Properties Of Soil

Question 1

How is soil formed?

Answer 1

Weathering of parent rock

Addition of organic materials

Question 2

Name the 3 ways rock weathers

Answer 2

Physical - heat cold rain etc
Chemical - water dissolves minerals
Biological - roots create fissures and dislodge Minerals also leave channels where water can travel and erode more rock.

Question 3

Name the 4 horizons in the soil

Answer 3

Organic layer
Topsoil
subsoil
Parent rock

Question 4

Properties of topsoil

Answer 4

Small lumps like crumbs
Most soil organisms 
Most organic matter
Dark - presence of humus
Contains most roots 
Warmer

Question 5

Define the term soil texture

Answer 5

The make up of the soil in terms of particle size e.g. The proportions of sand silt and clay

Question 6

Particle size of fine sand

Answer 6

0.06-0.2

Question 7

Particle size of silt

Answer 7

0.002-0.06

Question 8

Particle size of clay

Answer 8

Less than 0.002mm

Question 9

Describe characteristic of

Sandy loam

Answer 9

Feels gritty
Good drainage
Little water retention capability 
Little nutrient retention capability 
Quick to heat up 
No electrical charge

Question 10

Describe the characteristics of a silty loam

Answer 10

Feels silky and soapy when wet
Fair drainage
No electrical charge

Question 11

Describe the characteristics of a clay loam

Answer 11

Feels sticky when wet and hard when dry
Poor drainage
Good water retention 
Good nutrient retention 
Slow to heat up 
Negative electric charge

Question 12

Describe the term soil structure.

Answer 12

How the components of the soil are combined (minerals, organic matter and humus) - arrangement of particles.

Question 13

Describe key things crumb structure allows

Answer 13

Free water movement
Gaseous exchange
Through root exploration

Question 14

Describe the ideal tilth

Answer 14

0.5-5mm aggregates.
Inside these crumbs are predominantly small pores which hold water and between the crumbs are macropores which contain air when soil is at field capacity.

Question 15

What is saturation point

Answer 15

All pore spaces filled with water. No air present.

Question 16

What is field capacity

Answer 16

Large pores have drained of water and small pores hold maximum amount of water held against gravity.

Question 17

What is permanent wilting point?

Answer 17

Large and small pores are filled with air. Water held too tightly to soil particles to be liberated by roots. Plants will wilt and die.

Question 18

Role of water in the plant x3

Answer 18

Provides transport for minerals and food through xylem and phloem
Provides structural stability for non woody parts of plant by filling vacuoles
Directly participates in chemical reactions in plants such as photosynthesis.

Question 19

What is soil moisture deficit

Answer 19

Water that needs to be added to return soil to field capacity

Question 20

Describe single digging

Answer 20

Digging to depth of 1 spit.
Dig out first trench put to one side.
Second trench then dug into first trench.
Repeat process until last trench then fill with soil from first trench.

Question 21

How can root environment be improved and protected.

Answer 21

Cultivation - single and double digging, forking, taking, rotavating
Addition of organic and inorganic material
Managing soil water content - drainage and irrigation

Question 22

Advantages and disadvantages of cultivation x3

Answer 22

Ad
Prepares for planting 
Improves structure 
Exposes clods to winter weathering
Breaks up pans 
Allows fertilisers to be incorporated 
Buries crop remains and weeds
Dis
Disturbs natural structure -earthworms etc
Damages soil structure
Dormant seeds may be brought to the surface
Moisture may be lost from soil
Hard work

Question 23

Advantages and disadvantages of no dig

Answer 23

Ad
Preserves natural structure of the soil
Soil organisms not disturbed
Weed seeds not bought to the surface.
Less hard work
Bed system means harvesting can be done in any weather and drainage is improved
Dis
Pests may build up in soil
May be difficult to maintain fertility of soil
Fertility and structure not maintained in long term

Question 24

Symptoms of poor drainage

Answer 24

Poor plant growth 
Water collecting on surface
Soil constantly wet 
Mosses 
Blue/black colouring 
Smell

Question 25

How to increase drainage in any soil

Answer 25

Add organic matter | Add lime

Question 26

Why does adding lime (raising pH) improve drainage

Answer 26

Lime causes flocculation of clay particles. This is where clay particles group together to form larger particles improving structure of soil and making it less dense.

