Scientists at Rothamsted Research have calculated nearly one billion litres of rain fell on their 68ha grassland research centre in Devon last year.
In addition, they measured that 18m litres of rain fell in just 24 hours on the site in North Wyke last July, while around five million litres of water poured through their flumes, which measure all the water leaving experimental fields.
This is the first time this level of detail has been recorded at farm scale in the UK.
Rothamsted lead scientist Jennifer Dungait said: “As well as rainfall data, we also measured that some 70%, or 700m litres, was lost as surface or subsurface drainage.
“This has direct relevance to farmers. For example, we estimated silage yields were reduced by 50% in 2012, compared with 2011.”
Wet weather caused chaos and disruption across Devon and neighbouring South West counties last year.
The North Devon Show, due to take place on 1 August, was called off last July due to the awful weather. Following one of the wettest years on record, farmers were left with fields under water and a shortage of silage to feed stock.
New grass hybrids that may reduce flooding, developed with colleagues at the Institute of Biological, Environmental and Biological Research (IBERS), are currently being trialled on the North Wyke Farm platform site.
Rainfall records from the official Met Office weather station at the site extend back 31 years. They show that the mean 10-year annual rainfall until 2011 was 909mm. But this increased by one-third in 2012 at North Wyke.
Meteorologists have forecast more extreme weather over the next 100 years due to climate change, including periods of heavy rainfall and droughts.