Unit 3 - Practice Quiz

1 According to the ISSS (International Society of Soil Science) classification system, what is the particle size diameter range for silt?

2 Which law governs the settling velocity of soil particles in a liquid suspension, forming the basis of sedimentation analysis?

3 Which soil physical property is considered a basic property that cannot be easily altered by tillage or management practices?

4 What is the typical value assumed for the Particle Density (PD) of a normal mineral soil when actual data is unavailable?

5 Calculate the Total Porosity (%) of a soil if the Bulk Density is and the Particle Density is .

6 Which type of soil structure is typically found in the A-horizon of grassland soils and is considered best for agriculture?

7 What is the relationship between Bulk Density (BD) and Total Porosity?

8 In the Munsell soil color chart notation 10YR 5/6, what does the number 5 represent?

9 Which soil consistency term describes the range of water content where the soil exhibits plastic properties?

10 The specific heat of soil solids is approximately what fraction of the specific heat of water?

11 Under normal conditions, how does the concentration of Carbon Dioxide () in soil air compare to atmospheric air?

12 Which force is primarily responsible for the retention of water against gravity in micropores?

13 What is the pF value corresponding to the Field Capacity of a typical medium-textured soil?

14 The Permanent Wilting Point (PWP) is conventionally defined at a soil water potential of:

15 Which instrument is most suitable for measuring soil water tension in the wet range ($0$ to bar)?

16 The movement of heat through the soil profile is primarily governed by which law?

17 Which of the following creates Platy structure in soils?

18 If a soil sample has a moist weight of 150g, a dry weight of 120g, and a volume of 100 , what is its Bulk Density?

19 The difference between water retained at Field Capacity and the Permanent Wilting Point is known as:

20 Oxygen Diffusion Rate (ODR) becomes critical for root growth when it falls below:

21 Which textural class has the highest specific surface area?

22 The Hygroscopic Coefficient roughly corresponds to a soil water potential of:

23 Which gas exchange mechanism is the most dominant in soil aeration?

24 Soil Albedo refers to:

25 What is the effect of adding organic matter on Soil Bulk Density?

26 Which Atterberg limit represents the water content at which soil changes from a semi-solid to a plastic state?

27 In the capillary rise equation , what does represent?

28 Total soil water potential () is the sum of several components. Which component is always negative in unsaturated soils?

29 The phenomenon where the relationship between soil water content and water potential depends on whether the soil is drying (desorption) or wetting (sorption) is called:

30 Which of the following soils warms up the slowest in the spring?

31 A soil aggregate formed by natural processes is called a ped, whereas an artificial lump formed by tillage is called a:

32 Which form of water is held between the tension of -31 bars and roughly -10,000 bars?

33 Darcy's Law () describes the flow of water in saturated soil. What does K represent?

34 What is the mathematical definition of Particle Density?

35 Which structure type usually characterizes the B horizon (subsoil)?

36 The Textural Triangle utilizes the percentages of which fractions to determine soil class?

37 Thermal conductivity () is generally highest in:

38 Which instrument uses radioactive scattering to measure soil moisture content?

39 The ratio of the volume of voids (pores) to the volume of solids is known as:

40 A soil with a bulk density of is likely to have:

41 Gravitational water moves through the soil primarily through:

42 Which of the following contributes to high Soil Consistency (resistance to rupture) in dry soils?

43 In the context of soil air, aeration porosity refers to:

44 If the Plasticity Index (PI) of a soil is 0, the soil is:

45 The upward movement of water from a water table towards the root zone occurs via:

46 Infiltration refers to:

47 Which soil temperature regime is optimal for the nitrification process by bacteria?

48 Massive and Single-grained are termed as:

49 The Heat Capacity of a soil is defined as:

50 A pycnometer is a laboratory device typically used to determine: