SCSC 301 CORE EXAMS SET 2026/2027 QUESTIONS AND
SOLUTIONS RATED A+
✔✔Soil organic matter degradation will be greatest when_____________ - ✔✔There is
sufficient soil moisture and aeration at neutral pH and relatively warm temperatures to
degrade residue with high levels of N
✔✔**Organic matter tends to decrease the ___ of soils. - ✔✔bulk density
✔✔**___ is the element in residue that has the greatest effect on the rate of residue
decomposition. - ✔✔nitrogen
✔✔**The organic matter content of soils tends to decrease with increasing frequency of:
- ✔✔cultivation
✔✔A soil with C/N ratio of 600:1 could be a material such as_______ - ✔✔sawdust or
leaves that have a low N content and a high potential for N immobilization
✔✔**Poorly defined organic substances that are complex, resistant to decay, and
polymeric are ___ - ✔✔humic substances
✔✔Which of the following could be used to improve soil organic matter in a cropping
system? - ✔✔Reduce the plant materials that are harvested and return any residues
back to the field
✔✔If you had to guess, which environment would likely have the greatest soil organic
matter? - ✔✔northeast US
✔✔**Available water in soils is water held between the wilting coefficient and: - ✔✔field
capacity
✔✔Water that drains downward in a soil consists of water moving in response to
differences in: - ✔✔primarily gravitational potentials
✔✔Water enters a very clayey subsoil from a sandy surface soil: - ✔✔as soon as the
wetting front reaches it
✔✔In a soil containing large holes or channels that are closed at the surface, water
enters these large holes_______ - ✔✔only after the surrounding soil is saturated
✔✔Water moves downward in a profile from the B horizon (clay loam) into gravel layer
______. - ✔✔only after the B horizon is saturated
SOLUTIONS RATED A+
✔✔Soil organic matter degradation will be greatest when_____________ - ✔✔There is
sufficient soil moisture and aeration at neutral pH and relatively warm temperatures to
degrade residue with high levels of N
✔✔**Organic matter tends to decrease the ___ of soils. - ✔✔bulk density
✔✔**___ is the element in residue that has the greatest effect on the rate of residue
decomposition. - ✔✔nitrogen
✔✔**The organic matter content of soils tends to decrease with increasing frequency of:
- ✔✔cultivation
✔✔A soil with C/N ratio of 600:1 could be a material such as_______ - ✔✔sawdust or
leaves that have a low N content and a high potential for N immobilization
✔✔**Poorly defined organic substances that are complex, resistant to decay, and
polymeric are ___ - ✔✔humic substances
✔✔Which of the following could be used to improve soil organic matter in a cropping
system? - ✔✔Reduce the plant materials that are harvested and return any residues
back to the field
✔✔If you had to guess, which environment would likely have the greatest soil organic
matter? - ✔✔northeast US
✔✔**Available water in soils is water held between the wilting coefficient and: - ✔✔field
capacity
✔✔Water that drains downward in a soil consists of water moving in response to
differences in: - ✔✔primarily gravitational potentials
✔✔Water enters a very clayey subsoil from a sandy surface soil: - ✔✔as soon as the
wetting front reaches it
✔✔In a soil containing large holes or channels that are closed at the surface, water
enters these large holes_______ - ✔✔only after the surrounding soil is saturated
✔✔Water moves downward in a profile from the B horizon (clay loam) into gravel layer
______. - ✔✔only after the B horizon is saturated
