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Excessive boron (B) can pose toxicity to many plant species, and consequently restricts land utilization in B-laden regions. The purpose of this study was to identify “agretti” (Salsola soda) as an alternative B-tolerant food crop. Both pot and hydroponic experiments were conducted for measuring biomass, total phenolic content and B absorption of S. soda exposed to varied B treatments. Mineral element accumulation in S. soda growing in pots was also determined. No typical B toxicity symptoms were observed in pot experiment, and only slight B toxicity symptoms were observed in hydroponically-grown plants at 50, 100 and 200 mg B L−1 treatments. Biomass production was not affected in either experiment. The response of total phenolic content to B exposure varied with growing medium, parts of tissues, B treatments, and exposure times. Boron predominantly accumulated in leaves and increased with increasing B treatments in both experiments. Increased exposure time increased the transport of B from root to shoot. Increasing B treatment generally reduced the accumulation of phosphorus, manganese, selenium and arsenic, but increased the accumulation of B, molybdenum and cadmium in S. soda under specific B treatments, even the accumulation of such elements was still safe for human consumption. S. soda appears to be a promising alternative crop to grow in B-laden regions such as the western SJV of Central California.

Intensive agriculture and meat-based westernized diets have brought a heavy environmental burden to the planet. Legumes, or pulses, are members of the large Fabaceae (Leguminosae) family, which comprise about 5% of all plant species. They are ancient crops whose popularity both for farmers and consumers has gonethrough several stages of acceptance, and in recent years, legumes have regained their luster. This is due to a global understanding that: (1) farming systems need to promote biodiversity, (2) biological nitrogen fixation is an important tool to reduce the application of external chemical inputs, namely in the form of nitrogen fertil- izers, and that (3) plant-based foods have fewer adverse environmental effects per unit weight, per serving, per unit of energy, or per protein weight than do animal source foods, across various environmental indicators. Legumes play a key role in answering these three global challenges and are pivotal actors in the diversification and sustainable intensification of agriculture, particularly in light of new and urgent challenges such as climate change. In this chapter, we showcase the importance of legumes as contemporary agents of change, whose impacts start in the field, but then branch out into competitive global economies, modernized societies, and ultimately, improved food security and human health.

Intensive agriculture and meat-based westernized diets have brought a heavy environmental burden to the planet. Legumes, or pulses, are members of the large Fabaceae (Leguminosae) family, which comprise about 5% of all plant species. They are ancient crops whose popularity both for farmers and consumers has gone through several stages of acceptance, and in recent years, legumes have regained their luster. This is due to a global understanding that: (1) farming systems need to promote biodiversity, (2) biological nitrogen fixation is an important tool to reduce the application of external chemical inputs, namely in the form of nitrogen fertilizers, and that (3) plant-based foods have fewer adverse environmental effects per unit weight, per serving, per unit of energy, or per protein weight than do animal source foods, across various environmental indicators. Legumes play a key role in answering these three global challenges and are pivotal actors in the diversification and sustainable intensification of agriculture, particularly in light of new and urgent challenges such as climate change. In this chapter, we showcase the importance of legumes as contemporary agents of change, whose impacts start in the field, but then branch out into competitive global economies, modernized societies, and ultimately, improved food security and human health.

Sustainable agricultural practices are needed to face current threats to agricultural production in areas where water scarcity, recurrent droughts, and decreased soil quality are endangering productivity and food security. Deficit irrigation (DI) practices consist of reducing irrigation applied at levels below full crop evapotranspiration losses throughout the growing season or at specific phenological stages of the specific crop. The goal of our study was to evaluate the physiological response of table grapes subjected to DI relative to fruit quality. DI treatments were developed as a percentage of the grower practice (evapotranspiration losses are fully replenished by irrigation) on commercial fields of table grapes in central California. DI practices began in 2011 and were continued throughout 2015. Grape berries were analyzed for mineral elements, berry weight, diameter and firmness, carbon and nitrogen content, pH, soluble solids, and total phenolic compounds. RESULTS In this study, DI practices in all treatments did not significantly increase or decrease nutraceutical compounds in grape berry and measured physiological responses to DI were mixed, with significant variation between years. CONCLUSIONS This study showed that DI practices could be safely used in dry areas for at least four years without affecting the nutritional quality of grape berry in ?Crimson seedless? and ?Sugraone?. ? 2018 Society of Chemical Industry

