The
LTRAS site hosts a 100-year main experiment and various shorter-term
experiments, all focussed on improving the sustainability and environmental
impact of agriculture. The 100-year experiment was inspired by results
from other locations showing that short-term trends can be poor
predictors of long-term sustainability. At the Rothamsted Experiment
Station, in England, yields in one system increased for 40 years,
then decreased to near zero over the next 40 years. Soil properties
that determine yields, water use, and nitrate leaching change over
decades, not years. Organic matter doubled in another system at
Rothamsted, but it took 75 years.
We want
to understand the relationship between sustainability and external
inputs. Sustainability
will be determined from long-term trends in yield, profitability,
efficiency in use of limited resources (such as water or energy),
and environmental impact, such as leaching of nitrate or pesticides.
We are monitoring trends in key soil properties, such as organic
matter, weed seeds, pH, and salinity to see whether
any of these are good predictors for long-term sustainability. While
acting as an "early warning system" to detect gradual
but potentially harmful long-term trends, we also expect to make
important short-term contributions to agricultural science. Research
at LTRAS will contribute to the development of more sustainable
cropping systems, including both environmental and economic considerations.
The
LTRAS site hosts a 100-year main experiment and various shorter-term
experiments, all focussed on improving the sustainability and environmental
impact of agriculture. The 100-year experiment was inspired by results
from other locations showing that short-term trends can be poor
predictors of long-term sustainability. At the Rothamsted Experiment
Station, in England, yields in one system increased for 40 years,
then decreased to near zero over the next 40 years. Soil properties
that determine yields, water use, and nitrate leaching change over
decades, not years. Organic matter doubled in another system at
Rothamsted, but it took 75 years. 
will be determined from long-term trends in yield, profitability,
efficiency in use of limited resources (such as water or energy),
and environmental impact, such as leaching of nitrate or pesticides.
We are monitoring trends in key soil properties, such as organic
matter, weed seeds, pH, and salinity to see 
whether
any of these are good predictors for long-term sustainability. While
acting as an "early warning system" to detect gradual
but potentially harmful long-term trends, we also expect to make
important short-term contributions to agricultural science. Research
at LTRAS will contribute to the development of more sustainable
cropping systems, including both environmental and economic considerations.