Seed drill
Encyclopedia
Sowing
Sowing is the process of planting seeds.-Plants which are usually sown:Among the major field crops, oats, wheat, and rye are sowed, grasses and legumes are seeded, and maize and soybeans are planted...
device that precisely positions seeds in the soil and then covers them. Before the introduction of the seed drill, the common practice was to plant seeds by hand. Besides being wasteful, planting was very imprecise and led to a poor distribution of seeds
SEEDS
SEEDS is a voluntary organisation registered under the Societies Act of India....
, leading to low productivity. The use of a seed drill can improve the ratio of crop yield by as much as eight times.
Description
In older methods of planting, a field is initially prepared with a ploughPlough
The plough or plow is a tool used in farming for initial cultivation of soil in preparation for sowing seed or planting. It has been a basic instrument for most of recorded history, and represents one of the major advances in agriculture...
to e series of linear cuts known as furrows. The field is then seeded by throwing the seeds over the field, a method known as manual broadcasting. Seeds that landed in the furrows had better protection from the elements, and natural erosion or manual raking would preferentially cover them while leaving some exposed. The result was a field planted roughly in rows, but having a large number of plants outside the furrow lanes.
There are several downsides to this approach. The most obvious is that seeds that land outside the furrows will not have the growth shown by the plants sown in the furrow, since they are too shallow on the soil. Because of this, they are lost to the elements. Since the furrows represent only a portion of the field's area, and broadcasting distributes seeds fairly evenly, this results in considerable wastage of seeds. Less obvious are the effects of overseeding; all crops grow best at a certain density, which varies depending on the soil and weather conditions. Additional seeding above this limit will actually reduce crop yields, in spite of more plants being sown, as there will be competition among the plants for the minerals, water and the soil available. Another reason is that the mineral resources of the soil will also deplete at a much faster rate, thereby directly affecting the growth of the plants.
Uses
Drilling is the term used for the mechanized sowingSowing
Sowing is the process of planting seeds.-Plants which are usually sown:Among the major field crops, oats, wheat, and rye are sowed, grasses and legumes are seeded, and maize and soybeans are planted...
of an agricultural crop. A typical seed drill consists of a hopper of seeds arranged above a series of tubes that can be set at selected distances from each other to allow optimum growth of the resulting plants. in place of a hopper most commercial seeders use an air tank which uses a fan to create a vacuum which suck grain out of the tank meters it and blows grain into the drill. Arranged in front of the tubes are a series of knife blades known as coulters. In operation, the seed drill is dragged forward to allow the coulters to cut open the soil, with a metering mechanism on the hopper periodically allowing a number of seeds to fall into the tubes, and through them into the freshly cut soil. The result is a set of spaced seeding locations, which can then be covered by a built-in rake
Rake (tool)
A rake is a broom for outside; an horticultural implement consisting of a toothed bar fixed transversely to a handle, and used to collect leaves, hay, grass, etc., and, in gardening, for loosening the soil, light weeding and levelling, removing dead grass from...
.
The seed drill allows farmers to sow seeds in well-spaced rows at specific depths at a specific seed rate; each tube creates a hole of a specific depth, drops in one or more seeds, and covers it over. This invention gave farmers much greater control over the depth that the seed was planted and the ability to cover the seeds without back-tracking. This greater control meant that seeds germinated consistently and in good soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
. The result was an increased rate of germination, and a much-improved crop yield
Crop yield
In agriculture, crop yield is not only a measure of the yield of cereal per unit area of land under cultivation, yield is also the seed generation of the plant itself...
(up to eight times ).
A further important consideration was weed control. Broadcast seeding results in a random array of growing crops, making it difficult to control weed
Weed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
s using any method other than hand weeding. A field planted using a seed drill is much more uniform, typically in rows, allowing weeding with the hoe
Hoe (tool)
A hoe is an ancient and versatile agricultural tool used to move small amounts of soil. Common goals include weed control by agitating the surface of the soil around plants, piling soil around the base of plants , creating narrow furrows and shallow trenches for planting seeds and bulbs, to chop...
during the course of the growing season. Weeding by hand is laborious and poor weeding limits yield.
History
The first known European seed drill was attributed to Camillo Torello and patented by the Venetian Senate in 1566. A seed drill was described in detail by Tadeo Cavalina of Bologna
Bologna
Bologna is the capital city of Emilia-Romagna, in the Po Valley of Northern Italy. The city lies between the Po River and the Apennine Mountains, more specifically, between the Reno River and the Savena River. Bologna is a lively and cosmopolitan Italian college city, with spectacular history,...
in 1602. In England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
, the seed drill was further refined by Jethro Tull
Jethro Tull (agriculturist)
Jethro Tull was an English agricultural pioneer who helped bring about the British Agricultural Revolution. He perfected a horse-drawn seed drill in 1701 that economically sowed the seeds in neat rows, and later a horse-drawn hoe...
in 1701 in the Agricultural Revolution
British Agricultural Revolution
British Agricultural Revolution describes a period of development in Britain between the 17th century and the end of the 19th century, which saw an epoch-making increase in agricultural productivity and net output. This in turn supported unprecedented population growth, freeing up a significant...
. However, seed drills of this and successive types were both expensive and unreliable, as well as fragile. Seed drills would not come into widespread use in Europe until the mid-19th century.
Over the years seed drills have become more advanced and sophisticated but the technology has remained substantially the same. The first seed drills were small enough to be drawn by a single horse but the availability of steam and, later, gasoline tractors saw the development of larger and more efficient drills that allowed farmers to seed even larger tracts in a single day. Recent improvements to drills allow seed-drilling without prior tilling. This means that soils subject to erosion or moisture loss are protected until the seed germinates and grows enough to keep the soil in place. This also helps prevent soil loss by avoiding erosion after tilling.