WAEC SSCE - Agricultural Science - 2003

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The addition of calcium carbonate can improve a soil with a low pH value. Soil pH is a measure of the soil's acidity or alkalinity, with a pH of 7 being neutral, below 7 acidic, and above 7 alkaline. Calcium carbonate is an alkaline substance that reacts with soil acidity, raising the pH level towards a more neutral or alkaline range. By adding calcium carbonate to the soil, the soil becomes less acidic, which can help plants grow better because most plants prefer a slightly acidic to neutral soil pH. Additionally, the calcium in calcium carbonate can improve soil structure, making it easier for plant roots to penetrate and access water and nutrients.

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Spermatozoa are produced in the testicles. The testicles are part of the male reproductive system and are responsible for producing sperm as well as testosterone, a male hormone. Spermatozoa are the male reproductive cells that fertilize the female egg during sexual reproduction, leading to the formation of a zygote, which eventually develops into a fetus.

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The factor that usually affects the colour of egg yolk is the type of feed given to the laying hen. The colour of the yolk is determined by the pigments, primarily xanthophylls, that the hen ingests and deposits into the yolk as it is formed. Hens that are fed with diets rich in xanthophylls, such as corn or alfalfa, tend to produce yolks with a darker, more orange-yellow colour. On the other hand, hens that are fed with diets low in xanthophylls, such as wheat or barley, tend to produce yolks with a lighter, more yellowish colour. Other factors, such as age of the hen or type of housing, may indirectly affect the colour of the yolk by influencing the type of feed given to the hen, but they do not directly affect the colour of the yolk. The colour of the cock, however, has no effect on the colour of the yolk.

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To calculate the percentage water content of a soil sample, we need to know the weight of the water in the sample and the weight of the dry soil. The weight of the water can be calculated by subtracting the weight of the dry soil from the weight of the fresh soil. In this case, the weight of the water can be calculated as follows: Weight of water = Weight of fresh soil - Weight of dry soil = 180 g - 120 g = 60 g The weight of the water is 60g. To calculate the percentage water content, we divide the weight of the water by the weight of the fresh soil, and multiply the result by 100. Percentage water content = (Weight of water / Weight of fresh soil) x 100% = (60 g / 180 g) x 100% = 0.333 x 100% = 33.3% Therefore, the percentage water content of the soil sample is 33.3%. Therefore, the correct answer is 33.3%.

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Primary tillage equipment performs several functions in preparing the soil for planting, including turning over and inverting the topsoil, burying weeds and trash, and preparing the soil for secondary tillage. However, it is not primarily responsible for preparing ridges for planting. This is the job of secondary tillage equipment, such as bed shapers or furrowers. Primary tillage equipment is used to break up hard-packed soil, loosen compacted soil, and create a suitable seedbed for planting. It is typically heavier and more powerful than secondary tillage equipment and is used less frequently, usually only once a year or every few years, depending on the soil type and cropping system.

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An advantage of the individual system of land ownership is that it encourages long-term planning. When individuals own land, they have a personal stake in its management and are motivated to make investments and improvements that will increase its productivity and value over time. This encourages farmers to plan for the long-term, such as crop rotations, soil conservation, and other sustainable practices that benefit the land and the environment. In contrast, communal or government-owned land may be subject to short-term decisions or neglect, as multiple users have different priorities and may not feel personally responsible for its care. On the other hand, the fragmentation of land ownership may create challenges for large-scale agricultural production and may limit the ability of farmers to access credit or use their land as collateral. Additionally, individual ownership may also lead to land litigation if boundaries are unclear or disputes arise between neighboring landowners.

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The best method of introducing a new pesticide to rural farmers is through demonstration. This is because the farmers get to see the practical use of the pesticide and the effectiveness of the product. The demonstration provides an opportunity for the farmers to ask questions and receive answers from the extension agents or experts. The farmers can also observe the safety precautions that should be taken when handling the pesticide. This method is more practical and effective than circular letters or field trips. Farmers co-operatives could also be a good platform for introducing the new pesticide, but a demonstration would still be necessary to show the farmers how to use the product correctly.

