(a) State the law of diminishing returns in agricultural production. (2 marks) (b) The table below shows the relationship between quantities of fertilizers ...

(a) Law of diminishing returns

The law of diminishing returns states that when successive units of a variable factor are added to fixed factors of production, total output will initially increase, but after a certain point each additional unit of the variable factor adds less to total output than the preceding unit.

(b)(i) Input-output graph

Using the scale shown by the axes, plot the following points and join them with a smooth curve:

(b)(ii) Relationship between fertilizer input and sorghum yield

1. As fertilizer application increases from 0 to 36 bags, sorghum yield increases from 8 kg to 200 kg.
2. After about 24 bags, additional fertilizer gives progressively smaller increases in yield: 30 kg from 24 to 28 bags, 20 kg from 28 to 32 bags, and 10 kg from 32 to 36 bags. This is the stage of diminishing returns.
3. At 36 to 40 bags, the maximum yield of 200 kg is reached. Further application to 46 bags reduces yield to 190 kg, showing negative returns.

(c) Functions of an agricultural extension agent

1. Teaches and demonstrates improved farming methods and innovations to farmers.
2. Serves as a link between farmers, government and agricultural research institutions.
3. Disseminates agricultural information and advises farmers on farm management problems.
4. Assists farmers to obtain farm inputs, credit facilities and marketing information.

(d) Benefits of commodity boards in the marketing of agricultural produce in West Africa

1. They provide a ready market for agricultural commodities.
2. They announce guaranteed prices and help to stabilize farmers' incomes.
3. They carry out grading, standardization and quality control of produce.
4. They provide storage, processing, transportation and other marketing services.
5. They assist farmers with credit, subsidies, farm inputs and technical advice.