Al the activities in land preparation can be generally divided into two (2) categories;
- Primary cultivation.
- Secondary cultivation.
This includes the first activities done when opening up a piece of land or after removing the previous crop.
It involves activities like cutting trees, stamping, slashing and first Ploughing. It is a heavy job which uses heavy implements e.g. disc ploughs, moldboard plough, disc plough, chisel plough.
Importance/ objectives of primary cultivation
To break the hard soil surface.
To improve the aeration of the soil.
To burry the weeds and weed seeds.
To improve water infiltration.
To incorporate organic matter into the soil.
To prepare big lumps of soil for galvanization during secondary tillage.
To bring the leached minerals to the top soil.
To provide enough depth in the soil for root penetration and expansion.
To invert top soil and bring a fresh layer to the surface for further weathering.
It is usually done atleast 2 weeks after primary cultivation. It involves second Ploughing, leveling and harrowing of the seedbed.
The time of two weeks is to allow the weeds and the vegetation that were buried in primary cultivation to decompose/ germinate and grow such that they can be destroyed during secondary cultivation.
Objectives of secondary cultivation
To level the land/ ground in preparation for planting.
To incorporate/ mix manures and fertilizers in the soil.
To kill the weeds that have germinated after primary tillage.
To create the right tilth for the crop.
To break up the large lumps of soil after primary tillage.
To improve aeration, drainage and soil structure.
To control pests and diseases as they desiccate due to exposure to the sunshine.
To increase on the water infiltration.
NB: Tools used in secondary cultivation include: disc harrows, tine harrows, tined cultivators.