Agriculture Paper 1 Questions and Answers - Form 3 End Term 2 Exams 2022

QUESTIONS
SECTION A 30MKS

1. Name three branches of horticulture. (1 ½ mks)
2. State four advantages of organic farming. (2mks)
3. What is the importance of decomposers in agriculture. (1 mk)
4. State three basic economic concepts. (1 ½ mks)
5.      
   1. What is concession company? ( ½ mk)
   2. Give two examples of individual land tenure system. (1 mk)
6.    
   1. Differentiate between solifluction and landslide. (2 mks)
   2. Name four types of landslide. (2 mks)
7. Give three control measures of Blossom-end rot disease. (1 ½ mks)
8. How are crop pests classified according to the mode of feeding. (2 mks)
9. State any three effects of diseases to crops. (1 ½ mks)
10.      
    1. State six effects of weeds in a pasture crop. (3 mks)
    2. Define a weed. ( ½ mk)
11. List two ways of classifying herbicides based on mode of action. (1 mk)
12. State four factors considered when grading tomatoes for fresh market.(2 mks)
13. Give possible causes of swelling on roots of legumes. (1 mk)
14. What is a companion crop? (1 mk)
15. List two main methods of pruning. (2 mks)
16. State two functions of polythene sheet when used as mulch material.(1 mk)
17. Give any four factors that influence seed rates. (2 mks)

SECTION B: (20 MARKS)

18. The diagram below illustrates a crop. Study it and answer the questions that follow.
    
    
    1. Identify the parts labeled K, L and M. (3 mks)
    2. Apart from the parts mentioned above, list down five other vegetative materials used for crop propagation. (2 mks)
19. Study the diagram below and answer the questions that follow.
    
    
    1. What are the dimensions of the figure shown above? (1 mk)
    2. Name the parts labeled A, B , C and D. (2 mks)
    3. State the importance of level A in this set up. (1 mk)
    4. State two factors considered when selecting a site for a compost pit.(2 mks)
20. A farmer with one hectare of land requires 40kg of N in his farm. He applied CAN which costs Ksh 35 per kilogram. CAN contain 20kg N.
    1. Calculate the amount of CAN the farmer requires. (2 mks)
    2. How much will a farmer with one and a half hectares spend to apply in his farm? (3 mks)
    3. List five characteristics of nitrogenous fertilizers. (2 ½ mks)
    4. State the two methods employed during soil sampling. (1 mk)
    5. Define soil sampling. ( ½ mk)

SECTION C: (40 MARKS)

21.    
    1. Discuss the importance of crop rotation to a farmer. (12 mks)
    2. Discuss the factors that determine harvesting of a crop. (8 mks)
22.    
    1. Discuss the process of water treatment using a chemical treatment system. (12 mks)
    2. State and explain various methods used during land clearing. (8 mks)
23.    
    1. Explain various harmful effects of weeds. (10 mks)
    2. State ten cultural methods employed in pest control. (10 mks)

MARKING SCHEME

1. Name three branches of horticulture. (1 ½ mks)
   • Promology/fruit growing
   • Floriculture/flower growing
   • Olericulture/vegetable farming
2. State four advantages of organic farming. (2mks)
   Reduces pollution
   Improves soil water retention
   Improves soil texture
   Provides feed for soil microbes
   Improves soil water infiltration
3. What is the importance of decomposers in agriculture? (1 mk)
   Causes rotting of organic matter in soil f arming manure
4. State three basic economic concepts. (1 ½ mks)
   Opportunity cost
   Scarcity
   Preference and choice
5.    
   1. What is concession company? (1/2 mks)
      Tenure system in which the government rents land to a company for a specified period of time.
   2. Give two examples of individual land tenure system. (1 mk)
      Owner-operation
      Plantation and concession
      Landlordism/tenancy
6.    
   1. Differentiate between solifluction and landslide. (2 mks)
      Solifluction: slow movement of materials d own the slope
      Landslide: fast movement of materials downslope.
   2. Name four types of landslide. (2 mks)
      Debris fall
      Slump
      Debris slide/slip
      Rock slides
      Rock fall
7. Give three control measures of Blossom-end rot disease. (1 ½ mks)
   Regular watering
   Application of calcium compounds in soil
   Use of right amount of nitrogen.
8. How are crop pests classified according to the mode of feeding. (2 mks)
   Those with biting and chewing mouth parts
   Those with piercing and sucking mouth parts.
9. State any three effects of diseases to crops. (1 ½ mks)
   Lower yields/quantity
   Lower quality
   Increases cost of production.
10.      
    1. State six effects of weeds in a pasture crop. (3 mks)
       Reduce life span of the pasture
       Compete with pasture
       Reduce quality of pasture
       Reduce herbage yield
       Some cause poisoning of livestock
       Interfere with forage fertilization
    2. Define a weed – any crop growing where its not needed.
11. List two ways of classifying herbicides based on mode of action. (1 mk)
    Contact herbicides
    Systemic herbicides
12. State four factors considered when grading tomatoes for fresh market.(2 mks)
    Size of the fruits
    Shape
    Degree of ripeness
    Damage on tomatoes
13. Give possible causes of swelling on roots of legumes. (1 mk)
    Presence of rhizobium in the roots.
14. What is a companion crop? (1 mk)
    A crop grown in the field to help suppress weed growth and control erosion.
15. List two main methods of pruning. (2 mks)
    Pinching out
    Annual pruning
16. State two functions of polythene sheet when used as mulch material. (1 mk)
    Regulation of soil temperature
    Control of weeds
    Reduce soil erosion
    Conserves moisture
17. Give any four factors that influence seed rates. (2 mks)
    Desired crop stand
    Germination percentage
    Recommended spacing
    Purpose of the crop
    No. of seeds per hole
    Method of planting