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The term "ginning" applies to the crop of cotton. Ginning is the process of separating the cotton fiber from the seeds and other debris that are harvested along with the cotton. The cotton gin, which was invented by Eli Whitney in the late 18th century, is the machine that performs this process. The cotton gin uses a combination of mechanical teeth and air flow to separate the cotton fibers from the seeds and other unwanted materials. After ginning, the cotton fibers are baled and sent to textile mills where they are spun into thread and fabric.

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Cassava is mainly propagated by cuttings. Cuttings are stem pieces from a mature cassava plant, which are planted in soil to grow into new cassava plants. This method of propagation is preferred because cassava does not produce true seeds or they take a very long time to mature, and cuttings can be taken from a healthy and productive mother plant to ensure the genetic quality of the new plants. Additionally, cuttings are easy to handle, transport, and plant, and they can rapidly produce new plants that are ready for harvest in 8 to 18 months.

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Forestry is the science and practice of managing forests, including the maintenance and preservation of forested areas. It involves a wide range of activities, including timber harvesting, reforestation, and wildlife management. Out of the given options, the establishment of pasture is not typically considered a function of forestry. While some forestry practices may involve the removal of trees to create open areas for grazing, the primary focus of forestry is on the management and preservation of forested areas, rather than on pasture establishment. Forestry plays an important role in providing timber for building, as well as in the preservation of medicinal and economic trees. It also provides shelter and habitat for wildlife, as well as numerous other ecological benefits, such as carbon sequestration and soil conservation.

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Nitrogen may be lost from the soil through crop removal, soil erosion, and leaching, but not through irrigation. Crop removal occurs when plants absorb nitrogen from the soil and are harvested, taking the nitrogen with them. Soil erosion can lead to the loss of topsoil, which contains organic matter and nitrogen. Leaching occurs when excess water moves through the soil, carrying nitrogen with it and depositing it in groundwater or surface water. However, irrigation is the process of adding water to the soil, which does not remove or add nitrogen to the soil. Therefore, nitrogen is not lost from the soil through irrigation.

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The role of government in promoting agricultural development is significant. It includes formulating policies, providing rural infrastructure such as roads, electricity, and water supply, establishing and funding research centers, and breeding plants and animals to increase productivity. However, one of the options provided is not a role of the government in promoting agricultural development. Breeding of plants and animals is not a role of the government but rather a responsibility of agricultural research institutions and individual farmers. Hence, the correct answer is "breeding of plant and animals."

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The activities of middlemen can cause several problems for farmers and consumers. For example, they may reduce the profit margin of farmers by buying produce at low prices and selling them at high prices, which may lead to financial losses for farmers. They may also create an artificial scarcity of produce by hoarding goods and creating a shortage in the market. Additionally, they may inflate prices by charging high fees for their services or manipulating the market to their advantage. However, middlemen do not directly cause inadequate storage facilities, which is typically the responsibility of the government or other entities. Therefore, inadequate storage facilities would not be a problem caused by the activities of middlemen.

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Animals which chew the cud are ruminants. Ruminants are mammals that have a four-chambered stomach specialized for digesting tough plant materials such as grass and leaves. They include cattle, sheep, goats, deer, and giraffes. Ruminants are unique in that they digest their food in two stages, first by softening it in a fermentation chamber called the rumen, and then by regurgitating and re-chewing the partially digested food (cud) to break it down further. This process allows ruminants to extract more nutrients from plant material than other herbivores, making them important sources of meat, milk, and other animal products for human consumption.

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The option that is not a sign of heat in farm animals is "udder enlargement". Heat, also known as estrus, refers to the period when a female animal is receptive to mating. During heat, farm animals may exhibit signs such as restlessness, increased vocalization, decreased appetite, and a desire to be mounted by other animals. However, udder enlargement is not typically a sign of heat in farm animals. Udder enlargement usually occurs during pregnancy or after giving birth, when the animal is producing milk.

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The scientific name for guinea grass is Panicum maximum. Guinea grass is a tropical grass species that is commonly found in African countries. It is a tall, fast-growing grass that can grow up to 3 meters in height. Guinea grass is known for its high productivity, high nutritional value, and drought tolerance. It is a popular forage crop for livestock and is used for hay, silage, and pasture. Guinea grass is also used in erosion control and land reclamation projects due to its ability to establish quickly and provide good ground cover.

