Organic Matter

Question 0

Ion absorption and desorption: (2)

Answer 0

Absorbs/desorbs cations used as nutrients by plants.

Can hold large amounts, readily available to plants.

Question 1

Organic matter can strongly influence… (3)

Answer 1

Plant growth,
Soil fertility,
Over ecosystem functioning.

Question 2

Structure: (2)

Answer 2

Fungal strands and roots bind soil particles, reducing compaction, thus allowing water and air to pass to lower levels.

Humus binds clay, silt and sand particles.

Question 3

Cultivation: (2)

Answer 3

Greatly reduces the amount of organic matter.

Plant material is removed by harvesting.

Question 4

Vegetation: (1)

Answer 4

Extensive rooting systems provide more organic matter than forests do, which contribute from fallen leaves.

Question 5

Nutrient supply: (2)

Answer 5

Source of nitrogen, sulfur and phosphorus to plants.

Provides energy and carbon to organisms.

Question 6

Water holding capacity: (1)

Answer 6

Organic matter rich soils allow easier water infiltration and reduced run off.

Question 7

Climate: (2)

Answer 7

Greatest in cool, moist regions.

Lowest in warm, dry regions.

Question 8

Poorly drained, wet soils have a large amount of OM due to (3)

Answer 8

Greater run off.
Increased in plant growth.
Lower levels of oxygen in water, which slow the breakdown of OM.