WAEC SSCE - Agricultural Science - 2002

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A fixed factor of production in a crop production enterprise refers to a factor that remains constant regardless of the level of output. In this context, the size of the land is an example of a fixed factor of production because it is a fixed resource that cannot be increased or decreased in the short run. For instance, a farmer cannot quickly acquire additional land to produce more crops within a season. As such, the farmer must plan and manage the available land effectively to optimize crop yield and returns on investment.

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The source of water that is least useful for irrigation purposes is the sea. This is because seawater has high salinity levels which can damage crops and soil, making it unsuitable for irrigation. The high salt levels can cause the soil to become saline, making it difficult for crops to absorb water and nutrients, and eventually leading to crop failure. Therefore, while seawater can be used for other purposes such as desalination, it is not a suitable source of water for irrigation.

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During the process of photosynthesis, plants take in carbon dioxide from the atmosphere and use it along with water and sunlight to produce glucose and oxygen. This process occurs in the chloroplasts of plant cells and is essential for the growth and development of plants. As a result of photosynthesis, carbon is fixed into organic molecules, which are used as a source of energy for the plant and other organisms that consume it. Therefore, the correct answer is photosynthesis.

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Nitrogen is an essential nutrient for plant growth and development. However, plants cannot directly use atmospheric nitrogen gas. Instead, they take up nitrogen through their roots in the form of nitrate ions (NO3-) or ammonium ions (NH4+). Nitrate ions are the most common form of nitrogen taken up by plants from the soil. They are formed through the oxidation of ammonium by soil bacteria, and can be easily absorbed by plant roots. Therefore, the correct answer to the question is "nitrate ion".

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Selection and hybridization are methods of animal improvement. Animal improvement refers to the techniques or processes used to enhance the genetic makeup of livestock, such as selecting animals with desirable traits and breeding them together to produce offspring with even better characteristics. Selection involves choosing animals with desirable traits and breeding them to pass on those traits to their offspring, while hybridization involves crossing different breeds or species to produce offspring with the best characteristics of both parents. These methods help to improve the productivity, health, and quality of livestock, and can ultimately lead to increased profits for farmers.

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When the government provides subsidies in agriculture, it means that the government is giving financial assistance to farmers in the form of reduced prices on farm inputs like fertilizers, seeds, and machinery. This is done to make farming more affordable for farmers and to encourage them to produce more crops. The aim is to increase agricultural productivity and output, which would, in turn, lead to more food being produced for the population. Therefore, option A "farm inputs are made available to farmers at reduced prices" is the correct answer.

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An advantage of mechanization is that it allows for the carrying out of many farm operations with ease. Mechanization involves using machines and equipment to perform tasks that were traditionally done by hand. With mechanization, farmers can cover more ground and complete tasks more quickly, efficiently, and accurately. This can increase productivity and reduce labor costs. Additionally, mechanization can also help to reduce the physical strain on farmers and farm workers, leading to improved working conditions.

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The daily maintenance practice carried out on a disc harrow is cleaning the soil off the disc. This is because during its operation, the disc harrow cuts through the soil, and soil and debris can accumulate on the discs and impede its efficiency. Therefore, it is essential to clean the disc harrow after each use to ensure that the discs are free of soil and debris for optimal performance.

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Weeds which produce light and numerous seeds are normally dispersed by wind. This is because the seeds of such weeds are lightweight and often come equipped with structures that help them be carried by the wind over long distances. As the wind blows, it carries the seeds away from the parent plant and disperses them in different locations, allowing the weed to spread and colonize new areas. This method of seed dispersal by wind is known as anemochory.

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Animal power, which is the use of animals such as oxen, horses, or donkeys, is often used on the farm for ploughing. Ploughing is the process of turning over the soil to prepare it for planting, and animals can provide the necessary pulling power to operate a plough. While animal power can also be used for other activities such as harvesting, spraying, or planting, ploughing is often the most common use of animal power on the farm.

