AGRICULTURE Paper 1 Questions and Answers - Form 3 End Term 1 Exams 2023

SECTION A (30 MARKS)

Answer all Questions in this section

Give four advantages of practicing crop rotation (2mks)
Name any four records that should be kept by a poultry farmer (2mks)
Give two areas of study that make agriculture to be regarded as a science (1mk)
A farmer has the option of growing either wheat or maize in his one hectare of land. Wheat gives a return of sh 20000 while maize gives a return of sh.35000. What will be the opportunity cost? (1mk)
State any two conditions under which opportunity cost is zero
Give two practices that are commonly used in hardening seedlings in a nursery of kales (1mk)
Outline four advantages of tissue culture (2mks)
Name any four farming practices aimed at minimum tillage (2mks)
Outline four factors that determine the depth of planting (2mks)
State three factors that determine the quality of compost manure (1 ½mks)
Distinguish between under sowing and over sowing as used in pasture establishment (1mk)
State two disadvantages of shifting cultivation (1mk)
Name any four methods of treating seeds before planting (2mks)
Give four reasons why seeds may be preferred in crop propagation (2mks)
Differentiate between soil structure and soil texture (1mk)
State four reasons why burning of fields is discouraged in crop production (2mks)
Name three diseases that attack cabbage (1 ½ mks)
State four characteristics that make a crop suitable for green manure (2mks)
State four different types of irrigation that can be used by farmers (2mks)

SECTION B (20 MARKS)

Answer all questions

The diagram below illustrates some soil structures. Study it and answer the questions that follow.
1. Identify the soil structures F and G (2mks)
2. Name the parts labeled X and Y in diagram F (1mk)
3. Sate two ways through which structure G influences crop production (2mks)
The diagram below illustrates a type of fruit. Study nit and answer the questions that follow.
1. Identify the fruit (1mk)
2. Name the parts A-D ((4mks)
3. Name two crops propagated by the part labeled D (1MK)
The diagram below shows a method of layering. Study it and answer questions that follow
1. Identify the method of layering illustrated above (1mk)
2. State one circumstance in which this method of layering is recommended(1mk)
A maize farmer was advised to apply 150 kg CAN per hectare while topdressing the maize crop. CAN contains 21%N. calculate the amount of Nitrogen applied per hectare. (3mks)
The diagram below shows a seedling attacked by a certain pest.
1. Identify the pest (1mk)
2. Name any two types of vegetable crops likely to be attacked by the pests (2mks)
3. State two methods of controlling the above pest (2mks)

SECTION C (40 marks)

Choose any two questions from this section

1. Outline the effects of wind on agricultural products (11mks)
2. Briefly mention the importance of soil organic matter (9mks)
1. Describe the advantages of using seeds as planting materials (5mks)
2. Give reasons for raising vegetable seedling through a nursery (5mks)
3. Outline the process of chemical water treatment for use in the farm (10mks)
1. Explain five factors that determine spacing to be used in crops (10mks)
2. Describe six management practices carried out on a nursery bed (6mks)
3. Explain four advantages of grafting (4mks)

MARKING SCHEME

Give four advantages of practicing crop rotation (2mks)
- Maximum utilization of resources
- Control of soil borne pests and diseases
- Control of weeds
- Improvement of soil fertility
- Improves soil structure if grass layer is included
- Controls soil erosion
Name any four records that should be kept by a poultry farmer (2mks)
- Health records
- Production records
- Feeding records
- Inventory records
- Marketing records
Give two areas of study that make agriculture to be regarded as a science (1mk)
- Genetics
- Ecology
- Soil science
- Crop pathology
- Agricultural engineering
- Entomology
A farmer has the option of growing either wheat or maize in his one hectare of land. Wheat gives a return of sh 20000 while maize gives a return of sh.35000. What will be the opportunity cost? (1mk)
- Sh.20000 for growing wheat
State any two conditions under which opportunity cost is zero
- When there is no alternative
- When commodity is free
- When there is unlimited supply of resources
Give two practices that are commonly used in hardening seedlings in a nursery of kales (1mk)
- Reduce rate of watering
- Reduce shade
Outline four advantages of tissue culture (2mks)
- It is fast
- Produce pathogen free plants
- Mass propagation of propagates
- Requires less space
- Can be used to propagate seedless varieties
Name any four farming practices aimed at minimizing tillage (2mks)
- Mulching
- Uprooting/slashing weeds
- Use of herbicides to control weeds
- Use of cover crops
- Cultivating only the planting hole
Outline four factors that determine the depth of planting (2mks)
- Size of the seed
- Soil type
- Soil moisture content
- Type of germination
State three factors that determine the quality of compost manure (1 ½mks)
- Type of materials used
- Method of preparation
- Method of storage
- Length of decay
Distinguish between under sowing and over sowing as used in pasture establishment (1mk)
- Under sowing-establishment of a pasture crop under a cover crop
- Over sowing- establishment of a legume pasture in an existing grass pasture
State two disadvantages of shifting cultivation (1mk)
- Low total yield per unit area
- Time consuming
- No incentive to develop land
- Not practical in densely populated areas
Name any four methods of treating seeds before planting (2mks)
- Seed cleaning
- Seed inoculation
- Breaking seed dormancy
- Seed dressing
- Chitting
Give four reasons why seeds may be preferred in crop propagation (2mks)
- Less bulky
- Can be stored for a long time
- Planting can be mechanized
- Easy to control pests and diseases
- Cheaper to buy than vegetative materials
Differentiate between soil structure and soil texture (1mk)
- Soil structure is the relative arrangement of soil particles in aggregates while soil texture is the relative proportions of sand, silt and clay particles in a given soil sample
State four reasons why burning of fields is discouraged in crop production (2mks)
- Burn important soil organisms
- Burns organic matter
- Destroys soil structure
- Fire can destroy other structures
- Evaporates the soil moisture
Name three diseases that attack cabbage (1 ½ mks)
- Damping off
- Black rot
- Downy mildew
State four characteristics that make a crop suitable for green manure (2mks)
- Rapid growth rate
- Production of abundant foliage
- Leguminous
- Ability to decay quickly
- Hardy
State four different types of irrigation that can be used by farmers (2mks)
- Surface irrigation
- Overhead irrigation
- Sub surface
- Drip/trickle irrigation