SECTION B: (20 MARKS)

18. The diagram below illustrates a crop. Study it and answer the questions that follow.
    1. Identify the parts labeled K, L and M. (3 mks)
       K – Crown
       L – Slip
       M - Sucker
    2. Apart from the parts mentioned above, list down five other vegetative materials used for crop propagation. (2 mks)
       Corns
       Bulb
       Stem tuber
       Bulbils
       Splits
       Vines
       Sett
       Rhizomes
19. Study the diagram below and answer the questions that follow.
    1. What are the dimensions of the figure shown above? (1 mk)
       1.2m x 1.2m x 1.2m
    2. Name the parts labeled A, B , C and D. (2 mks)
       • Topsoil
       • Ash
       • Organic manure
       • grass, leaves, refuse
    3. State the importance of level A in this set up. (1 mk)
       Introduces micro-organisms necessary for decomposition.
    4. State two factors considered when selecting a site for a compost pit. (2 mks)
       A well drained place
       Direction of prevailing wind
       Size of the farm
       Accessibility.
20. A farmer with one hectare of land requires 40kg of N in his farm. He applied
    CAN which costs Ksh 35 per kilogram. CAN contain 20kg N.
    1. Calculate the amount of CAN the farmer requires. (2 mks)
       20kgN = 100kg CAN √ (1mk)
       40Kg = ?
       40 X 100 = 200kg CAN √ (1mk)
            20
    2. How much will a farmer with one and a half hectares spend to apply in his farm? (3 mks)
       200kg CAN = 1hec √ ( 1mk)
       ? 1.5 hec
       200 x 1.5 = 300kg CAN √ (1mk)
            1
       ∴ 1kg CAN = 35/-
       300kg CAN = 300 X 35
       = 10,500/- √ (1mk)
    3. List five characteristics of nitrogenous fertilizers. (2 ½ mks)
       Highly soluble
       Highly volatile
       Hygroscopic
       Scorching effect
       Short residual effect
    4. State the two methods employed during soil sampling. (1 mk)
       Traverse
       Zigzag
    5. Define soil sampling – this is collecting of sample of soil to represent the whole land.

SECTION C: (40 MARKS)

21.        
    1. Discuss the importance of crop rotation to a farmer. (12 mks)
       There is maximum utilization of nutrients. Different crops vary in their nutrient requirement in terms of type and depth of absorption.
       Helps in control of soil-borne pests and diseases. Some pests and diseases specific to various crops are easily curbed by alternating crops from different families.
       Controls weeds: Weeds associated with certain crops are easily controlled e.gstriga in grass family crops.
       Helps to improve soil fertility: Inclusion of a leguminous crop in the program helps to restore soil fertility.
       Improves soil structure: Glass hay when included in the rotation restores soil structure.
       Helps to control soil erosion: Crops with poor growth cover should be alternated with those having good cover to prevent/control soil erosion.
    2. Discuss the factors that determine harvesting of a crop. (8 mks)
       Use or purpose of the crop: The intended aim of planting a crop is considered e.g maize for silage making is harvested bust before flowering.
       Concentration of the required chemicals: Guided by the part being harvested e.g in coffee, the ripe berries are the ones harvested.
       Market demand: Consumers preference should be considered e.g harvesting maize at green stage for fresh market.
       Weather conditions: Dry spell is most preferred for most crops to prevent losses.
       Market price and profit margin, harvesting can be delayed or done early depending on the trends in the market.
22.    
    1. Discuss the process of water treatment using a chemical treatment system. (12 mks)
       Stage 1: Filtration at water intake
       Water is passed through a series of sieves of different mesh before entering the intake pipe.
       State II: Softening of water
       Water flows to a mixing chamber where soda ash and aluminiumsulphate are added in equal proportions.
       State III Coagulation and sedimentation
       Water moves to large open tanks where solid particles settle down. Air circulation in water also occurs to remove bad smells.
       Stage IV : Filtration
       Water is made to pass through a filtration tank with layers of different sizes of gravel and sand. This is to remove the remaining solid particles.
       Stage V: Chlorination
       In the chlorination tank, some small amount of chlorine is added depending on the amount of water to kill micro-organisms
       State VI: Storage
       Treated water is stored in large tank before distribution to consumers.
    2. State and explain various methods used during land leasing. (8 mks)
       Tree felling: Involves cutting down trees
       Burning: Fire is set on the vegetation. However, care should be taken to prevent speed to unintended grasses.
       Use of chemicals: employs use of herbicides which kill weeds faster.
23.      
    1. Explain various harmful effects of weeds. (10 mks)
       Lower quality of agriculture produce
       Some weeds are poisonous to man and livestock e.g thorn apple.
       Some weeds act as alternate host for insect pests and diseases.
       Some weeds are parasitic to cultivated crops e.g witch weed in maize.
       Weeds compete with crops for nutrient, space, light and soil moisture.
       Some weeds are difficult to control e.g stinging nettle.
       Some block irrigation channels, affect oxygen levels in water.
       Some have allelopathic effect-surpress growth of crops
       Weeds lower quality of pastures
       Block navigation.
    2. State ten cultural methods employed in pest control. (10 mks)
       Timely planting
       Timely harvesting
       Proper tillage
       Close season
       Trap cropping
       Crop rotation
       Planting resistant crop varieties
       Field hygiene
       Altering micro-climate
       Crop nutrition
       Destruction of alternate hosts
       Use of clean planting materials
       Proper spacing
       Use of organic manure
       Irrigation