COMPARING THE MICROBIAL BIOMASS CARBON AND NITROGEN CONTENTS OF TOBACCO GROWING SOILS WITH SCANNING ELECTRON MICROSCOPY AND SOME SOIL PARAMETERS

Abstract

The soil microbial biomass carbon (MBC) and nitrogen (MBN) contents that comprise the vivid and dynamic part of soils and are the living and active part of soil organic matter are the main indicators that reveal the quality of soil. In this study, soil MBC and MBN levels in tobacco, planted commonly under rain-fed and irrigated conditions, have been compared with Scanning electron microscopy (SEM) and some soil parameters. In the tobacco planted soils within the study area, a statistically meaningful difference, with an error ratio of 5%, has been found between irrigated rain (IR) and rain-fed (RF) conditions in terms of saturation value, sand%, clay%, EC, OM, OC, C:N, P, Fe, Mn and microbial biomass carbon and nitrogen contents of soils (p < 0.05). Soil microbial biomass has been found to be C-mic 228.050 mu g g(-1), N-mic 31.662 mu g g(-1) under rain-fed conditions; and C-mic 389.418 mu g g(-1), N-mic 74.768 mu g g(-1) under irrigated conditions. It is thought that the existence of clay with high smectite levels in rain-fed conditions is thought to be helping to maintain the mineraliable SOC within the macro-aggregates. In other words, organo-mineral complexes have developed and stayed in soil without SOC degradation. Under irrigated conditions, it is believed that organic fertiliser applications could enhance the durability and resistance of aggregates.