Sowing: Wikis

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Sowing is the process of planting seeds.

Contents

Sowing in practice

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Pre-treatment of seed and soil before sowing

Tropical fruit such as avocado also benefit from special seed treatments (specifically invented for that particular tropical fruit)

Before sowing, certain seeds first require a treatment prior to the sowing process. This treatment may be seed scarification, stratification, seed soaking or seed cleaning with cold (or medium hot) water.


Seed soaking is generally done by placing seeds in medium hot water for at least 24 to up to 48 hours [1] Seed cleaning is done especially with fruit (as the flesh of the fruit around the seed can quickly become prone to attack from insects or plagues.[2] [3] To clean the seed, usually seed rubbings with cloth/paper is performed, sometimes assisted with a seed washing [4]. Seed washing is generally done by submerging cleansed seeds 20 minutes in 50 degree Celsius water [5]. This (rather hot than moderately hot) water kills any organisms that may have survived on the skin of a seed. Especially with easily infected tropical fruit such as lychees and rambutans, seed washing with high temperature water is vital.

In addition to the mentioned seed pretreatments, seed germination is also assisted when disease-free soil is used. Especially when trying to germinate difficult seed (e.g. certain tropical fruit), prior treatment of the soil (along with the usage of the most suitable soil; e.g. potting soil, prepared soil or other substrates) is vital. The two most used soil treatments are pasteurisation and sterilisation. Depending on the necessity, pasteurisation is to be preferred as this does not kill all organisms. Sterilisation can be done when trying to grow truly difficult crops. To pasteurise the soil, the soil is heated for 15 minutes in an oven of 120 °C. [6]

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. In planting, wider rows (generally 75 cm (30 in) or more) are used, and the intent is to have precise, even spacing between individual seeds in the row; various mechanisms have been devised to count out individual seeds at exact intervals.Difference between sowing and planting must not be forgotten.

Regular rows of maize in a field in Indiana.

Sowing depth

In seeding, little if any soil is placed over the seeds. More precisely, seeds can be generally sown into the soil by maintaining a planting depth of about 2-3 times the size of the seed.

Sowing types and patterns

For hand sowing, several sowing types exist; these include [7]:

  • Flat sowing
  • Ridge sowing
  • Wide bed sowing

Several patterns for sowing may be used together with these types; these include:

  • Regular rows
  • Rows that are indented at the even rows (so that the seeds are placed in a crossed pattern). This method is much better, as more light may fall on the seedlings as they come out.

Types of sowing

Hand sowing

Hand sowing is the process of casting handfuls of seed over prepared ground: broadcasting. Usually, a drag or harrow is employed to incorporate the seed into the soil. Though labor intensive for any but small areas, this method is still used in some situations. Practice is required to sow evenly and at the desired rate. A hand seeder can be used for sowing, though it is less of a help than it is for the smaller seeds of grasses and legumes.

A tray used in horticulture (for sowing and taking plant cuttings)

Hand sowing may be combined with pre-sowing in seed trays. This allows the plants to come to strength indoors during cold periods (eg spring in temperate countries).

In agriculture, most seed is now sown using a seed drill, which offers greater precision; seed is sown evenly and at the desired rate. The drill also places the seed at a measured distance below the soil, so that less seed is required. The standard design uses a fluted feed metering system, which is volumetric in nature; individual seeds are not counted. Rows are typically about 10-30 cm apart, depending on the crop species and growing conditions. Several row opener types are used depending on soil type and local tradition. Grain drills are most often drawn by tractors, but can also be pulled by horses. Pickup trucks are sometimes used, since little draft is required.

A seed rate of about 100 kg of seed per hectare (2 bushels per acre) is typical, though rates vary considerably depending on crop species, soil conditions, and farmer's preference. Excessive rates can cause the crop to lodge, while too thin a rate will result in poor utilisation of the land, competition with weeds and a reduction in the yield.

Open field

Open-field refers to the form of sowing used historically in the agricultural context whereby fields are prepared generically and left open, as the name suggests, before being sown directly with seed. The seed is frequently left uncovered at the surface of the soil before germinating and therefore exposed to the prevailing climate and conditions. This is in contrast to the seedbed method used more commonly in domestic gardening or more specific (modern) agricultural scenarios where the seed is applied beneath the soil surface and monitored and manually tended frequently to ensure more successful growth rates and better yields.

See also

References

  1. ^ Pre-sowing treatments of seed
  2. ^ Sprout safety: how to combat contamination of seed
  3. ^ Seed Germination, Theory and Practice'; by Dr. Norman C. Deno
  4. ^ Seed cleaning by seed washings and seed rubbings
  5. ^ Exotische vruchten kweken by Dr. Gabriele Lehari
  6. ^ Exotische vruchten kweken by Dr. Gabriele Lehari
  7. ^ Types of sowing types

