Grassland temperature sum
The grassland temperature sum ( GTS ) is a special form of the growth degree days that is used in agro-meteorology . It is used to determine the date for starting field work in Central Europe after winter.
A heat sum is generally a certain air temperature of a day added up over the days of a period. The cumulative corrected GTS , which is weighted by month , is used in particular :
All positive daily means are recorded from the beginning of the year. In January it is multiplied by the factor 0.5, in February by the factor 0.75, and from March the “full” daily value (multiplied by the factor 1) is then included in the calculation.
If the sum of 200 is exceeded in spring, the sustainable beginning of vegetation has been reached. The background is the nitrogen uptake and processing of the soil, which depends on this total temperature. In middle latitudes, this is usually achieved in the course of March, at the turn of early spring to mid-spring . The annual total is typically around 1000.
proof
- Total grassland temperature Zurich-Wetzikon ( Memento from March 14, 2013 in the Internet Archive )
- Grassland temperature, growth degree days, heat and cold sum groitzsch-wetter.de
Individual evidence
- ↑ so there is metheo.ethz.ch for 2012 in Zurich-Wittikon: 605 (200 approx. 25.3.); groitzsch-wetter.de for Groitzsch, Saxony: 2007 (hot year): 1264.9 (200 on March 1st), 2010 (cool year): 865.8 (200 on March 29th)