Term 2 - 2024

AGRICULTURE
(MARKING SCHEME PAPER 1)
FORM FOUR

SECTION A (30MARKS)
Answer all the questions in this section in the space provided.
1. Advantages of intensive farming. (2mks)
- Increases production per unit area
- Farm supervision is easy
- Ideal for densely populated area/small land holdings
- Utilizes technology to increase production
½ x 4 = 2mks

2. Benefits of agroforestry to a maize crop. (2mks)

- Leguminous trees fix nitrogen into the soil
- Trees acts as wind breaks
- Trees stabilizes soil against soil erosion
- Leaf litter decompose forming humus/recycle nutrients
- Trees act as water catchment area/conserve water
½ x 4 = 2mks

3. Plant part used for vegetative propagation of each of the following plants.
(i) Sisal - Bulbils/suckers (½ mk)
(ii) Pyrethrum - splits (½ mk)
(iii) Sweet potatoes – vine /stem cutting (reject cutting alone) (½ mk)
(iv) Sugar cane – setts (½ mk)

4. Cultural ways of controlling couch grass (2mks)

(i) Mulching
(ii) Cover cropping
(iii) Crop rotation
(iv) Proper spacing
(v) Clean seed bed
(vi) Flooding
(vii) Timely planting
½ x 4 = 2mks

5. Sources of underground water (1½mks)

 Springs
 Boreholes
 Wells
½ x 3 = 1 ½ mks

6. Causes of blossom end of rot in tomatoes (1½mks)

 Irregular watering

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  Lack of calcium
 Excessive use of nitrogen
½ x 3 = 1 ½ mks

7. Qualities of a good green manuring plant (1½mks)

 Hardy
 Fast growth
 Ability to rot quickly
 Highly leafy
 Leguminous
½ x 3 = 1 ½ mks

8. Reasons for practicing minimum tillage. (2mks)

 Reduce cost of cultivation
 Control soil erosion
 Improve soil structure
 Conserve water
½ x 4 = 2mks

9. Records that should be kept by a poultry farms. (2mks)

- Health records
- Feeding records
- Labour records
- Egg production records
- Marketing records
- Inventory records
½ x 4 = 2mks

10. Ways in which pastures are classified (1½mks)

- Pasture stand; pure/mixed stand
- Pasture establishment; Natural/artificial
- Ecological zone
½ x 3 = 1 ½ mks

11. Ways in which land reforms can be implemented in Kenya. (2mks)

 Land consolidation.
 Land adjudication and registration/issue of title deeds
 Improve land legislation
 Tenancy reforms
 Land settlement and resettlement
½ x 4 = 2mks

12. Factors that determine the stage at which a crop is harvested. (2mks)
 Market price/market demand
 Weather conditions
 Purpose/intended use
 Taste and preference/form required
 Concentration of required chemical/colour/maturity
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 ½ x 4 = 2mks

13. Beneficial effects of weeds to a farmer. (2mks)

 Some are edible to man
 Some have medicinal value e.g Datura strommonium/thorn apple
 Control soil erosion
 Some provide food to livestock
 Releases humus after decomposition
½ x 4 = 2mks

14. Advantages of practicing crop rotation. (2mks)

 Maximum use of nutrients
 Control buildup of pests and diseases
 Control weeds
 Improve soil fertility when legumes are included
 Control soil erosion when cover crops are included
 Improves soil structure if grass lay is included
½ x 4 = 2mks (reject if underlined word is missing)

15. Name four methods of controlling pests. (2mks)

 Biological methods – accept specific example
 Chemical method
 Cultural method – accept specific example
 Physical/mechanical method – accept specific examples
 Legislation.
½ x 4 = 2mks

16. Distinguish between intensive hedgerow and border planting forms of agroforestry (2mk)
- Intensive hedgerow – Trees or shrubs are planted in between rows of crops
- Border planting – Trees or shrubs are planted on the border of the farm.

SECTION B (20 MARKS)

Answer all the questions in this section in the spaces provided.

