FALL TERM - Sep 30

September 30

Today we talk about primary and secondary cultivators, and although we were familiar with the words till, no-till, and ploughing, we learnt that there are several types of tillage:

Tnau Agri Portal. Types of Tillage http://agritech.tnau.ac.in/agriculture/agri_tillage_typesoftillage.html

Tillage is also defined by the type of activity (From FAO: Conservation Agriculture. Machinery, Tools and Equipment):

• Inversion: this type of tillage turns over the soil in the part that is worked. Surface layers are completely incorporated and deeper soil layers are brought to the surface. The argument that ploughing controls weeds is not valid when done every year, as the same amount of weed seeds is brought to the surface.
• Mixture: this operation mixes all materials more or less homogeneously to a certain soil depth, which is usually around 10 cm.
• Ripping: this type of tillage breaks the soil open, in order to loosen the soil without moving the clods, for instance in soil de-compaction operations (subsoiling).
• Pulverize: this operation crumbles the soil clods in order to form a very fine horizon, i.e. the seedbed. It is executed within a few centimetres from the surface.

At least four types of tillage operations can be distinguished in a conventional system (From FAO: Conservation Agriculture. Machinery, Tools and Equipment):

• Clearing the land and management of residues, including burning fallow vegetation or residues.
• Primary tillage.
• Secondary tillage.
• Crop management activities, like weeding, ridging, breaking crusts, etc.