Soil organic matter content according to different management system within long-term experiment | Vsebnost organske snovi v tleh v odvisnosti od načina gospodarjenja znotraj trajnega poskusa

English. Within the long-term field experiments at IOSDV Rakičan, Slovenia, the impact of organic matter management system and mineral nitrogen fertilization on the soil organic matter content was studied in the period 1994-2008. The annual balance of Corg was calculated on the basis of the quantity of added organic fertilizers ("Bavarian method", "VDLUFA method"), while the "Swiss method" also consider the quantity of Corg in the topsoil in the calculation. The following management systems were selected: system A - no organic matter, system B - farmyard manure ploughing in, system C - straw/catch crop ploughing in. Four different mineral N rates (N0, N1, N2, N3) were evaluated. In 2008 the Corg content in topsoil (0-25 cm) was measured according to ISO 10694. Farmyard manure (FYM) fertilization significantly influenced the content of Corg, while the straw application did not result in the significant increase of Corg content. Mineral nitrogen fertilization did not impact Corg content within system A. In system B and system C positive effect of nitrogen fertilization on the Corg content was detected. However, statistically significant impact of mineral N on a higher Corg content was not determined. All three methods underestimated the actual analysed results, although, we can determine the "Swiss method" as the most precise and appropriate for this site-specific location.

Slovenian. V statičnem poskusu IOSDV Rakičan, Slovenija smo preučevali vpliv gospodarjenja z organskimi gnojili in vpliv gnojenja z mineralnimi dušikom na vsebnost organske snovi v tleh v letih 1994 do 2008. Letna bilanca Corg je bila izračunana na podlagi količin dodanih organskih gnojil pri "Bavarski metodi" in " VDLUFA metodi", medtem ko se je pri " Švicarski metodi" v izračunih upoštevalo tudi stanje Corg v tleh. Vključeni sistemi gospodarjenja so bili: sistem A - gospodarjenje brez organskega gnojenja, sistem B - gnojenje s hlevskim gnojem, sistem C - zaoravanje slame/podorin. Preučevane so bile štiri stopnje gnojenja z mineralnim dušikom: N0, N1, N2 in N3. V letu 2008 je bila izmerjena vsebnost Corg v globini od 0 do 25 cm po standardu ISO 10694. Gnojenje s hlevskim gnojem je značilno povečalo vsebnost Corg, medtem ko gnojenje s slamo ni imelo takšnega vpliva. V sistemu brez organskih gnojil gnojenje z mineralnim dušikom ni doprineslo k povečanju vsebnosti Corg. Kljub pozitivnemu vplivu gnojenja z mineralnim dušikom na vsebnost Corg v sistemu B in C, pa vpliv ni bil statistično značilen. Izračuni vseh treh metod podcenijo dejanske rezultate laboratorijskih analiz posameznega vzorca. Še najbolj se omenjenim rezultatom približajo vsebnosti Corg, izračunane s "Švicarsko metodo", zato lahko povzamemo, da je slednja najbolj primerna za določitev Corg za preučevano lokacijo.