Microbiological properties of soils in natural grasslands

Abstract

Microbiological and basic agrochemical soil properties (0-30 cm) in natural grasslands have been examined in four locations: three in the location Pester, at the altitudes between 1176 and 1342 m, and one in Bogovoda, at the altitude of 123 m. The soils in the examined locations were slightly acid (pH 5.32 - 6.31), with a high humus content (3.20 - 8.74%). The tested soils had low phosphorus contents. Potassium contents were higher, especially in the location Pester at 1237 m. In spite of a high total number of microbes Azotobacter sp. could not be found in the examined soils. Ammonifiers and free nitrogen-fixing bacteria were registered in high populations. Physico-chemical soil properties considerably affected the numbers of fungi and actinomycetes. The acid reaction of the soils was probably the reason for a high population of fungi and a low population of actinomycetes. The highest value of dehydro-genase activity (1042 ŋgTPF g-1 of soil) was obtained in the highest location in Pester, the lowest in the location of Bogovoda.

Cilj istraživanja je da se na osnovu zastupljenosti pojedinih grupa mikroorganizama i aktivnosti dehidrogenaze sagleda biogenost zemljišta pod prirodnim travnjacima. Mikrobiološka i osnovna agrohemijska svojstva zemljišta prirodnih travnjaka ispitana su na četiri lokaliteta (do 30 cm) tri na Pešteru na nadmorskoj visini od 1176-1342 m, i pašnjak u Bogovođi na nadmorskoj visini 123 m. Ispitivana zemljišta su blago kisela, bez karbonata sa različitim sadržajem humusa (od 8,74-3,20%) i niskim sadržajem fosfora. Zastupljenost Azotobacter-a nije utvrđena u ispitivanim zemljištima. Ukupan broj mikroogranizama, amonifikatori i gljive su veoma zastupljeni na ovim zemljištima. Najniža vrednost dehidrogenazne aktivosti izmerena je na lokalitetu Bogovođa u odnosu na zemljište travnjaka na Pešteru.