Evolution of the microbial population of a cultivated soil with organic matter input under semi-arid conditions (Tiaret, Algeria)

To establish the link between soil, plant and climate, it is necessary to study the soil biological state. The work is particularly concerned with monitoring the levels of microorganisms such as: actinomycetes, aerobic bacteria, azotobacters and fungi of a cultivated soil under exogenous organic matter input in the semi-arid region (Tiaret, Algeria). Amended soil samples were prepared from horse manure at different doses (0%, 20%, and 40%) and then put into a wheat crop. These samples were subjected to microbial characterization according to the different vegetative stages of wheat growth. The results obtained during this research revealed that the 20% horse manure doses that seem to be the most effective (P<0.01) and generated the stimulation of a good microbial proliferation and even more around the roots of the amended soils than in soil without a crop; coinciding with the tillering stage of the wheat crop (P<0.001). As could be predicted, the behavior of the microflora is related not only to the phenological stages of wheat growth but also to soil climatic conditions. Positive interactions have been demonstrated between plants, organic amendment and rhizosphere organisms with their heterogeneity.