SOIL AND WATER MANAGEMENT
EXAM QUESTIONS AND ANSWERS 100%
PASS 2026/2027
What is soil texture? - ANS -Texture is determined by the % of sand, silt and clay
- Surface area of the particles determine their physical and chemical properties (water holding
capacity, CEC, etc.)
- Texture is an inherent physical property which does not change
Bulk density - ANS - The mass of dry soil per unit of bulk volume
- Soils with a high proportion of pore space to solids have lower bulk densities that soils that are
more compact
- Intensive tillage increases Bd
- Crop residue lowers Bd
- More organic matter, lower Bd
- Lower Bd = improved structure
- Compaction increases Bd
Soil structure - ANS - The grouping or arrangement of soil particles
Soil aggregate - ANS Many soil particles held together in a single mass or cluster such as a
block, prism, plate, or crumb.
2026/2027 ALLRIGHTS RESERVED
1
, Benefits of well developed soil aggregation - ANS - Granular or crumb
- Improves soil drainage
- Improves aeration
- Improves root development
- Reduces the degree of compaction and crusting from tillage
Soil Aggregation - ANS - Well developed soil aggregation will have more macropores.
- Macropores promote drainage, aeration, faster water infiltration, and lower Bd.
- Soil aggregation is most improved by perennial crops
- Silt loams hold the highest amount of available water
- Clay soils hold the highest amount of total water
Factors that affect soil aggregation - ANS -Tillage: breaks down the soil structure
- Cropping systems: the less tillage, the better the structure
- Soil organisms: more microbes, better aggregation
- High residue crops improve soil aggregation
Sources of OM - ANS - Plant residues
- Manure
- Sewage sludge/biosolids
Benefits of OM - ANS - Binds soil particles together into aggregates
- A source of nutrients thru decomposition
- Retains cations (increases CEC)
As OM increases... - ANS - Water holding capacity increases
- Surface crusting reduced
- Water infiltration rates increase
2026/2027 ALLRIGHTS RESERVED
2
EXAM QUESTIONS AND ANSWERS 100%
PASS 2026/2027
What is soil texture? - ANS -Texture is determined by the % of sand, silt and clay
- Surface area of the particles determine their physical and chemical properties (water holding
capacity, CEC, etc.)
- Texture is an inherent physical property which does not change
Bulk density - ANS - The mass of dry soil per unit of bulk volume
- Soils with a high proportion of pore space to solids have lower bulk densities that soils that are
more compact
- Intensive tillage increases Bd
- Crop residue lowers Bd
- More organic matter, lower Bd
- Lower Bd = improved structure
- Compaction increases Bd
Soil structure - ANS - The grouping or arrangement of soil particles
Soil aggregate - ANS Many soil particles held together in a single mass or cluster such as a
block, prism, plate, or crumb.
2026/2027 ALLRIGHTS RESERVED
1
, Benefits of well developed soil aggregation - ANS - Granular or crumb
- Improves soil drainage
- Improves aeration
- Improves root development
- Reduces the degree of compaction and crusting from tillage
Soil Aggregation - ANS - Well developed soil aggregation will have more macropores.
- Macropores promote drainage, aeration, faster water infiltration, and lower Bd.
- Soil aggregation is most improved by perennial crops
- Silt loams hold the highest amount of available water
- Clay soils hold the highest amount of total water
Factors that affect soil aggregation - ANS -Tillage: breaks down the soil structure
- Cropping systems: the less tillage, the better the structure
- Soil organisms: more microbes, better aggregation
- High residue crops improve soil aggregation
Sources of OM - ANS - Plant residues
- Manure
- Sewage sludge/biosolids
Benefits of OM - ANS - Binds soil particles together into aggregates
- A source of nutrients thru decomposition
- Retains cations (increases CEC)
As OM increases... - ANS - Water holding capacity increases
- Surface crusting reduced
- Water infiltration rates increase
2026/2027 ALLRIGHTS RESERVED
2
