Agriculture Paper 1 Questions and Answers - Form 4 Term 3 Opener Exams 2023

• This paper consists of three sections; A, B and C
• Answer ALL the questions in sections A and B
• Answer any TWO questions in section C
• All answers to be written in English

SECTION A (30 Mks)

Answer all questions in the spaces provided

1.  
   1. Name three forms of horticulture practiced in Kenya. (1 ½ mks)
   2. State three ways in which ranching can be improved. (1 ½ mks)
2.  
   1. State three factors that determine the depth of cultivation.  (1 ½ mks)
   2. Name three implements that can be used to carry out sub – soiling (1 ½ mks)
3. Name four reasons for treating water before use. (2 mks)
4. State four limitations of sprinkler irrigation (2 mks )
5. Give the use of the following in the preparation of compost manure. (2 mks)
   1. Calcium Ammonium Nitrate
   2. Top soil
   3. Well decomposed manure
   4. Wood ash
6. Give four uses of farm records. (2mks)
7. State four roles of calcium in plants. (2 mks)
8. Give four problems associated with use of vegetative planting materials (2 mks)
9. State four importances of grafting and budding in crop production. (2 mks)
10. State four limitations of land – lordism and tenancy. (2 mks)
11. Giving examples, state two ways in which weeds can be classified according to plant morphology.    (2 mks)
12. Name four legumes grown in high altitude areas (2 mks)
13. State four factors to consider when drawing a farm plan. (2 mks)
14. Name four books of accounts . (2 mks)

SECTION B (30 MARKS)

ANSWER ALL QUESTIONS IN THE SPACES PROVIDED

15. The diagram below shows a section of a plant from which the planting material illustrated was obtained.
    
    1. Identify the planting material illustrated  (1 mk)
    2. Give two reasons why only the middle part of the plant was used to prepare the planting material (2 mks)
    3. Apart from using the middle part, explain two precautions that should be observed when preparing the illustrated materials
       (2 mks)
16. The diagram below illustrates water storage structures. 
    
    1. Identify the structure labeled E (1 mk)
    2. Give two reasons why farmers prefer structure F to E. (2 mks)
    3. State two maintenance practices for the structure labeled F (2mks)
17. The diagram below illustrates the law of demand in agricultural marketing. Study it answer the questions that follow.
    
    1. Give a reason for the shape of the circle labeled A (1 mk)
    2. if the price of the commodity remains constant, explain four factors that can cause the curve to shift from A to B.
18. Below is a diagram showing a crop disease
             
    1. Identify the crop disease (1 mk)
    2. State three control measures for the crop disease. (3 mks)
    3. Name the category in which the crop disease is classified. (1 mk)

SECTION C (40 MARKS)

ANSWER ANY TWO QUESTIONS FROM THIS SECTION IN THE SPACES PROVIDED

19.  
    1. Explain how each of the properties of rainfall and light influence crop rotation.
       1. Rainfall    (8 mks
       2. Light
    2. Explain four environmental factors that influence effectiveness of herbicides                      (8 mks)
20.  
    1. Discuss cabbage production under the following sub – headings.
       1. Varieties (2 mks)
       2. Field management (3 mks)
       3. Harvesting and marketing
    2. Explain five problems associated with agricultural credit (5 mks)
    3.  
       1. Describe the procedure of harvesting pyrethrum (4 mks)
       2. Explain the precautions that should be observed during the harvesting of pyrethrum (4 mks)
21.  
    1. Explain five advantages of mulching in crop production (5 mks)
    2. Explain the three stages in propagation of plants by tissue culture in crop production (7 mks)
       1. Stage 1 –
       2. Stage 2 –
       3. Stage 3 – .
    3.  
       1. State five roles of trees in soil and water conservation. (5 mks)
       2. Explain three care and management required of agro forestry trees (3 mks)

MARKING SCHEME

SECTION A (30 Mks)