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Among the given options, the most flexible and adaptable source of farm power is human power. Human power refers to the use of human labor to perform various farm operations like planting, weeding, harvesting, and transportation of crops. It is flexible because human labor can easily adapt to different farm conditions and tasks. For instance, a person can switch from weeding to planting or harvesting without requiring additional equipment or training. Human power is also adaptable because it can be used in different types and sizes of farms, from small family farms to large commercial farms. Additionally, human power does not require fuel or machinery, making it a cost-effective option for small-scale farmers. Therefore, human power is the most flexible and adaptable source of farm power among the given options.

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A sow, which is a female pig, is normally expected to farrow (give birth to piglets) twice a year. This is because the gestation period of a sow is about 3 months, 3 weeks, and 3 days, which means that a sow can have two litters of piglets in a year. However, the number of piglets in each litter can vary depending on various factors such as the breed of the sow, the health of the sow, and the quality of the feed.

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The process of inducing root development on portions of stems still attached to the parent plant is known as layering. This is a method of propagating new plants from existing plants. In layering, a portion of the stem of a plant is bent down and partially buried in the soil, while still attached to the parent plant. Roots will grow from this buried portion of the stem, and once the roots are well established, the new plant can be separated from the parent plant and grown independently.

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Sexual propagation involves the use of seeds. In this method, plants are propagated through the union of male and female reproductive cells, resulting in the development of seeds. The seeds can be collected, stored and sown in order to grow new plants with similar characteristics to the parent plant. This method is commonly used for crops, vegetables, and fruit trees. Sexual propagation has the advantage of producing plants that are genetically diverse, which may increase their resistance to diseases and pests.

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The major problem of grains storage in the rain forest zone of West Africa is high humidity. This is because the high humidity in the environment provides a suitable condition for microorganisms, insects, and pests to grow, thereby leading to spoilage of the grains. The moisture content in the grains also increases due to the high humidity, which can lead to germination and spoilage. Therefore, controlling the humidity level during storage is crucial to prevent spoilage and preserve the quality of the grains.

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Grit is mostly found in the gizzard of poultry. The gizzard is a muscular part of the digestive tract of birds that is responsible for grinding and breaking down food. It contains small stones, or grit, which are swallowed by birds and help to mechanically break down the food as it passes through the gizzard. The proventriculus is a glandular stomach that secretes digestive enzymes, while the cloaca is the common opening through which waste products and eggs are expelled. The rectum is the final part of the digestive tract where feces are stored before being excreted.

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To calculate the interest on the loan, we use the formula: Interest = Principal x Rate x Time Where Principal is the amount borrowed, Rate is the interest rate, and Time is the duration of the loan. In this case, the Principal is N120,000.00, the Rate is 9% or 0.09 in decimal form, and the Time is one year. So, Interest = N120,000.00 x 0.09 x 1 Interest = N10,800.00 Therefore, the interest to be paid on the loan is N10,800.00. Option A is the correct answer.

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Mosaic disease affects cassava and tobacco. It is a viral disease that causes a mosaic-like pattern on the leaves of infected plants. The affected leaves usually become distorted, stunted and mottled with light and dark green patches. The virus is transmitted by insects, such as whiteflies and aphids, and also through the use of infected plant materials for propagation. The disease can cause significant yield losses in affected crops, and control measures such as the use of resistant varieties and insecticides are often recommended.

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The crop that requires shade in the early stages of its growth in the field is cocoa. Cocoa plants need to be grown in partial shade in the early years of growth, which helps them to establish well and protect them from the direct sun. As they mature, the shade can be gradually reduced until the plants are fully exposed to the sun. Coconut, banana, and cotton do not require shade during their early stages of growth.

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Excessive nitrogen application on maize plants can have different effects depending on the stage of growth and the level of nitrogen applied. However, in general, the most common effect is high vegetative growth with low yield. This is because excess nitrogen encourages the plant to produce more leaves and stems at the expense of grain production. This phenomenon is commonly known as "luxury consumption" and can lead to taller, bushier plants that have a reduced ability to produce grains. Therefore, while nitrogen is essential for plant growth and development, excessive application can lead to negative consequences for maize production.