In arid regions, saline soils naturally rich in trace elements require identifying new crops and implementing management strategies for sustaining crop production and protecting water quality. Poor quality water produced from such soils can be utilized to grow specialty crops that are specifically selected for tolerance to high salt and B, such as pomegranates. The goal of this study was to evaluate the physiological responses related to nutritional quality in fruit from 1-year-old pomegranate trees irrigated for 3 years with typical poor quality water (i.e., that found in the western San Joaquin Valley, CA) containing high salinity (ranging from 3 to 9 dS m−1), Se (0.25 mg Se L−1) and B (4 mg B L−1) in a micro-plot tile system where the root system was laterally confined. This study shows that the young pomegranate trees tolerated irrigation with poor water quality containing high salinity, Se and B for 3 years. Under these treatments and growing conditions, fruit were smaller but contained higher concentrations of phenolic compounds than the same variety of pomegranates grown under unconfined root system and irrigated with good quality water. The juice produced from fruit collected from these trees contained Se (up to 0.24 mg L−1), as well as high concentrations of nutrients, including antioxidant phenolic compounds. The production of nutrient-enriched pomegranate fruit and juice may represent higher market value crop products using the poor quality water as a source of irrigation.

Sustainable agricultural practices are needed to face current threats to agricultural production in areas where water scarcity, recurrent droughts, and decreased soil quality are endangering productivity and food security. Deficit irrigation (DI) practices consist of reducing irrigation applied at levels below full crop evapotranspiration losses throughout the growing season or at specific phenological stages of the specific crop. The goal of our study was to evaluate the physiological response of table grapes subjected to DI relative to fruit quality. DI treatments were developed as a percentage of the grower practice (evapotranspiration losses are fully replenished by irrigation) on commercial fields of table grapes in central California. DI practices began in 2011 and were continued throughout 2015. Grape berries were analyzed for mineral elements, berry weight, diameter and firmness, carbon and nitrogen content, pH, soluble solids, and total phenolic compounds.In this study, DI practices in all treatments did not significantly increase or decrease nutraceutical compounds in grape berry and measured physiological responses to DI were mixed, with significant variation between years.This study showed that DI practices could be safely used in dry areas for at least four years without affecting the nutritional quality of grape berry in 'Crimson seedless' and 'Sugraone'. © 2018 Society of Chemical Industry.

Plant and Soil, 284 (1-2), ISSN:0032-079X, ISSN:1573-5036

Urbanization, industrial development, and intensive agriculture have caused soil contamination and land degradation in many areas of the world. Salinization is one important factor contributing to land degradation and it affects agricultural production and environmental quality. When salinization is combined with soil pollution by trace elements, as it occurs in many arid and semi-arid regions around the world, strategies to phyto-manage pollutants and sustain crop production need to be implemented. In this study, we present the case of saline soils in the West side of Central California which contain naturally-occurring selenium (Se), boron (B), and other salts, such as NaCl, CaCl2, Na2SO4, and Na2SeO4. To sustain crop production on Se- and B-laden arid saline soils, we investigated the potential of the halophyte "agretti" (Salsola soda L.) as an alternative crop. The aim of our greenhouse study was to examine adaptability, B tolerance, and Se accumulation by S. soda grown on soils collected from a typical saline-laden field site located on the West side of the San Joaquin Valley (SJV). Our results showed that S. soda tolerates the saline (EC ∼ 10 dS m(-1)) and B-laden soils (10 mg B L(-1)) of the SJV even with the additional irrigation of saline and B rich water (EC ∼ 3 dS m(-1) and 4 mg B L(-1)). Under these growing conditions, the plant can accumulate high concentrations of Na (80 g Na kg(-1) DW), B (100 mg B kg(-1) DW), and Se (3-4 mg Se kg(-1) DW) without showing toxicity symptoms. Hence, S. soda showed promising potential as a plant species that can be grown in B-laden saline soils and accumulate and potentially manage excessive soluble Se and B in soil.