Answer All questions in the spaces provided

1.  
   1. Name three forms of horticulture practiced in Kenya. (1 ½ mks)
      • floriculture
      • olericuture
      • pomoculture (3X ½ = 1 ½ mks)
   2. State three ways in which ranching can be improved. (1 ½ mks)
      • Provision of watering points to the pastoral communities
      • Providing mineral concentrate supplements especially in times of drought
      • Adopting breeding programs that improve the genetic makeup, improving productivity. (3X ½ = 1 ½ mks)
2.  
   1. State three factors that determine the depth of cultivation.  (1 ½ mks)
      • Type of crop to be planted
      • Implements used/available
      • Type of soil (3X ½ = 1 ½ mks)
   2. Name three implements that can be used to carry out sub – soiling (1 ½ mks)
      • Subsoilers
      • Chisel plough
      • Cultivators (3X ½ = 1 ½ mks)
3. Name four reasons for treating water before use. (2 mks)
   • Remove excess chemicals
   • Kill disease causing micro – organisms
   • Remove solid sediments
   • Remove bad taste and smell (4 X ½ = 2 mks)
4. State four limitations of sprinkler irrigation (2 mks )
   • Expensive installations are required
   • Encourages fungal diseases
   • Causes soil erosion
   • May require the establishment of wind break
   • Maintenance requires a lot of skill and it’s expensive. (4 X ½ = 2 mks)
5. Give the use of the following in the preparation of compost manure. (2 mks)
   1. Calcium Ammonium Nitrate
      • To raise the level of Nitrogen in the resulting manure
   2. Top soil
      • To introduce micro – organisms responsible for decomposition 
   3. Well decomposed manure
      • To provide food and shelter for micro – organisms
   4. Wood ash
      • To raise the level of phosphorus and potassium in the resulting manure (4X ½ = 2 mks)
6. Give four uses of farm records. (2mks)
   • Compare performance of different enterprises
   • Show history of the farm
   • Guide in planning and budgeting
   • Detect losses or theft
   • Assessment of income tax
   • Determine value of the farm (assets and liabilities)\
   • Easy to share profits and losses
   • Settling disputes among heirs
   • Show whether its making profit or losses and obtain credit
   • Supporting insurance claims
   • Provide labour information, i.e. NSSF
   • Helps in selling assets, i.e. animals and machinery. (4 X ½ = 2 mks)
7. State four roles of calcium in plants. (2 mks)
   • Promotes formation of aggregates
   • Increases bacterial activities i.e. Nitrogen fixation
   • Raises pH (pH5 to pH 6-7) making P and K available
   • Strengthens plant cell walls
   • Necessary in protein synthesis           (4 X ½ = 2 mks)
8. Give four problems associated with use of vegetative planting materials (2 mks)
   • Does not result in new crop variety
   • Keeping the material free of disease is difficult
   • Materials cannot be stored for long
   • Materials are bulky, thus difficult to store and transport. (4 X ½ = 2 mks)
9. State four importances of grafting and budding in crop production. (2 mks)
   • Plants with desirable root characteristics but with undesirable products may be utilized
   • Facilitates the changing of the top from undesirable to desirable
   • Possible to grow more than one type of fruit or flower on same plant
   • Propagate clones
   • Repair broken trees
   • Shorten the maturity age. (4 X ½ = 2 mks)
10. State four limitations of land – lordism and tenancy. (2 mks)
    • If tenants have no written agreement, they will have no incentive on the land
    • Where lease period is short, no incentives to make long term investments
    • Land rates are not fixed, may lead to overexploitation of tenants
    • Where lease is short, consideration is profit maximization, not concerned with land improvement.        (4 X ½ = 2 mks)
11. Giving examples, state two ways in which weeds can be classified according to plant morphology.  (2 mks)
    • Narrow – leaved weeds e.g. couch grass
    • Broad - leaved weeds e.g. black jack
12. Name four legumes grown in high altitude areas (2 mks)
    • Kenya white clovers
    • Lonsiana white clovers
    • Subterranean clovers
    • Lucerne (4 X ½ = 2 mks)
13. State four factors to consider when drawing a farm plan. (2 mks)
    • Size of the farm
    • Environmental factors
    • Current trends in labour markets
    • Farmer’s objectives and preferences
    • Possible production enterprises
    • Existing market conditions and price trends
    • Availability and cost of farm inputs
    • Security
    • Communication and transport facilities
    • Government policy (4 X ½ = 2 mks)
14. Name four books of accounts . (2 mks)
    • Ledger
    • Inventory
    • Cash book
    • Journal (4 X ½ = 2 mks)