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Smut disease is a disease that affects cereal crops such as corn, wheat, and barley. It is caused by a fungus. The fungus infects the developing grain and causes it to become filled with a dark, powdery substance. This substance is actually a mass of spores that will be spread by the wind to other plants. As a result, smut disease can cause significant damage to cereal crops, reducing yield and quality.

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The correct term used to describe the process of giving birth in farm animals is "parturition". This process refers to the act of delivering young offspring, such as calves, lambs, piglets, or chicks, from the mother's uterus to the outside world. During parturition, the muscles of the uterus contract and push the fetus through the birth canal until it is born. It is an essential stage in the reproductive cycle of farm animals and is carefully monitored by farmers and veterinarians to ensure the health of both the mother and offspring.

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The class of nutrients that is used mainly for energy production in farm animals is carbohydrates. Carbohydrates are broken down into glucose which is then used by the animal's body for energy production. Proteins, vitamins, and minerals have other important functions in the animal's body, such as building tissues, regulating metabolic processes, and maintaining good health, but they are not primarily used for energy production.

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The variety of maize that is less susceptible to weevil attack is flint maize. This is because flint maize has a harder kernel compared to other varieties of maize, making it difficult for weevils to penetrate and cause damage. Yellow maize, floury maize, and sweet maize have a relatively softer kernel, and are therefore more susceptible to weevil attack.

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Moths, aphids, and mealy bugs cause damage to crops by their piercing and sucking activities. These pests use their mouthparts to pierce the plant tissues and suck the sap or plant juices out of the plant. This can cause damage to the plant's structure, affect its growth and development, and even lead to the plant's death. Additionally, these pests can also transmit diseases to the plant while feeding. Therefore, it is important to control these pests to prevent damage to crops and ensure optimal plant growth and development.

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Birds temporarily store their food in the crop. The crop is an expandable pouch located at the base of a bird's neck that connects to the esophagus. When a bird eats, food is stored in the crop until it moves on to the next part of the digestive system. The crop allows birds to consume large amounts of food quickly and then digest it slowly over time. It also allows them to store food to bring back to their nests or young.

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Improvement of yam through breeding is difficult because it possesses no sexual reproductive system. Unlike many other crops, yam does not produce flowers or seeds that can be used in conventional breeding techniques. Instead, yam is propagated vegetatively, which means that new plants are grown from sections of the tuber. This makes it difficult to introduce new genetic material into yam populations and to create new varieties with desirable traits. Additionally, yam plants are often heterozygous, which means that their genes do not segregate in a predictable manner, making it difficult to select for specific traits through breeding. Therefore, improving yam through breeding is a time-consuming and difficult process that requires a lot of expertise and resources.

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Metamorphic rocks are formed by changes in pre-existing rocks through the application of heat and pressure. As the rocks are buried deep within the Earth's crust, they are subjected to high temperatures and pressures, causing them to undergo changes in their mineral composition, texture, and structure. These changes occur due to the recrystallization of minerals and the reorientation of grains in the rock. The heat and pressure cause the atoms and molecules within the rock to become more tightly packed, resulting in a denser and more compact rock. Therefore, the correct factors involved in the formation of metamorphic rocks are heat and pressure.

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Weevils can be controlled by storing dry grain in air-tight containers. Weevils are a type of beetle that infest stored grains and can cause significant damage to crops. By storing dry grain in air-tight containers, the weevils are denied access to the grain and are unable to lay their eggs. Without the eggs, the weevil population cannot reproduce and the infestation can be controlled. Additionally, proper sanitation and cleaning of storage facilities can help prevent weevil infestations from occurring in the first place.

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The question is asking for the problem that is NOT a cause of wastage of perishable farm produce. The answer is "inadequate water supply in rural areas". This is because water supply, although important for agricultural activities, is not directly linked to the issue of perishable farm produce wastage. The other options are directly linked to the problem, as inadequate storage and processing facilities can lead to spoilage, poor roads leading to rural areas can cause delays and damage to produce during transportation, and inadequate plying of rural roads can lead to difficulties in transporting produce to markets on time.