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The important forage crop in West Africa is giant star grass. Giant star grass is a highly productive perennial grass with high crude protein content and digestibility. It is an excellent forage crop for livestock and is commonly used in West Africa for grazing and cut-and-carry systems. It is also resistant to drought and can tolerate low soil fertility, making it a valuable crop for farmers in the region.

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Poor management may cause fish diseases in a pond. Poor management practices such as overfeeding, overcrowding, poor water quality management, lack of proper aeration and filtration systems, and improper use of chemicals can lead to stress in fish, making them more susceptible to diseases. The stress may weaken the immune system of the fish, making them more vulnerable to infections and diseases.

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The sugar that is most commonly found in the blood of animals is glucose. Glucose is a monosaccharide, which is a type of carbohydrate that provides energy to cells. It is the primary source of energy for the brain, nervous system, and red blood cells. Glucose is produced during digestion of carbohydrates and is transported in the bloodstream to provide energy for various metabolic processes in the body. It is also stored in the liver and muscles as glycogen.

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When soils are poorly drained, the air content of the soil is reduced. Poorly drained soils are saturated with water which fills up the pores between the soil particles. As a result, the air content in the soil is reduced, leading to anaerobic conditions that can negatively affect plant growth. Oxygen is required for the respiration of roots and soil microorganisms, and without it, the rate of decomposition can be slowed down. Additionally, anaerobic conditions can lead to the production of toxic substances in the soil that can inhibit plant growth. Therefore, proper drainage is important for maintaining a healthy soil environment for plants to grow.

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Rabbits are usually kept in special cages known as hutches. These hutches are made with wire mesh, wood, or plastic, and are designed to provide a comfortable and safe living environment for the rabbits. Hutches are raised off the ground to prevent predators from attacking the rabbits, and they also provide good ventilation to help regulate the temperature and humidity levels. Additionally, hutches are designed to allow for easy cleaning and maintenance, which helps to promote good health and hygiene for the rabbits.

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Sudden death without any visible sign of sickness is the symptom that indicates anthrax disease. Anthrax is a bacterial disease caused by Bacillus anthracis, which can affect both humans and animals. It is known to cause sudden death in animals without any visible signs of sickness, making it a dangerous disease that requires immediate attention. The other options listed are not typical symptoms of anthrax disease. Persistent coughing may be indicative of respiratory infections or diseases, abortion in the seventh month of gestation could be caused by several factors, and prolonged diarrhea may be a sign of gastrointestinal disorders.

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Subsistence agriculture involves the production of food crops and/or livestock for consumption by the farmer and their family. It is characterized by the use of traditional farming practices and low levels of technology and capital inputs. The main goal of subsistence agriculture is to provide food and other basic necessities for the family, rather than producing for sale or export. It typically relies heavily on family labour, with little or no mechanization. Subsistence agriculture is prevalent in many developing countries and in rural areas of developed countries.

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The correct answer is "causes plant roots to wilt". Waterlogging is a condition in which the soil becomes saturated with water, leading to the reduction or lack of oxygen available to plant roots. This situation can affect plant development by inhibiting the activities of microorganisms that are essential for nutrient availability, thereby reducing nutrient uptake and leading to the eventual death of plant roots. Waterlogging also encourages leaching, which is the loss of nutrients from the soil, leading to reduced crop yield. The condition does not cause plant roots to wilt. Instead, the roots become swollen and may turn brown or black due to lack of oxygen, leading to plant death.

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When N'dama cows are mated by Muturu bulls, the system of breeding that is practiced is crossbreeding. Crossbreeding is the process of mating individuals from two different breeds or populations. In this case, N'dama cows and Muturu bulls belong to different breeds. Crossbreeding is usually done to produce offspring with desirable traits that are not present in the parent breeds. The offspring of crossbreeding are usually more vigorous and healthy than their parents, a phenomenon known as hybrid vigor or heterosis.

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The growing of both forest trees and arable crops simultaneously on the same piece of land is called the taungya system. This system involves planting forest trees on a piece of land, and then, during the early stages of forest growth, intercropping with annual crops. The crops help to shade the trees, control weeds and increase the fertility of the soil. As the trees grow and mature, they are thinned to create more light for the remaining trees, which eventually form a dense forest canopy. The taungya system is often used in tropical countries as a way to provide both food and timber resources while also conserving the environment.

