Brett H Robinson

University of Canterbury | UC · Department of Chemistry

The land application of biosolids can result in the unacceptable accumulation of Trace Elements (TEs) in agricultural soil and potentially introduce xenobiotics and pathogens into the food chain. Phytoremediation of biosolids aims to minimize this risk, while producing valuable biomass. Willows, well known to accumulate zinc (Zn), are used extensiv...

Phytoextraction has been proposed in many papers as a low‐cost method for remediating contaminated soil. However, if national regulation is based on total metal(oid) concentrations in soil, phytoextraction is generally infeasible because of the long time required for remediation. Assessing phytoextraction requires the determination of the dynamic r...

Palm kernel expeller (PKE) is a biowaste by-product of palm oil processing in Southeast Asia that is exported as stock fodder. Global production of PKE totals 11M t yr−1, of which New Zealand imports 1.9M t yr−1, worth >USD 325M, most of which supports NZ’s dairy herd of 5.5M cows. We aimed to determine the concentrations of the chemical elements i...

Background Experimental work using pot trials and mesocosm studies has indicated that species combinations are more effective than single species mitigating the soil nutrient constraints that limit pasture productivity in New Zealand’s hill country, but there is little field evidence to support this.AimWe question whether coexistence of species pro...

Potentially, the restoration of native ecosystems could be combined with the land application of treated municipal wastewater (TMW), reducing TMW discharge into waterbodies. High levels of nutrients, pathogens, and other contaminants from TMW can degrade water quality. The land application of TMW onto native vegetation reduces the nutrient load in...

Rhizobial nitrogen fixation in legumes provides spillover benefits to neighbouring plants such as pasture grasses. Generally, it is understood to be unidirectional between plant functional groups, providing a benefit from legumes to grasses. We question whether bidirectional complementarity also exists in terms of exploiting the wider soil nutrient...

Background Experimental work using pot trials and mesocosm studies has indicated that species combinations are more effective in mitigating the soil nutrient constraints that limit pasture productivity in New Zealand’s hill country, but there is little field evidence to support this. Aim We question whether coexistence of species provides an opport...

Background Combinations of grasses and nitrogen-fixing legumes are ubiquitous in most natural and derived pastoral grasslands. This was not formerly the case in New Zealand’s unique indigenous grasslands that are now frequently impacted by exotic pasture grasses and legumes. Understanding the co-existence of native and exotic plants is the broad fo...

The aim of this study was to investigate the compatibility of plants with contrasting root systems, in terms of procurement of limiting soil nutrients. Paired combinations of species of proteas and grasses were grown in a pot experiment using soil from a site with impoverished vegetation and degraded soil. The soil contained sufficient N but was lo...

Annually, over 30 million dry tonnes of biosolids are produced worldwide, most of which are disposed into landfills or discharged into waterbodies, exacerbating eutrophication and water-borne diseases. Bioconversion of biosolids using Black Soldier Fly larvae (BSFL) can produce high-value biomass (protein, lipids, and chitin) while reducing the vol...

Exotic lumbricid earthworms have had some limited success colonising productive agricultural pastures in New Zealand, in place of native megascolecid species that did not adapt to the conversion from native vegetation cover. Native earthworms in lowland intensively-farmed landscapes are now almost entirely restricted to small fragments of native ve...

African oil palm (Elaeis guineensis) is grown on 17,000,000 hectares in Southeast Asia, producing oil and the by-product, palm kernel expeller (PKE), for export. Elaeis guineensis is typically produced on weathered acidic soils, with fertilisers and fungicides used to increase production. These amendments can contain elevated concentrations of trac...

Background Combination of grasses and nitrogen-fixing legumes are ubiquitous in most natural and derived pastoral grasslands. This was not formerly the case in New Zealand’s unique indigenous grasslands that are now frequently impacted by exotic pasture grasses and legumes. Understanding the co-existence of native and exotic plants is the broad foc...

Novel research has demonstrated that the roots of some bioactive plants-called pathogen phytoremediation plants-enhance die-off of pathogenic organisms in the soil. Strategic establishment of pathogen phytor-emediation plants may reduce the transport of human pathogens to water sources. Such plantings could be used in riparian margins, as buffer st...

Phytomanagement uses plants and soil conditioners to create value on contaminated land while minimizing environmental risk. This work was carried out on a metal(loid)-contaminated site and aimed at assessing the suitability of Salvia sclarea L. (sage) and Coriandrum sativum L. (coriander) combined with an arbuscular mycorrhizal fungus (AMF) inocula...

Acquiring soil hydrothermal information using process-based models is important for agricultural management in dry alpine regions where in situ data collection is difficult. However, few modeling studies have considered the soil airflow transport mechanism for arid regions especially, the presence of dry airflow in soil can affect water and heat tr...

Chinese wolfberry (Lycium barbarum L.) can efficiently ameliorate land deterioration and increase farmers’ incomes on the Tibetan Plateau. Therefore, it has been widely grown in this region in the past decades. The aims of this study were to clarify the patterns of water sources and water use efficiency under 3 management practices to determine the...