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Grain legumes are a group of crops that are grown for their edible seeds, which are high in protein and other nutrients. Legumes are also important because they can fix atmospheric nitrogen into the soil, which helps to improve soil fertility. Out of the given options, pigeon is an example of a grain legume. Pigeon pea, also known as red gram, is a widely cultivated legume crop that is grown in many parts of the world, particularly in South Asia and East Africa. The seeds of pigeon pea are a rich source of protein, and the crop is also used as a forage for livestock. Maize, sorghum, and millet are not examples of grain legumes. Maize and sorghum are both cereal crops that are grown for their edible grains, while millet is a small-seeded grass that is grown as a cereal crop in many parts of the world. While these crops are important sources of food and feed, they are not classified as grain legumes.

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An advantage of the communal land tenure system is that each member of the community can own land. In communal land systems, land is owned by the community as a whole, rather than by individuals. This allows for a more equitable distribution of land, as each member of the community has access to land for their own use. This can be especially important in areas where land is scarce or where traditional cultural practices emphasize communal land ownership. Additionally, communal land tenure systems can also foster a sense of community and cooperation, as members work together to manage and care for the land. This can lead to the sharing of knowledge and resources, and can encourage sustainable land management practices. However, communal land tenure systems may also have disadvantages, such as a lack of incentive for individual investment in land and potential conflicts over land use and management.

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Mechanization refers to the use of machines and equipment to carry out agricultural activities in a more efficient and productive manner. The use of machines and equipment can help to increase yields, reduce labor costs, and improve overall efficiency. Out of the given options, clearing land with a cutlass does not clearly describe the art of mechanization. Clearing land with a cutlass is a manual process that involves using a handheld tool to remove vegetation and other obstacles. While it is a common method of land preparation in some parts of the world, it is not a mechanized process. In contrast, using milking machines on dairy animals, harvesting maize with a harvester, and using a tractor to apply herbicides are all examples of mechanized processes. Using milking machines can help to speed up the milking process and reduce labor costs, while using a harvester to harvest maize can help to increase yields and reduce the amount of manual labor required. Using a tractor to apply herbicides can help to ensure that herbicides are applied evenly and efficiently, and can help to reduce the amount of herbicide required.

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Plant quarantine was introduced to control incoming diseases and pests. Plant quarantine refers to the measures taken to prevent the spread of plant diseases and pests across borders. The main objective of plant quarantine is to control the introduction and spread of harmful pests and diseases from one country to another through the movement of plants, plant products, and other regulated articles. By controlling the spread of these pests and diseases, plant quarantine helps to protect the agricultural productivity and biodiversity of a country.

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The main use of a Gunter's cabin is taking measurements of distance. A Gunter's cabin is a device used for measuring distances, and it was invented by Edmund Gunter, a mathematician and astronomer in the 17th century. It consists of a rectangular wooden box with a glass window on one side and a series of brass rods or chains inside that are used for measuring distances. The Gunter's cabin is placed at the starting point of a measurement, and the person taking the measurement looks through the glass window to line up the cabin with the target. They then count the number of chains or rods required to reach the target to determine the distance. The Gunter's cabin is an early form of surveying equipment and is still used today in some cases.

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Management practices in a piggery include various activities that help to promote the health and well-being of the pigs and maximize their productivity. These practices typically include disinfecting pens, regular cleaning of feed and water troughs, and isolating sick animals to prevent the spread of disease. However, weekly vaccination of pigs is not a common management practice in many piggeries. While vaccination can be an effective way to prevent the spread of certain diseases, it may not be necessary to do so every week, depending on the specific diseases prevalent in the area and the health status of the herd. Other management practices that are commonly employed in a piggery include regular feeding and monitoring of the pigs, proper waste disposal, and regular veterinary checkups.

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Nitrogen is an essential nutrient that plays a critical role in plant growth and development. It is a constituent of proteins, nucleic acids, and other essential compounds. When plants lack nitrogen, they may exhibit a range of symptoms. Stunted growth, lower protein content of crop products, and general yellowing of leaves are some of the common signs of nitrogen deficiency in plants. However, excessive growth is not a typical symptom of nitrogen deficiency. In fact, when plants lack nitrogen, their growth is often stunted because nitrogen is required for the production of essential growth hormones. Therefore, the answer to the question is "excessive growth."

