Comparison of effects exerted by bio-fertilizers, NPK fertilizers, and cultivation methods on soil respiration in Chernozem soil

Abstract

Soil respiration is a significant indicator of soil microbial activity; global soil respiration and decomposition processes release yearly to the atmosphere a total of 220 billion tons of carbon dioxide. Therefore, studies on the whole- or one particular aspect of soil carbon cycle aiming at optimizing agricultural carbon dioxide emissions or improving carbon sequestration contribute to a sustainable agriculture practice. In this paper we present the effects of biofertilizer application (Bacillus megaterium, Bacillus circulans, and Pseudomonas putida) on soil respiration in chernozem soil. Experiments were performed at Látókép Experimental Station, belonging to the University of Debrecen, Hungary. Additionally, we compare our results with findings of prior studies related to commercial NPK fertilizer applications (in four doses: N60P45K45; N120P90K90; N180 P135K135;  and N240P180K180),  and two different cultivation methods (ploughed, loosened, RTK in rows, and RTK between rows); these investigations were conducted at the same experimental station. Our results indicate lower tendency for soil respiration, when biofertilizers are applied as compared to commercialNPK fertilizers, which enables to decrease CO2 emission in the environment.We also discuss a unit change indifferent alkali absorption-based methods (Oxitop and Witkamp) to facilitate comparability of recently acquired data with results of previous long-term fertilization experiments.