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The correct answer is "unlimited ability to digest fibre". Pigs are known for their high feed conversion rate, fast growth rate, and high prolificacy. However, unlike ruminants like cows and sheep, pigs have a limited ability to digest fibre. This is because they have a simple stomach and lack the specialized microorganisms necessary to break down complex carbohydrates in fibrous materials like hay and straw. As a result, pigs require a diet that is high in energy and low in fibre to support their growth and production.

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The effect that is not a consequence of 'introduction' in crop improvement is "hampering the growth of local varieties." When a new crop is introduced, it may have various benefits, such as higher yield, improved quality, and faster maturity than local varieties. However, it does not necessarily mean that it will harm the growth of local varieties. In fact, sometimes the introduced crop can bring new genetic traits that can be crossed with the local variety to produce even better varieties. Therefore, the statement that "introduced crops hamper the growth of local varieties" is not a valid effect of crop introduction.

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Capillarity is the ability of water to move upwards through soil against the force of gravity. The rate of capillarity in soil is influenced by the size of the soil particles. Smaller soil particles have greater surface area per unit volume, which increases the forces of attraction between the water and the soil particles, resulting in higher capillarity. Therefore, capillarity is highest in soil with smaller particles, such as clay. Thus, the correct answer is clay.

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Parturition in farm animals marks the end of gestation. Gestation refers to the period of pregnancy when the young one is developing inside the mother's womb. Parturition, also known as giving birth, is the process of expelling the young one from the mother's body at the end of gestation. Once the young one is born, the mother starts lactating, and a new cycle begins.

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Foot and mouth disease is caused by a virus. The virus can affect cloven-hoofed animals such as cattle, sheep, pigs, goats, and deer, and can cause fever and blister-like sores on the tongue, lips, and hooves. The disease can lead to decreased milk production in cows and weight loss, which can result in economic losses for farmers. It is highly contagious and can spread rapidly among livestock, making it a significant concern for animal health officials.

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The most important factor that limits agricultural production in West Africa is rainfall. This is because most of West Africa is located within the tropics and experiences a wet-dry climate. The rainy season is relatively short, lasting only a few months, while the dry season is long and severe. Therefore, farmers rely heavily on rainfall for crop production, and when there is insufficient rainfall, crop yield is greatly reduced, resulting in food insecurity. Additionally, unpredictable rainfall patterns, as a result of climate change, further exacerbate the problem of limited agricultural production in the region.

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The most unreliable source of power supply to the farm among the options listed is wind. This is because wind energy is highly dependent on weather conditions, and its supply can vary greatly from day to day or even hour to hour. Wind turbines can only generate electricity when there is sufficient wind speed, and if the wind is too strong, the turbines have to be shut down to avoid damage. In addition, wind power generation requires large initial investments and can be affected by issues such as noise pollution and bird mortality. On the other hand, electricity, animal, and machine power can be more reliable as they are not as affected by weather conditions and can be controlled more easily.

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The primary purpose of establishing wildlife reserves is to prevent the extinction of wild animals. Wildlife reserves are established to protect wild animals and their habitats from human encroachment and exploitation. By designating an area as a wildlife reserve, it becomes illegal to hunt, capture, or kill animals within its boundaries, thus providing a safe space for them to thrive and reproduce. The reserves also allow scientists to study the behavior and ecology of different species, which can help in developing strategies for their conservation. Overall, wildlife reserves play a vital role in maintaining the biodiversity of our planet and ensuring that future generations can enjoy the beauty and diversity of our natural world.

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Plant quarantine regulations are enforced to prevent the introduction of foreign pests and diseases. This is done to protect domestic crops and the environment from the harmful effects of invasive species that could cause economic and ecological damage. These regulations are put in place to ensure that plants and plant products that enter a country or region are free from pests and diseases, or are subjected to appropriate measures to control or eradicate any such pests and diseases. This helps to maintain the health and productivity of agricultural crops and preserves biodiversity.

