Some agricultural soils in North America are lead (Pb)-enriched as a result of the application of lead arsenate (PbHAsO4) insecticide. A controlled-environment experiment was conducted with Pb-enriched Canning soil series in Nova Scotia, Canada, to evaluate the remediation potential of 10 plant species in combination with the fungicide benomyl applied as a soil drench to suppress mycorrhizae. Overall, the highest biomass was provided by yellow poppy followed by Indian mustard and thorn apple. The application of benomyl increased Pb concentration in thorn apple tissue but not in the other crops. The phytoremediation potential (Pb removal with the harvested biomass) was higher with clary sage, alyssum, garden sage, and Indian mustard with benomyl treatments and lower in the Swiss chard, thorn apple without benomyl, and in the geranium with benomyl treatments. The results suggest that some plants can be used for phytoremediation of mildly Pb-contaminated soils.
Valtcho D. Zheljazkov and Tess Astatkie
S.J. Locascio and G.J. Hochmuth
Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] were grown with three rates each of lime, gypsum, and K during two seasons to evaluate their effects on fruit production and mineral concentration. The first experimental site was a recently cleared Sparr fine sand with an initial water pH of 5.0 and Mehlich I extractable K of 8 mg·kg-1 (very low) and 20 mg·kg-1 Ca (very low). The second site was a virgin Pomona fine sand with a water pH of 4.8, 28 mg·kg-1 K (low), and 612 mg·kg-1 Ca (high). `Crimson Sweet' fruit yields were reduced 10% with an increase in lime rate from 0 to 4.48 t·ha-1 in the first season. In the second season, lime rate had no effect on yield. In both seasons, fruit yields were reduced 14% with an increase in Ca from gypsum from 0 to 1.12 t·ha-1. On the soil testing very low in K, yield increased with an increase in K rate from 90 to 224 kg·ha-1 with no lime or gypsum. On the soil testing low in K, greatest yields were obtained with 90 kg·ha-1 K with no lime and gypsum. Application of lime and gypsum increased Ca and decreased K in seedlings but not consistently in older leaf and fruit tissues. An increase in K application increased leaf K in the first season but not in the second. Fruit firmness and soluble solids content were not consistently affected by treatment during the two seasons. Thus, on soils low in toxic elements (Mn and Al) such as used in this study, watermelon will grow well and tolerate a wide range of soil pH values without additional Ca from lime or gypsum.
Mondher Bouden and Jacques-Andre Rioux
The richness of the organic residues in certain fertilizing elements justifies their valorization in horticulture. However, their contents in pathogenic and toxic elements can restrict their use. In this context, this study was conducted in order to evaluate the effect of three organic residues on the environmental medium and the risks of water contamination by the release of heavy metals. Physocarpus opulifolius `Nanus' was transplanted into four substrates. The control substrate contained 4 peatmoss: 5 composted conifer bark: 1 fine crushed gravel (by volume). The three other substrates (25% of peatmoss was substituted by organic residue) contained 10% of fresh bio-filters (FBF), 10% of composted sewage sludges (CSS), or 10% of de-inking sludges (CDS). The pots (5l) were placed in plastic vats and the drainage water was recovered in vessels (17l). The experimental design was in complete blocks with six replications. Samples of the drainage water were collected every 2 weeks for analysis. The pots were fertilized every week (400 mg/Ll of N) and growth parameters were statistically analyzed by ANOVA. The chemical analysis of the residues proves that they contain weak concentrations in organic contaminants. There is an accumulation of
Meredith V. Melendez, Joseph R. Heckman, Stephanie Murphy, and Frank D’Amico
/2. Woods End Lab, Mount Vernon, ME Davis, R.D. Beckett, P.H.T. 1978 Upper critical levels of toxic elements in plants New Phytol. 80 23 32 Evans, I. Solberg, E. Huber, D. 2007 Mineral nutrition and plant disease. APS Press, St. Paul, MN He, Z. Endale, D
Ida Di Mola, Youssef Rouphael, Giuseppe Colla, Massimo Fagnano, Roberta Paradiso, and Mauro Mori
concentration in the irrigation water. The reduction in photosynthetic capacity in response to salinity could be correlated to the accumulation of toxic elements Na or Cl in leaf tissues as observed previously in several vegetable crops ( Colla et al., 2012
Lisa E. Richardson-Calfee, J. Roger Harris, Robert H. Jones, and Jody K. Fanelli
quality (e.g., nutrient, water, and oxygen availability, soil temperature, toxic elements, and fungal/microbial populations). Plasticity in the response of root turnover rates to changes in soil environment may be considered a fitness attribute because
Jehanzeb Khan, Yubin Yang, Qiang Fu, Weiqiang Shao, Jianke Wang, Li Shen, Yan Huai, Guy Kateta Malangisha, Abid Ali, Ahmed Mahmoud, Yi Lin, Yongyuan Ren, Jinghua Yang, Zhongyuan Hu, and Mingfang Zhang
Radziemska, M. Bęś, A. Gusiatin, Z.M. Majewski, G. Mazur, Z. Bilgin, A. Jaskulska, I. Brtnický, M. 2020 Immobilization of potentially toxic elements (PTE) by mineral-based amendments: Remediation of contaminated soils in post-industrial sites Minerals 10 87