Agricultural Science 2019 Jamb Examination

Agricultural extension agents provide education and training to groups such as individual farmers, commercial farmers, cooperatives, and even non-governmental organizations involved in agricultural development. Political parties, however, are not directly involved in agricultural production and thus are not a target group.

A good extension worker should have organizational ability, initiative, clear judgment, patience, and communication skills. Involvement in local politics can create bias and reduce trust among farmers, which hinders effective extension work. Therefore, this is not a desirable quality.

A disc plough consists of components such as discs, disc scrapers, coulters, beams, and furrow wheels. A planter, however, is a separate machine used for sowing seeds, and it is not a component of a disc plough.

The disc plough is designed for primary tillage, breaking up hard soil and creating wide ridges, while the disc harrow is used for secondary tillage, breaking clods into finer particles and leveling the soil. This key distinction is captured in option A.

A castrated cockerel is known as a capon. Caponization is done to improve meat quality by reducing aggression and promoting tender flesh. A pullet refers to a young female chicken, a hen is an adult female, and a broiler is raised specifically for meat.

The New Zealand White is a well-known breed of rabbit that is widely used in meat and fur production as well as laboratory research. It is not associated with goats, cattle, or rats.

Newcastle disease is a highly contagious viral disease that primarily affects poultry birds such as chickens, turkeys, and pigeons. It causes respiratory distress, nervous symptoms, and a sharp decline in egg production. It does not affect cattle, goats, or fish.

When planning a farmstead, factors such as accessibility, topography, and soil type are crucial for efficiency and productivity. Irrigation, while important in crop production, is not a key determinant in the initial layout and planning of farmstead structures.

Legumes are unique in that they form a symbiotic relationship with nitrogen-fixing bacteria (Rhizobium) in root nodules. This relationship enriches the soil with nitrogen, making legumes important in crop rotation and soil fertility. Grasses do not have this ability. Hence, option B is correct.

The A-horizon, also known as the topsoil, is the most biologically active layer of soil. It contains high levels of organic matter from decomposed plants and animals, providing food for microorganisms, earthworms, and other soil fauna. This layer is rich in nutrients and has a good structure for supporting plant roots, making it critical for crop production.