Tillage: Meaning, Definition, Objective and Types

Tillage is a traditional agricultural practice that is the first stage of crop production in a variety of environments. This method creates the ideal conditions for seed germination, root and shoot growth, and harvests by carefully adjusting the soil. Tillage has evolved with the help of modern agricultural techniques to achieve a balance between productivity and the environment. From conventional agricultural plowing to state-of-the-art conservation techniques, it has a major impact on crop productivity and agriculture. Let’s learn more about tillage, its objectives, and mainly its types in the following article.

Tillage: What is it?

The word tillage is derived from two Anglo-Saxon words Tilian and Teolian, which means to plough and prepare the soil for the seed to plant, to cultivate, and to crop production. The Father of Tillage, Jethro Tull suggested that thorough ploughing is necessary to make soil into very fine particles. Tillage is the process of mechanically modifying soil using tools to create desired conditions for ideal crop growth, seedling establishment, and seed germination. Tillage produces a physical condition on the soil known as ’tilth’. The tilth could be categorized as moderate, fine, or coarse particles.

Objectives of Tillage

The major objectives of tillage are:

• Seedbed Preparation: It involves tillage which loosens and makes friable soil bed to encourage root growth and seed germination.
• Weed Control: Tillage reduces competition for sunlight, water, and nutrients by uprooting or burying weeds which inhibits their growth.
• Soil Aeration and Drainage: By releasing compacted layers and enabling oxygen to reach plant roots tillage promotes soil aeration. Additionally, it improves drainage which lowers the chance of waterlogging.
• Incorporation of Organic Matter: Tillage aids in the soil’s nutrient enrichment and fertility enhancement by incorporating organic amendments such as manure or compost.
• Pest Control: By exposing pests to adverse environments or predators tillage can disrupt pest habitats and lower pest populations.
• Soil Reshaping: Tillage may occasionally be utilized to reshape the soil surface to improve erosion prevention, water management, or land leveling.

Types of Tillage

Tillage operations are important for agricultural management with the help of various techniques aiming at preparing the soil for ideal crop growth. These tillage operations are differentiated into two types:

• On- Season Tillage
• Off- Season Tillage

On-season tillages are done within the crop season to prepare the field for planting or maintaining crop health. This involves deep soil loosening, weed control, incorporation of organic matter, weed management, soil aeration, and nutrient application. On-season tillage is further categorized into preparatory tillage and after-cultivation tillage, also known as inter-tillage. Preparatory Tillage is also of two types. Check the table for more.

Off-season tillages are done outside the crop season like periods of dormancy, to help soil frame for future crop season. This involves soil conservation practices, erosion control, and incorporation of cover crops to improve soil structure and fertility in preparation for crops. Off-season tillage may be, post-harvest tillage, summer tillage, winter tillage, and fallow tillage.

Modern Concepts in Tillage

The first step in conventional tillage is primary tillage which turns and breaks up the soil. To prepare a seedbed for planting or sowing secondary tillage is done. Since the introduction of herbicides in intensive farming systems tillage has a new meaning. Ploughs’ heavy usage causes a hard pan in the subsoil which hinders infiltration. It is more prone to runoff as well as erosion. It increases soil degradation and requires a lot of capital. Modernity helps prevent these negative effects. Types of modern concepts are:

1. Minimum Tillage
2. Zero Tillage or No Tillage
3. Stubble mulch Tillage
4. Conservation Tillage

Minimum Tillage:

In this tillage operations are reduced to get a good seed bed. This type of tillage can be done in three different ways:

• Row-zone Tillage: Primary tillage is done with mould board plough in the entire area of the field and secondary tillage is reduced within a row zone.
• Plough plant Tillage: In this technique, after primary tillage one run is done over the field, the row zone is pulverized and seeds are sown by the planter.
• Wheel track tillage: In this technique, after primary tillage tractors are used for sowing and the wheels of the tractor pulverize the row zone in which planting is done.

Zero Tillage or No Tillage

In this type of tillage, a new crop is planted in the same soilbed or residues of the previous crop without any changes done in the soil bed. But this is done only when all the weeds are controlled by the use of herbicides. Zero tillage is applicable for soils with a coarse-textured surface horizon, good
internal drainage, high biological activity of soil fauna, favorable initial soil structure, and an
adequate quantity of crop residue as mulch.

One of the methods of zero tillage is till planting in which a wide sweep and trash bar clear a strip over the previous crop row and the planter opens a narrow strip into which seeds are planted and
covered.

Stubble mulch Tillage

Soil is protected throughout the times either by growing a crop or by leaving crop residues on its surface. Blades are used to cut the top of soil up to 12 to 15 cm depth in the first operation after harvest and the depth of cut is reduced during subsequent operations. In this technique, two types of methods are used:

• A wide sweep and trash bar is used to clear a strip and a narrow planter shoe opens a narrow furrow into which seeds are placed.
• A narrow chisel is used to cut soil at a depth of 15-30 cm leaving all residue on the surface of the soil. It shatters the tillage pans and planting is done with special planters.

Conservation Tillage

In this technique, organic residues are not inverted into the soil but they remain on the surface and act as a protective layer against soil erosion and soil moisture evaporation. If stubble forms the protective cover on the surface, it is usually referred to as stubble mulch tillage. It is almost a year-round system in which plant residues are managed with undercut residues, loss of the soil, and killing up of the weeds.

Main Field Preparation

Preparatory cultivation and post-cultivation are the two broad categories into which tillage operations belong. The activities carried out before cultivation are known as preliminary cultivation or tillage.
Main field preparation is the term used to describe this preparatory cultivation. The primary field setup includes the following three procedures: primary tillage, secondary tillage, and sowing layout. A few of the essential fundamental tillage tools include the disc plow, country plough, mould board plough, chisel plough, and so forth. Harrows and cultivators are typically utilized for secondary tillage. However, as both procedures are mostly performed with the same tool, there could not be a significant practical difference between the first two (primary and secondary tillages). Cultivators and country ploughs are utilized for both tasks. Following thorough ploughing, the field was altered to create planting-suitable features like beds, channels, pits, ridges, and furrows based on the needs of the crops. Such changes to the field are necessary for increased agricultural yields.