Climatology higher latitudes. Models can range from relatively simple to quite complex: In contrast to meteorology, which focuses on short term weather systems lasting up to a few weeks, climatology studies the frequency and trends of those systems. It studies the periodicity of weather events over years to millennia, as well as changes in long-term average weather patterns, in relation to atmospheric conditions. study both the nature of climates – local, regional or global – and the natural or human-induced factors that cause climates to change. Climatology considers the past and can help predict future climate change. Phenomena of climatological interest
Long-term experiment from legumes for a decade or more. The Old Rotation showed that nitrogen from legumes can balance nitrogen removed in a harvested crop over the long term. A key point is that the nitrogen in the legumes was not removed, as it would be with a soybean crop, but was plowed under as a green manure. 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. Long-term agricultural experiments that have been started more recently include the Long-Term Research on Agricultural Systems