2.Plant Nutrition Flashcards
(33 cards)
1
Q
What is the standard way to reduce pH?
A
- Sulphur - converted to Sulphuric acid by micro organisms
- Aluminum sulphate (fertiliser)
- Pine needles used as a mulch
2
Q
What is the standard way to raise pH?
A
- Add lime (Chalk) in autumn
- Spent mushroom compost
- Calcium carbonate
3
Q
What are the advantages of liming?
A
- Raises pH and can make other nutrients available
- Provides calcium
- Encourages worm and bacteria population
- Discourages some diseases such as clubroot in brassicas
- Makes clay soils workable by flocculation (improved aeration, drainage)
4
Q
Name 2 plants that prefer acid soils (calcifuges).
A
- Rhododendron
- Camelia japonica
5
Q
Name 2 plants for neutral soils.
A
- Iris spp
- Aster spp
6
Q
Name 2 plants for alkaline soils (calcicoles).
A
- Clematis alpina
- Viburnum tinus
7
Q
What is meant by fertiliser?
A
- Concentrated form of nutrients applied to the plant environment to increase and sustain plant growth
- Can be organic or inorganic
8
Q
What is meant by soluble fertiliser?
Give an example.
A
- Dissolves immediately with water
- Ammonium sulphate
9
Q
What is meant by slow-release fertiliser?
Give an example.
A
- Doesn’t dissolve immediately with water but provides nutrients in soluble form over a long period of time
- Degrade slowly, usually under the influence of soil micro-organisms to release their nutrients
- Dependant on soil temperature
Hoof & horn / Bone meal
10
Q
What is meant by a straight fertiliser?
Give an example.
A
- Supply one major nutrient
- Usually used to provide different nutrients at different times of the year, or to correct particular nutrient deficiencies
- Usually inorganic
Ammonium nitrate (N)
11
Q
What is meant by a compound fertiliser?
Give an example.
A
- They may be organic or inorganic, or contain both
- Supply two or more of the major nutrients
Growmore (NPK)
12
Q
What is meant by a controlled-release fertiliser?
Give an example.
A
- Granules of inorganic fertilisers coated with a porous material, so release at right time for plant
- Water enters the granule and the fertilisers leach out into the surrounding soil
- The warmer the soil, the faster the leaching; this corresponds to plant growth which is faster in warm weather
- By varying the thickness of the coating granules can be designed to feed plants for different periods of time.
Osmocote
13
Q
What is meant by base dressing and when would you apply it?
A
- Fertiliser incorporated into soil at final prep stage
- Dug in before sowing/planting
- Spread over surface and forked/raked into top 10cm
- E.g Triplesuperphosphate applied to seed bed
14
Q
What is meant by top dressing and when would you apply it?
A
- Added to surface of soil of established plants
- Lightly forked into soil surface
- Usually compound fertiliser
- E.g lawn feed applied in autumn
15
Q
What is meant by liquid feed and when would you apply it?
A
- Fertilisers dissolved in water
- Applied to the soil or growing media, directed to the roots of plants
- Mostly used on pot plants, outdoor containers
- E.g. Tomorite may be applied to tomato plants growing in pots in a greenhouse
16
Q
What is meant by foliar feed and when would you apply it?
A
- Application of fertiliser in a diluted form to the foliage of the plant
- Fast acting
- Used to correct nutrient deficiencies
- Wasteful as a lower percentage of the nutrients supplied actually enter the plant
- E.g. a foliar feed of Epsom salts may be applied to correct magnesium deficiency in the foliage of apple trees
17
Q
Name organic fertilisers.
A
- Fish, blood and bone (N,P,K)
- Poultry manure (N)
- Bonemeal (P, N)
- Comfrey tea (K)
18
Q
Name inorganic fertilisers.
A
- Growmore (N,P,K)
- Ammonium sulphate (N)
- Potassium sulphate (K)
- Triple super-phosphate (P, Ca)
19
Q
Why is pH 6.5 the most suitable pH for a wide range of plants in the UK?
A
- Availability of nutrients is at its highest
- Soil organism activity is at its optimum
20
Q
What are immobile nutrients?
Name 4 examples
A
Nutrients which do not easily move within the plant
- calcium (Ca)
- iron (Fe)
- sulphur (S)
- boron (B)
21
Q
What are mobile nutrients?
Name 4 examples.
A
The nutrients which move around within the plant
- nitrogen (N) in the form of nitrate
- phosphorus (P) in the form of phosphate
- potassium (K)
- magnesium (Mg)
22
Q
State whether each of these materials are acid, neutral or alkaline?
