Growth responses of crop and weed species to heavy metals in pot and field experiments

Abstract

Greenhouse and field studies were performed to examine the growth responses and possible phytoremediation capacity towards heavy metals of several Brassicaceae (Brassica alba, Brassica carinata, Brassica napus and Brassica nigra) and Poaceae (durum wheat and barley). Soils used featured total concentrations of Cr, Cu, Pb and Zn largely exceeding the maximum levels permitted by the Italian laws. Different organic amendments were tested such as a compost and the plant growth-promoting rhizobacterium Bacillus licheniformis. In the greenhouse experiment, plant length, leaf area index and shoots dry matter were evaluated periodically for the Brassicaceae examined. Whereas plant length, grains production, weight of 1,000 seeds, ear fertility and tiller density were determined under field conditions at the end of the crop cycle for wheat and barley. In general, the species tested appeared to be tolerant to high heavy metal concentrations in soil, and slightly significant differences were found for all parameters considered. A marked growth increase was shown to occur for Brassicaceae cultivated on compost- and bacillus-amended contaminated soils, with respect to non-amended contaminated soils. With some exception, higher growth parameters were measured for wheat and barley plants cropped from contaminated soils in comparison to non-contaminated soils. Further, bacillus amendment enhanced the length of wheat and barley plants in both non-contaminated and contaminated soils, while different effects were observed for the other parameters evaluated.

Heavy Metal Uptake by Herbs. IV. Influence of Soil pH on the Content of Heavy Metals in Valeriana officinalis L.

“…European and Polish domestic regulations are restricted to cadmium, lead, and chromium (WHO 2007 ; Pharmeuropa 2008 ; Regulation of the Minister of Health 2003 ) only. However, many other heavy metals also introduce plant stress, among which zinc, manganese, and copper are the most important (Cheng 2003 ; Farrag et al 2012 ).…”

“…Due to the varied bioavailability of heavy metals in soil, their concentration in herbs available on the market may vary significantly (Kalny et al 2007 ; Kandziora-Ciupa et al 2013 ). Heavy metal uptake by plants is a complex soil-plant process, influenced by many factors such as plant species, genotype, availability, and mobility of metals in soil, soil properties, and all the biogeochemical processes and the microbial activity, at the rhizosphere level, which influence metal mobility and availability to plants (Gębski 1998 ; Kabata-Pendias and Pendias 1999 ; Radanovic et al 2002 ; Sady and Smoleń 2004 ; Farrag et al 2012 ; Nadgórska-Socha et al 2013 ). The latter were studied in detail, and there is a common understanding reported in the literature that soil pH is the major factor influencing the mobility and bioavailability of heavy metals to plants (Cheng 2003 ; Domańska and Filipek 2011 ; Ginocchio et al 2002 ; Kukier et al 2004 ; Pikuła and Stępień 2007 ; Wang et al 2006 ).…”

A Pilot Study to Determine the Substrate Threshold for Heavy Metal Toxicity in Groundcover Plants Used in Urban Landscapes

“…Cd, Cr, and Ni have been found in contaminated urban soils (Lavado et al, 1998;Naz et al, 2015), as have Cu, Pb, and Zn (Kabala and Singh, 2001; Yoon et al, 2006). Therefore, it is necessary to identify plant species that are resistant to several different kinds of heavy metals, which are able to survive, grow, and reproduce by excluding or accumulating metals present at very high levels in the soil (Franiel and Babczyńska, 2011;Farrag et al, 2012). However, a limited amount of research has been dedicated to describing the behavior of plants capable of accumulating heavy metals in soils contaminated with a number of different metals.…”

Germination and Early Growth ofBrassica junceain Copper Mine Tailings Amended with Technosol and Compost

“…Composts are a common tool for remediating metal contaminated soils [ 9 , 10 ]. Modern management of waste has generated different types of composts, such as green compost from the agriculture sector, compost from household waste, or compost based on municipal sludge, among others [ 11 ].…”