Lactuca sativa growth in compacted and non-compacted semi-arid alkaline soil under phosphate fertilizer treatment and cadmium contamination

Abstract

Soil compaction is known to drastically modify soil properties and hence to affect both plants growth and metals distribution in the soil. Phosphate amendment is generally used to improve plants production but unfortunately it also gives rise to higher metal contamination in soils and plants. In this study, the effects of various parameters on the growth of Lactuca sativa including soil density, phosphate fertilization and cadmium contamination, were investigated. In particular, the migration of cadmium in the soil columns, its accumulation and translocation in lettuces were also examined. Lactuca sativa was selected as a model plant because it is widely cultivated in alkaline clay soils of eastern Mediterranean countries. Two levels of soil compaction (1.2 and 1.4 g.cm-3), two rates of P amendment (0 and 109 mg P.kg-1), and two levels of Cd contamination (0 and 84 mg Cd.kg-1) were used in 24 model columns with a factorial randomized block experimental design. Soil compaction increased considerably both leaf area and dry weight of roots and shoots, whereas both chlorophyll content and NRA decreased. For the two soil bulk densities, the phosphate fertilizer improved lettuce growth characterized by plant height, dry matter, leaf number and NRA, whereas Cd contamination altered those parameters and increased the chlorophyll content. In soils contaminated with cadmium, the combination of compaction and phosphate fertilization resulted in a significant decrease in Cd migration along the soil columns. Cd uptake by plants increased in Cd treated soils; its accumulation was found to be more important than in plants grown in P-Cd treated soil where Cd uptake was clearly reduced in shoots and roots.

Bioabsorption and Bioaccumulation of Cadmium in the Straw and Grain of Maize (Zea mays L.) in Growing Soils Contaminated with Cadmium in Different Environment

“…Mean TF in the present study (3.26) is higher than the results reported by Liu et al [ 36 ], which could be mainly influenced by soil pH in that study (pH between 8.31 and 9.06) and generate decreased Cd availability to the soil solution; this differs from the pH in the present study, which fluctuated between 5.74 and 8.25 ( Table 1 ). The observed TF values in the present study (TF > 1) ( Table 6 ) concur with results mentioned by other authors, who indicate TF values of 2.6 [ 33 ]. These results could classify these cultivars as plants with high Cd translocation efficiency from the roots to the aerial part [ 32 ].…”

“…The translocation factor (TF) or mobilization ratio determines the relative displacement of Cd from the concentration of the plant part in the soil (root) toward the aerial parts of the plant (grain and straw). It is calculated by the following equations [ 33 ]: TF grain = C grain /C root TF straw = C straw /C root where C grain , C straw , and C root are the Cd concentrations in the grain, straw, and root, respectively.…”

Early Toxic Effects of Cd²⁺ on Photosynthetic Activity of Six Freshwater Algae Species

“…The accumulated energy was then dissipated in the forms of heat and/or fluorescence, displaying enhanced fluorescent intensity, which might affect the determination of chlorophyll fluorescent parameters [39]. Second, treatments with low concentrations of Cd 2+ have been reported to increase chlorophyll content in Lolium multiflorum [40] and Lactuca sativa [41]. Accumulation of chlorophyll should also increase the chlorophyll fluorescent parameters.…”

Nickel, Copper, Zinc and Cadmium Fractionation in Mangrove Sediments, Red Sea, Egypt

“…Significant correlations (P < 0.02) have been found between P and Ni (r = 0.82), Cu (r = 0.88), Zn (r = 0.78), Cd (r = 0.79), Fe (r = 0.93) and Co (r = 0.94) concentrations in both sites suggesting that the main source of these elements may be derived from a geogenic source (rock phosphate) or rock phosphate behave as adsorptive agent (Azzi et al, 2017). Although multi (Table 1).…”