Peat, Coir, Green manure, Composted bracken, Wood ash, Ammonium sulphate
A
Peat – Acidic
Coir – Neutral
Green manure – Acid
Composted bracken – Neutral
Wood ash – Alkaline
Ammonium sulphate – Acid
23
Q
Benefits and limitations of organic fertilisers?
A
Benefits:
- Generally safe to use - no risk of toxic build up
- Sustainable (animal and plant material)
- Provide a steady supply of nutrients of over a long period
- They do not react so readily with other fertilisers
- Encourage soil micro organisms
Limitations:
- Often slow acting and need to be applied well in advance of planting
- The amounts of nutrients may vary considerably
- Breakdown by micro organisms is dependent on temperature
24
Q
What are the benefits and limitations of inorganic fertilisers?
A
Benefits:
- Precise nutrient content
- As they are more concentrated only small amounts are needed
- Water soluble and not temp dependent
- Nutrients are available to plant immediately and do not need micro organisms to break them down first
Limitations:
- Many react with other fertilisers so care is required if combining them.
- Can be detrimental to soil organisms
- Environmental concerns such as run-off into watercourses
- High environmental impact - fossil fuels
25
What is meant by the term **pH**?
* Expresses the amount of **acidity** or **alkalinity** in the soil
* Between 1 - 14
* **7** is Neutral
* Below 7 = Acidic
* Above 7 = Alkaline
* PH of **6.5** is ideal for most plants (6-7)
26
Why do plants need **nitrogen**?
Symptoms of **Excess/Deficiency**
* **Large amounts** needed
* Leaf/ **vegetative green growth**
* The dark green pigment in plants (i.e. **chlorophyll**)
* Most easily **leached** from the soil
Excess
* Excessive **Soft, lush leafy growth**
* **Vulnerable** to pests/disease
* Easily **damaged** by cold
Deficiency
* **Slow** growth
* **Yellowing** of leaves ( **Chlorosis** - due to lack of chlorophyll)
* **Bluing** of older leaves
* More noticeable in **older** leaves
27
Why do plants need **phosphorus**?
Symptoms of **Excess/Deficiency**
* Plays a vital role in **energy transfer** - Produces ATP
* Needed in **meristematic tissue** for shoot and root growth
* Essential to **seed formation and germination,**often found in large quantities in seed
Excess
* Reduces plants **ability to take up micro-nutrients**
* **Yellowing** of leaves/Poor health
Deficiency
* **Weak/poor root growth** - Poor plant development
* **Stunted** new growth
* **Blue/purple** leaf and stem colouring
28
Why do plants need **potassium**?
Symptoms of **Excess/Deficiency**
* Needed for **flower/fruit** formation
* Increases plant **hardiness**
* **Osmotic regulator** – critical in **reducing water loss** from leaf stomata and **increasing uptake of water** via the roots
Excess
* Leads to **nitrogen** deficiency
* **Yellowing** of leaves
* **Slow** growth
Deficiency
* **Poor flowering or fruiting, yields**
* **Brown/ scorched** areas on leaf tips/edge
29
Why do plants need **calcium**?
Symptoms of **Deficiency**
* Integral part of **plant cell walls** – holds cell wall together after cell division
* Promotes **cell division (meristems)** especially in root tips
Deficiency
* **Weakened** cell walls
* **Stunted growth**
* Inward **curling, pale** young leaves
30
Why do plants need **magnesium**?
Symptoms of **Deficiency**
* Key component of **chlorophyll**, plays a critical role in **photosynthesis**
* **For healthy leaves**
Deficiency
* **Yellowing** of leaves **between the veins**
31
Why do plants need **Iron**
Symptoms of **Deficiency**
* Involved with **chlorophyll** production
Deficiency
* **Yellowing of leaves between the veins**– younger ones first
* **Failure** to flower and fruit
32
List **3 Major and 3 Minor** nutrients
Major
* Nitrogen (N)
* Phosphorus/ Phosphate (P)
* Potassium/ Potash (K)
Minor
* Calcium (Ca)
* Magnesium (Mg)
* Iron (Fe)
33
List key effect of soil **PH** on **organisms** within the soil
* **Worms** and beneficial bacteria **do not like acidic** soils - raising PH is more beneficial to these organisms
* **Clubroot** is more common in **acidic** soils
* Common **scab of potatoes** occurs in **alkaline** soils
* **Overtime** soils become **more acidic** due to rain, the activity of soil organisms and added fertilisers