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Coccidiosis is a disease caused by the invasion of the intestinal tract of livestock by coccidian parasites. To treat coccidiosis, sulphamethazine is commonly used. Sulphamethazine is an antibiotic that is effective in treating coccidiosis because it targets the coccidian parasites, which cause the disease. Sulphamethazine works by blocking the growth and reproduction of the coccidian parasites, which helps to reduce the severity of the infection and promote recovery in affected animals.

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Newcastle disease attacks poultry. It is a highly contagious viral disease that affects domestic and wild birds, including chickens, turkeys, and pigeons. The virus is spread through contact with infected birds, their droppings, or contaminated equipment, and can cause respiratory, nervous, and digestive symptoms in infected birds. Newcastle disease can have a significant impact on poultry production, as infected birds may die or require culling to prevent the spread of the disease. While other animals may be susceptible to other diseases, Newcastle disease specifically affects poultry.

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The most efficient irrigation method on large scale farms is overhead irrigation facilities. This is because the irrigation system can cover a large area of land with minimal effort, and the water can be applied evenly to the crops. Overhead irrigation facilities can be in the form of center pivot or linear move systems, which can irrigate thousands of hectares of farmland. Additionally, this method reduces the amount of water lost due to evaporation, runoff, or deep percolation, making it a more efficient use of water resources.

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Farm records are essential for managing a farm effectively and efficiently. They provide important information about the farm's operations and performance, which can be used for future planning and decision-making. Additionally, farm records can help to determine the profitability of the farm, assess the quality of farm produce, and provide information to determine the creditworthiness of farmers. However, one reason that farm records may not be important is for assessing the quality of farm produce. While farm records can provide information about the production of crops and animals, they do not necessarily provide information about the quality of the produce itself. Quality assessments are typically conducted through laboratory tests or physical inspections, rather than through farm records. Therefore, while farm records are important for many reasons, they may not be directly related to assessing the quality of farm produce.

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Sexing in animal production is the process of separating the male animals from the female animals. This is done to facilitate selective breeding, as it allows farmers and animal breeders to control the reproduction of their livestock. By separating male and female animals, breeders can ensure that only the desired individuals mate and produce offspring with desirable traits. This helps to improve the quality and productivity of the herd or flock, as well as maintaining the health of the animals.

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The correct answer is "land conservation". Soil formation is a natural process influenced by various factors including topography, parent material, climate, biota, and time. The topography of an area determines the drainage and accumulation of soil materials. Parent material refers to the underlying geological material that soil is formed from. Climate influences soil formation by affecting the rate of weathering, erosion, and organic matter decomposition. Biota refers to the living organisms that contribute to the formation of soil through decomposition and nutrient cycling. Land conservation is a human activity that aims to prevent soil degradation and erosion through the implementation of various practices. It does not directly influence the natural process of soil formation.

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(a) Life cycle of the bean beetle (bean weevil, Callosobruchus maculatus)

1. The adult female lays her eggs on the surface of the bean seeds, either on the field or in store.
2. Each egg hatches into a larva (grub).
3. The larva bores into the bean seed and feeds on the cotyledons inside.
4. Within the seed the larva grows and then changes into a pupa.
5. The pupa develops into an adult beetle.
6. The adult bores its way out of the seed, mates and the female lays eggs again, so the cycle repeats. (Egg to adult in about three to four weeks.)

(b)(i) Four damages done by cotton stainer to cotton plants on the field

1. It pierces and sucks sap from the bolls, buds and young shoots, weakening the plant.
2. It stains the cotton lint yellow or brown, lowering its quality and market value.
3. It introduces fungi and bacteria into the bolls, causing internal boll rot.
4. It causes premature dropping of buds and immature bolls, reducing yield.

