Nitrate contamination of groundwater is an important problem. The transport of leached nitrate from the root zone to groundwater takes approximately 30 to 60 years.

Governments around the globe are trimming their support for agricultural R&D, giving greater scrutiny to the support that they do provide, and reforming the public agencies that fund, oversee, and carry out the research.

Two empirical regularities in the beef-cattle sector have been observed for a long time. First, the time-series for cattle stock exhibits strong cyclicity with a period of several years.