1911 encyclopedia

Up to date as of January 14, 2010

From LoveToKnow 1911

SOWING (from "to sow," O. Eng. sawan, cf. Du. zaaijen, Ger. saen, &c.; the root is seen in Lat. serere, cf. "seed"), in agriculture, the planting of seed for the raising of crops. The scattering of seed by hand is the simplest and oldest method of delivering seed to the earth, and is still preferred by some farmers and in certain circumstances. The sower carries the receptacle for the seed, a zinc "seed-lip," seed-sheet or basket, slung over his shoulder, and walking up and down the ridges of the field scatters handfuls of grain with a semicircular sweep of the arm across the body. The "casts" must not overlap too much, the seed must not fall more thickly at one point of the cast than at another, and the standard of seeding per acre must be rigidly adhered to; hence manual-sowing demands considerable skill and experience. It is still preferred in some districts for the sowing of corn crops; and in some cases the plough is followed by a furrow-presser, the seed falling into the hollows made by it, though under ordinary circumstances the face of the field as left in "seams" by the furrow-slices from the plough is in a suitable condition for broadcasting. So well, indeed, is the ploughing done in many countries that broadcasting gives perfectly good results, and broadcasting machines reaching up to 15 ft. wide are in common use in place of hand-sowing, as these get over the ground more quickly and deposit the seed more regularly than an ordinary workman does by hand.

It was long recognized that the precision which is of the essence of good sowing could be better attained by mechanical means, and as early as 1662 a sowing-machine was invented by Joseph Locatelli in Carinthia. In England the early history of mechanical sowing is chiefly connected with the name of Jethro Tull, who about 1730 invented the corn-drill.' Cooke's drill brought out in 1783 was the definite precursor of the modern drill. The drill, besides depositing the seed at a uniform depth, sows it in parallel rows at equal distances from one another and thus makes possible the use of the horse hoe and facilitates the suppression of weeds amongst growing crops, the latter advantage being specially marked in the case of root crops. The "cup-feed" and the "force-feed" are the commonest and most generally useful types. The cup-drill consists of a long box carried upon wheels and divided diagonally into two sections by a partition. The forward section contains the seed which drops through apertures, the size of which can be regulated by slides, to the bottom section. A spindle geared to the groundwheels by cogs passes longitudinally through the centre of this section and carries disks, round the rims of which are fitted small cups. As the horses pull the drill forward, the spindle and disks revolve and the cups scoop up the seed and pour it into the funnels; thence it proceeds down a series of tubes or "spouts" and drops into shallow furrows traced by small coulters travelling immediately in front of the streams of seed. The coulters can be raised or lowered by levers and are kept down to their work by weights or pressers, which can be regulated according as deep or shallow sowing is required.

FIG. I. - Rear view of Corn and Fertilizer Single Disk Drill.

In the force-feed type of drill the seed falls through apertures in the bottom of the seed-hopper into funnels, through which extends a shaft carrying bowl-shaped wheels, one for each (fig. I). These wheels are either spirallygrooved inside or else cogged and serve to feed the seed regularly into the tubes. Instead of coulters, the drill is often fitted with shoes or revolving disks, similar in action to those of the disk-harrow. The tooth and brush pinion, the perforated disk and the chain feed drills, are other types differentiated according to FIG. 2. - Disk Coulter. the method by which the seed is fed from the hopper and the kind of crop being sown.

Liquid-manure drills distribute chemical manure mixed with water and are often fitted with a seed-box for root seeds, the manure and the seed being deposited through the same spout. Drills are also made in which dry fertilizers may be deposited with the seed in a similar manner.

The wheelbarrow seeder, a long box pierced with openings and carried transversely on a skeleton wheelbarrow, is used for sowing grass seed.

' The machine devised by Josiah Worlidge about 1669 was ineffective in practice and differed totally in structure from that of Tull.

In the United States the maize or Indian-corn crop exceeds all others in value, and machines used in planting and handling this crop are of great importance. Corn (maize) is sometimes listed or planted in a continuous row like wheat, and for this purpose a machine known as a lister is employed.

In its general construction this machine is a sulky plough, having a double mould-board, which turns the furrow in both directions. Immediately behind the plough is a sub-soiler for deepening the furrow and penetrating to the moist soil below the surface. A seedbox is mounted on the plough beam, and is provided with a feed-plate operated by a shaft geared to one of the wheels. The seed is FIG. 3. - Maize Lister.

delivered to the furrow in rear of the mould-boards and covered by two shovels fixed behind which turn the soil back into the furrow. It is, however, more common to plant maize in hills, which are spaced equally from each other and form rows in both directions, so that a cultivator may be driven between them. This work is done by a machine called a check-row corn planter.

In using the corn planter, a wire, having buttons attached thereto, at intervals corresponding to the distance between the hills, is first stretched across the field and anchored at its ends. This wire is then placed upon the guide rollers at the side of the machine and passes between the jaws of a forked lever, which is connected at its other end with a rock-shaft passing across the machine and serving to oscillate a feed-plate in the bottom of each seed-hopper. As the buttons on the check-wire strike the forked lever, the latter is drawn to the rear and causes the feed-plate to drop the seed through the tubes into the open space between the plates of the furrowing shoe. A reel at the rear of the machine is used to take up the check-wire as the planter progresses.

In another corn planter the check-wire is dispensed with, and the machine is provided with a shaft carrying two reels, the blades of which are at a distance apart equal to the distance between the hills of corn, and thus measure the intervals at which the corn is to be dropped. A rod, extending from the side of the machine, and carrying a small wheel, marks the next row and serves as a guide to the driver.

See J. B. Davidson and L. W. Chase, Farm Machinery and Farm Motors, p. 132 (New York, 1908). 1908).


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