Tillage

Tillage

The word tillage is derived from ‘Anglo-Saxon’ words Tilian and Teolian, meaning ‘to plough and 

prepare soil for seed to sow, to cultivate and to raise crops’. Jethrotull, who is considered as father 

of tillage (Jethrotull also coined the term weed and Zero tillage) suggested that thorough 

ploughing is necessary so as to make the soil into fine particles.

Tillage is the mechanical manipulation of soil with tools and implements for obtaining conditions

Ideal for seed germination, seedling establishment and growth of crops.

Tilth is the physical condition of soil obtained out of tillage (or) it is the result of tillage. The tilth

may be a coarse tilth, fine tilth or moderate tilth.

Objectives of tillage:

The main objectives of tillage are,

• To prepare a good seed bed which helps the germination of seeds.

• To create conditions in the soil suited for better growth of crops.

• To control the weeds effectively.

• To make the soil capable for absorbing more rain water.

• To mix up the manure and fertilizers uniformly in the soil.

• To aerate the soil.

• To provide adequate seed-soil contact to permit water flow to seed and seedling roots.

• To remove the hard pan and to increase the soil depth.

To achieve these objectives, the soil is disturbed / opened up and turned over.

Influence of tillage on soil physical properties:

➢ Pore space: Tillage breaks the hard pan and compacted layers of the soil, this turns large 

aggregates of soil particles into finer ones. Finer aggregates are loosely staked in a random 

manner. This results in increase in pore space between the aggregates. 

➢ Soil structure: The primary soil particles viz sand, silt and clay are usually grouped 

together to form aggregates. The arrangement of primary soil particles and their aggregates 

into certain defined pattern is called soil structure. Soil with crumb structure is considered 

best for cultivation of crops since it has more pore space. Soils which do not have 

aggregates with naturally preserved boundaries are called structure less soil. Moisture is 

required for formation of aggregates. When soil is subjected to tillage at optimum moisture, 

crumb structure is developed so that loss of soil by erosion is greatly reduced. Soil structure 

is destroyed when tillage is carried out at inappropriate soil moisture.

➢ Bulk density: Bulk density is the mass of a unit volume of soil(volume include both solid 

and pore space). Bulk density of fine textured soil is less(due to more pore space) than 

coarse textured soil. After tillage soil is loosened, the volume increases without any effect 

on weight. Therefore bulk density of tilled soil is less than untilled soil.

▪ Bulk Density (B.D)= weight of soil/volume of solids and pores.

➢ Soil colour: soil with more organic matter are dark colour of soil. Tillage increases the 

oxidation and decomposition of organic matter resulting in fading of colour.

➢ Soil Water: The amount of water in soil increases with increase pore space, soil depth and 

roughness, all these increases with tillage.

➢ Soil temperature: Tillage loosens the soil surface resulting in decrease in thermal conductivity and 

heat capacity.

Types of tillage: 

 Tillage operations may be grouped into

1. Conventional 

2. Conservation

Conventional tillage

Conventional tillage is again of two type : 

1. On season tillage and 

2. Off season tillage

1. On-season tillage

Tillage operations that are done for raising crops in the same season or at the onset of the crop 

season are known as on-season tillage. 

They may be preparatory cultivation and after

cultivation.

A. Preparatory tillage: This refers to tillage operations that are done to prepare the field for raising

crops. It consists of deep opening and loosening of the soil to bring about a desirable tilth as well as

to incorporate or uproot weeds and crop stubble when the soil is in a workable condition.

