It is widely recognized that agriculture is an important sector which ensure the human food and the existence of life. Food production depends on numerous factors, among which the technological level achieved and soil quality that is achieved that production (M. Nicolescu et al., 2008). With increasing of world population, under continuous reduction of productive agricultural area per inhabitant, the overall capacity of food production in agriculture will be under continued pressure (Lal, 1995). In the future, expansion of agriculture in areas not covered in culture is not possible, land is presented with a reduced fertility, and technical and economic performances are almost impossible. In many cases, anthropogenic degradation is increasing, representing a real threat to terrestrial ecosystems in balance. The concept of sustainability as an opportunity in agriculture, involving the choice for the future of those technologies to support the complex development of this area of activity (Elisabeta Dumitru et al., 2005). The ntroduction or removal from natural systems of additional quantities of energy and other artificial products can lead to their disruption, which requires that human activity to link with the natural ability to integrate them with beneficial effects for human and ecological balance. Concerning the above factors at SCDA Şimnic Craiova was initiated in 1965 the long-term experiments that have been pursued in addition to the influence of mineral and organic fertilization on the production and its quality but also the effects arising from the fertilization to the soil - the main means of production in agriculture - in terms of its development agro productive potential. In the present study we present results obtained in wheat production fall in the range 2005 - 2008 in the bi factorial experience (rotation x fertilization) and studied how these two factors have influenced the evolution of agro productive characteristics of the brown reddish soil. The A factor- rotation – has 5 levels: monoculture, rotation of 2 years wheat-corn, rotation of 3 years pea-wheat-corn, rotation of 4 years sunflower-wheat-corn-wheat in which wheat has two prior. The B factor B - agro fond - has 5 levels: unfertilized, N 100, P 60, N 100 P 60, and 20 t/ha manure. The work has generated a high degree of originality of results obtained on the evolution of wheat production achieved in different rotation, the best species are highlighted prior to this culture and also the analytical results of soil samples taken from each variant tested on agro productive changes to features of soil in the central area of Oltenia. Analyzing the bacterial micro flora (quantitative and qualitative aspects) in long-term experience on the effect of crop rotation and fertilization on wheat crops on the brown reddish soil were obtained increased total numbers of heterotrophic bacteria, indicating a strong effect at rizosphera level, with higher values in the monoculture of wheat, a situation due to large amount of plant debris left after wheat crops always heavier than the other hoeing crops.

wheat; rotation; fertilization; bacterial micro flora

Presentation: oral