Different plants are known to have different soil microbial communities associated with them. Agricultural management practices such as fertiliser and pesticide addition, crop rotation, and grazing animals can lead to different microbial communities in the associated agricultural soils. Soil dilution plates, most-probable-number (MPN), community level physiological profiling (CLPP), and buried slide technique as well as some measured soil physicochemical parameters were used to determine changes during the growing season in the ecosystem profile in wheat fields subjected to wheat monoculture or wheat in annual rotation with medic/clover pasture. Statistical analyses showed that soil moisture had an over-riding effect on seasonal fluctuations in soil physicochemical and microbial populations. While within season soil microbial activity could be differentiated between wheat fields under rotational and monoculture management, these differences were not significant. 1. Introduction Soil quality is essential for plant and animal health, maintenance of the environment, and sustained biological productivity [1]. Soil microbes play a pivotal role in maintaining soil quality [2, 3]. Microbial diversity of the rhizosphere is believed to be beneficial for soil health [4] and the trophic interactions within the rhizosphere can affect the aboveground community of plants [5]. Our understanding of soil microbial functioning in this plant-microbe interaction has generally been limited [6, 7]. Plant variety has a significant influence on the associated soil microbial community, as measured by community-level physiological profiling (CLPP) by Dunfield and Germida [8]. These authors also found that seasonal differences in this community were not permanent. Marschner et al. [9] found that the rhizosphere microbial community was plant species-specific, while Morgan et al. [4] stated that the root exudates from different plants and even different cultivars of the same plants differed and these caused differences in the rhizosphere communities associated with the plants. Thus, it could be expected that the microbial communities under wheat monoculture and wheat in rotation with legume pasture would differ significantly. Various role players are more frequently requesting information on the impact of land use management practices on the physical, chemical, and biological fertility of soils [1]. There exists little knowledge about how management systems influence microbial communities and as a result the fertility of the soil [10]. When physicochemical properties of a soil are
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