Improved approaches are needed to assess bioavailability of hydrophobic organic compounds in contaminated soils. Performance of thin-film solid-phase extraction (TF-SPE) using vials coated with ethylene vinyl acetate was compared to earthworm bioassay (Lumbricus terrestris). A DDT and dieldrin contaminated soil was amended with four organic carbon materials to assess the change in bioavailability. Addition of organic carbon significantly lowered bioavailability for all compounds except for 4,4'-DDT. Equilibrium concentrations of compounds in the polymer were correlated with uptake by earthworms after 48d exposure (R(2) = 0.97; p 0.001), indicating TF-SPE provided an accurate uptake simulation. Bioavailability of residues in soil was compared with a spiked soil aged for 90d in laboratory. Dieldrin and DDX were respectively 18% and 11% less bioavailable in contaminated soil relative to spiked soil despite40yr of aging. Results show that TF-SPE can be useful in examining potential risks associated with contaminated soils and to test effectiveness of remediation efforts.

An improved understanding of the Ni root-to-shoot translocation mechanism in hyperaccumulators is necessary to increase Ni uptake efficiency for phytoextraction technologies. It has been presumed that an important aspect of Ni translocation and storage involves chelation with organic ligands. It has been reported that exposing several Ni hyperaccumulator species of Alyssum to Ni elicited a large increase in the histidine level of the xylem sap. In later studies it was shown that as time progressed the histidine:Ni ratio dropped considerably. Moreover, previous studies analyzed the relationship between Ni and ligands in plants that were exposed to Ni only for a few hours and therefore obtained results that are unlikely to represent field soils where plants are at steady-state Ni uptake. The aim of this study was to understand the quantitative relationship between Ni and organic ligands in the xylem sap of various Alyssum genotypes or species that reached steady-state Ni uptake after being exposed to Ni in either nutrient solution or serpentine soil for up to 6 weeks. Total Ni concentration, 17 amino acids, 9 organic acids, and nicotianamine were measured in xylem sap of 100-day old plants of Alyssum. Results showed that the concentration of Ni in xylem sap of various Alyssum genotypes was 10–100 fold higher than the concentration of histidine, malate, citrate, and nicotianamine, which were the predominant Ni ligands measured in the sap. When the physiology of the whole plant is taken into account, our results indicate that the concentration of organic chelators is too low to account for the complexation of all the Ni present in the xylem sap of Alyssum at steady-state Ni hyperaccumulation, and suggest that most of the Ni in xylem sap of this species is present as the hydrated cation.

This study assessed potential bioaccumulation of various trace elements in grasses and earthworms as a consequence of soil incorporation of organic amendments for in situ remediation of an orchard field soil contaminated with organochlorine and Pb pesticide residues. In this experiment, four organic amendments of differing total organic carbon content and quality (two types of composted manure, composted biosolids, and biochar) were added to a contaminated orchard field soil, planted with two types of grasses, and tested for their ability to reduce bioaccumulation of organochlorine pesticides and metals in earthworms. The experiment was carried out in 4-L soil microcosms in a controlled environment for 90 days. After 45 days of orchardgrass or perennial ryegrass growth, Lumbricus terrestris L. were introduced to the microcosms and exposed to the experimental soils for 45 days before the experiment was ended. Total trace element concentrations in the added organic amendments were below recommended safe levels and their phytoavailablity and earthworm availability remained low during a 90-day bioremediation study. At the end of the experiment, total tissue concentrations of Cu, Cd, Mn, Pb, and Zn in earthworms and grasses were below recommended safe levels. Total concentrations of Pb in test soil were similar to maximum background levels of Pb recorded in soils in the Eastern USA (100 mg kg−1 d.w.) because of previous application of orchard pesticides. Addition of aged dairy manure compost and presence of grasses was effective in reducing the accumulation of soil-derived Pb in earthworms, thus reducing the risk of soil Pb entry into wildlife food chains.