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Encouraging afforestation in the arid regions of West Africa is most important to serve as windbreak. This is because the arid regions of West Africa experience strong winds, which can lead to soil erosion, damage to crops, and loss of topsoil nutrients. Afforestation, which involves planting trees and other vegetation, can help to break the force of the wind, reduce soil erosion, and help to retain soil moisture. The trees also provide shade, which can help to reduce the surface temperature of the soil and create a more suitable microclimate for plant growth. Additionally, the trees provide habitats for birds and other wildlife, which can help to maintain ecological balance in the area.

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Farm accounts are financial records of all the farm income, expenses, and profits. These records help the farmer to manage the farm as a business by tracking expenses and income, identifying areas of profitability and loss, and making informed decisions about production, marketing, and financial management. By keeping records, farmers can identify areas where costs can be reduced and profits increased, and can also make informed decisions on whether to expand or contract their farming operations. Furthermore, by tracking expenses, farmers can budget their resources effectively and adopt modern farming techniques that will maximize their profits.

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Agricultural extension programme promotes the practical application of useful agricultural information to farmers. It is a service that provides farmers with knowledge and skills to improve their agricultural practices and increase productivity. The goal of extension programs is to disseminate research-based information to farmers, helping them adopt new technologies, management practices, and marketing strategies. The programme aims to improve the standard of living of farmers by providing education and training that enhances their farming activities.

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An acidic soil can be neutralized by the addition of wood ash. Wood ash contains calcium, magnesium, and potassium compounds, which can react with the acidic soil and neutralize it. The reaction forms water and salts, which help to increase the soil's pH, making it less acidic. Additionally, wood ash also contains nutrients such as phosphorus and potassium, which are essential for plant growth. However, it is important to note that excessive use of wood ash can lead to an alkaline soil, which is also not ideal for plant growth.

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(a) Six types of land tenure systems

1. Communal land tenure (land owned by the community/village).
2. Inheritance land tenure (land passed down within the family).
3. Freehold land tenure (outright individual ownership by purchase).
4. Leasehold land tenure (land held for a fixed period by agreement).
5. Rent/tenant land tenure (land held by paying rent to the owner).
6. Gift land tenure (land acquired as a gift).

(Others acceptable: pledge tenure, tenant-at-will, government/state land acquisition.)

(b) Five reasons why the government should enforce land use legislation

• To ensure orderly and planned use of land, preventing indiscriminate development.
• To make land readily available and accessible for large-scale agricultural production.
• To reduce or settle disputes and litigation over land ownership.
• To make it easier for farmers to obtain land as collateral to secure agricultural loans.
• To prevent fragmentation of land into uneconomically small holdings.
• To promote conservation and prevent misuse or degradation of land resources.
• To ensure fair distribution of land and check land speculation by a few individuals.

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(a) Definition of disease

A disease is any departure from the normal state of health of an animal in which the body or some of its parts fail to function properly, usually caused by a pathogen, deficiency or disorder.

(b) Difference between resistance and susceptibility

Resistance is the natural ability of an animal to withstand or overcome infection by a disease-causing organism without becoming ill, whereas susceptibility is the inability of an animal to withstand infection, so that it easily falls sick when exposed to the pathogen.

(c) Four economic importance of animal disease

• It causes death of animals, leading to loss of stock and capital.
• It reduces productivity (lower milk, meat, egg and wool yield).
• It increases the cost of production through spending on drugs and veterinary care.
• It lowers the market value/quality of animals and their products; some diseases (zoonoses) are transmissible to man.

(d) Three factors that determine the degree of resistance

• The breed and heredity of the animal.
• The age and general health/nutritional status of the animal.
• Previous exposure or vaccination that confers immunity.

(e) Three conditions that may inactivate a pathogenic organism

• Exposure to high temperature/heat (e.g. boiling, pasteurisation).
• Application of disinfectants and antiseptics.
• Exposure to sunlight (ultraviolet radiation) and drying.

