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

SECTION A (30MKS)

Answer all questions in the spaces provided.

1. State four factors influencing the choice of the farming methods a farmer may use. (2mks)
2. State four advantages of drip irrigation. (2mks)
3. Outline four farming practices that destroy soil structure. (2mks)
4. State four reasons why a farmer may fail to get profit from a farming enterprise. (2mks)
5. Give four advantages of preparing land early for planting sorghum. (2mks)
6. Differentiate between hybrid and composite as used in crop production. (2mks)
7. What is meant by term domestication as used in Agricultural production? (1mk)
8. Highlight two ways of hardening off tomato seedlings before transplanting. (1mk)
9. Give a reason as to why a farmer is supposed to observe the following precautions in the farm. (2mks)
   1. Always store farm yard manure under a shade.
   2. Wear gloves while applying nitrogenous fertilizers.
10. Give two reasons for conserving forage. (1mk)
11. Outline four ways in which grass help to conserve soil. (2mks)
12. Give two signs of blight in a field of tomatoes. (1mk)
13. State two factors that adapt weeds excellently to their environment. (1mk)
14. Give two reasons for inoculating legume seeds before planting. (1mk)
15. Give two reasons why most of Kenyan farmers practice small scale farming. (1mk)
16. Define the law of profit maximization. (1mk)
17. Distinguish between stocking rate and carrying capacity as used in forage production. (2mks)
18. Outline four ways a farmer can use to improve labour productivity in the farm. (2mks)
19. State 4 ways of modifying soil pH. (2mks)
    
    SECTION B (20MKS)
    Answer all questions in the spaces provided.
20. The diagram below illustrates different methods used in crop propagation. Study the diagrams and answer the questions that follow.
                                                            
    1. Identify the methods of crop propagation illustrated by A, B and D. (3mks)
       A:
       B:
       D:
    2. Identify the parts labelled X and Y in diagram A. (2mks)
       X: …………………………………………………………………………………………………….
       Y: …………………………………………………………………………………………………….
    3. Under what conditions is method C used by farmers. (1mk)
    4. Give two advantages of using the method illustrated in diagram D after bananas are planted in the main field. (2mks)
21. The diagram below illustrates some common weed. Study it carefully and answer the questions that follow.
                                                               
    1. Identify the weeds labelled A and B. (2mks)
       A: 
       B:
    2. State one factor that makes weed B difficult to control in a pasture field. (1mk)
    3. State one economic importance of each of the weeds labelled A and B. (2mks)
       A: 
       B:
22. The diagrams below illustrate different methods used in soil and water conservation. Study the methods and answer the questions that follow.
                                                    
    1. Identify the methods illustrated by (i) (ii) and (iii). (3mks)
    2. State two methods by which the structure in (iii) controls soil erosion. (2mks)
    3. Name two materials used to make the structure in (iii) above. (2mks)
       
       SECTION C (40MKS)
       Answer any two questions from this section.
23. 1. Describe production of Napier grass under the following sub-headings.
       1. Land preparation (2mks)
       2. Planting and planting materials (2mks)
       3. Fertilizer application (2mks)
       4. Defoliation (2mks)
       5. Weed control (2mks)
    2. Explain six factors that can influence a well-designed crop rotation programme. (6mks)
    3. Give four signs that would enable you to identify compost manure that is ready for use. (4mks)
24. 1. Describe procedure of preparing silage. (5mks)
    2. Outline five precautions taken in harvesting tea. (5marks)
    3. Describe the management practices carries out in a cabbage nursery. (10mks)
25.  
    1. Describe process of water treatment in a water treatment plant. (10mks)
    2. Briefly explain four factors influencing mass wasting. (4marks)
    3. Explain six cultural methods of controlling crop diseases. (6mks)

                                                                                     MARKING SCHEME 

SECTION A (30MKS) 