Recent studies have shown that application of phytohormones to shoots of Alyssum murale increased biomass production but did not increase Ni shoot concentration. Increased biomass and Ni phytoextraction efficiency is useful to achieve economically viable phytomining. The objective of this study was to evaluate the effect of two types of phytohormones on the Ni phytoextraction capacity of four Alyssum species. Two different commercially available phytohormones (Cytokin and Promalin) based on cytokinins and/or gibberellins were applied on shoot biomass of four Ni hyperaccumulating Alyssum species (A. corsicum, A. malacitanum, A. murale, and A. pintodasilvae). Cytokin was applied in two concentrations and promalin in one concentration. The application of phytohormones had no clear positive effect on biomass production, Ni accumulation and Ni phytoextraction efficiency in the studied Alyssum species. A. malacitanum was the only species in which a significantly negative effect of these treatments was observed (in Ni uptake). A slightly positive response to promalin treatment was observed in the biomass production and Ni phytoextraction efficiency of A. corsicum. Although this effect was not significant it does indicate a potential application of these approaches to improve phytoextraction ability. Further studies will be needed to identify the most adequate phytohormone treatment as well as the appropriate concentrations and application times.

Aims Past studies have demonstrated that hyperaccumulators absorb Ni from the same labile pools in soil as normal plant species. This study investigated whether the Ni hyperaccumulator plant Alyssum corsicum possesses distinct extraction mechanisms for different Ni species present in soils. Different Ni species have different solubilities and potential bioavailabilities to roots.

Hyperaccumulator species of the genera Alyssum can accumulate 100 times more Ni than normal crops and are therefore used for phytomining and phytoextraction of nickel contaminated soils. Basic studies on the physiology and metal uptake mechanisms of these plants are needed to increase efficiency and uptake capacity of Nickel (Ni) by hyperaccumulators. Recent attempts to disclose if those hyperaccumulator species require higher Ni level than normal plants failed because of the high Ni content in the seeds (7000-9000 microg g(-1)). In this study, we attempted to use chelator buffered nutrient solution to deplete Ni from the seed/seed coat and to obtain low Ni seedlings of Alyssum cultivars to be used in physiology studies. HEDTA-buffered nutrient solution did not deplete Ni from the seeds, perhaps because Ni was mainly localized within the seedling embryonic tissues with greatest Ni enrichment in the cotyledons and hypocotyls. We could not observe any positive correlation between seed fitness and germination capacity with seed Ni content. Investigation of nickel localization in Alyssum seeds using synchrotron X-ray microfluorescence (micro-SXRF) showed that nickel is localized in the embryonic tissues with greatest Ni enrichment observed in the cotyledons and hypocotyl.

To determine if the Ni-hyperaccumulator Alyssum corsicum can absorb Ni from the kinetically inert crystalline mineral NiO(s) (bunsenite). A. corsicum and A. montanum plants were grown for 30 days in a serpentine Hoagland solution. NiO was provided at 0 or 0.1 g L−1 (1.34 mmol L−1) as reagent grade NiO particles

Performance of compost and biochar amendments for in situ risk mitigation of aged DDT, DDE and dieldrin residues in an old orchard soil was examined. The change in bioavailability of pesticide residues to Lumbricus terrestris L. relative to the unamended control soil was assessed using 4-L soil microcosms with and without plant cover in a 48-day experiment. The use of aged dairy manure compost and biosolids compost was found to be effective, especially in the planted treatments, at lowering the bioavailability factor (BAF) by 18-39%; however, BAF results for DDT in the unplanted soil treatments were unaffected or increased. The pine chip biochar utilized in this experiment was ineffective at lower the BAF of pesticides in the soil. The US EPA Soil Screening Level approach was used with our measured values. Addition of 10% of the aged dairy manure compost reduced the average hazard quotient values to below 1.0 for DDT + DDE and dieldrin. Results indicate this sustainable approach is appropriate to minimize risks to wildlife in areas of marginal organochlorine pesticide contamination. Application of this remediation approach has potential for use internationally in areas where historical pesticide contamination of soils remains a threat to wildlife populations.

Trace elements (TEs) occur at minor concentration (>1 g kg−1) in the organisms, and some are essential nutrients (Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, B, and Cl) for animals and plants. As a consequence of human activities such as industrial production, mining, transport, and agriculture, they are released in the environment at high concentrations. TEs can accumulate over time under specific environmental conditions, thus becoming environmental contaminants (Cs, Cr, W, U, Cd, Hg, Tl, Pb, Sn, As, Sb, Se). The environmental risk of TEs is associated with the mobility and bioavailability of the metals more than their total concentration. When they become environmentally mobile and move between media (i.e. soil to water), they can enter the food chain by being taken up by plants and animals. TEs cannot be degraded or broken down and at high concentration are toxic to organisms and tend to bioaccumulate in the environment. For example, selenium (Se) is a naturally occurring element with a wide distribution in almost all parent materials on Earth. At low concentration, Se is an essential nutrient but at high concentration is toxic. In the western side of the San Joaquin Valley in California, soils contain significant quantities of soluble mineral salts and trace elements such as Se and boron (B) that have been leached into shallow groundwater and/or drainage waters because of irrigation practices at Kesterson Reservoir in California. Soluble Se bioaccumulated in the avian food chain and resulted in an environmental disaster with high mortality and reproduction failure of migratory birds (Letey et al. 2002; Ohlendorf et al. 1986).