(b)(ii) Four alternate hosts of cotton stainer

1. Okra
2. Hibiscus (roselle/soborodo)
3. Baobab
4. Kola (and other Malvaceae plants)

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(a) Four marketing agents

1. Wholesalers
2. Retailers
3. Commission agents/brokers
4. Middlemen (assemblers)

(b)(i) Four characteristic features of co-operative societies

1. Voluntary and open membership.
2. Democratic control (one member, one vote).
3. Members contribute capital through shares and share profits/dividends.
4. Formed to promote the common economic interest of members, with limited interest on capital.

(b)(ii) Four advantages of co-operative societies in agriculture

1. They provide credit/loans to members at low interest.
2. They enable members to buy farm inputs in bulk at cheaper rates.
3. They provide a better and larger market for members' produce, ensuring fair prices.
4. They give members access to storage, processing facilities and useful farming information.

(c)(i) Three merits of individual (personal) contact in extension method

1. It allows the farmer's specific problems to be identified and solved directly.
2. It builds trust and a good relationship between the farmer and the extension agent.
3. It is effective in persuading the farmer to adopt new practices.

(c)(ii) Three Agricultural Extension Programmes (in Nigeria)

1. Agricultural Development Projects (ADPs).
2. National Agricultural Extension and Research Liaison Services (NAERLS).
3. Training and Visit (T&V) extension system (and Farmer Field Schools).

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(a) Six sources of farm power

1. Human (manual) power
2. Animal (draught) power
3. Mechanical power (tractors, engines, machines)
4. Electrical power
5. Wind power
6. Solar power (and water power is also acceptable)

(b) How five of the sources are utilised on the farm

• Human power: supplies the muscular energy used for operations such as clearing, hoeing, planting, weeding, harvesting and carrying loads with simple hand tools.
• Animal power: draught animals such as oxen, horses and donkeys are yoked to ploughs, harrows and carts to till the soil and to transport farm produce.
• Mechanical power: tractors and engines drive ploughs, harrows, planters, sprayers, harvesters and pumping machines, doing heavy field work quickly.
• Electrical power: runs pumping machines for irrigation, lighting in poultry houses, incubators, grinding and processing machines and refrigeration for storing produce.
• Solar power: provides heat for drying grains and crops, warms brooding houses and, through solar panels, generates electricity for farm use.

(c) Two disadvantages each of any four sources

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(a) Three factors of production in agriculture

1. Land: the natural resource on which farming takes place. It provides the soil, water and space for crops and livestock, and its reward is rent. Its supply is fixed and its quality varies from place to place.
2. Labour: the human effort, both physical and mental, applied to production, such as clearing, planting, weeding and management. Its reward is wages/salary. Labour may be skilled or unskilled, family or hired.
3. Capital: all man-made assets used to aid production, such as tools, machines, farm buildings, seeds, fertilisers and money. Its reward is interest. Capital increases the efficiency and output of the farm.

(A fourth factor, management (entrepreneur), which organises the other three and whose reward is profit, is also accepted.)

(b) Four functions of a farm manager

1. Planning the farm operations and deciding what, when and how to produce.
2. Organising and coordinating the land, labour and capital of the farm.
3. Directing and supervising farm workers and operations.
4. Keeping farm records and marketing the farm produce (and controlling finances).

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Rinderpest and Newcastle disease

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(a) Four factors to consider when siting a fish pond

1. Adequate and reliable source of clean water.
2. Suitable soil that can hold water (clayey/loamy soil with good water retention).
3. Gentle slope of the land to allow easy filling and draining of the pond.
4. Nearness to market, road and source of feed, and freedom from flooding or pollution.

(b) Six ways of maintaining a fish pond

• Regular feeding: supply supplementary feed at correct times and amounts for good growth.
• Liming and fertilising: apply lime to correct acidity and fertiliser/manure to promote natural food (plankton).
• Control of water level and quality: maintain the correct depth and change or aerate water to keep oxygen adequate.
• Removal of predators and weeds: clear aquatic weeds and eliminate snakes, birds and predatory fish.
• Control of pests and diseases: observe the fish regularly and treat or isolate diseased stock.
• Repair of pond structures: check and mend the dykes, inlets, outlets and screens to prevent leakage and escape of fish.

Rinderpest and Newcastle disease

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(a) What is land?

Land is the natural, immovable portion of the earth's surface, together with all the free gifts of nature on and beneath it (soil, water, minerals, vegetation and air), which man uses for agricultural and other productive purposes.