Question 27

What are some causes of excess water

Answer 27

Compaction of soil Run off from patios and driveways High water table

Question 28

How to deal with excess water

Answer 28

Lay drainage pipes leading to a ditch French drains to soakaways Building raised beds Appropriate planting

Question 29

Methods of applying water

Answer 29

Watering can Hoses Sprinklers Trickle lines or seep hoses

Question 30

How to add water i.e. When and how much?

Answer 30

Apply in large quantities back to field capacity only

Question 31

3 categories of organic matter

Answer 31

Dead organisms Living organisms Humus

Question 32

How does addition of organic matter influence soil structure

Answer 32

Soil is physically opened up thus creating improved aeration Improves water holding capacity - particularly humus Source of nutrients as decomposes Soil warms up quicker as humus is dark Helps to form stable crumbs

Question 33

Describe the characteristics and use for well rotted farmyard manure Benefits and limitations

Answer 33

``` Good all year round conditioner Carbon rich Encourages earthworms Limits Must be well rotted Danger of pesticide residues Nutrient values vary widely depending on amounts of bedding incorporated ```

Question 34

Describe the characteristics and use for garden compost | Benefits and limitations

Answer 34

``` Soil improver and mulch Basis of no dig systems Convenient Green - recycling and no need for transport Cheap Limits May contain pests, weed seeds and diseases Decomposition can take up to a year Some decomposition may be incomplete ```

Question 35

Describe the characteristics and use for mushroom compost | Benefits and limitations

Answer 35

``` Raises pH - alternative to liming Soil improves Mulch or work in Good for brassicas Mushrooms pop up Relatively cheap Good soil conditioner Limits Not good for all plants due to alkaline Mushrooms pop up ```

Question 36

Describe the characteristics and use for composted municipal/green waste Benefits and limitations

Answer 36

Like garden compost Can be mixed with coir etc to make good container compost For soil improvement Good soil conditioner Recycled garden waste High temperatures mean weeds pests and diseases killed off Limits May contain rubbish High wood content so can have high carbon content

Question 37

Describe the characteristics and use for Leaf mould | Benefits and limitations

Answer 37

``` Attractive mulch for ornamental horticulture Excellent soil conditioner Neutral pH or if pine acidic Limits Low nutrient content Small amount from large piles of leaves Slow process to decomposition ```

Question 38

Describe the characteristics and use for chipped bark | Benefits and limitations

Answer 38

``` Mulch Looks natural under shrubs and trees Lasts a long time Weeds don't germinate in it. Various sizes Limits Robs soil of nitrogen Birds throw it around Slugs and snails lay eggs in it. ```

Question 39

Describe the characteristics and use for composted straw | Benefits and limitations

Answer 39

``` Strulch (chopped straw) as mulch Light and easy to put down Knits together so doesn't blow away. Limits Low nutrient content Possible herbicide residues. ```

Question 40

Describe the characteristics and use for green manure. | Benefits and limitations

Answer 40

Instead of mulch or compost Provides improved soil structure, aeration, water holding Adds nutrients especially nitrogen fixing Weed suppressant Protects from erosion May provide flowers for pollinators Limits Hard work Can encourage slugs Can be difficult to get back to fine seed bed.

Question 41

Purposes of mulching

Answer 41

``` Decorative finish Weed suppressant Moisture retention Protect surface of soil and from erosion Modifying soil temperatures ```

Question 42

Names some non organic mulches

Answer 42

Minerals Tumbled glass Sheets such as polythene woven fibres

Question 43

Conditions for successful composting

Answer 43

``` Air (oxygen) Water - not too much. Roof good Ratio of green to brown mix PH not too acid High temperatures Suitable heap size - right surface area to volume ratio ```

Question 44

How to make a hotbed

Answer 44

Horse manure in container in winter 30cm When it starts to give off heat cover with 15cm of soil Plant into the soil Gives off heat for a couple of months

Question 45

How to make a wormer

Answer 45

Container with a tap and divided into 2 compartments separated by drainage plate. Place kitchen waste into composter on top of drainage plate with brandling worms several 100 Worms digest waste and any liquid drains down and can be used as fertiliser

Question 46

How to make comfrey or nettle tea

Answer 46

``` Place a handful of cut up comfrey leaves in a bucket. Cover with water and a lid Leave for 2-3 weeks (stirring daily) Dilute liquid 1-10 Comfrey rich in potassium Nettles in nitrogen ```

Question 47

How would you use comfrey tea?

Answer 47

Liquid feed for fruiting plants