National and regional net nitrogen balances in Finland in 1990-2005

Nitrogen (N) balance has been identified as a principal agri-environmental indicator. In addition to national N balances, calculation of N balances for different agricultural regions is also recommended. In this study, national and regional net N balances for Finland were calculated. The net N balance is the result of deducting the NH3-N losses from manure and fertilisers from the gross N balance. The N balance calculation was based on data for Finnish Rural Centres and calculated per cultivated hectare. The main data inputs for the calculations were agricultural and environmental statistics, coefficients of manure excretion and crop N concentrations. Finnish national net N balance decreased from 90 kg ha–1 in 1990 to 50 kg ha–1 in 2005. The decrease in regional N balances was of the same magnitude. The main reason for the lower N balances was reduced use of mineral N fertilisers. Variation in the N balances was due to yield levels varying according to growing season conditions. The Rural Centres with intensive animal production tended to generate the highest N balances

Kasvipeitteisyys, eroosio ja ravinnekuormitus : kirjallisuuskatsaus

vokKirjasto Aj-kMK

Kevyt syysmuokkaus puntarissa

Kyntöä kevyempi syysmuokkaus näyttäisi hieman vähentävän typen huuhtoutumista. Samalla se kuitenkin myös lisää vesistöjä rehevöittävän fosforin päästöjä. Tutkimuksessa havaittiinkin, että typen ja fosforin päästöjen samanaikainen vähentäminen voi olla hankalaa. Tämän vuoksi tarvitaan yhä enemmän lohkokohtaista harkintaa siitä, minkä ravinteen kuormituksen rajoittaminen on kulloinkin tärkeintä.vokmk

Suomen peltojen maalajit, multavuus ja fosforipitoisuus : Vuodet 1996–2000 ja 2005–2009

Julkaisuun on koottu tietoja Suomen peltomaiden muokkauskerroksen lajitekoostumuksesta (maalajista), orgaanisen aineksen määrästä (multavuudesta), happamuudesta ja maan viljavuusfosforipitoisuudesta vuosilta 1996–2000 (noin 880 000 maanäytettä) ja 2005–2009 (noin miljoona näytettä). Maanäytteet ovat viljelijöiden tai maatalousneuvojien ottamia osana vapaaehtoista maatalouden ympäristökorvausta. 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.201

Effective green manuring via biogas production

The preliminary results show that the benefit from anaerobic digestion of the green manure leys seem to be based more on biogas energy production than for higher yields after anaerobic digestion. The N leaching risk is under determination

Glyfosaatin ja AMPAn kulkeutuminen veden mukana savimaalta

201

Effects of agricultural land use on dissolved organic carbon and nitrogen in surface runoff and subsurface drainage

Dissolved organic carbon (DOC) load in discharges from cultivated soils may have negative impacts on surface waters. The magnitude of the load may vary according to soil properties or agricultural management practices. This study quantifies the DOC load of cultivated mineral soils and investigates whether the load is affected by agricultural practices. Discharge volumes and concentrations of DOC and dissolved organic nitrogen (DON) were continually measured at three sites from surface runoff and artificial subsurface drainage or from combined total discharge over a two-year period (2012-2014). Two experimental sites in South-West Finland had clayey soils (with soil carbon contents of 2.7-5.9% in the topmost soil layer), and the third site in West-Central Finland had sandy soil (soil carbon contents of 4.3-6.2%). Permanent grassland, organic manure application, mineral fertilization, and conventional ploughing or no-till activities were studied. Furthermore, the biodegradable DOC pool of surface runoff and subsurface drainage water from no-till and ploughed fields was estimated in a 2-month incubation experiment with natural bacterial communities collected from the Baltic Sea seawater. The annual DOC and DON loads were affected by discharge volume and seasonal weather conditions. The loads varied between 25-52 kg ha(-1) and 0.8-3.2 kg ha(-1), respectively, and were comparable to those from boreal forests with similar soil types. The DOC load increased with increasing topsoil carbon content at all sites. There were slightly higher DOC concentrations and DOC load from permanent grassland, but otherwise we could not distinguish any clear management-induced differences in the total DOC loads. While only 6-17% of the DOC in discharge water was biologically degraded during the 2-month incubation, the proportion of biodegradable (labile) DOC in surface runoff appeared to increase when soil was ploughed compared to no-till. (c) 2017 Elsevier B.V. All rights reserved.Peer reviewe