(b) Six uses of land

1. Cultivation of crops (arable and plantation farming).
2. Rearing of livestock and establishment of pastures.
3. Construction of farm buildings, houses and roads.
4. Forestry and establishment of plantations.
5. Fish farming and construction of dams or reservoirs.
6. Mining and quarrying of minerals.

(c) Four ways an agricultural land may appreciate in value

1. Construction of good access roads and provision of infrastructure near the land.
2. Improvement of soil fertility through manuring, liming and good management.
3. Provision of irrigation, drainage or water supply on the land.
4. Development of the land with buildings, fencing and permanent tree crops, or increased demand as the population around it grows.

(d) Five benefits derived from soil organisms in agriculture

1. They decompose organic matter and release nutrients into the soil.
2. They aid in the formation of humus, improving soil structure and fertility.
3. Some (for example Rhizobium) fix atmospheric nitrogen for plant use.
4. They improve soil aeration and drainage by burrowing and mixing the soil.
5. They help in nutrient cycling and in breaking down toxic substances, keeping the soil healthy.

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Reading the plan. The farm is a trapezium with the two parallel boundaries measuring 70 m (top, BC) and 90 m (bottom, AD), and the perpendicular distance between them AB = 45 m.

(a) Area of the land in hectares

Converting to hectares, using \(1\ \text{hectare} = 10\,000\ \text{m}^2\):

(b) Number of planting materials required

Step 1: Share the land between the crops.

Step 2: Ground area occupied by one plant.

Step 3: Number of plants = crop area ÷ area per plant.

The farm requires 180 plantain suckers and 144 pineapple suckers.

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(a) Four functions of each macro-nutrient in plant nutrition

(i) Nitrogen

1. Promotes vegetative growth and the development of leaves and stems.
2. Forms an essential part of proteins, enzymes and protoplasm.
3. Is a constituent of chlorophyll, giving leaves their green colour.
4. Improves the quality and yield of leafy crops.

(ii) Phosphorus

1. Promotes healthy root development and establishment of seedlings.
2. Aids flowering, fruiting and seed formation, hastening crop maturity.
3. Is involved in energy transfer within the plant (as part of ATP).
4. Strengthens the plant and improves resistance to disease and lodging.

(iii) Potassium

1. Strengthens stems and straw, reducing lodging.
2. Aids the formation, movement and storage of carbohydrates and sugars.
3. Improves resistance to diseases and to drought.
4. Regulates the opening and closing of stomata and the water balance of the plant.

(b) Four factors that affect the availability of nutrients to crops

1. Soil pH (acidity or alkalinity).
2. Soil moisture content.
3. Soil temperature.
4. Presence of soil organic matter and micro-organisms (and soil texture/aeration).

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(a) Three ways each factor affects agricultural development

(i) Poor tools and implements

• They lower productivity because only small areas can be cultivated with crude hand tools.
• They cause drudgery and make farm work slow and tiring, discouraging the youth from farming.
• They lead to poor quality of farm operations and waste of time and energy, keeping output at subsistence level.

(ii) Poor storage facilities

• They cause heavy post-harvest losses through spoilage of produce.
• They expose produce to attack by pests and rodents, reducing quality.
• They force farmers into distress sales at low prices soon after harvest, reducing income and causing food scarcity later.

(b) One solution to the problem of poor tools and implements

Provide improved and modern farm machinery and implements to farmers at subsidized prices (mechanization), supported by training and credit facilities.

(c) Three objectives each

(i) Land Use Act

• To make land easily available and accessible for agricultural and other development.
• To ensure fair and equitable distribution of land among citizens.
• To control land speculation and reduce land disputes and litigation.

(ii) Quarantine programme

• To prevent the introduction and spread of pests and diseases from one place to another.
• To inspect and certify imported and exported plants and animals.
• To isolate, treat or destroy infected plants and animals so as to protect local agriculture.

(iii) Government agricultural loan and subsidy schemes

• To provide farmers with credit and finance for production.
• To reduce the cost of farm inputs through subsidy so that more farmers can afford them.
• To encourage increased production, mechanization and the entry of new farmers into agriculture.