Long-term experiment

A long-term experiment is an experimental procedure that runs through a long period of time, in order to test a hypothesis or observe a phenomenon that takes place at an extremely slow rate.

Experiments at Rothamsted showed that "grain yields can be sustained (and even increased) for almost 150 years in monocultures of wheat and barley given organic or inorganic fertilizer annually".

[2] These results show that practices considered unsustainable by some advocates of sustainable agriculture may preserve "the ability of a farm to produce perpetually", at least under some circumstances.

In the Old Rotation, the green manure was grown during the winter to supply nitrogen to a summer crop (cotton); this would be less practical in colder climates.

[6][7] The experiment comprises two oak wooden boxes containing duplicate samples, to be kept at the University of Edinburgh and the Natural History Museum.

In addition to the core experiment, there are a variety of samples including dried agar plates and endoliths for investigation over long periods.

[citation needed] One of the wooden boxes was delivered to the Natural History Museum on 27 February 2015, and will be curated within the cyanobacterial collection.

[8][9] Experiments with the evolution of maize under artificial selection for oil and protein content represent more years, but far fewer generations (only 65).

A number of other areas, sometimes called involuntary parks, can be regarded as long time ecological experiments, because they have been abandoned by humans and returned to near-feral condition.

The Grant Study at the Laboratory of Adult Development in the Department of Psychiatry at Brigham and Women's Hospital, a Harvard Medical School affiliate, is conducting a longitudinal study of human adult development, by following two groups of individuals as they age (268 Harvard graduates and 456 males from inner-city Boston).