Microbial abundance and activity in chernozem under different cropping systems

Abstract

The study monitored microbial abundance and dehydrogenase activity in chernozem soil under different cropping systems. Soil samples were taken from the long-term trials Crop Rotations and IOSDV, at the Rimski Šančevi experimental field of the Institute of Field and Vegetable Crops. The soil samples were collected in two years from ten cropping systems at three sampling depths. Number of the examined microbial groups was assessed by the indirect dilution method, while dehydrogenase enzyme activity was measured spectrophotometrically. Number of the tested microbial groups and dehydrogenase activity varied significantly depending on the cropping system and year of study, while sampling depth significantly affected enzyme activity. The highest number of microorganisms was obtained in non-agricultural soil and unfertilized soil under 2-year and 3-year rotation, while the highest dehydrogenase activity was recorded in non-agricultural soil and soil under wheat grown in monoculture.

Cilj ovih istraživanja bio je utvrđivanje mikrobiološke brojnosti i dehidrogenazne aktivnosti u černozemu u zavisnosti od sistema gajenja. Uzorci zemljišta su prikupljeni na višegodišnjim ogledima Plodoredi i IOSDV, na eksperimentalnom polju Rimski šančevi Instituta za ratarstvo i povrtarstvo. Zemljište je uzorkovano tokom dve godine iz deset sistema gajenja i tri dubine. Brojnost mikroorganizama utvrđena je indirektnom metodom razređenja, dok je aktivnost dehidrogenaze određena spektrofotometrijski. Brojnost ispitivanih grupa mikroorganizama i dehidrogenazna aktivnost značajno su varirali u zavisnosti od sistema gajenja i godine ispitivanja, dok je dubina uzorkovanja značajno uticala na aktivnost enzima. Najveća brojnost mikroorganizma utvrđena je u nepoljoprivrednom zemljištu i zemljištu pod neđubrenim dvopoljem i tropoljem, dok je najviša dehidrogenazna aktivnost zabeležena u nepoljoprivrednom zemljištu i zemljištu pod monokulturom pšenice.