Farm Power And Machinery (1+1)

Furrow openers

The furrow openers are provided in a seed drill for opening a furrow. The seed tube conducts the seed from the feed mechanism into the boot from where they fall into the furrows.
Type of furrow openers
There are different type of furrow openers, which are: a) Shovel type, b) Shoe type and c) Disc type (single disc, double disc).
a) Shovel Type

• Shovel type furrow opener are the widely used in seed drills. There are three of shovels in use. They are: (a) reversible shovel (b) single point shovel and (c) spear point shovel.
• Shovel type openers are best suited for stony or root infested fields. These shovels are bolted to the flat iron shanks at the point where boots are fitted which carry the end of the seed tubes. In order to prevent shock loads due to obstructions, springs are provided. It is easy in construction, cheaper and easily repairable. It is very common with usual seed drill.
b) Shoe Type

• It works well in trashy soils where the seed beds are not smoothly prepared.
  
• They are made from two flat pieces of steel welded together to form a cutting edge.
  
• It is specially suited for black cotton soil. Shoe is made of carbon steel having minimum carbon content of 0.5 per cent with a minimum thickness of 4 mm.
c) Disc Type
They are two types:

i) Single disc type

• It is furrow opener consisting of one concave disc. Disc type furrow openers are found suitable where plant debris or trash mulches are used.
  
• It consists of a curved disc made of hardened steel. It is set at an angle which while operating, shift the soil to one side making a small ridge.
  
• The disc is kept clean by two scrapers, one toe shaped at the convex side and one ‘T’ shaped at the concave side.
  
• It works in sticky soils also, but the discs are costly and maintenance work is a bit difficult.
ii) Double disc type

• In double disc type furrow opener there are two flat discs, set at an angle to each other.
• The disc opens a clean furrow and leaves a small ridge in the center. The seeds are dropped between the two discs, providing more accurate placement.
• It is suitable for trashy lands. Seed drills attached with tractors having high speeds, usually use this type of furrow opener.

Parts of furrow opener
The furrow opener consists of Tine, shovel, seed tube and boot for seed and fertilizer.
Tine: A thin pointed projection of a implement such as fork or pitchfork
Shovel- It is made of carbon steel having carbon content of 0.5 per cent and a minimum thickness of 4.0 mm.
Seed tube - It is a tube which carries the seeds from the metering device to the boot. Seed tubes are provided at the lowest lines through suitable boots and furrow openers. The most common to the furrow lines through suitable boots and furrow openers. The most common type of seed tube is the steel ribbon one. The ribbon is rolled in the form in such a way that lower edge of the tube is thinner than the edge. Polythene or rubber tubes are also used of this purpose. The minimum diameter of seed and fertilizer tube is 25 mm.
Boot - It is a part of the sowing machine which conveys the seeds or fertilizers from the delivery tube to the furrow. It is bolted or welded to the tine. It is a harrow casting, into which the lower end of the seed tube is inserted and to which the furrow openers are attached.