(a)
Weed | Botanical Name | Method of Dispersal
--- | --- | ---
Goat weed | Ageratum conyzoides | Wind and animals
Siam weed | Chromolaena odorata | Wind and animals
Water leaf | Talinum triangulare | Water and animals
(b)
(i) Physical factors affecting land availability for agriculture include: soil type, climate, and topography. For example, land with poor soil fertility or a steep slope may not be suitable for agriculture.
(ii) Economic factors affecting land availability for agriculture include: land prices, land tenure systems, and market demand for agricultural products. For example, high land prices may make it difficult for small-scale farmers to access land, while strong demand for certain crops may lead to land conversion from other uses.
(c)
Four effects of pollution on agricultural lands and ponds include: reduced soil fertility, loss of biodiversity, contamination of crops and water sources, and reduced fish populations. Pollution can also lead to increased disease incidence in both plants and animals.
(d)
Two ways of minimizing land and pond pollution include: reducing the use of chemical fertilizers and pesticides, and implementing proper waste management practices. For example, farmers can use organic fertilizers and biological pest control methods to reduce chemical pollution, while waste from livestock can be properly managed through composting or other methods to reduce contamination of water sources.