Introduction to Tillage

Tillage is the mechanical manipulation of the soil with tools and implements to make soil conditions suitable for better seed germination and crop growth whereas, tilth is a physical condition of the soil resulting from tillage.

Tilth is a loose powdery, smooth, aerable, granular and crumbly soil condition with optimum moisture contents which are suitable for working and germination of seeds and other propagules, in other words, tilth is the ideal seed bed.

CHARACTERISTICS OF GOOD TILTH

1. A soil in good tilth is the soil which is most suitable for the germination of the seeds and crop stand.
2. A soil in good tilth has uniform size of the aggregates and friability/mellowness (the ability to form crumbly clods as the soil dries) is fair.
3. The water holding capacity and aeration of the soil is also good for proper aeration and water flow through the soil to the germinating seeds.

OBJECTIVES OF TILLAGE

The main objectives of tillage are to;
� remove other sprouting materials remaining from previous crops or weeds
� incorporate crop residues and other organic matter to the soil to increase fertility of the soil
� control weeds through manual or mechanical removal
� modify soil temperature
� improve physical conditions of the soil
� conserve soil by minimizing the soil erosion
� conserve the soil moisture
� level the field for efficient water management
� break hard pans in the soil to improve drainage and crop requirements
� increase the water holding capacity of the soil
� prepare seed bed fit for seed germination, growth and better crop stand
� open up soil for easy root penetration and growth
� improve aeration and porosity to promote the growth of roots and other useful microbes in the rhizosphere
� enhance the biochemical activities in the soil which are helpful for better crop stand
� ensure through mixing of manures and fertilizers pesticides in the soil
� exploit the rain water in the arid zones to maximum potential

TYPES OF TILTH

Fine Tilth symbolizes the fine powdery condition of the soil. Fine seedbed is required for small seeded crops such as onion, berseem and tobacco.
Coarse Tilth symbolizes the rough cloddy condition of the soil. Coarse seedbed is needed for bold seeded crops such as sorghum, cotton and chickpea.