(a) Explain the following terms used in agricultural ecology:
(i) Soil texture
(ii) Soil profile.
(b) (i) Discuss three advantages of grafting.
(ii) Mention two crops that could be propagated by grafting.
(c) State four cultural practices that could be used to replenish nutrients in the soil.
(d) List four measures that could be adopted by farmers to control pests in grain stores.
Explanation
(a) Explanation of terms used in agricultural ecology
(i) Soil texture- The relative proportion of particles of various sizes present in a given soil sample
- Measure of coarseness or fineness of a soil sample
-Used in soil classification
- Relative percentage of sand, silt, and clay in a soil sample
(ii) Soil structure
- The arrangement of soil particles into aggregates and the pores between them
- Aggregation of soil particles into different shapes soil and sizes
-Determines the rate of water percolation/ infiltration in the soil
(iii) Soil profile
- The vertical section of soil showing the various layers/horizons
- The different layers are underlining bedrock, weathered materials, subsoil, and topsoil
-Each layer is differentiated in terms of colour, texture, and organic matter
(b) (i) Advantages of grafting
- Useful for propagating plants whose cuttings are difficult to root
- Rapidly increase the number of desirable cultivars
- Provides disease resistance to a susceptible but desirable cultivar
- Used to change plant form
-Assist in repairing damaged plant parts
- Suitable for virus indexing -
- Helps plants to adapt to adverse soil/climatic/ environmental conditions
- Quickens maturity/fruiting
- Breeding true to type uniform plants
(ii) Tree crops that could be propagated by grafting
-Mango
- Avocado pear
- Rubber
- Breadfruit/jack fruit
- Soursop
- Citrus/any named citrus Kola
- Cashew
- Guava
- Cocoa
- Coffee
- Apple
- Moringa
(c) Cultural practices that could be used to replenish plant nutrients in the soil
- Planting of cover crops Planting of shade treescrop rotation
- Liming
- Agro
- forestry/ Alley cropping
- Organic manuring
- Mulching
- Fertilizer application
- Fallowing
(d) Measures farmers could adopt to control pests in grain stores
- Well constructed storage buildings/structures to prevent the entry of rodents and other pests
- Concrete floors/walls to prevent insects and rodents from creating hiding places
- Timely harvesting
- Removal of infested grains before storage
- Proper drying of grains before storage
- Stores should be well ventilated
- Stores should be rain/damp proof
- Store produce on a raised platform
- Inspect store regularly to detect pest infestation
- Fumigate store before storage and after removing old stock or consignment
- Use poisonous baits/rodenticides/pesticides
- Set traps to kill rodents
-Use hermetic air tight containers to store grains
- Clean/disinfect grain store before storage