DOI: 10.5593/SGEM2014/B61/S25.048


A. Djukic, L. Mandic, S. V. Moracanin, A. Stanojkovic
Wednesday 1 October 2014 by Libadmin2014

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-20-9 / ISSN 1314-2704, June 19-25, 2014, Book 6, Vol. 1, 343-350 pp

Safe food production is essentially dependent on safe primary agricultural production which, inter alia, involves a reduction in the use of agrochemicals. However, their uncontrolled use for increased productivity is a frequent practice which ignores their disastrous effect on the biosphere and, hence, the quality of primary products. Soil microorganisms are important parameters used in assessing the quality and level of pollution of the biogeosphere and plant products. Therefore, the objective of this study was to evaluate the effect of different application rates of mineral nitrogen fertilizerz on soil microbial characteristics (total microbial count, numbers of ammonifiers and proteolytic activity) and potato yield, and their potential replacement with biological fertilizers (produced from nitrogen fixing strains of Klebsiella planticola). The experiment was conducted at the experimental field of the Biotechnical Faculty in Podgorica in a randomized block design in four replications. The test plant was potato cultivar ‘Kennebeck’. The trial included five treatments: unfertilized control; treatment N1 - 100 kg/ha CAN (calcium ammonium nitrate, 27% N); treatment N2 - 200 kg/ha CAN; treatment N3 - 300 kg/ha CAN; treatment with Enteroplantin, a Klebsiella planticola-based biofertilizer. The total microbial count and the numbers of ammonifiers were determined by the plate culture method using appropriate selective media, and proteinase activity was assessed by titration with FeCl3. Results suggest that low nitrogen fertilizer rates improved soil microbial characteristics, whereas the highest application rate (300 kg/ha CAN) reduced all of the traits analyzed, except proteolytic activity. The highest increase in soil biological characteristics was observed in the treatments involving biofertilizer use, which led to increased plant
growth and tuber yield of potato, compared to mineral nitrogen fertilization.
The present results suggest that reduction in the use of mineral fertilizers through their replacement or supplementation with biofertilizers is recommended in safe food production.

Keywords: biofertilization, potato, microorganisms, soil, mineral nitrogen, yield