Correct Answer: A. Ecosystem

Explanation

(a)Sources of irrigation water

- Rivers

- Lakes - Streams

- Ponds -

- Bore-holes

- Wells

- Reservoirs

- Springs

- Brooks

- Dams

(b) Advantages and disadvantages of irrigating farmlands

Advantages

- Makes early planting possible

- Adds water to the soil/supply moisture to the soil for plant growth

- Helps to soften the soil for easy tillage operations

- Facilitates the survival of crops during drought

- Farmers become less dependent on rainfall

- Helps lower soil temperature

- Ensures all-year-round production

- Modifies both soil and plant environment

- Enhances microbial decomposition of organic matter in the soil

- Dissolves nutrients for root absorption

- Can be used to apply liquid fertilizers(fertigation)

Disadvantages

- High cost of irrigation equipment

- Increased salinity

- Disease transmission is possible

- Leads to build-up and spread of pests

- Vectors of diseases e.g. snails, tsetse flies, mosquitoes may breed in

irrigated areas

- Movement of farm machinery may be hindered

- May lead to leaching

- May lead to erosion/flooding

- Encourages the growth and spread of weeds

(c) Ways by which the soil loses nutrients

- Mechanical land clearing/bulldozing of virgin forests

- Crop removal/harvesting

- Continuous cropping

- Leaching

- Burning

- Overgrazing

- Erosion

- Oxidation

- reduction

- Chelation

(d) Reasons for manuring in crop production

- Improves the activities of soil organisms like earthworms

- Improves the structure of the soil

- Improves aeration within the soil

- Regulates soil temperature

- Buffering effects improve the acid-base reaction of the soil/assists in regulating soil pH

- Improves water holding capacity in sandy soil

- Improves water infiltration in clay soil

- Controls soil erosion

- Adds nutrients to the soil/improves soil fertility

- Increases cat ion exchange capacity of the soil

- Used for the control of nematodes in the soil

(e) Ways by which environmental factors affect agricultural production

(i) Temperature

- High temperature may cause heat stress/death of farm animals

- A necessary condition for germination of seeds

- Affects distribution of crops

- Affects distribution of animals

- High temperature increases evapo-transpiration

- High temperature reduces the performance of livestock/fish

- Temperature affects the ripening and maturity of fruits

- Affects microbial activities in relation to mineralization of organicsubstances

- Temperature affects productivity of human labour/draught animal

(ii) Soil micro-organisms

- Cause diseases in plants

- Bacteria in root nodules can fix nitrogen directly to plants and soils

- Reduce the quantity and quality of crops e.g. potato, yam

- Help in the decomposition of plant materials to form humus

ii)Wind

- Influences the rate of transpiration

- Causes evaporation in the soil

-

Correct Answer: A. wedding

Correct Answer: C) Rabbit

Correct Answer: B. Vaccinating animals

Explanation

2(a)(i) Explanation of farm surveying: Farm surveying is the process of measuring and mapping out the position, topography, size and boundary of an area of farmland.

(ii) Reasons why farm surveying is important

-It helps to determine the size or hectarage of farmland

- Used for feasibility studies

- Enables the farmers to make proper use of the land

- Farmers can determine where to site and locate certain buildings or structures in the farm

- Farm maps or soil maps help in planning the farmstead

- Results from surveying help to describe the characteristics and features of the various soil units used for soil classification.

- The yield or productivity of farmland can be projected

- Results of farm survey can be used as collateral for conditions securing loan from financial institutions

- Facilitates acquisition of certificate of occupancy (c of o)

- Surveying helps to determine the gradients of the farmland

- Roads and other access ways can be constructed with knowledge derived from surveying.

(b) Problems facing agricultural development in West Africa (i) Inadequate finance/credit facilities (ii) Poor rural infrastructural facilities(iii) Low level of technical know - how (iv) Poor marketing system (v) .Poor pricing system (vi) Inadequate transport facilities (vii) Inadequate storage facilities (viii) Inadequate processing facilities (ix) Socio-cultural constraints (x)Poor extension services (xi) Poverty among farmers (xii) Conservatism(xiii) Inadequate supply (xiv) Poor land tenure system(xv) Environmental degradation e.g oil spillage, desertification, drought, erosion, deforestation etc.(xvi) Problem of Pests (xvii) Problem of Diseases (xviii) Inconsistency in government policies/political instability. (xix) Use of crude tools (xx) Inadequate/expensive farm inputs.

(c) Factors that may affect the efficiency of draught animals Health of the animal/diseases, Pests, Food intake, Breed of the animal/genetic make-up, Weight of the animal, Age of the animal, Poor management of the animal, Harness used for hitching, Sex of the animal, Training given to the animal, Climate/environmental factors

Correct Answer: B. the mineral composition of rock is changed in chemical weathering.

Correct Answer: D. foot and mouth disease

Correct Answer: B. nematode

Explanation

(a) Reasons why agriculture has not been fully mechanized in West Africa:

(i) small farm holding/land fragmentation /land tenure system

(ii) farming systems do not encourage mechanization

(iii) no access roads for machines

(iv) it is costly or expensive to hire machines and most farmers are poor

(v) high running costs for machinery

(vi) heavy tree stumps left after land clearing hinders use of machinery

(vii) machines/implements are expensive to purchase

(viii) inadequate capital/ credit facilities

(ix) spare parts are not easily available

(x) technical know-how may be a problem

(xi) inadequate extension service/education for farmers/illiteracy

(xii) unfavourable soil terrain/topography.

(xiii) availability of labourers/ farm hands

(xiv) non-availability of tropicalised machinery/inadequate machines

(xv) machines are costly to maintain (xvi) poor market structures/system for agricultural produce discourages farmers from large scale production.

(b)(i) Characteristics of subsistence agriculture: (i) mostly practiced by peasant farmers. (ii) involves small plot of land. (iii) use of local tools e.g. hoes, machetes (iv) there is no specialisation (v) employs unskilled labour (vi) returns/output are low (vii) family labour involved (viii) provides only for the basic need of the family (ix) little surplus for sale (x) little/low capital involved (xii) heavy reliance on natural rainfall. (xiii) Production of food crops only (xiv) limited use of Agrochemicals (xv) unimproved varieties of crops and breeds of animals are used (xvi) mixed cropping is usually practised.

(ii) Characteristics of commercial agriculture: (i) sole cropping system is usually practised (ii) cultivation of large hectares of land (10 involves huge investment of money (iv) hired labour is involved (v) operations are mechanized (vi) skilled labour employed (vii) yield is usually high (viii) only rich farmers are engaged in it (ix) imp roved varieties of crops and breeds of animals are used (x) irrigation may be practiced (xi) records are kept (xii) use of agro-chemicals.