The Park Grass Experiment is a biological study originally set up to test the effect of fertilizers and manures on hay yields. The scientific experiment is located at the

Rothamsted Research Rothamsted Research, previously known as the Rothamsted Experimental Station and then the Institute of Arable Crops Research, is one of the oldest agricultural research institutions in the world, having been founded in 1843. It is located at Harp ...

in the

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ...

county of

Hertfordshire Hertfordshire ( or ; often abbreviated Herts) is one of the home counties in southern England. It borders Bedfordshire and Cambridgeshire to the north, Essex to the east, Greater London to the south, and Buckinghamshire to the west. For gov ...

, and is notable as one of the longest-running experiments of modern science, as it was initiated in 1856 and has been continually monitored ever since. The experiment was originally designed to answer agricultural questions but has since proved an invaluable resource for studying

natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. Cha ...

and

biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic ('' genetic variability''), species ('' species diversity''), and ecosystem ('' ecosystem diversity'') ...

. The treatments under study were found to be affecting the botanical make-up of the plots and the ecology of the field and it has been studied ever since. In spring, the field is a colourful tapestry of flowers and grasses, some plots still having the wide range of plants that most

meadows A meadow ( ) is an open habitat, or field, vegetated by grasses, herbs, and other non-woody plants. Trees or shrubs may sparsely populate meadows, as long as these areas maintain an open character. Meadows may be naturally occurring or artificia ...

probably contained hundreds of years ago. Over its history, Park Grass has: * demonstrated that conventional field trials probably underestimate threats to plant biodiversity from long term changes, such as

soil acidification Soil acidification is the buildup of hydrogen cations, which reduces the soil pH. Chemically, this happens when a proton donor gets added to the soil. The donor can be an acid, such as nitric acid, sulfuric acid, or carbonic acid. It can also be a ...

, * shown how plant species richness, biomass and pH are related, * demonstrated that competition between plants can make the effects of climatic variation on communities more extreme, * provided one of the first demonstrations of local evolutionary change under different selection pressures and * endowed us with an archive of soil and hay samples that have been used to track the history of

atmospheric pollution Air pollution is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. There are many different types ...

, including

nuclear fallout Nuclear fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioac ...

Bibliography

Rothamsted Research: Classical Experiments
*{{Citation , doi = 10.1111/j.1365-2745.2006.01145.x , title = The Park Grass Experiment 1856-2006: its contribution to ecology , year = 2006 , journal = Journal of Ecology , pages = 801–814 , volume = 94 , issue = 4 , last1 = Silvertown , first1 = J. , last2 = Poulton , first2 = P. , last3 = Johnston , first3 = E. , last4 = Edwards , first4 = G. , last5 = Heard , first5 = M. , last6 = Biss , first6 = P.M. , doi-access= free Biodiversity Ecological experiments Grasslands