Tillage

Tillage

                Tillage in general may be defined as the mechanical manipulation of soil for any purpose.

From agriculture point of view

Tillage involves the breaking, stirring, turning or conditioning of soil surface to develop a favorable soil environment for the germination and growth of crops.

Objective of tillage

Ø  To develop a desirable soil structure for seed bed or root zone

Ø  To increase soil aeration by loosening soil and thereby reducing soil density

Ø  To minimize soil resistance to root penetration

Ø  To control weeds or to eradicate unwanted plants

Ø  To improve soil fertility by incorporating crop residues or green manuring crops etc

Ø  To minimize soil erosion by employing deep tillage, mulch tillage, contour tillage

Ø  To establish specific soil surface configuration such as beds, furrows, ridges etc for planting, irrigation, drainage or harvesting operations etc

Ø  To incorporate and mix fertilizer, pesticides or soil amendments into the soil

Ø  To accomplish segregation of roots, rocks, foreign objects from soil

Ø  To break hardpan, tillage pan or sodic pan developed underneath the root zone

Tillage terminologies

Ø  Tilth

It is defined as degree of aggregation of soil particles. Ideal tilth is secured when soil is aggregated into crumble like particles that allow free access of air and water and not easily broken down by rainfall.

Ø  Tillage tool:

It is defined as an individual soil working element such as disc blade, cultivator shovel, tine of cultivator etc

Ø  Tillage implement:

        A tillage implement is made of a single tillage tool or a group of tillage tools, together with a frame, wheels (if any) control and protection devices and any other structural and power transmission components.

Types of tillage

Tillage operation are often classified as

Ø  Primary tillage

Ø  Secondary tillage

Primary tillage

                The initial breaking up of soil after crop harvest is generally called as primary tillage

Secondary tillage

                The operation carried out after primary tillage such as breaking / pulverization of clods to prepare seed bed ready for planting is called as secondary tillage.

Conventional Tillage:

                Both primary and secondary tillage operations are involved

Reduced Tillage:

                No. of primary tillage operations are reduced to minimum

                e.g. Minimum tillage, zero tillage and no tillage

Minimum tillage

                It refers to the cultivation of only that part of the soil on which is going to be used for seeding/sowing of crops. This is some times called as strip tillage or zone tillage.

Objectives:

Ø  To reduce mechanical energy and labor requirement.

Ø  To conserve moisture in draught hits areas by controlling water evaporation and reduce soil erosion.

To save time by doing operations necessary to optimize soil conditions for crop growth

Zero tillage

                It is termed as direct drilling or seeding. In this tillage method, seed is directly drilled or planted into the stubbled field of previous crop by opening upto 5 to 8 cm soil strip with the help of zero till drill.

Mulch tillage/conservation tillage

                This tillage involves cutting the roots of weeds and plants and leaving the crop residues over the soil surface or mix into the top few centimeters of soil. The main purpose of the tillage is to reduce the wind and water erosion + moisture conservation.

Types of tillage implements

Primary tillage implements

Secondary tillage implements

Primary tillage implements

                These implements are used for initial/major soil working operation. They are normally designed to cut and invert the soil and thereby reduce soil strength, incorporate plant materials and rearrange aggregates. The primary implements are given as;

Ø  Mould board plow

Ø  Disc plow

Ø  Chisel plow

Ø  Sub soiler

Secondary tillage implements

                These implements are used after primary tillage implements mainly to pulverize the soil. Secondary implements are used to prepare seed bed by greater pulverization. The secondary implements work at comparatively shallow depths ranging from 3 to 6 inches. Secondary tillage implements are

Ø  Disc harrow

Ø  Bar harrow

Ø  Tine cultivator

Ø  Sweep cultivator

Ø  Rotavator

Primary tillage implements

Mould board (MB) plow:

Ø  It is used after harvesting the crop to cut/loosen and invert the soil into furrow slices with varying degree of pulverization depending upon type of mould board plow, soil type and speed of plowing.

The specific functions of MB plow are;

Ø  To cut and break the soil

Ø  To lift the soil

Ø  To turn the soil

Ø  To pulverize the soil

Ø  To burry weeds, trash, and manure

Ø  To plough deep