(a) With the aid of an annotated diagram only, illustrate the water cycle. (b) State three forms in which water exists in the soil (c) List five importance of water to crops.
Explanation
(a) See the diagram of water cycle below
(b) Forms in which water exists in the soil are: (I) hygroscopic water(ii) capillary water. (iii) gravitational water.
(c) Importance of water to crops are:
(i) provides medium for absorption of mineral salts.
(ii) facilitates the transfer of nutrients to other parts of the plants where they are used in various metabolic processes.
(iii) water is an essential raw material in the process of photosynthesis.
(iv) used for hydrolizing food substances such as starch, proteins, fats and oils for easy transportation to other parts of the plant.
(v) water facilitates enzymatic activities occuring in crop plants.
(vi) it is a constituent of plant protoplasm.
(vii) the loss of water through transpi-ration is important for keeping the stomata open in gaseous exchange for respiration and photosynthesis.
(viii) it has a cooling effect on crops.
(ix) it helps to maintain plant turgor/turgidity.