5.1 Introduction to soil systems

Question 1

Outline and provide a breif discription of various horizons of soil?

Answer 1

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o- leaf litter rich in organic matter

a- mineral horizon at the surface showing organic matter enrichment (humus)

e-subsurface horizon, showing depletion of organic matter, clay, iron and aluminium compounds.

b- subsoil horizon showing enrichment of clay material, iron, aluminium or organic compounds.

c- the horizon of loosed or unsocilidated material.

r- hard bed rock

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Question 2

What are some inputs inot the soil systm?

Answer 2

organic material (leaf litter) inorganic material from parent material, precipitation, energy.

Question 3

what are some storages in the soil system?

Answer 3

organic matter, organisms, nutrients, minerals, air, water

Question 4

what are some outputs in the soil system?

Answer 4

erosion,soil creep and uptake by plants.

Question 5

what are some transfers in the soil systems?

Answer 5

biological mixing, translocation + leaching

Question 6

what are some transformations in the soil system?

Answer 6

decomposition, weathering nutrient cycles.

Question 7

There is a document of a systms dirgam reprewsenting a soil systm called ‘hot girl soils’ learn hwo to draw it.

Answer 7

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Question 8

explain why the soil system can be viewed as an ecosystem?

Answer 8

it is made up of minirals, organic matter, gasses and liquids which form a habitat for many living organisms, including bacteria, fungi, earthworms and other invertibrates such as mites, spiders and snails.

Question 9

what are the three types of soil partical you need to know of, and what are their partical size in mm?

Answer 9

Clay- less than 0.002

silt- 0.002- 0.05

sand- 0.05- 2

Question 10

outline the properties of soil mainly consisted of clay?

Answer 10

poor- water infiltration rate, extraction and ease of working.

good water holding capacity and nutirent status.

Question 11

outline the properties of soil mainly consisted of silt?

Answer 11

medium- water infiltration rates, nutrient status and ease of working.

medium poor water holding capacity and extraction.

Question 12

outline the properties of soil mainly consisted of sand?

Answer 12

good- watwer infeltration rates and ease of working.

poor watwer holding capacity and nutrient status.

Question 13

what partical composition in % makes up silty clay?

Answer 13

50 clay

50 silt

0 sand

Question 14

what partical composition in % makes up clay loam?

Answer 14

30 clay

30 silt

40- sand

Question 15

what partical composition in % makes up loam?

Answer 15

20 clay

40 silt

40 sand

Question 16

what partical composition in % makes up clay?

Answer 16

60 clay

20 silt

20 sand

Question 17

describe how you could test for partical composition of soil using sives?

Answer 17

dry out the soil and pass it through a sieres of sleves of decreasing mesh size – first 2mm, than 0.5mm and finally 0.005 mm, seperating the potions of clay, sand a silt particals.

Question 18

describe how you could test for particle composition of soil using the jar method?

Answer 18

place a sample of soil in a jar, fill it with water, shake it vigorously, and then level to settle.

The heaviest partical will settle first (sand) and the lighter particals will settle last.

Question 19

what can you do after both the experiments to test for partical composition of soil?

Answer 19

after you can measure he relative abundance of each of the particle sizes.

Question 20

one the hot girl spil document thee is another long answer wich needs adressing, have a look at it?

Answer 20

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Question 21

what is biological mixing?

Answer 21

In the soil, there is biomass in the form of living organisms, which transfer throughout the soil as they are mobile, and can help move materials around within the soil.

Question 22

what is leaching in the soil system?

Answer 22

leaching is the loss of water-soluble plant nutrients from the soil, due to rain and irrigation.

Question 23

discribe and explain the relative fertility of clay soil, sandy soil and loam?

Answer 23

Soil texture is an important property of soil, as it determines the fertility of soil and the primary productivity.

Loam soils are ideal for agriculture, the sand particles ensure good drainage and a good air supply to the root. The clay particles retain water and supplies nutrients so they are fertile The silt particles help to hold the sand and clay particles together so they can be worked easily. This results in high primary productivity.

clay soil while having better nutrient status and water-holding capacity has poorer infiltration rates, aeration and ease of working. This results in quite low primary productivity.

Sandy soils have good infiltration rates aeration and ease of working but have low primary productivity due to low water holding capacity and nutrient status.