SECTION B (20 MARKS)

The diagram below illustrates some soil structures. Study it and answer the questions that follow.
1. Identify the soil structures F and G (2mks)
  - F- granular
  - G - platy
2. Name the parts labeled X and Y in diagram F (1mk)
  - X - humus with clay
  - Y - air space
3. Sate two ways through which structure G influences crop production (2mks)
  - Impedes drainage/ water infiltration
  - Prevent root penetration
  - Influences soil aeration
The diagram below illustrates a type of fruit. Study nit and answer the questions that follow
1. Identify the fruit (1mk)
  - Pineapple fruit
2. Name the parts A-D ((4mks)
  - A-crown
  - B-fruit
  - C-slip
  - D-suckers
3. Name two crops propagated by the part labeled D (1MK)
  - Sisal
  - Banana
The diagram below shows a method of layering study it and answer questions that follow
1. Identify the method of layering illustrated above (1mk)
  - Marcotting/ aerial
2. State one circumstance in which this method of layering is recommended (1mk)
  - When the branch is hard and cannot bend to reach the ground
A maize farmer was advised to apply 150 kg CAN per hectare while topdressing the maize crop. CAN contains 21%N. calculate the amount of Nitrogen applied per hectare. (3mks)
21 kg N= 100 kg CAN
²¹/₁₀₀ ×150 = 31.5 kg N/ha
The diagram below shows a seedling attacked by a certain pest.
1. Identify the pest (1mk)
  - Cut worm
2. Name any two types of vegetable crops likely to be attacked by the pests (2mks)
  - Cabbage
  - Kales
  - Tomatoes
3. State two methods of controlling the above pest (2mks)
  - Use of appropriate pesticide
  - Physically picking and killing
  - Crop rotation

SECTION C (40 marks)

Choose any two questions from this section

1. Outline the effects of wind on agricultural products (11mks)
  - Causes soil erosion
  - Acts as a pollination agent
  - Acts as a seed disposal agent
  - Causes destruction of crops
  - Spreads pathogens
  - Spreads weed seeds
  - Causes destruction of farm structures
  - Influences relative humidity
  - Causes stress by chilling of livestock and crops
2. Briefly mention the importance of soil organic matter (9mks)
  - Buffers soil ph
  - Increases microbial activities
  - Binds the soil particles together hence improving soil structure
  - Increases soil fertility
  - Improves workability of the soil
  - Improves soil water retention capacity
  - Improves water infiltration
  - Reduces soil toxicity from pesticides
1. Describe the advantages of using seeds as planting materials (5mks)
  - Planting can be mechanized
  - Less bulky
  - Seeds can be mixed with fertilizers easily
  - Easily available hence are cheaper planting materials
  - Easy to treat against soil borne pests and diseases
  - Possible to develop new crop varieties
  - Seeds can be stored easily awaiting better conditions
  - Easy to handle
2. Give reasons for raising vegetable seedling through a nursery (5mks)
  - Many seedlings produced
  - Easy to carry out management practices
  - Easy to plant small seeds
  - Provide optimum growth condition
  - Allow transplanting of strong and healthy seeds
  - Reduce time taken in the field
  - Extra seedlings sold to earn income
3. Outline the process of chemical water treatment for use in the farm (10mks)
  - filtration at intake
    Water passed through a series of sieves
  - softening of water
    Soda ash added to soften
  - Coagulation, sedimentation
    Alum added to coagulate, Bilharzia worms killed
  - Filtration
    Water passed through different layers of gravel
  - Chlorination
    small amounts of Chlorine added to kill micro organisms
  - Storage
    water stored in tanks and distilled
1. Explain five factors that determine spacing to be used in crops (10mks)
  - Type of machinery to be used
  - Soil fertility
  - Size of the plants
  - Crop stand either pure or mixed
  - Number of seeds per hole
  - Moisture availability
  - Use of the crop
  - Pest and disease control
2. Describe six management practices carried out on a nursery bed (6mks)
  - Watering
  - Mulching
  - Weed control
  - Pricking out
  - Shading
  - Pest and disease control
  - Hardening off
3. Explain four advantages of grafting (4mks)
  - Helps to repair damaged trees
  - Helps to shorten maturity age
  - Helps to change the top of tree from undesirable to desirable
  - Make it possible to produce more than one type of fruit
  - Helps to utilize plants with desirable root characteristics such as disease resistance to produce more desirable produce.