With the ever-increasing demand for lithium (Li) for portable energy storage devices, there is a global concern associated with environmental contamination of Li, via the production, use, and disposal of Li-containing products, including mobile phones and mood-stabilizing drugs. While geogenic Li is sparingly soluble, Li added to soil is one of the...

Soil properties in the foraging range of honeybees influence honey composition. We aimed to determine relationships between the antimicrobial properties of New Zealand mānuka (Leptospermum scoparium) honey and elemental concentrations in the honey, plants, and soils. We analyzed soils, plants, and fresh mānuka honey samples from the Wairarapa regio...

BACKGROUND Most countries set regulatory values for the total trace element (TE) concentrations in soil, but there is growing interest in using a risk‐based approach to evaluate the bioavailable TE using dilute salt extractants or other soil parameters, including pH and organic carbon. This study compares the current regulatory system (based on tot...

Dissolved organic matter (DOM) release from Cd contaminated soils been linked to mobilisation of the metal as Cd-DOM complexes and this may be exacerbated by organic matter-rich soil amendments. The quantity and quality of the DOM can determine the proportion of dissolved Cd that partitions to mobile complexes and their stability and, thus, the pot...

Thallium is a relatively toxic and valuable element, for which there are fast-growing hyperaccumulators that have the highest bioaccumulation coefficients (plant/soil concentration quotients) of any non-essential element. As with other elements, many Tl-hyperaccumulating plants are in the Brassicaceae family. In contrast, hyperaccumulation of the p...

We aim to understand the impact of ecological restoration on soil biogeochemistry, and the interrelationship between vegetation and soil phosphorus. In a study of two different-aged soils in coastal New Zealand, soils are described along a transition from abandoned agricultural pasture, through 6-year old restoration plots, towards forest fragments...

Phytoextraction endeavors to remove contaminants—e.g. metal(loid)s—from polluted soils through root uptake and accumulation in the harvested plant parts. Many articles propound phytoextraction as a low‐cost means of cleaning up such polluted soils. However, if legislation is based on total soil metal(loid)s, phytoextraction is generally infeasible...

Pteris vittata (PV) and Pteris quadriaurita (PQ) are reported to hyperaccumulate arsenic (As) when grown in As-rich soil. Yet, little is known about the impact of their unique As accumulation mechanisms on As transformations and cycling at the soil-root interface. Using a combined approach of two-dimensional (2D), sub-mm scale solute imaging of ars...

Although pesticides are widely used in agriculture, industry and households, they pose a risk to human health and ecosystems. Based on target organisms, the main types of pesticides are herbicides, insecticides and fungicides , of which herbicides accounted for 46% of the total pesticide usage worldwide. The movement of pesticides into water bodies...

The relative ease with which cadmium (Cd) in agricultural soils can transfer to crop plants can pose a potential health risk to consumers. However, efforts to predict and mitigate these risks are often confounded by the various factors that influence metal accumulation in the edible plant parts. The aim of this work was to identify key drivers that...

Compared to discharge into waterways, land application of treated municipal effluent (TME) can reduce the need for both inorganic fertilizers and irrigation. However, TME irrigation may result in the accumulation of phosphorus (P) or trace elements in soil, and increased salinity and sodicity, which could damage soil structure and reduce infiltrati...

Silver nanoparticles (AgNPs) from industrial use, discharged via the land application of sewage sludge, are interacting with soil biota, including earthworms. In affected organisms, excessive production of reactive oxygen species can result in lipid peroxidation, shifting the balance between oxidants and antioxidants to cause oxidative stress. We d...

The arsenic concentration is an important issue in compost production. The main inputs of a compost factory, including kerbsides, green wastes, food industry wastes, and river weeds are investigated in this study. Also, this study investigated how treated timbers, ashes, and other contamination can impact arsenic concentration in compost production...

Industrial activities, aging pipe infrastructure and other sources contribute to metal contamination in drinking water, an issue in many urban environments. To safeguard human health, the Ministry of Health (MoH) has maximum acceptable values for the concentrations of trace metals in drinking water supplied to New Zealand homes (DWSNZ, 2008). Conta...

The Loess Plateau of China is a major apple-cultivating region, but much of the Plateau is water-limited, and the expansion of apple-growing is putting pressure on soil water resources. Plants’ water consumption patterns have been intensively studied to facilitate formulation of robust agricultural strategies, but previous studies have generally ap...

Biowastes can enhance the establishment of New Zealand (NZ) native vegetation, particularly on degraded land, where biological or physicochemical deficiencies limit plant growth. We identified critical success factors influencing selection and use of biowastes for a) growing native plants and b) rehabilitating native ecosystems. These were: weed co...

Overview of progress to date on using innovative riparian restoration techniques in addition to ecological, environmental and soci-cultural indicators to improve water quality and ecosystem health in a degraded catchment

Iodine (I) is an essential trace element commonly deficient in agricultural systems. Whereas there is much information on I in food crops, there is a lacuna of knowledge on the environmental factors that affect pasture I concentrations. We aimed to identify the most important environmental factors affecting the concentration of I in New Zealand pas...