1.  
   • Land size
   • Socio-cultural factors
   • Tastes and preferences
   • Climatic conditions
   • Technical skills of the farmer
   • Market availability          4 x ½ = (2mks)
2.  
   • Minimizes labour
   • Can be practiced on both slopy and flat areas
   • No soil erosion
   • Controls fungal diseases
   • Economical use of water             4 x ½ = (2mks)
3.  
   • Use of heavy machinery on wet soil
   • Working the soil when too wet or too dry
   • Over cultivation/pulverization of the soil
   • Monoculture               4 x ½ = (2mks)
4.  
   • Failure to reduce cost of production
   • Not using improved production technics
   • Failing to look for proper market
   • Wrong enterprise chosen           2 x ½ = (1mk)
5.  
   • Allows adequate time for organic matter to decompose
   • Allows adequate time for weeds to be dehydrated
   • Allows for early planting so that crops establish early before the weeds grow
   • Allows for soil borne pathogens and pests to die
   • Minimizes labour competition.               4 x ½ = (2mks)
6. • Hybrid – a crop developed by crossing different crop varieties under controlled pollination
   • Composite – a crop developed under uncontrolled pollination.   2x1= (2mks)
7. Domestication – process where both crops/plants and animals/ livestock depend on human beings for existence. 1x1 = (1mk)
8.  
   • Gradual removal of shade
   • Gradual reduction in amount of water applied
   • Gradual reduction in frequency of water applied       2 x ½ = (1mk)
9.  
   1.  
      • Volatilization of nitrates to Ammonia gas
      • Leaching
      • Washed away             1x1 = (1mk)
   2. Corrosive   1x1 = (1mk)
10.  
    • Distribute forage throughout the year
    • Provide feed for dry season
    • Better full utilization of land
    • Source of income e.g. selling baled hay             2 x ½ = (1mk)
11.  
    • Grass holds soil particles together
    • Grass cover reduces run-off speed
    • Grass reduces the impact of rain drops hence reducing splash erosion.    3 x ½ = (1 ½ mks)
12.  
    • Dry brown lesions on stems, leaves and fruits
    • Affected parts appear rotten
    • Fruits fall off prematurely    2 x ½ = (1mk)
13.  
    • Produce large quantities of seeds
    • Seeds remain viable in soil for long
    • Weeds have effective means of dispersal
    • Weeds have ability to propagate both by seeds and vegetatively
    • Weeds have elaborate root system
    • Some weeds have underground structures that are difficult to control
    • Some are able to survive with limited nutrients          2 x ½ = (1mk)
14.  
    • Introduce nitrogen fixing bacteria to fix Nitrogen.
    • Promote Nitrogen fixation before planting    2 x ½ = (1mk)
15.  
    • Small pieces of land/land scarcity
    • Lack of enough capital
    • Lack of enough labour
    • Lack of enough technology   2 x ½ = (1mk)
16. • States that profit is maximum where total cost of production is minimum and Net revenue is maximum
    • Where margin revenue and marginal cost are the same   1 x1 = (1mk)
17.  
    • Stocking rate – Number of animals/ livestock maintained per unit area of land
    • Carrying capacity – Ability of forage stand to maintain a particular number of livestock units per unit area.    2x1 = (2mks)
18.  
    • Training
    • Mechanization
    • Improve terms and conditions
    • Labour supervision   4 x ½ = (2mks)
19.  
    • Application of lime
    • Application of basic fertilizer
    • Application of acidic fertilizer
    • Application of Sulphur         4 x ½ = (2mks)
      
      SECTION B (20MKS)
20.  
    1. A- side grafting
       B- layering (Trench)
       C – Marcotting
       D – tissue culture      3 x 1= (3mks)
    2.  
       • X- Scion
       • Y- Root stock    2 x 1 = (2mks)
    3. Hard wood where stem cannot bend easily to reach the ground.  1x1 = (1mk)
    4.  
       • Early maturing
       • Big bunch
       • High annual yield
       • Control viral diseases   2 x 1 = (2mks)
21.  
    1.  
       1. - Stinging Netle (Urtica masaica)
       2. - Nut grass (cyperus rotundus)  2x1 = (2mks)
    2. Has underground bulbs     1x1 = (1mk)
    3.  
       • A - Raises cost of production/difficult to control
       • B - Lowers quality of pasture   2x1 = (2mks)
22.  
    1.  
       1. Cut off drain
       2. Bench terraces
       3. Gabion/porous dam      3x1 = (3mks)
    2.  
       • Reduce erosive force of run-off.
       • Trap soil flow through stones   2x1 = (2mks)
    3.  
       • Wire mesh
       • Stones /gravel  2x1 = (2mks)
         
         SECTION C (40MKS)
23.  
    1. 
       
