AGRICULTURE FORM 2 REVISION KITS MODEL03052023003
- Sources of soil nutrients
Parent rock ,
Manure/humus
Inorganic fertilisers
- Roles of soil water
Solvent for nutrients
Cooling in plants
Raw material for photosynthesis
- Advantages of compound fertilizer
Cheaper and more convenient to apply saving on time, cost and labour
Balanced in all plant nutrients
Easy to store as they do not form lumps when stored for long
- Effects of high temperature on crop production.
Improves quality in some crops such pineapples
May lead to wilting of crops
May reduce quality in some crops such grapes
Leads to faster growth rate
May increase disease incidences
- Ways of improving the structure of sandy soils.
Application of organic matter/manure into the soil
Minimum tillage
Tilling at the right moisture content
Crop rotation
Cover cropping
Mulching
Intercropping
Mixed cropping
- Reasons for rolling when planting wheat crop.
Makes the seed come into contacts with the soil moisture
Promote uniform germination of the tiny seeds
Protect the top soil layer and tiny seeds from being blown away by wind. (any 2×1=2mks) - Information found in a land title deed
Name and ID number of farmer
Date of possession
Size of land
Type of ownership
Sign and seal of registering officer
- Types of vegetables
Fruit vegetables
Leaf vegetables
Stem vegetables
Flower vegetables
- Agents of soil erosion
Water
Wind
Human activities
(any 3x ½ =1 ½ mks)
- Factors influencing soil erosion
Topography
Type of soil
Soil depth
Vegetation cover
Overstocking
deforestation
- Methods of water harvesting in the farm
Dams
Weirs
Ponds
Roof catchment
Rock catchment
Use of wells
(4x ½ =2 mks)
- Factors that are considered when selecting a nursery site.
Well sheltered place
Security
Previous cropping
Topography
Nearest to the water source
Type of the soil.
- Difference between intercropping and Monocroping
Monocroping > growing of one type of crop in a piece of land
Intercropping > growing of two or more crops in a particular piece of land at the same time or the crops take more time growing together
- Ways in which consolidation helps to improve farm management.
Proper supervision of land
Economic use of time and saving on transportation cost
Agricultural advice by extension officer
Soil conservation and land improvement
Constructions of permanent structures e.g. fencing and building
Economic operations of activities
Weeds, pest and diseases control is enhanced
Sound farm planning and adoption of crop rotation programme.
- Ways in which weeds are classified based on growth cycle.
Annual weeds
Perennial weeds
Biennial weeds
- Functions of the following parts of a knapsack sprayer?
Nozzle- Atomizes the spray
Trigger- Regulates the spraying
Pneumatic lever – Generates the spraying pressure.
SECTION B (20 MARKS)
- (a) Name of weed – Black jack (1mk)
(b) Reason why it is difficult to control the weed.
Produces many seeds
Has efficient mode of dispersal
(c) Reasons for controlling the weed in a crop field.
To avoid competition for nutrients, moisture and light
- Its seeds may affect the quality of Agricultural produce e.g. wool
- May irritate workers in the farm
- Prick and irritate workers
(2 x 1 = 2mks)
(d) Stage of growth at which the weed should be controlled using a post emergence herbicide - 10 – 15cm high
- 2 – 4 weeks after emergence
- Before flowiling
-Reason = it has not produced seed which may geminate to new weeds
- i) Name of method of soil conservation illustrated
- Cut –off drain/diversion ditch (1×1=1mk) ii) Ways of strengthening the embankment at the lower side of the diagram
- Planting of trees
- Planting of grass
(2×1=2 mks)
iii) Areas into which the water collected above is discharged
- Into an artificial water way
- Into a natural water way such river
- Onto non-erodable stony or rock ground
- Onto grassland with well-established grass cover.
- a) Name of the pests illustrated
- P – Locust Q – Armyworm R – Cut worms S – Ballworm
b) Kind of mouth part in the above pests
Biting and chewing mouth parts
.
c) Ways in which pests can be classified depending on their habitat
- Field pests
- Storage pests
d) Methods that can be used to control the pests
Use of appropriate insecticide
Use of certified seeds
Crop rotation
(1x1=1mk)
SECTION C (4O MARKS)
- a) Harmful Effects of Weeds
• Weeds compete with crops for nutrients, space, light and soil moisture.
• Some weeds, for example, Striga spp are parasitic to cultivated crops such as maize.
• Some weeds lower the quality of agricultural produce for example:
Mexican marigold gives undesirable flavour to milk if dairy cows feed on it.