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17. The following illustrations show different production function curves in agricultural economics. Study
them and answer the questions which follows;
(a) Identify the production function curves labeled A, B and C
A – Increasing returns production (1mk)
B – Constant returns production. (1mk)
C – Decreasing returns production (1mk)
Reject if the word returns is missing.

(b) What does the law derived from the production function labeled C state? (1mk)
- If successive units of one variable input are added to fixed quantities of other inputs, a point is
reached when additional/extra/marginal product per additional unit of input declines.
1 x 1 = 1mk

(c) Which one of the three production functions curves is rare in Agriculture (1mk)
(i) B 1 x 1 = 1mk
(ii) Other factors influencing/limiting agricultural production e.g.
 Weather
 Biotic factor
 Disease attack
1 x 1 = 1mk (Reject if the answer in C (i) above is wrong.

18. The table below shows the population and gross domestic products of countries A and B
Country Gross Domestic product Population
(million Ksh) (million)
A 1800 36
B 1200 15
(a) Calculate the per capita income for each country show your working (2mks)
Calculation of per capital income
Gross Domestic product
Per capita income =
population

1800
A= =50
36

1200
B= =80
15
1 x 2 = 2mks

(b) Which of the two countries is more developed economically (1mk)

B 1 x 1 = 1mk
(c) Give a reason for your answer in (b) above (1mk)
B has a higher per capita income
1 x 1 = 1mk

(d) How can agriculture increase the gross domestic product of a country (1mk)
By creating employment/developing industries/increasing production.
1 x 1 = 1mk

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19. The diagram below illustrate investigation on a property of soil using soil samples labeled J, K and L.
(a) Name the property of soil being investigated (1mk)
 Soil capillarity 1 x 1 = 1mk
(b) What is the relationship between the soil property above and the size of soil particles? (1mk)
 The smaller the size of the particles the greater the force of capillarity.
1 x 1 = 1mk

(c) Which soil sample would be suitable for growing paddy rice? (1mk)
 L 1 x 1 = 1mk

(d) Give a reason for your answer in (c) above (1mk)

- Has the highest capillarity/has the highest water holding capacity.
1 x 1 = 1mk

20. The following is a list of nutrients: copper, calcium, nitrogen, molybodenum, zinc, phosphorus, carbon,
sulphur, iron and magnesium. Which of the above nutrients are;
(a) Macro – nutrients (1mk)
 Calcium, Nitrogen, Phosphorus, Carbon, Sulphur and Magnesium
(Award 1 mark of all the five macro – nutrients are present. Penalize fully if any of the macro
– nutrients is missing.
(b) Micro – nutrient (1mk)
 Copper, molybodenum, Zinc and Iron
(Award 1 mark of all the four micro – nutrient are there)
(c) Fertilizer elements (1mk)
 Nitrogen and Phosphorus
(Award 1 mark if the two are present)
(d) Liming elements (1mk)
 Calcium, Magnesium and Sulphur.
(Award 1 mark if the three are present
(e) Primary macro nutrients (1mk)
 Nitrogen and Phosphorus
(Award 1 mark if the two nutrients are presents

SECTION C
Answer any two questions in this section in the spaces provided after question.
21.
(a) Functions of a live fence in a farm. (5mks)
 Act as windbreak
 Some are used as a fodder for the livestock e.g tickberry
 Some may provide edible fruits e.g Kei apple

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  Have aesthetic value
 Provide security
 Mark the boundary when planted on a border lines
1 x 5 = 5mks

(b) Describe various risks and uncertainties in crop farming (10mks)

 Technology uncertainty – farmers may not be sure of the effective of new production
technology
 Price uncertainty – This is due to fluctuation of commodity prices.
 Personal injury or sickness – This may affect the ability of the farmer to work
 Government policy – this may change with time making farmer to incur losses
 Demand for a commodity uncertainty – this results in a loss when market demand is low.
 Yield uncertainty – A farmer cannot accurately project how much to expect
 Pest and disease outbreak – this may lower the yield
 Obsolescence – the farmer may invest in a technology which will become obsolete.
 Natural catastrophes – this include floods, earthquakes, storms etc.
 Labour uncertainty
 Political instability
 Theft of crop
 Fire risk/ownership uncertainty
1 x 10 = 10mks

