DIAGNOSIS OF THE DIAZOTROPHE STATE OF ARABLE SOILS AND RECOMMENDATION OF N FERTILIZER CONTRIBUTIONS

摘要

Method for diagnosing the diazotrophic state of arable soils and advocating fertilization of the current crop comprising; ? only one autumn survey of the mineral nitrogen content (Nm) of the soil surface by soil sampling, without having to take the entire rooting zone and / or the vadose zone for analysis; ? an integral index consisting of a numerical sum indicative of the incidence of post - burial time units of soil cellulosic residues (RCsol) plus, or minus, favorable, as the case may be, to a maximum of diazotrophic activity ( Nif) soil bacteria; ? a recommendation concerning the rationing of the previously calculated dose X (dX). and four steps; (ix) determination of meteorology affecting the kinetics of Nm concentrations in the upper vadose zone of the soil by rainfall generation from monthly climatic averages, (x) followed by milli-molarity (mM) in Nm of the soil solution over time, advantageously following burial of RCsol as a function of the number of days post-burial (jpe), (xi) quantification of the negative feedback by Nm of the diazotrophy (Nif) of the bacterial flora of the soil in relation to its maximum activity according to the above-mentioned mM Nm of the soil solution, and (xii) integration over time (jpe) of the fraction of the diazotrophic activity (Nif) of the flora bacterial soil relative to its maximum when the mM of the Nm of the soil solution = 0.00.