Lemola, Riitta; Uusitalo, Risto; Hyväluoma, Jari; Sarvi, Minna; Turtola, Eila (2018)
luke-luobio_17_2018.gif (14.12Kt)
luke-luobio_17_2018.pdf (5.244Mt)
Hyväluoma, Jari
http://urn.fi/URN:ISBN:978-952-326-558-5
Aiemmissa yhteenvedoissa tiedot on esitetty jakaumien keskilukuina ja varsinaiset jakaumat vain kuvina ilman jaottelua maalajien mukaan. Tässä julkaisussa tiedot on raportoitu maalajiryhmittäin koko valtakunnan, ELY-keskusten ja yksittäisten kuntien tasolla. Kuntatason tietoja on mahdollista koota esimerkiksi vesistöjen valuma-alueita kattaviksi tietueiksi.
Fosfori on tärkeä kasvinravinne ja samalla kriittinen maatalouden vesistövaikutusten kannalta. Raportin liitetaulukoissa esitetään maan viljavuusfosforin keskiarvot, mediaanit ja jakaumat. Fosforilukujen jakaumat esitetetään tiiviisti summajakaumina, joista voidaan palauttaa alkuperäisten jakaumien muodot. Palautetut jakaumat vastaavat alkuperäisiä jakaumia sitä paremmin, mitä suurempaan tulosjoukkoon tiedot perustuvat.
Summaries based on large data sets on soil test phosphorus (STP) concentrations, soil types, organic matter contents and pH of Finnish agricultural soils have been earlier published at intervals, and they cover data analysed from 1955 to 1985. This report is another publication in this tradition and it covers two more recent 5-yr periods, 1996–2000 and 2005–2009.
Data for our report were obtained from commercial soil testing laboratories, and includes results of about 880,000 soil samples for the period 1996–2000, and about one million samples for the period 2005–2009. The Finnish Agri-Environmental Programme (FAEP), in effect since 1995, stipulates farmers to sample their fields every 5 years in a commercial soil testing laboratory. Hence, data of the two reported 5-yr periods should, by and large, include data from the same field population. Commitment to the FAEP has been high ever since the Programmes were launched; FEAP regulations cover over 90% of the farms and about 95% of the agricultural land in the country. Agricultural land in Finland comprises of about 2.3 million hectares, so one sample in our dataset would on average correspond to about 2.5 hectare field area.
In the earlier statistics, STP were reported as means and median values, distributions were only shown in figures, and the STP distributions of different soil types were not separable. In this report, we tabulate STP distributions according to soil types as cumulative frequencies. These can be backtransformed to original distributions with one STP unit resolution; the larger are the number of data and the narrower it’s distribution over the STP scale, the better back-transformed distributions correspond to the original ones. Data are made available for different scales: the whole country, administrative regions, and individual municipalities. The municipality level data allows building subsets according to river or lake catchment borders, as example.