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(a)(i) Five effects of irrigation on crop production

• It supplies water to crops during the dry season, allowing all-year-round cultivation.
• It increases crop yield by ensuring adequate moisture for growth.
• It dissolves soil nutrients and makes them available to plant roots.
• It aids seed germination and establishment of seedlings.
• It reduces the risk of crop failure caused by drought.
• (Negative) Excess or poor irrigation can cause waterlogging, leaching of nutrients and salinity/salt build-up.

(a)(ii) Five effects of drainage on crop production

• It removes excess water from the soil and prevents waterlogging.
• It improves soil aeration, giving roots enough oxygen for respiration.
• It warms the soil, promoting seed germination and root growth.
• It improves soil structure and workability for cultivation.
• It reduces the incidence of soil-borne diseases associated with wet soils.
• (Negative) Over-drainage can dry out the soil and remove needed moisture and nutrients.

(b) Four methods of surface irrigation

1. Basin/flooding irrigation.
2. Furrow irrigation.
3. Border (border-strip) irrigation.
4. Wild flooding / check-basin irrigation.

(c) Two main reasons why surface drainage is often necessary

• To remove excess rain or flood water from the surface and prevent waterlogging of crops.
• To improve soil aeration and workability so that crop roots and farm operations are not hindered.

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(a) Hired labour

Hired labour refers to the workers engaged and paid wages or salaries by the farmer to perform farm operations. Such labourers are not members of the farmer family and may be employed on a permanent, casual or contract basis.

(b) Fixed capital

Fixed capital refers to the durable assets of the farm that are used again and again over a long period and are not used up in a single production cycle. Examples include land, farm buildings, tractors, machinery and farm implements.

(c) Working capital

Working capital (also called circulating or operating capital) refers to the assets that are used up within a single production cycle and must be replaced each season. Examples include seeds, fertilizers, agro-chemicals, feeds, fuel and cash for paying wages.

(d) Management

Management is the factor of production that involves organising, planning, coordinating and controlling the other factors of production (land, labour and capital) and taking decisions to achieve the farm objectives at a profit. The manager bears the risks and uncertainties of the farm business.

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(a) Fungal disease, viral disease and pest of four crops

(Candidate needs any four crops only.)

(b) Six general control measures of crop diseases

• Plant disease-resistant/tolerant varieties.
• Use certified, disease-free seeds and planting materials.
• Practise crop rotation to break the disease cycle.
• Practise good field sanitation by removing and burning infected plants.
• Apply appropriate chemicals such as fungicides.
• Control insect vectors that spread diseases.
• (Also: proper spacing to reduce humidity, and early planting.)

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(a)(i) What is culling?

Culling is the removal or elimination of unproductive, sick, weak, old or undesirable animals from a herd or flock so that only healthy and productive animals are kept.

(a)(ii) Three reasons why culling is practised

• To remove unproductive and uneconomical animals and reduce cost of feeding.
• To eliminate sick, weak and diseased animals and check the spread of disease.
• To improve the quality of the herd/flock through selection of the best breeding stock.

(b)(i) Deep litter system

Advantages

• Birds move about freely and exercise, giving good health.
• Lower cost of construction and equipment.
• Litter can be used as manure and birds can obtain some vitamin B from it.

Disadvantages

• Diseases and parasites spread easily among birds in contact with litter.
• Difficult to detect and cull sick or non-laying birds individually.
• Damp litter causes ammonia build-up and disease; eggs may be dirty or eaten.

(b)(ii) Battery cage system

Advantages

• Easy identification and culling of individual sick or non-laying birds.
• Reduced spread of diseases and parasites since birds do not touch droppings.
• Clean eggs are obtained and egg laying is easily recorded.

Disadvantages

• High cost of purchasing and installing the cages.
• Birds lack exercise and may develop weak bones or cage fatigue.
• Requires skilled labour and steady management; vices such as feather pecking may occur.

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(a) Four methods of weed dispersal

• Wind dispersal: light seeds with hairs or wings (e.g. Tridax, Spear grass) are blown by wind.
• Water dispersal: seeds are carried by run-off water and streams to new sites.
• Animal dispersal: seeds with hooks or spines stick to animal fur, or are eaten and passed out in droppings.
• Self/explosive dispersal: the fruit bursts open on drying and flings the seeds away (e.g. Centrosema).
• (Man/agents also disperse weed seeds through contaminated crop seed, farm implements and manure.)

