There are three methods of planting crops by direct seeding: broadcast, hill, and drill. Actual planting is done either manually or with a mechanical planter. Another technique, called dibbling, is a form of hill planting.
Note: For cereals, the word “seed” which refers to the plant structure that is sown is here used interchangeably with “grain.” Technically, however, the grain of rice consists of the brown rice and the enveloping rice hull. The hull is composed of the lemma, palea, and other tissues. The brown rice is technically a fruit called “caryopsis” consisting of a seed enclosed by the pericarp. For corn, the structure which is interchangeably called seed, grain and kernel is likewise a caryopsis. (Click here to read Parts of a Seed on separate window).
Broadcasting or sabog tanim, also called scatter planting, is a method of planting by which seeds (or grains) are scattered over a well prepared soil. There are no plant-to-plant spacing and arrangement. As a result, there are plants which may grow singly while others may occur in pair or in bunches of several plants.
method is common in crops with small seeds that are capable of
germination and sustained growth without soil cover. Examples are
rice , millets, mungbean, cowpea and forage crops. However, there are
no exact limitations. In addition to small seeds like those of forage crops, relatively large seeds including those of trees
can be released from a plane or helicopter. Such a broadcasting
technique is specially called aerial seeding.
With hand broadcasting, a volume of seeds is held by one hand and thrown with a wide swath. Skill is important to ensure a more or less even distribution per unit ground area based on the desired seeding rate.
In lowland rice, the seeds are broadcasted on puddled soil or over water and allowed to germinate without covering. The broadcast method of direct seeding is also common with mungbean and cowpea grown as residual crop after rice or as green manure.
Contact with the soil will improve seed germination and seedling establishment. In a pastureland, a heavy herd of animals may be released right after broadcasting of pasture crop seeds. As they move around, their hooves will press the seeds downward.
Hill planting is a planting method by which plants are arranged in equidistant rows and uniform hill-to-hill distances within the row. It is also called checkrow planting because on top view the hills appear as arranged uniformly at the intersections of squares of an imaginary chekerboard.
A “hill” is that specific spot on the ground where a plant or a group of plants is grown. Mounded bases of plants are likened to miniature hills.
Applied in direct seeding, this planting method consists of dropping seeds in holes made by a dibbler (or dibble) or any tool for digging small holes. With furrows, the seeds are commonly dropped at the bottom. But with mechanized farming, a combine furrower-planter (more oftenly also with a fertilizer applicator) is commonly used. Where a dibbler (or dibble, example a pointed piece of wood or a stick) is used to bore holes on the ground, hill planting is otherwise called dibbling.
There's a common practice in direct seeding of corn immediately following the making of furrows:
The farmer walks forward from end to end of a freshly made furrow, dropping seeds towards the bottom of the depression. He does not carry a measuring tool, he just estimates distances on the ground with impressive accuracy borne of long experience.
To cover the seeds, he merely sweeps the ridge at either side of the furrow by the inner side with one foot to push some soil over the seed. In a continuous flow of movement, that same foot rests on top of the hill. As he lifts his rear foot and steps forward, his weight becomes concentrated on that foot over the hill and presses the soil covering the seed. Each forward step means one seed planted, properly covered.
For further clarification, the square pattern of plant arrangement that is responsible for the term "checkrow" is now rarely practiced in annual crops like cereals and grain legumes or pulses. Now the common planting arrangement is rectangular, that is, two adjacent hills in a row and another two adjacent hills at the next row will form a rectangle on top view.
To illustrate, consider direct seeding corn at a planting distance of 75 cm x 25 cm at 1 plant per hill. This means that rows are 75 cm apart and hill to hill distance is 25 cm within the row. Viewed from the top, 4 closest hills (2 hills in each row) will form a rectangle with length of 75 cm and width of 25 cm. This will mean also that each 1-plant hill will have a ground area (GA) of 1,875 sq cm or 0.1875 sq m, i.e., 75 cm x 25 cm = 1,875 cm2 = 0.1875 m2. This ground area serves as the "homelot" of 1 single plant.
On the other hand, assuming that the same row-to-row distance of 75 cm is maintained, the planting distance should be 75 cm x 75 cm to make a square planting arrangement. Consequently, each hill will have a ground area of 5,625 cm2 or 0.5625 m2, i.e., GA = 75 cm x 75 cm = 5,625 cm2 = 0.5625 m2. To equalize with the above planting distance, 3 seeds should be direct-seeded per hill. That is, 3 multiplied by the above 25-cm hill-to-hill distance is equal to 75 cm, the hill-to-hill distance for the herein given 75 cm x 75 cm spacing. This means that the ground area of 0.5625 m2 is shared by 3 plants occupying every hill. Divide by 3, and the average ground area for 1 plant is exactly the same as the above.
Direct seeding in corn where two or more seeds are sown per hill is an old practice although sometimes hill farmers still do it.
The drill method of planting is another technique of direct seeding by which seeds are released continuously in a row while moving forward at uniform speed. The release of seeds is analogous to pouring water from a bottle with a small opening until water is completely exhausted. The bottle is refilled, and the process is repeated again and again.
Manual drilling applies to small seeds like rice, sorghum, millet, and mungbean and is usually done by hand alone. It can also be accomplished by placing small, roundish seeds in a bottle with a hole on the cover. The seeds are simply released by tilting and slightly shaking the bottle so that the seeds drop one after the other or in a cascade through the hole and towards the ground.
The seeds are drilled with or without furrows. In rice, drilling in puddled soil in linear direction is a modification of seed broadcasting in which plants are dispersed without plant-to-plant spacing. But in rainfed sorghum, mungbean, and other grain legumes, it is a common practice to drill the seeds at the bottom of well spaced furrows. The seeds are immediately covered with soil by raking or by foot and usually slightly pressed.
If the three direct seeding methods are ranked from most to least arranged plants, the hill method will occupy the top rank, at the middle will be the drill method, and at the bottom will be broadcasting. But as to ease in performing the planting operation, it's the other way around.
(Ben G. Bareja 2015, edited Apr. 30, 2019)