method of evaluation of the carbon efficiency (ce) of soil microbial population in the presence of plant roots underground biomass and mineral nitrogen balances fall (mnc), and advocating the use of microorganisms reintroduced by inoculation to v aloriser the biomass.by processing data in an index of agronomic and soil carbon efficiency of the bacterial fraction (lac) (mic) of soil microflora, ecbac \/ ecmic, characterized in that it comprises the following steps.representative sample of the area or volume of soil will be incorporated into the biomass of plant origin.determination of nmr to determine, in the light of mnc, the ratio n: c (rbmic) trims.determination of the c \/ n ratio of the soil sample (rcnsol) to decide, on the basis of the ratio between the rcnsol fungal fraction (program) and bacterial (lac), soil (rfb).determination of the ratio of n: c (rbbac) as a function of rbmic we adjusted the rfb.determination of the fraction of ec (bac) ecbac) and mic (ecmic).determination of the efficiency index of carbon on ecbac \/ ecmic, lac, compared to that of icm.determination of the index ecbac \/ ecmic, and assessment of the index, compared with a critical value between the values of 0.90 and 0.95 and 1.00, indicating a good level of about 1.0 to efficiently use back by inoculating microorganisms developing such underground biomass of plant origin.Procédé dévaluation de lefficience carbonée (eC) des populations microbiennes du sol en présence de biomasses dorigines végétales souterraines et de reliquats automnaux dazote minéral (rNm), et de préconisation de lutilisation de microorganismes réintroduits par inoculation pouvant valoriser ces biomasses, par transformation de données agronomiques et pédologiques en un indice de lefficience carbonée relative de la fraction bactérienne (BAC) de la microflore (MIC) du sol, eCBAC/eCMIC, caractérisé en ce quil comprend les étapes suivantes échantillonnage représentatif de la zone ou du volume de sol dans lequel seront in
