(a) State three methods of irrigating a small nursery. (b) Enumerate three factors to be considered in the choice of each of: (i) surface irrigation method (ii) sub-surface irrigation method. (c) .State two advantages of subsurface irrigation (d) Enumerate five ways by which the build-up of diseases could be reduced on an irrigated farm.
Explanation
(a) Methods of irrigating a small nurse (i) manual sprinkling e.g. hand, brooms, brush. (ii) Use of watering Can (iii) Drip irrigation (iv) Channel irrigation (v) Sprinkler irrigation. (b) Factors to be considered in choosing the method of: (i) surface irrigation (1) topography/sloppy land (2) soil type (3) type of crop to be grown (4) size of the farm/land. . (ii) Surface irrigation: (1) permeability of substratum (2) level of water table (3) soil texture / capillarity (4) soil structure (c) Advantage of subsurface irrigation: (i) By irrigation it is possible to maintain water at optimum depth for crop need (ii) In addition, water use efficiency is high (iii) It also ensures low evaporation losses from soils (iv) doers not create obstructions/obstacles when carrying out cultural practices (d) Reduction of disease built up in an irrigated farm may be achieved through: (i) use of disease resistant varieties (ii) crop rotation (iii) use of appropriate chemicals, (iv) use of clean tools (v) use of clean/healthy planting, materials (vi) destruction of diseased crops to prevent its spread (vii) avoidance of excessive irrigation/drain excess water (viii) weed control