(c) Functions of young farmers clubs in Kenya (5mks)

 Involvement in workshops and seminars related to agriculture.
 Participating in exhibitions and competitions at Ask shows.
 Involvement in agricultural projects at club level.
 Participating in young farmers club annual rallies
 Participate in national ploughing contest.
 Participate in exchange programme
 Participate in national tree planting activities.
1 x 5 = 5mks

22.
(a) Factors that should be considered in farm planning (10mks)
 Size of the farm – this determines the number of enterprises possible.
 Environmental factors/climate/soil type – this will determine specific enterprises that are
possible in an arta.
 Transport and communication – this ensures produce reach market and inputs are easily
accessed.
 Government policy – this ensures that laws are followed.
 Farmer objective and preferences – a farmer will have a sense of ownership of the farm plan for
motivation.
 Trend in labour market – This ensures labour availability through the season
 Existing market conditions and price trends – this ensures what is sold is at an appropriate price

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  Possible production enterprises – the farmer to choose the most profitable and convenient
enterprise.
2 x 5 = 10mks

(b) Explain the different ways in which each of the following environmental factors influence crop
production.
(i) Wind (5mks)
 Strong wind increases the rate of evaporation/evapotranspiration/wilting
 Help in pollination of crops
 Strong winds have a cooling effect which influences rate of physiological processes
 Strong winds may cause lodging/destruction of certain crops.
 Wind can spread diseases/pests
 Used in winnowing/cleaning grains
1 x 5 = 5mks

(ii) Temperature (5mks)

 It affects quality of certain crops eg. pineapple
 Causes increase in incidences of pests/diseases.
 Low temperature causes frost injury
 Influences distribution of crops
 High temperature increases rate of evapotranspiration hence wilting
 Influences the rate of physiological processes in crop.
1 x 5 = 5mks

23.
(a) Information contained in a purchase order. (5mks)
 Quantities of the goods
 Types of good required
 Date of order
 Date within which the ordered goods should be delivered
 Person who orders the goods
 Person who authorized the order
 Cost of goods/each item
 Name of the supplier
 Serial number
 Total amount/cost involved

1 x 5 = 5mks
(b) Harvesting of tea (7mks)
 Leaves are picked selectively for the highest quality
 Pluck top two leaves and a bud for fine plucking/three leaves and a bud for coarse plucking
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  Use a plucking stick to maintain the plucking table
 Pluck at 5 – 7 days interval in rainy season and 10 – 14 days in a dry period.
 Put the plucked tea in a woven basket to facilitate air circulation/prevent fermentation.
 Do not compress the leaves in this basket to prevent heating up/browning.
 Put plucked tea in cool and shaded place.
 Deliver the plucked tea to the factory same day.
1 x 7 = 7mks

(c) Cultural methods of controlling soil erosion (8mks)

 Contour farming – cultivation and planting done across the slope hence in holding water thereby
increasing infiltration and reducing run off.
 Mulching covers the soil thereby reducing splash erosion/reduce the speed of run off.
 Strip cropping – alternating strips of crops that give good soil cover with those that give little
soil cover controls movement of soil particles hence control soil erosion.
 Vegetated water ways – this slows down run off/trap eroded soil particles thereby preventing
soil erosion.
 Afforestation/re-afforestation – trees protect soil from splash erosion by atomizing rain
drop/encourage water infiltration/protect soil from wind which could detach and remove soil
particles.
 Intercropping – crops which do not cover soil and crops that have good ground cover should be
planted together to prevent splash erosion/surface run off.
 Minimum tillage –this maintains good soil structure.
 Cover cropping – this spread over the surface of soil hence protect soil from effects of
raindrops.
 Crop rotation – maintains soil cover for protection against soil erosion/improved soil structure.
 Correct spacing – this ensures adequate soil cover.
 Grass strips/filter strips – they are left between cultivated/cropped strips of land to reduce speed
of water and filter out trodden soil.
 Agroforestry – this intercepts raindrops/stabilizes soil acts as wind breaks.
 Rotational grazing – this allows grass to recover thus prevent soil erosion.
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1 x 8 = 8mks