Land preparation consists of two major operations, plowing and harrowing; they are also called tillage practices or operations. Plowing and harrowing of land are tillage operations that involve the mechanical pulverization of the soil to create favorable conditions for the growth of crop through two set of operations; these operations are the foremost preplanting operations that must be carried out prior to cultivation however, these soil preparation operations are not the same. There is a clear difference between plowing and harrowing; the purpose of these operation is different same as the tool used to carry out these operations
There are different methods of land preparation in agriculture; zero tillage, minimum tillage and conventional tillage. The duration of plowing and harrowing in each tillage operation differs. In zero tillage, plowing and harrowing is not done at all; this method is a traditional method of tillage that requires only the use of hoe and cutlass to till the soil before planting. In minimum tillage, plowing is done once or twice but harrowing is not done; this method aims to disturb the soil minimally; lastly, in conventional tillage, it is the combination of minimum tillage and harrowing. The land is plowed twice at an interval of two (2) weeks and harrowing is done afterward; this is the commercial system of tillage. It facilitates better soil-seed contact, easy flow of nutrients, greatly reduce weed competition for light and nutrients, and improve other conditions within the soil for best growth of plant.
Plowing of the soil helps break the soil clods and hard compacted soil into piece for good root developmet of the crop. Similarly, harrowing is that land preparation operation that helsp to further break the clods of soil into smaller bits creating a well aerated and smooth soil for cultivation.
Plowing and harrowing of the soil can adversely affect the soil if not properly done as excessive tillage tends to raise the soil erodibility, causing significant soil loss to erosion. To achieve a better result for soil conservation, the depth of plowing must vary, the tilling must be reduced and tilled only when soil moisture is in the good limit.
Major Difference between Plowing and Harrowing
Plowing and harrowing are different tillage operations in the preparation of land for crop establishment in terms of purpose and implements used. Tillage practices include all operation used for the function of modifying the soil characteristics; it costs about 30% of the total cost of cultivation. Tillage provides a favorable soil environment for plant growth.
Plowing and Types of plough
Plowing is the mechanical manipulation of land intended for plant cultivation; it is the first and most important tillage operation as it helps to loosen the soil for further soil preparation operations. The primary purpose of plowing is to turn over the uppermost soil, bringing up fresh nutrients to the soil surface, while at the same time burying debris, weeds and crop remains to decay and become part of the soil components. The name of the land preparation tool used for plowing operation is the Plough; this implement helps in loosening or turning the soil before sowing seed or planting.
Types of plough
There are different types of Ploughs used for tillage operation; the type of plough used is dependent on the nature of the soil structures. These types of plough are listed below:
- Mould Board Plough
- Disc Type Plough
- Rotary Plough
- Chisel or sub surface Plough
- Sub Soiler Plough.
Ploughs were traditionally drawn by draft animals such as oxen and horses; however, technology has further improved the system of land preparation, making plowing operation easier to do. Ploughs are now drawn by tractors. A plough may have a wooden, iron or steel frame, with a blade attached to cut and loosen the soil. The plowing depth of 15- 20cm range is generally adequate, and there is seldom any advantage in going deeper.
During plowing, trenches are made as the plough cuts into the soil, these trenches are called furrows. Between two furrows is an elevation of soil called ridges where crops like cassava, maize, watermelon etc can be planted. One of the benefits of plowing is, it makes a ready-made planting medium (ridges) for planting; thus, eliminating the need or cost for making ridges. In addition, plowing also helps to incorporate crop residues into the soil to decay and serve as a source of for soil microorganisms and nutrients for the plants. Introducing the crop residues also enables a summer rainfall to penetrate deeper into the soil, improving the soil’s moisture.
Harrowing and Types of Harrow
Harrowing is a tillage operation or activity that further breaks the soil into smaller fragments or bits for improved soil condition such as better aeration, improved percolation, weeds and weed seeds elimination, and pest control. In conventional tillage, after the two plowing operations, leaving the soil as rough and highly coarse particles, harrowing does the job of “combing” the soil to create a smooth surface for planting. This tillage operation makes the soil smooth and neat, elimination all forms of week; such land is best for planting. The name of the implement for this tillage operation is called the Harrow.
Harrow is an implement for breaking up and smoothing out the surface of the soil to allow shallow cultivation in operations such as preparation of seedbed, covering seeds, elimination of pest nests, and destroying weed seedlings.
Types of Harrow
There are four general types of harrows;
- Disc harrows
- Tine harrows (including spring-tooth harrows, drag harrows, and spike harrows),
- Chain harrows, and chain-disk harrows.
In this way, A harrow is distinct in its effect from the plough, which is used for deeper tillage. The type of harrow used for soil preparation management depends on the harrowing operation, whether it’s intended for incorporating the crop residue or just leveling the soil structure for further planting operation. The purpose of harrowing the soil is generally to break up clods (lumps of soil) and to provide a finer soil surface finish, an improved tilt or soil structure that is suitable for seedbed construction with best soil condition.
A well-harrowed soil possesses a fine, crumbled, and leveled surface, with a low degree of pulverization; it also removes weeds and covers seed after sowing
Benefits Of Plowing And Harrowing
The following are benefits and advantages of plowing and harrowing before cultivation.
- They create a better planting medium
- They improve the soil structure
- Increase soil conditions for better planting
- Elimination of weeds and pests through harrowing during conventional tillage
- Enhances plant yield by creating a suitable medium for growth.
It is highly recommended to carry out these tillage operations, especially harrowing, during soil preparation for planting. The benefits of plowing and harrowing on the soil suitability and plant yield cannot be overlooked.