Observation

This question was fairly popular among the candidates. Although many of them were unable to mention the functions of the ridger.

The expected answers include:

• (a)        Functions of farm implements during tillage operation

(i)         Disc plough

• Breaks soil into clods/lumps
• Can be used on sticky soil
• Buries weed deep into the soil
• Facilitates infiltration of water
• Promotes soil aeration
• Prepares the land for harrowing
• Works on strong, dry stony soil 
• The furrow wheels enables it to roll over obstacles

                (ii)    Disc Harrow

• Pulverises the soil into fine tilth/breaks up soil lumps/clods
• Buries weed and crop residue
• Can be used to mix both organic and inorganic fertilizer with the soil
• Chops plant stumps into smaller bits/pieces
• Eases the penetration of root and tuber crops after use
• Eases the percolation of water
• Can be used to cover seeds after broadcasting
• Levels the soil

               (iii)    Ridger

• Produces ridges for cultivation of tuber crops
• Gathers rich top soil together
• Helps to control erosion/run off 
• Helps to increase soil aeration
• Prevents the growth of weeds
• Facilitates harvesting of shallow rooted crop e.g. groundnut, white potato

            (b)        Ways by which soil air is important
-     Essential for roots respiration
-     Soil organisms also require air for respiration
-     Helps in the germination of seeds
-     It is inversely related to soil water content
-     Helps in the absorption of plant nutrients
-     Essential for root development
-     Needed in the nitrogen and carbon cycles
-     Carbon dioxide and sulphur IV oxide react with soil water to form weak acids     
which aid weathering of parent materials

            (c)        Examples of cultural method of controlling insect-pests on the farm
-           Crop rotation                                       -           Flooding
-           Planting healthy plant materials          -           Good spacing of crops
-           Close-season practices                        -           Pruning
-           Tillage operations                               -           Timely harvesting
-           Use of insect traps                              -           Weeding/farm sanitation
-           Hand-picking /destruction of insects  -           Burning crop residues
-           Timely planting of crops                    -           Mulching
-           Use of pest tolerant varieties of crops