Types of preparatory tillage

a. Primary tillage

b. Secondary tillage

a. Primary tillage: The tillage operation that is done after the harvest of crop to bring the 

land under cultivation is known as primary tillage or ploughing. Ploughing is the opening of 

compact soil with the help of different ploughs. Country plough, mould board plough, bose 

plough, tractor and power tiller drawn implements are used for primary tillage.

b. Secondary tillage: The tillage operations that are performed on the soil after primary 

tillage to bring a good soil tilth are known as secondary tillage. Secondary tillage consists of 

lighter or finer operation which is done to clean the soil, break the clods and incorporate the 

manure and fertilizers. Harrowing and planking is done to serve those purposes. Planking is 

done to crush the hard clods, level the soil surface and to compact the soil lightly. Harrows, 

cultivators, Guntakas and spade are used for secondary tillage.

c. Layout of seed bed:This is also one of the components of preparatory tillage. Leveling 

board, buck scrapers etc. are used for leveling and markers are used for layout of seedbed.

B. After cultivation (Inter tillage): The tillage operations that are carried out in the standing crop

after the sowing or planting and prior to the harvesting of the crop plants are called after tillage.

This is also called as inter cultivation or post seeding/ planting cultivation. It includes harrowing,

hoeing, weeding, earthing up, drilling or side dressing of fertilizers etc. Spade, hoe, weeders etc.

are used for inter cultivation.

2. Off-season tillage: 

Tillage operations done for conditioning the soil suitable for the forthcoming main season crop are 

called off-season tillage. Off season tillage may be, post harvest tillage, summer tillage, winter 

tillage and fallow tillage, sub soiling, clean tillage.

Demerits of conventional tillage

➢ Continuous use of heavy ploughs create hard pan in the subsoil, results in poor infiltration. 

➢ It is more susceptible to run-off and erosion. 

➢ It is capital intensive and increase soil degradation. 

➢ It increases the degradation of organic matter in soil which and soil become nutrient 

deficient.

➢ Tillage cause release of CO2 in atmosphere due to rapid increase in life activities in soil 

including microorganisms and faster degradation of organic matter due to better flow of air 

and water in the soil.

Conservation tillage:

Conservation tillage system tries to solve the problems arising due to conventional, tillage without 

much affecting the production. Some agronomists define conservation tillage as a type of tillage 

operation in which we Ploughing the field with lesser number of passes over the entire land or 

ploughing only in the required space of the land and then sowing is called conservation tillage.

Different types of conservation tillage are described below.

1. Minimum tillage: It aims at reducing tillage operations to the minimum necessity for ensuring a 

good seed bed. The advantages of minimum tillage over conventional tillage are,

➢ The cost and time for field preparation is reduced by reducing the number of field

➢ operations.

➢ Soil compaction is comparatively less.

➢ Soil structure is not destroyed.

➢ Water loss through runoff and erosion is minimum.

➢ Water storage in the plough layer is increased.

Tillage can be reduced in 2 ways

1. By omitting operations which do not give much benefit when compared to the cost.

2. By combining agricultural operations like seeding and fertilizer application.

The minimum tillage systems can be grouped into the following categories,

1. Row zone tillage: Primary tillage is done with mould board plough in the entire area of the field; 

secondary tillage operations like discing and harrowing are reduced and done only in row zone.

2. Plough plant tillage: After the primary tillage, a special planter is used for sowing. In one run 

over the field, the row zone is pulverized and seeds are sown by the planter

3. Wheel track tillage : Primary ploughing is done as usual. Tractor is used for sowing; the wheels 

of the tractor pulverize the row zone in which planting is done.

In all these systems, primary tillage is as usual. However, secondary tillage is replaced by direct 

sowing in which sown seed is covered in the row zone with the equipment used for sowing.

2. Zero tillage (No tillage): In this, new crop is planted in the residues of the previous crop without 

any prior soil tillage or seed bed preparation and it is possible 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, favourable initial soil structure and an

adequate quantity of crop residue as mulch. These conditions are generally found in Alfisols, 

Oxisols and Ultisols in the humid and sub-humid tropics.

Till planting

Till planting is one method of practicing zero tillage. A wide sweep and trash bar clears a strip over 

the previous crop row and planter opens a narrow strip into which seeds are planted and covered. 

Here, herbicide functions are extended. Before sowing, the vegetation present has to be destroyed 

for which broad spectrum non selective herbicides like glyposate, paraquat and diquat are used.

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