- Operations in Land Preparation
- Minimum Tillage:
- A piece of land which is prepared is known as seedbed.
- A seedbed is a piece of land that is prepared ready to receive planting materials.
Reasons for Seedbed Preparation;
- To enable water to infiltrate.
- To kill weeds
- To improve soil aeration
- To destroy pests and diseases.
- To incorporate organic matter in the soil.
- For easy planting.
- To facilitate root penetration.
- Clearing of land is necessary when:
- Opening up a virgin land.
- A stalk growing crop was previously planted.
- There is long interval between primary and secondary cultivation.
- Land was left fallow for a long time.
- Tree felling and removal of stumps and roots.
- Use of chemicals.
Note: Burning should be avoided where possible since it;
- Leads to loss of organic matter,
- Kills soil organisms
- Destroys soil structure and plant nutrients.
- This is the initial breaking of land.
- It is done early before the onset of the rains to:
- Give time for soil organisms to act on organic matter.
- Allow gaseous exchange to take place, thus carbon dioxide diffuses out of the soil while oxygen enters into the soil.
- Allow other operations to take place in time.
Reasons for primary cultivation:
- Remove weeds.
- Burry organic matter.
- Open up soil for infiltration of water and air.
- Expose pests and disease causing organisms.
- Soften the soil for easy planting.
Operations in primary cultivation
- Hand digging ;
Use of hand tools ;
- Mechanical cultivation ;
Use of mouldboard ploughs;
- Disc ploughs,
- Chisel ploughs,
- Use of Ox-Ploughs ;
Which can be drawn by;
Depth of Cultivation
- The type of crop to be planted/size of seed.
- The implements available.
- The type of soil.
Choice of Implement
- The condition of land.
- The type of tilth required/type of crop.
- Depth of cultivation.
- These are refinement practices on the seedbed that follow primary cultivation.
- It is also known as harrowing.
Reasons for secondary Tillage:
- To remove the germinating weeds.
- To break soil clods to produce required tilth.
- To level the seedbed for uniform planting.
- To incorporate organic matter/manure into the soil.
Factors determining number of secondary cultivation:
- Soil moisture content.
- Size of the planting materials.
- Condition of the soil after primary cultivation.
- Slope of the land.
- The process of digging soil on a continuous line and heaping on one side to produce a furrow and a bund (ridge).
- It is important for root crops, to allow root expansion and for soil and water conservation.
- It is the compaction of the soil to produce a firm surface which increases seed-soil contact and prevents wind erosion.
- Production of an even, uniform surface which promotes uniform planting.
- This is deep cultivation into the subsoil layer to break up any hardpan which might have developed.
It is done for the following reasons:-
- To facilitate drainage.
- Bring up leached nutrients to the surface.
- Increase aeration of the soil.
- To improve root penetration.
- The implements used include chisel plough and subsoilers.
- This is the application of a combination of farming practices with the aim of reducing the disturbance of the soil.
Examples of which include:
- Use of herbicides.
- Mulching and cover-cropping.
- Timely operations to prevent weed infestation.
- Strip cultivation.
- Uprooting and slashing of weeds.
- To reduce cost of cultivation.
- To control soil erosion.
- To preserve soil moisture.
- To prevent root exposure and damage.
- To reconstruct destroyed soil structure.