Seed drill
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The seed drill was invented by Jethro Tull in 1701: It allowed farmers to sow seeds in well-spaced rows at specific depths. Prior to this farmers simply cast seeds on the ground, by hand, for them to grow where they landed (broadcasting). Some of the broadcast seeds were cast on unprepared ground where they never germinated, germinated prematurely only to be killed by frost or died from lack of access to water and fertilizer.
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.
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 or otherwise preparing the soil. 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.
External links
- Tiscali encyclopedia article on seed drills (http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0006239.html)
- Conservation tillage (http://www.fao.org/ag/ags/agse/3ero/harare/PartII/27Choud.htm)
- Zero Tillage seed drilling in Pakistan (http://www.pakissan.com/english/newtech/use.of.water.shtml)de:Drillmaschine