SECTION B (30 MARKS)

ANSWER ALL QUESTIONS IN THE SPACES PROVIDED

15. The diagram below shows a section of a plant from which the planting material illustrated was obtained.
    1. Identify the planting material illustrated  (1 mk)
       • Stem cutting
    2. Give two reasons why only the middle part of the plant was used to prepare the planting material (2 mks)
       • Top part tend to rot when planted
       • Bottom part takes longer to root
    3. Apart from using the middle part, explain two precautions that should be observed when preparing the illustrated materials
       (2 mks)
       • Place it in water until it is planted to prevent dehydration
       • Each cutting should have a leaf and a bud for photosynthesis and establishment respectively
       • Use a sharp knife or blade to prevent breaking of the cutting
       • Make slanting cuts to prevent accumulation of moisture.
16. The diagram below illustrates water storage structures.
    1. Identify the structure labeled E (1 mk)
       • Weir
    2. Give two reasons why farmers prefer structure F to E. (2 mks)
       • Water levels is regulated
       • Can be used to generate HEP
       • Stores large volume of water
    3. State two maintenance practices for the structure labeled F (2 mks)
       • Disilting/dredging
       • Remove trees and bushes from wall to prevent cracks and water seepage
       • Repairing broken/ worn out parts
17. The diagram below illustrates the law of demand in agricultural marketing. Study it answer the questions that follow.
    1. Give a reason for the shape of the circle labeled A (1 mk)
       • As the price of commodity increases the quantity demand decreases and vice versa.
    2. if the price of the commodity remains constant,explain four factors that can cause the curve to shift from A to B.
       • If there is increase in the income of consumers.
       • Affective advertisement / sales promotion.
       • Increase in the price of a related / substitute.
       • If there is an increase in population.
       • Taste and preference.
       • If the quality of the commodity goes up.
18. Below is a diagram showing a crop disease
    1. Identify the crop disease (1 mk)
       • Maize smut
    2. State three control measures for the crop disease. (3 mks)
       • Ensure field hygiene
       • Use of certified seeds
       • Use of resistant varieties
       • Rogueing
       • Crop rotation
    3. Name the category in which the crop disease is classified. (1 mk)
       • Fungal disease

SECTION C (40 MARKS)

