Plant tolerance to soil salinity in the conception of the Iaşi School of Soil Science

Abstract

The paper represents a synthesis of the research carried out by the Soil Science Department within the Agronomical University of Iasi concerning the tolerance of cultivated plants to soil salinity in non-irrigated agriculture. Salt tolerance was established by analysing the decrease in crop yield for each kind of plants, with the increase of soil salinity in layer roots. The experiments were conducted on 22 grass species and numerous hybrids, 28 grape cultivars and seven fruit-tree species. In each case, the following tolerance coefficients were established: 1. The sensitivity threshold for an excess of soluble salts, Cl-, SO4 2-, pH level; 2. The plant-drying threshold; 3. The tolerance interval; 4. The relative agronomical tolerance; 5. The yield decrease (in %) for a total salt increase unit (10 mg ss). Finally, the species were grouped in four categories depending on the coefficients of tolerance to soil salinity, as follows: a) tolerant; b) moderately tolerant; c) moderately sensitive and d) very sensitive (table 2 and 4).