The influence of cattle rearing intensity on humus and mineral content and dynamics | Vpliv intenzivnosti govedoreje na vsebnost in dinamiko humusa in hranil

anglais. Different cattle rearing intensities on farms can affect humus and nutrient content and dynamics. To determine general humus, phosphorus and potassium content in field soils we examined the results of 175 analyses of field soil samples. Analysed field soil samples were collected in different areas of Slovenia. To investigate the influence of cattle rearing intensity on humus and nutrient content and dynamics we selected seven plots on three farms on which intensive cattle breeding is practisized. Impact of intensive cattle breeding was assessed with a help of analysis of soil samples from this plots. The chemical analysis which were used to evaluate general humus, phosphorus and potassium content were made in the period 1989–2002. Analysed field soil samples on selected farms were collected in the period 1977–2002. Fertilising schemes, which were used to calculate the soil humus balance, were made for the period of four or five years. The analyses of field soils on humus, phosphorus and potassium content show that fields in Slovenia are well provided with humus, phosphorus and potassium. The average soil humus content is 3.75%, soil phosphorus content 26.38 mg P2O5/100 g soil and soil potassium content 32.32 mg K2O/100 g soil. Soil humus balance is mostly (72.8%) positive. The soil humus content on selected plots declined with the exception of plot Cb. However, the soil humus balance on these farms in the last period, the period 1998–2002, 1994–1998 for plot Ba, has been positive. For that reason is the soil humus content lately probably increasing. Soils on selected plots showed good values for phosphorus but less for potassium. The supply with phosphorus is increasing, while the supply with potassium is mostly in decrease.

slovène. Različna intenzivnost govedoreje na kmetijah lahko vpliva na dinamiko in oskrbljenost tal s humusom in hranili. Za pregled splošne oskrbljenosti njivskih tal s humusom, fosforjem in kalijem smo obdelali rezultate 175 analiz vzorcev, ki so bili odvzeti v različnih območjih Slovenije. Za primerjavo in ugotavljanje vpliva intenzivnega kmetovanja na vsebnost in dinamiko humusa in hranil smo pregledali oskrbljenost tal s humusom, fosforjem in kalijem na sedmih parcelah treh posebej izbranih intenzivnih govedorejskih kmetij. Kemične analize tal, katerih rezultate smo obdelali za oceno splošne oskrbljenosti slovenskih njivskih tal s humusom, fosforjem in kalijem, so bile narejene v obdobju od leta 1989 do 2002. Vzorci tal na izbranih kmetijah so bili odvzeti in analizirani v obdobju od leta 1977 do leta 2002. Gnojilni načrti, s pomočjo katerih smo izračunali bilanco humusa, so bili narejeni za obdobje štirih ali petih let. Ugotovili smo, da so tla v Sloveniji dobro oskrbljena s humusom, fosforjem in kalijem. Poprečna vsebnost humusa v analiziranih vzorcih njivskih tal je 3,75 %, fosforja 26,38 mg P2O5/100 g tal in kalija 32,32 mg K2O/100 g tal. Bilanca humusa je v večini primerov (72,8 %) pozitivna. Na preučenih parcelah se je vsebnost humusa, z izjemo parcele Cb, zmanjšala. V zadnjem obdobju, to je obdobje 1998–2002, oz. 1994–1998, parcela Ba, je bila bilanca humusa na vseh sedmih parcelah pozitivna, zato se vsebnost humusa verjetno ponovno povečuje. Tla na izbranih parcelah so dobro oskrbljena s fosforjem in slabše s kalijem. Oskrbljenost s fosforjem se povečuje, oskrbljenost s kalijem pa večinoma zmanjšuje.