ANSWER ANY TWO QUESTIONS FROM THIS SECTION IN THE SPACES PROVIDED

19.  
    1. Explain how each of the properties of rainfall and light influence crop rotation.
       1. Rainfall    (8 mks
          • Reliability – determines the timing of land preparation and planting
          • Amount – determines the type of crop to grow
          • Distribution – influences the type and variety of crops to grow in an area.
          • Intensity – high rainfall intensity damages crops and causes soil erosion
            NB// property 4X1 = 4mks
            Explanation 4X1 = 4 mks
       2. Light
          • Intensity – the rate of photosynthesis increases with increase in light intensity
          • Duration – determines the flowering and types of crops to grow i.e. short – day, long – day / day neutral plants.
          • Wavelength – plants absorb light of specific wavelength making natural light more suitable for photosynthesis
            NB// property 4X1 = 4mks
            Explanation 4X1 = 4 mks
    2. Explain four environmental factors that influence effectiveness of herbicides       (8 mks)
       • Wind – deflects herbicides to unwanted areas
       • Rain – may wash away the herbicides to have pro – longed effects on weeds
       • Soil – should be moist to soak the herbicides to have pro – longed effects on weeds.
       • Light – should be of high intensity to optimum to ensure that the weeds are physiological active / minimizes loss of herbicides by evaporation
20.  
    1. Discuss cabbage production under the following sub – headings.
       1. Varieties (2 mks)
          • Early maturing varieties i.e. sugar loaf, mukuki, golden acres, Gloria hybrid, and Copenhagen market.
          • Late maturing varieties, i.e. Early drum head, savoy, prize drum – head, perfection surc – head.
       2. Field management (3 mks)
          • Top – dressing. Top dress at 20 – 25 cm, one teaspoonful of SA or CAN and repeat 3 – 4 weeks after.
          • Weeding – ensure field is weed – free, hand weeding.
          • Pest control – i.e. aphids, cutworms
          • Disease control – i.e. dumping off, black rot, dowing middew.
       3. Harvesting and marketing
          • Takes 3 – 4 months after transplanting
          • Heads are cut when solid and compact.
          • Sold in wholesale or single in urban or rural areas
    2. Explain five problems associated with agricultural credit (5 mks)
       • Lack of collaterals
       • Diversion of loans to other uses
       • High interest rates
       • Assets used as collateral may be auctioned for non – repayment
       • Lack of knowledge / skills to manage finances
       • Lack of proper record keeping
    3.  
       1. Describe the procedure of harvesting pyrethrum (4 mks)
          • Pick flowers selectively / pick flowers with horizontal petals
          • Use forefingers and the thumb
          • Pick by twisting the heads so that no stem is left attached
          • Put the picked flowers in woven basket
       2. Explain the precautions that should be observed during the harvesting of pyrethrum (4 mks)
          • Picking starts 3 – 4 months after planting to maintain quality
          • Picked flowers are put in woven baskets to allow ventilation and avoid fermentation of flowers
          • Wet flowers should not be picked because they heat up and ferment
          • Picked flowers should not be compacted to avoid heating up and fermenting
          • A suitable picking interval 14 – 21 days is maintained to avoid harvesting over blown flowers
          • Break the flower stalk to maintain quality
          • Avoid picking an open flower.
21.  
    1. Explain five advantages of mulching in crop production (5 mks)
       • Prevents water evaporation, maintaining moisture in the soil for crop use
       • Acts as an insulator, modifies or regulate the soil temperature
       • Controls soil erosion by reducing the speed of running water, intercepting rain drops increasing rate of infiltration.
       • Controls the weeds by suppressing their growth
       • Organic materials are decomposed by soil micro – organisms resulting in to humus, improving soil structure and water holding capacity.
       • Organic materials improve soil fertility by releasing nutrients after decomposition.
    2. Explain the three stages in propagation of plants by tissue culture in crop production (7 mks)
       1. Stage 1 – establishing the aseptic culture
          • Developing the propagule by enhancing cell division and enlargement (2X1 = 2mks)
       2. Stage 2 – sub culturing to rapidly multiply the propagules through somatic development of embryos to produce auxiliary buds and adventitious roots. (1X1=1mk)
       3. Stage 3 – preparation of the propagule for the establishment in the soil through
          • Rooting of the regenerated plantlets
          • Hardening the plantlets
          • Converting the plantlets from heterotrophic to autotrophic mode of nutrition. (4X1=4mks)
    3.  
       1. State five roles of trees in soil and water conservation. (5 mks)
          • Protect the soil below from raindrop erosion by reducing the force with which it falls on to the ground
          • Provides shade and reduce loss of moisture through evaporation
          • Acts as wind breakers
          • The roots of trees bind soil particles together.
          • Reduces speed of running water thus reducing its erosive power
          • The leaves decay to supply humus which improves soil structure and increases water infiltration into the soil
       2. Explain three care and management required of agro forestry trees (3 mks)
          • Protection
          • Pruning and training
          • Grafting old trees.