Wednesday, November 7, 2007 - 10:00 AM
262-2

Sustainable Crop Production, Rotations or Monoculture: Some Results from Long-Term Experiments at Rothamsted.

A.E. Johnny Johnston, Rothamsted Research, Soil Science Dept, Harpenden Herts, United Kingdom

In the UK in medieval times growing food for man was based on a 2-course rotation, fallow, cereal, followed later by fallow, grain legume, cereal. The mid-1700s saw the introduction of the Norfolk 4-course rotation, turnips, barley, legume, and winter wheat. This rotation, practised on the permanent arable soils of the farm, produced food for man and winter feed for animals that spent the summer foraging for food on permanent grassland and in the woods. In this farming system, which became the backbone of agriculture throughout much of Europe, weeds, pests and diseases were controlled adequately. When it became possible to supplement the supply of nutrients from the soil and any available organic manure by using fertilizers productivity was increased. The 1930’s saw the introduction of ley-arable farming, the alternation of a short period of arable crops, grown in rotation, with a short period of temporary grass or a forage legume. Permanent arable cropping, with crops grown in rotation, and ley-arable cropping continued until the 1950s and then there was a change. Increasing specialisation saw farms becoming based on all arable cropping or devoted solely to animal husbandry. Often this split was related to climate and topography, Animal husbandry in the wetter, hilly areas, arable cropping in the drier areas with deeper more fertile soils. Then, where arable cropping predominated, rotations began to give way if not totally to at least to cropping with combinable crops. The reasons for and effects of these changes will be discussed.

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Back to The ASA-CSSA-SSSA International Annual Meetings (November 4-8, 2007)