VOLUM OMAGIAL - Facultatea de Ştiinţe ale Naturii şi Ştiinţe Agricole

Ovidius University Annals of Natural Sciences, Biology – Ecology Series Volume 14, 2010
DATA ON THE DYNAMICS OF SOME MICROBIAL GROUPS IN SOILS
WITH DIFFERENT TROPHIC STATUS IN CUMPĂNA REGION (DOBROUDJA)
Elena DELCĂ
Ovidius University of Constanţa, Faculty of Natural Sciences and Agricultural Sciences
Mamaia Avenue, No. 124, Constanţa, 900527, Romania,
Doctoral school Biology, Specialization Ecology
__________________________________________________________________________________________
Abstract: The aim of paper was to assess the effect of administration of organic amendments on the dynamics of
the abundance of microbial groups significant in nutrient cycling in soils. Abundance of total culturable bacteria
ranged from 19.93x10 6 UFC/g dry soil, to 501.79x10 6 UFC/g dry soil. When soil was supplemented with manure
microbial density showed a significant increase 501.79x10 6 UFC/g dry soil compared with control variant.
Bacterial density increased significantly as value, too, following the administration of specific biofertilizers
(Biovin, Bactofil Professional; Mycos Green), up to 142.13 x106UFC/g dry soil. Inorganic fertilizers did not
have a positive effect on microbial density values, being more or less similar to those reported for the control.
Our preliminary data show that organic amendments with complex composition have a direct effect on the
abundance and diversity of soil and influence indirectly the microbial metabolism and nutrient cycling rate.
Keywords: humus, microorganisms, bioactivators, fertility
_________________________________________________________________________________________
1. Introduction
To start and propose a suitable biological soil
reconstruction plan it was necessary to initiate a
series of observations and experiments in a
characteristic agroecosystem of Dobroudja (Cumpana
commune) in order to assess the current biological
status. Using new agricultural technology, and adding
different fertilizers the experiments have the aim to
improve the number and activity of soil
microorganism and indirectly to enhance the rate of
organic matter decomposition. This would improve
over time the soil structure and restore the stock of
humus in the soil.
2. Material and Methods
The experiments have taken place on a 7.5 ha
plot situated in the outside of Cumpana, in Constanta
district. Josef wheat was cultivated on the entire area,
which was divided in 7 variants, each variant being
administered a different type of fertilizer in different
quantities and periods, as follows:
- Variant I - only chemical fertilizers - 100kg/ha
N15P25K15 in autumn, 150kg/ha NH4NO3 at the
beginning of spring;
- Variant II – Biovin organic fertilizer 400kg/ha and
Biovin 30 of l/ha, ½ at herbicide stage and ½ at flour
stage;
- Variant III – garden soil - 15t/ha in autumn;
- Variant VI – l/ha of Biovin 30, ½ at herbicide stage
and ½ at flour stage;
- Variant V – Biovin 150kg/ha administered during
sowing, 150kg/ha NH4NO3, 40kg/ha at the beginning
of spring, 50kg/ha at herbicide stage and 60kg/ha at
flour stage;
- Variant VI – Biovin 375kg/ha, liquid Biovin 30 of
l/ha, ½ at herbicide stage and ½ at flour stage, 1mc
Green Mycos, 1l Bactofil Professional;
- Variant – March – were not applied amendments.
Biovin Fertilizers are being administered for the
first time in Dobrogea.
Biovin is being produced through a
technological process from grape kernels. 12 years of
western research proved the following: it aerates the
soil, improves it (it contains up to 70% humus
makers), and purveys all plants with nutritive
elements and biostimulators, it enriches the soil with
ISSN-1453-1267 © 2010 Ovidius University Press