       • Land preparation
          - Done during dry season
          - Clearing vegetation
          - Remove stumps
          - Remove perennial weeds
          - Carry cultivation to harrow to moderate tilth
          - Ridging making furrows of 90-100cm apart
          - Make hole on top of ridges 50cm apart
          - Fill holes with phosphatic fertilizer and organic manure      2x1 = (2mks)
       • Planting and planting materials
          - Select desirable variety as per ecological zone
          - Place stem cutting i.e 2-3 nodes/splits in the holes made in the ridges at onset of long rain in slanting angle of 45⁰
          - Add phosphatic fertilizer mixed with organic manure
          - Cover with soil and firm at base to avoid erosion/exposure of material        2x1= (2mks)
       • Fertilizer application
          - Top dress with nitrogenous fertilizer at base of stump 6-8wks after planting/weeding
          - Top-dress at onset of rains
          - Top dress after harvesting for high yield and regeneration   2x1 = (2mks)
       • Defoliation
          - When 3-5 months/1.5m high
          - Use sharp panga to avoid damaging stump and suppress regrowth
          - Cut 2.5-5cm above ground
          - When leaves proportion is greater than stems    2x1= (2mks)
       • Weed control
          - Uproot with hands
          - Slashing/cutting at base of woody weed with panga
          - Digging with jembe during dry and rainy season
          - Mulching at base of stump to suppress weed
          - No herbicide use to avoid poisoning livestock. 2x1= (2mks)
    2.  
       • Crop root depth
       • Crop nutrient requirement
       • Weed control
       • Pests and diseases control
       • Soil fertility
       • Soil structure       6x1= (6mks)
    3.  
       • Volume of heap/material in the heap goes down
       • Materials break easily to small pieces when pressed between finger
       • Growth of fungi/moulds in manure
       • Temperature of the material goes down        4x1 = (4mks)
24.  
    1. Silage making procedure
       • Prepare silo before harvesting depending on amount to be ensiled
       • Cut crop and wilt for 6-12hrs
       • Chop
       • Put in silo at 10-12cm and compact
       • Fill silo rapidly (less than 2 day)
       • Check temperature (maintain at 32⁰C)
       • Cover with polythene sheet or dry grass to protect from air and water
       • Dig a trench around silo       5x1= (5mks)
    2. Precautions taken in harvesting tea;
       • Plucked tea should be put in woven baskets and not polythene to allow free air movement.
       • Pluck two leaves and a bud only because 3-4 leaves colder leaves) lower the quality due to low level of caffeine
       • Leaves should not be compressed in the baskets as this can cause them to heat up and turn brown.
       • Plucked tea should be kept cool and shaded while plucking continues and awaiting transportation to the factory.
       • Plucked tea should be taken to the factory the same day it is harvested. (1 x5 = 5marks)
    3. Management practices in a cabbage nursery
       • Regular watering/morning and evening
       • Weed control by uprooting
       • Pricking out – remove weak seedlings and transfer to seedling bed
       • Mulching – apply a light mulch after sowing and remove when seedling shot to emerge
       • Shading – apply shade above the nursery
       • Pest control – spray suitable pesticide
       • Disease control – spray suitable fungicides
       • Hardening off – gradual removal of shade and reduce rate of watering        5 x 2= (10mks)
25.  
    1.  
       • Filtration at intake - use sieve to remove large particles
       • Softening – Add soda ash to soften water
       • Add allum to allow coagulation and settling of particles
       • Filtration – water passes through different sizes of particles in a filtration tank
       • Chlorination – Chlorine added in chlorination tank
       • Storage – water stored in large well protected ranks
       • Distribution – By piping or pumping to consumers    Any 5x2= (10mks)
    2. Briefly explain four factors influencing mass wasting. (4marks)
       • The slope of the land-Steep slopes leads to faster movement of materials.
       • The nature of material-Mass wasting occurs easily where massive rocks overlie sedimentary rocks which have clay material underneath and also if the material contains a lot of water.
       • Climate-Heavy rainy periods encourage wasting
       • Vegetation cover- It is easy and faster in bare ground than where it is covered with vegetation.
       • Human activities-E.g deforestation, building, quarring etc interferes with the stability of surface layers.
       • Forces within the earth’s crust e.g earth tremors and some volcanic eruptions.
    3.  
       • Using healthy planting material
       • Using disease resistant varieties
       • Proper drying of cereals and pulses
       • Heat treatment
       • Proper spacing
       • Proper spacing
       • Proper seedbed preparation
       • Held hygiene   6x1 = (6mks)