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8/2/2019 Bezana Zanovuyo and Nogaga Madoda

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IMPORTANCES OF SOIL CULTIVATION IN

AGRICULTURE

By Bezana Zanovuyo&

Nogaga Madoda


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WHAT IS SOIL CULTIVATION? Cultivation is the loosening and breaking up (tilling) of the soil in order to better prepare it for planting. It is a practice which is designed to improve the condition of the soil for plating purposes.

One of the most common reasons to practice soil cultivation is to address soil which has become compacted. Soil cultivation can also include adding soil amendments to improve the health of the soil. Compost is a classic and widely used example of a soil amendment, added to the soil with the goal of making it more

rich The soil organic matter can be seen as the darker layer beginning at the soil surface. Organic matter acts as a glue to

bind soil particles into aggregates. Therefore, a soil high in organic matter will generally be well structured. This isespecially true in loamy textured soils.

A productive pasture phase over a number of years will improve the structure of most soils, because the organic mattercontent will increase under pasture. This improvement will begin at the surface (since this is where plant residue andmanure from stock is deposited) and slowly move down into the topsoil over time.

When a soil is cultivated, soil aggregates are broken down and soil is aerated. This exposes soil organic matter, speeds

up the breakdown of soil organic matter, and is harmful to soil structure. Therefore, reducing tillage can improve soilstructure. The principle of cultivation is to turn the soil into a fine tilt to provide the ideal environment for seeds togerminate. Cultivation was also a traditional form of weed control. The climate of most European countries is wet andcool, allowing organic matter to build up in soils even when they are

Cultivated.


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AIMS OF SOIL CULTIVATION

Creating good growing conditions for plants There are many reasons for cultivating the soil. The most

important ones are to:

Loosen the soil to facilitate the penetration of plant roots. Improve the aeration (nitrogen and oxygen from the air). Encourage the activity of the soil organisms.Increase infiltration of water. Reduce evaporation.Destiny or control weeds and soil pests. Incorporate crop residues and manures into the soil.Prepare the site for seeds and seedlings.Repair soil compaction caused by previous activities


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IMPORTANCE OF CULTIVATION IN AGRICULTURE

ADVANTAGES OF CULTIVATION

Cultivation is conducted for a variety of good reasons. It is important that cultivation ofthe soil does not create as many problems as it solves. Some advantages of cultivation are:

Soil cultivation (or digging) is mainly carried out to bury weeds and debris. This is usually followed by surface preparation for sowing and planting Cultivation improves soil structure by breaking compaction, plus it also offers the

chance to apply fertilizer, manure and lime Only minimum cultivation is needed because over-cultivating can damage the soil

structure, such as bringing stones on the top soil which will disturb the growth of cropsplants.

It is often a form of weed control. It can play a part in pest management. For example, tillage is recommended to reduce

the number of overwintering heliothis pupae in paddocks where susceptible summercrops such as sweet corn and tomatoes are grown.

It may reduce the occurrence of soil-borne diseases which tend to attack crops. Soil-borne

Diseases such as rhizoctonia can be a problem in soils where crops are planted usingdirect drill or zero till.

It roughens the soil surface to help retain moisture.


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DISADVANTAGES OF CULTIVATION

Cultivation has the potential to destroy soil structure and make soils moreprone to other forms of degradation, such as erosion.

Incorrect use of cultivation can have the following effects: There may be a reduction in soil organic matter (including nutrients) and

therefore a Decline in soil structure. provide the ideal environment for seeds to germinate Good soil structure is important for good Root growth and water penetration (drainage by rainfall or irrigation). Cultivation that mixes surface soil with subsurface soil will lead to a dilution

of organic matter (which is most concentrated at the soil surface). This will

mean that crusts are more likely to form after cultivation. Cultivation can make hard setting and crusting problems worse, Since soil organic matter and stable aggregates are destroyed. Cultivation can bring sodic material to the soil surface. This can cause or

increase soil crusting.


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SOIL PREPARATION OF AGRICULTURAL LAND

Several factors affect the method of soilpreparation:

length of growing season annual distribution of rainfall

soil type

slope of the land

type of crops to be produced

size of farm

level of technology


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CHISEL PLOUGH Chisel plough

Chisel plough

Chisel ploughs are used to

shatter but not turn ormove the soil. They workon the same principle asrippers, but in the top30 cm of the soil. Again,

the soil must be dry tomoist, otherwise theplough will smear and sealthe soil surfaces.


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Ripper (subsoil)

Ripper (subsoil) Ripper (subsoiler) Rippers or subsoilers break up

compacted soil below the depth reachedby conventional cultivation, to improve

drainage and aeration. There are severaltypes of deep rippers: vertical, agro plow,parabolic, C shank (SJ) and Para plow,and they can reach 3090 cm into thesoil. Most have slanted tines or a sharplyangled leading point to lessen the powerrequired to pull the ripper. This designalso helps lift and shatter the subsoil sothat any compacted layer is broken up.

Soil should be reasonably dry when it isripped. Ripping wet soil does not shatterthe subsoil and can smear and seal thesoil beside the ripper tine. Smearedsurfaces prevent air, water and rootsmoving through the soil.


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Disc plough

Disc plough Disc ploughs and offset discs Disc ploughs break up undisturbed soil

by inverting it to bury surface weeds andtrash. Regular use of disc ploughs

reduces soil aggregates to small particlesand produces a compacted layer orplough pan which prevents air, water orroots penetrating the subsoil. When itrains, soil particles on the surfacecollapse together to form a crust whichrepels air and water and is difficult forseedlings to break through. Offset discploughs, which have two rows of discsrunning at angles to each other, serve asimilar purpose. They are usually used asa second tillage implement, and forinitial tillage on lighter soils.


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Harrows

Harrows

Harrows are used for

seedbed preparation andlight surface cultivationto remove weeds afterseeding. If used regularlythey will break down andpulverize the soilstructure


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Rotary hoe

Rotary hoe

Rotary hoes aerate the soiland provide a fine seedbed.

However, in the process,the rotating shoes compactthe soil underneath thelevel they are aerating, anddestroy the soil structure

by pulverizing the seedbed,leading to crusting andcompaction when the soilis wet.


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Cultivated soil.


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Cultivated soil.


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Surface runoff & erosion


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Poorly developed roots as the results of

soil structure

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