Crop Rotation

[Drusilla]

Can anybody explain the difference between three and four field crop rotation for a tearful nine year old? Please keep it simple and an idea of the crops employed in the two systems would help. Many thanks!

[shaneystar]

From the end of the Middle Ages until the 20th century, the three-year rotation was practised by farmers in Europe with a rotation: rye or winter wheat, followed by spring oats or barley, then letting the soil rest (fallow) during the third stage. The fact that suitable rotations made it possible to restore or to maintain a productive soil has long been recognised.
A four-field rotation was pioneered by the Dutch and popularised by the British agriculturist Charles Townshend in the 18th century. The system (wheat, barley, turnips and clover), opened up a fodder crop and grazing crop allowing livestock to be bred year-round. The four field rotation was a key development in the British Agricultural Revolution.
This is taken from wikipedia.
http://en.wikipedia.org/wiki/Three-field_system.

[Octavius]

Some crops use up the nitrates in the soil and others, like beans and peas, restore them.

By changing what crop grows in a field each year the natural cycles can be used to improve growth and take away the need for artificial fertilisers and chemical based growth promoters. Crop rotation improves the environment by returning most organic waste to the soil, increasing humus levels and allowing nature's cycles to work.
In the middle ages, the general rotation could be wheat the first year, barley the next, and the third year the land would lay fallow with nothing growing in it or the plot was left to grazing, thus getting manure into the soil to improve it for the following year.

[ursula62]

You might find these links helpful:

Three field rotation:

http://www.staffs.ac.uk/schools/sciences/geography/staff/harrist/304/304lec5.htm#3field

Four year crop rotation: http://www.schoolshistory.org.uk/agriculturalrevolution. htm

http://www.staffs.ac.uk/schools/sciences/geography/staff/harrist/304/304lec5.htm#4field

[Drusilla]

Thank you all for your answers, you've been lifesavers!!!