Devils horsewhip, black jack, bristly fox-tail and others get attached to sheep wool thus lowering its quality.
• Some weeds are poisonous to human beings and livestock for example:
Thorn apple (Datura stramonium)
Sodom apple (Solanum incanum)
• Some weeds have allelopathic effects to cultivated crops.
• Water weeds block irrigation channels.
• Aquatic weeds such as Salvinia in Lake Naivasha and water hyacinth in Lake Victoria affect fishing.
• Some weeds are alternate hosts for insects, pests and disease causing organisms for example:
Wild oat (avena fatua) is an alternate host for rusts.
Mallow (malva verticillata) is an alternate host for cotton stainers.
• Weeds lower the quality of pasture for example:
Tickberry (Lantana camara)
Nut grass (Cyperus rotundus),
Manyatta grass (Eleusine jaegeri)
• Some weeds irritate workers thus reducing the efficiency in which they are controlled for example:
Double thorn (Oxygonum sinuatum),
Stinging nettle (Urtica massaica) ,
Devil’s horse whip (Achyranthes aspera).
b) Harmful Effects of Crop Pests
• Pests such as squirrels and rodents, unearth planted seeds, resulting in poor germination.
• Some pests like nematodes, termites and moles damage crop roots causing wilting and death of the crops.
• They lower the quality and quantity of farm produce.
• They increase the cost of production since farmers will incur expenses in purchasing chemicals to control them.
• They transmit diseases to crops for example, aphids transmit streak virus disease in maize.
• Chemicals used to control the pests cause pollution to the environment.
• They exterminate the crop by feeding on them for example eating embryo of the seed.
- i. a) Tomatoes varieties
• Fresh market varieties:
Money maker,
Marglobe, hundred fold,
Beef eater,
Hot set,
Super marmande
Ponderosa.
• Processing varieties:
Kenya beauty,
San -marzano,
Roma,
Heinz 13S0,
Primabel,
Rutgers hybrid
Cal-J
b) Transplanting
Done in the morning, late evening or on a humid day
Health and vigorously growing seedlings should be lifted using a garden trowel
Seedlings to be planted to the depth they were in the nursery
ii) Field management practices
Mulching-smothers weeds and to conserve soil water
Gapping – to attain the correct crop population and increase productivity
Weeding- to encourage health growth of crops
Top-dressing – encourages vegetative growth and fruit formation since nitrogenous fertilizers are used
Irrigation – during the dry season to facilitate faster growth
Pest and disease control – To improve quality of produce, appropriate method should be used
Staking – To prevent disease control and encourage harvesting of clean fruits
Pruning – it controls cropping, encourages production of quality fruits and makes it easier to carry out other field management practices. (any 6×2=12mks)
iii) Harvesting and marketing
harvesting time/stage depends on the use of the tomato fruit. Fruits for processing should be harvested after ripening on the plant while those for local consumption should be harvested when ripening starts. The tomatoes are then packed in wooden crates and transported to market places
(any 3×1=3 mks)
- a)
Soil fertility-materials derived from fertile origins end up in different destination
Creation of lakes- moulds or blocks of rocks have dammed rivers courses causing temporarily lakes
Damaging property and causing loss of life e.g. farmland, buildings, homes, lines of communications/transport routes/loss of life.
Soil erosion-on steep slopes
Permanent scars on landscape-No support for vegetation and remain unattractive.
Tourist attraction-e.g. weeping rocks of Kakamega or kit Mikai in Seme, Kisumu County
(Any 6×1=6mks)
b). Biological or Cultural Control Measures
These measures are applicable where land slope is between 2-12%.
• Grass strips/filter strips;
These are narrow uncultivated strips along the contour left between cultivated strips.
• Cover cropping ;
The establishment of a crop that spreads out over the surface of the soil to provide it with a cover.
• Contour farming ;
Carrying out all land operations along the contour.
• Mulching ;
Covering of the soil with either organic or synthetic materials.
• Proper cropping systems such as:
Crop rotation
Correct spacing
Inter-cropping
Ridging/furrowing
Strip cropping
• Controlled grazing;
Proper stocking rate, rotational grazing.
• Strip cropping;
Growing crops which give little ground cover in alternate strips with crops such as beans which have a good ground cover.
• Afforestation/re-afforestation.
Afforestation – growing of trees where non-existed.
Re-afforestation – growing of trees where they have been cut down.
Agroforestry – land use that involves the growing of trees in combination with crops and pastures on the same piece of land