Exam 7: Soil Aeration and Temperature

If you owned a dairy farm with poorly drained clay soils in a humid temperate region which of the following would be most satisfactory from the standpoint of soil aeration and temperature?

The heat of vaporization of water is 540 cal/g.A soil containing 30 kg water per 100 kg soil solids lost one sixth of that water by evaporation.If one tenth of the energy needed to evaporate the water came from the soil solids how much would the temperature of those solids be lowered?

Soil temperatures under an organic mulch will likely be lower than that of bare soils in the summer but higher than that of bare soils in the winter.

The specific heat of soil solids is significantly higher than that of water.

A soil on the south facing slope in Canada is likely to be drier and warmer than a comparable soil on a north facing slope.

Heat pumps can take advantage of the fact that subsoils are generally warmer in the winter and cooler in the summer than the atmospheric air.

A mineral soil has a water content of 25 kg water per 100 kg dry soil.What is the approximate specific heat of this soil, expressed in calories per kilogram?

Alternate freezing and thawing of soils results in the "heaving" of plants and the destruction of shallow building foundations.This effect is due primarily to _____.

Which of the following practices would encourage higher soil temperatures in the spring in a humid-temperate area?

An increase of 5 oC in soil temperature is likely to increase shoot growth on most plants much more than a similar increase in the air temperature.

Reduced forms of iron and manganese along with soil organic matter largely control the color of well-drained soils.

Anaerobic conditions commonly prevail in liberally watered flower pots with mineral soil as the growing medium even though the containers have holes for drainage in the bottom of the pot.

The process of aerobic respiration is a significant source of which of the following gases?

Which of the following actions would best assure good aeration in a soil?

In acid soils you would be concerned if the redox potential was low since it could mean a deficiency of some plant nutrients such as iron and manganese.

The partial pressure of CO₂ in the soil pores is higher than the partial pressure of this gas in the atmosphere.

The alternate freezing and thawing of soils results in the upward heaving of plants and building foundations.

The primary characteristic of subsoils that accounts for the ability of ground circulating heat pumps to moderate temperatures in houses in both summer and winter is _____.

The bulk of gaseous interchange in soils takes place by _____.

A wildlife biologist in South Africa notes that the soils on south-facing slopes are wetter and deeper than those on north-facing slopes, and therefore support more wildlife.What likely accounts for this difference?