consideration of nutrient management for most ornamental landscaping applications.

Accepted Answer

The answer of The cost of fertilizer is the main...

Question 14

Most research has shown that at both high and low fertilization levels, about 15 to 20% of the nitrogen applied as fertilizer will be lost by leaching from medium textured soils growing corn.

Accepted Answer

The answer of Most research has shown that at both...

Question 15

Most synthetic chemical fertilizers are inorganic salts.

Accepted Answer

Synthetic chemical fertilizers typically contain inorganic salts such as ammonium nitrate, potassium sulfate, and superphosphate.

Question 16

When banding fertilizer, the material should be placed about 1 or 2 cm below the seed being planted.

Accepted Answer

Banding fertilizer typically involves placing the fertilizer 2 to 5 cm to the side and 2 to 5 cm below the seed to avoid seed damage from high concentrations of fertilizer salts.

Question 17

As runoff water flows across a grassed buffer strip, the concentrations of N and P in the water decrease slowly at first, but if the buffer strip is sufficiently wide, major reductions in these concentrations will occur just before the water leaves the buffer.

Accepted Answer

The answer of As runoff water flows across a grassed...

Question 18

Land application of treated sewage sludge is an effective means of recycling nutrients back to the soil from which they were originally taken.

Accepted Answer

The answer of Land application of treated sewage sludge is...

Question 19

Broadcast application usually requires less fertilizer to achieve a given level of plant response than does banding.

Accepted Answer

Banding often requires less fertilizer to achieve a given level of plant response because it places nutrients closer to the plant roots, making them more readily available and reducing losses to the environment.

Question 20

The forestry industry uses fertilizers most often to treat old growth stands that will produce valuable lumber

Accepted Answer

The forestry industry does not typically use fertilizers on old growth stands, as these forests have developed without human intervention and are often self-sustaining. Fertilizers may be used in some cases to encourage the growth of young stands, but this is not the primary use of fertilizers in forestry.

Quiz 13: Practical Nutrient Management