Nickel (Ni) is essential for all plants due to its role in urease activation. Demonstration of Ni essentiality has required exceptional effort to purify nutrient solutions to remove Ni; thus, an improved technique would make study of Ni deficiency more available to diverse researchers. As part of our research on Ni hyperaccumulation by plants, we developed chelator-buffered nutrient solutions with very low buffered activity of free Ni2+, and tested growth of Alyssum murale (Goldentuft Madwort), A. corsicum (Madwort), A. montanum (Mountain Alyssum) and Lycopersicon esculentum (Tomato). We used a modified Hoagland nutrient solution with 2 mM Mg and 1 mM Ca to simulate serpentine soil solutions. We could use hydroxyethyl-ethylene-diaminetriacetate (HEDTA) to achieve Ni2+ activity levels as low as 10-16 M, and cyclohexane-ethylenediamine-tetraacetate (CDTA) to supply higher activities of buffered Ni2+ compared with HEDTA; however, we were unable to obtain proof of induced Ni-deficiency, even with ure...

International audience; This paper describes work carried out within the EU-funded FOOTPRINT project to characterize the diversity of European agricultural and environmental conditions with respect to parameters which most influence the environmental fate of pesticides. Pan-European datasets for soils, climate, land cover and cropping were intersected, using GIS, to identify the full range of unique combinations of climate, soil and crop types which characterize European agriculture. The resulting FOOTPRINT European agro-environmental dataset constitutes a large number of polygons (approximately 1,700,000) with attribute data files for i) area fractions of annual crops related to each arable-type polygon (as an indicator of its probability of occurrence); and, ii) area fractions of each soil type in each polygon (as an indicator of its probability of occurrence). A total of 25,044 unique combinations of climate zones, agricultural land cover classes, administrative units and soil map units were identified. The same soil/crop combinations occur in many polygons which have the same climate while the fractions of the soils and arable crops are different. The number of unique combinations of climate, soil and agricultural land cover class is therefore only 7961. 26-year daily meteorological data, soil profile characteristics and crop management features were associated with each unique combination. The agro-environmental scenarios developed can be used to underpin the parameterization of environmental fate models for pesticides and should also have relevance for other agricultural pollutants. The implications for the improvement and further development of risk assessment procedures for pesticides are discussed.

International audience; The radiological impact of radionuclides released to the terrestrial environment is usually predicted with mathematical models in which the transfer of radionuclides from soil to the plant is described with the transfer factor (TF). This paper questions the validity of the protocols proposed by the International Atomic Energy Agency to measure TF in the field and in greenhouses conditions. We grew maize (Zea mays L.) both in the field after a surface application of radionuclides ([54]Mn, Co, [65]Zn, and [134]Cs) and in a greenhouse with the same soil that has received the same fertilization and that had been previously sieved and homogeneously labeled with the same radionuclides before being repacked in pots. The analysis of the displacement of radionuclides in the field soil profile showed a higher concentration of the surface-applied radionuclides in the preferential flow path (PFP) in comparison to the soil matrix indicating that they infiltrated heterogeneously in the soil profile due to the structure-induced nonuniform water flow. A significantly higher recovery of [57]Co and [134]Cs was observed in the plants grown in the field soil, whereas no differences in the recovery of [54]Mn and Zn between the two experiments were detected. These results suggest that (i) under field conditions the soil-to-plant transfer of radionuclides that co-exist as stable elements present at low concentrations in the soil and in the plant is higher than that measured under greenhouse conditions and (ii) the implicit assumption made when calculating the TF (that radionuclides are homogeneously distributed in the soil profile) is not valid, thereby preventing the calculation of an average concentration to obtain the TF parameter.