(b) Three mechanical methods of weed control

• Hand pulling / hoeing of weeds.
• Slashing or cutting with a cutlass.
• Mowing, tillage or ploughing to uproot and bury weeds.

Three cultural methods of weed control

• Mulching the soil surface to smother weeds.
• Crop rotation to break the weed life-cycle.
• Use of close/proper spacing and cover crops to shade out weeds.
• (Flooding of fields and timely land preparation are also acceptable.)

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(a)(i) Five objectives of the Farm Settlement Scheme

• To reduce rural-urban migration by making farming attractive and rewarding to young school leavers.
• To modernise agriculture through the use of improved inputs, mechanisation and better farming techniques.
• To provide gainful employment for youths and reduce unemployment.
• To increase the production of food and industrial raw materials.
• To serve as demonstration centres where surrounding farmers can learn improved practices.

(a)(ii) Five objectives of the Agricultural Development Programme (ADP)

• To increase food production and raise the income of small-scale farmers.
• To provide rural infrastructure such as feeder roads, boreholes and storage facilities.
• To make improved inputs (fertilizer, improved seeds, agro-chemicals) available to farmers at the right time.
• To provide effective extension services and technical advice to farmers.
• To carry out adaptive research suited to the local farming conditions.

(b) Roles of cooperative organisations in agricultural production

• They provide credit and loans to member farmers at low interest rates.
• They buy farm inputs in bulk and supply them to members at cheaper prices.
• They market members produce collectively, thereby securing better prices.
• They provide storage and processing facilities for members produce.
• They educate members on improved farming methods.
• They provide farm machinery and equipment for members to hire.

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(a) Three functions of nitrogen in crop plants

• It is a major component of proteins, enzymes and protoplasm needed for growth.
• It is a constituent of chlorophyll, giving leaves their green colour for photosynthesis.
• It promotes vegetative growth, producing healthy leaves and stems.

(b) Four effects of excess soil nitrogen

• Excessive vegetative (leafy) growth at the expense of flowering and fruiting.
• Delayed maturity of the crop.
• Weak, succulent stems that lodge (fall over) easily.
• Increased susceptibility to pests and diseases; scorching of plants at very high levels.

Three effects of nitrogen deficiency

• Yellowing of leaves (chlorosis), beginning with the older leaves.
• Stunted growth and small leaves.
• Reduced yield and premature shedding of leaves.

(c) Three other ways (apart from lightning) by which nitrogen is added to the soil

• Fixation of atmospheric nitrogen by nitrogen-fixing bacteria (e.g. Rhizobium in legume root nodules).
• Application of nitrogenous fertilizers (e.g. urea, sulphate of ammonia).
• Addition of organic manure and decayed plant and animal remains.

(d) Six soil micronutrients

1. Iron (Fe)
2. Manganese (Mn)
3. Zinc (Zn)
4. Copper (Cu)
5. Boron (B)
6. Molybdenum (Mo)

(Chlorine, Cl, is also acceptable.)

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(a) The term marketing

Marketing is the sum total of all the activities and services involved in moving agricultural produce from the producer (farmer) to the final consumer. It covers assembling, processing, storage, transportation, grading, pricing, buying and selling of the produce.

(b) Five importance of marketing in agriculture

• It moves produce from areas of surplus to areas of scarcity/need.
• It provides income to farmers and creates employment for many people.
• It stabilises prices of agricultural produce and matches supply with demand.
• It encourages increased production by ensuring farmers can sell their output.
• It makes goods available to consumers at the right time, place and form.

(c) Five marketing functions

1. Assembling/collection of produce.
2. Processing of produce.
3. Storage of produce.
4. Transportation of produce.
5. Grading and standardisation.
6. Buying and selling (exchange).

(d) Four ways marketing of agricultural produce can be encouraged

• Provision of good roads and transportation facilities.
• Provision of storage and processing facilities to reduce spoilage.
• Establishment of marketing boards and cooperative societies.
• Provision of credit facilities and reliable market information to farmers and traders.