## 4 Discussion
The authors, based on mathematical models related to ECE--electrical conductivity (EC) of saturated paste extract of soil and EC--electrical conductivity (EC) of irrigation water, divided 19 vegetables and crops into four categories: Sensitive, moderately sensitive, moderately tolerant, or tolerant to soil salt content. Out of 19 vegetables and crops, considered by the two authors in their analysis, six were sensitive, ten moderately sensitive, two moderately tolerant, and only one tolerant. Based on this analysis, for instance, asparagus was tolerant, red beet was moderately tolerant, tomato was moderately sensitive, and beans were sensitive. In the last decades researchers focused their attention on the possibility that organic amendments, including compost, could cope with the damaging effects of soil salinity on crops and vegetables. [PERSON] and [PERSON] [37] recently summarized the positive effect of compost on physical-chemical and biological soil characteristics and restoration of crop productivity. In our experiment we observed how compost soil amendment was able to cope with the detrimental effect, on the seedlings of all four tested crops (maize, tomato, sunflower, and quinoa), caused by the salty water irrigation, which increased the EC, and soil salt concentration up to 20 dS m\({}^{-1}\) and 0.135 M, respectively. These values of EC and salt concentration are well known to usually cause reduction of growth, biomass, and yield to crops and vegetables [7], which are considered, except quinoa, glycopytes. The data we collected for tomato confirmed the analysis of [PERSON] and [PERSON], who considered this vegetable as moderately sensitive. However, compost amendment partly counteracted the negative effects of high salt soil content, in fact CC150 and CC300 showed a considerably greater organ biomass when compared to C group, and no substantial differences for stem length and diameter also when compared with CC group. Seedlings of sunflower and maize C and CC groups did not show any significant difference in the case of the stem length, however their diameter increased significantly when compost was added to the soils, as well as all the other treated crops, suggesting that the seedlings of the C group of sunflower and maize were more streamlined respect to those amended with compost. Stem length and diameter were significantly reduced in almost all treatments CC300, except for stem length in the quinoa group. The dry biomass of the three organs (roots, stems and leaves) increased in all CC groups when compared to the C group (control), while a slight or null decrease when the glycopytes crops were treated with NaCl 150 mM. It is probable that compost reduces the stress effect due to salt water irrigation. However, soil irrigation with NaCl 300 mM had, in general, a statistically significant effect on all the glycopytes, in particular on maize, which resulted to be the most sensitive one to NaCl treatments, and in particular to that of 300 mM; in fact, in this case (CC300) all seedlings were dead at the end of the experiment. [PERSON] et al., has recently shown [38] that compost addition to a sodic soil improved quality, increasing nutrient uptake and stimulating its chemical properties. The resilience and growth promotion in wheat seedlings were attributed by the authors to a significant improvement in the relative water, chlorophyll, K+ leaf content, and, contemporary, to a reduction of the oxidative stress due to a more limited activities of the involved in the response to abiotic stresses enzymes (e.g., SOD, APX, etc. ), and to the expression of the corresponding genes (_CAT_, _APX_, and _MnSOD_). In our experiment a quite similar situation was observed for the four assayed crops; their increased resilience to high soil EC was most likely due to the same kind of stress response that [PERSON] and co-workers showed in the case of wheat.