Evaluation spatiale et temporelle de la salinité dans une parcelle agricole dans la plaine de la Mina (W. Relizane).

Abstract

Knowledge of the spatial distribution of soil salinity and its evolution over time becomes necessary in order to arrive at strategie for sustainable agricultural development. The conventional method of determining salinity by measuring the electrical conductivity of an extract of soil saturated (CEps) remains difficult because of the great spatial variability of the salt contents from one point to another, which makes this method laborious. As an alternative solution, electromagnetic induction (EM38) can be used to facilitate rapid measurement of soil salinity in situ. It is fast and allows a high density of measurement points. This spatial evolution of soil salinity by using this method on a representative plot of the Mina (Relizane) plains. A set of 64 measurement of electromagnetic conductivity (CEM) was performed on a regular 50*50 m grid with the EM38 instrument, while 17 samples were taken for CEps determination. Linear regression models were used to convert CEM values to CEps. kriging was used to extrapolate to non-sampled locations. The elaboration of the salinity map was based on these predicted values. The results showed two levels of soil salinity (saline and very saline). The saline profiles are descending. The statistical analysis of the results allowed us to establish regression equations because of significant correlations between the CEM of the studied soils on the one hand the CEps, the humidity and the organic matter on the otherhand.