Restoring plants to the riparian zone is regarded as management best practice in river restoration and has the potential to reduce the impact of nitrogen (N) pollution on aquatic organisms and improve water quality for human use. Plant characteristics and the interplay of hydrology and biogeochemistry control N retention in the riparian zone. The b...

Wheat ( L.) grain is a contributing source of dietary Cd in New Zealand, but despite this, there is a dearth of information on Cd concentrations in wheat and the factors that affect uptake. We measured Cd concentrations in 12 wheat cultivars grown in field sites across New Zealand and also assessed the soil, plant, and crop factors that have been r...

Potatoes are a staple food in New Zealand and a contributing source of dietary cadmium (Cd), although there is little information nationally on the soil and plant factors that affect Cd concentrations in the crop. We measured Cd concentrations in 10 commercial potato cultivars grown in three field sites across New Zealand and assessed the soil fact...

Root foraging may increase plant nutrient acquisition at the cost of reducing the total volume of soil explored, thereby reducing the chance of the roots encountering additional patches. Patches in soil seldom contain just one nutrient: the patch may also have distinct textural, hydrological, and toxicological characteristics. We sought to determin...

Biowastes are unwanted materials of biological origin. They include biosolids, dairy shed effluent, and sawdust. When applied to soil, biowastes can provide plant nutrients, but also introduce heavy metals, pathogens, or xenobiotics. Biowastes could improve degraded or low-fertility soils and generate revenue through the production of non-food prod...

The rhizosphere is the volume of soil where the chemical (pH, redox potential, nutrient concentration and root exudates), physical (temperature, water availability and soil structure) and biological characteristics (microbial and fungal associations) are shaped by plant-microbe-soil interactions. Communications between roots and between soil microo...

Cadmium accumulates in soils that receive repeated applications of Cd-rich superphosphate fertilizers. There is evidence that adding clovers to a crop solubilizes soil Cd, increasing the bioavailability of Cd. This can lead to high plant Cd concentrations. This research aimed to test whether liming-induced increases in pH in mixed crops of clovers...

Gallium (Ga) and indium (In) are increasingly susceptible to soil contamination via disposal of electronic equipment. Chemically similar to aluminium (Al), these elements may be mobile and bioavailable under acidic conditions. We sought to determine extent and nature of Ga and In mobility in the soil - plant system and thus their potential to enter...

The accumulation of Cd in soils worldwide has increased the demand for methods to reduce the metal's plant bioavailability. Organic matter rich soil amendments have been shown to be effective in achieving this. However, it is not known how long these amendments can retain the Cd, and whether dissolved organic matter (DOM) released from them can enh...

Contamination of soil with lithium (Li) is likely to increase due to its wider dispersal in the environment, associated in particular, with the disposal of the now ubiquitous Li-ion batteries. There is, however, a paucity of information on the behaviour of Li in the soil-plant system. We measured the sorption of added Li to soil, and uptake of Li b...

Thallium is a highly toxic and valuable element for which there are known fast-growing hyperaccumulator plants that have some of the greatest bioaccumulation coefficients (plant/soil concentration quotients) of any non-essential element. As with other elements, many hyperaccumulators discovered to date are in the Brassicaceae family. In contrast, h...

Laboratory incubation studies were used to investigate whether and how variability of different plant litters modifies the mobility of nitrogen in soil. Fallen plant foliage from native New Zealand plants of diverse fibre and nutrient content were selected, with C :N ratios ranging from 14 to 102. Different litters provided substantially different...

Soil phosphorus (P) is a critical nutrient for plant growth and is an important determinant of vegetation development and long-term ecosystem sustainability. We investigated the effects of rhizosphere-earthworm-guano interactions on soil P dynamics in a mesocosm involving two species of native New Zealand earthworms (Megascolecidae Sp.1 and Maoridr...

Biosolids could potentially be used for reforestation of degraded soils in New Zealand with native vegetation. Many native plant species of New Zealand thrive in low-fertility soils, and there is scant knowledge about their nutrient requirements. Therefore, it is unclear whether they will respond positively to the addition of biosolids. We used a p...

Repeated applications of Cd-rich phosphate fertilizers have resulted in elevated concentrations of this toxic element in some New Zealand soils. Exceedance of the food safety standard for Cd (0.1 mg kg⁻¹ fresh weight) has been reported for potato (Solanum tuberosum L.). Composts may efficiently sorb Cd in soil and therefore reduce its phytoavailabi...

Soil pollution by trace elements (TEs) from mining and industrial activity is widespread and presents a risk to humans and ecosystems. The use of trees to immobilize TEs (phytostabilization) is a low-cost and effective method of soil remediation. We aimed to determine the chemical composition of leaves and flower buds of Eucalyptus camaldulensis in...

Values of pollution load index (PLI) for two soil depths at the seven sites sampled in the Guadiamar River valley (SW Spain). (DOCX)

Allometric measures of E. camaldulensis trees in each sampling site (mean values ± SE; n = 3). Tree height, trunk diameter at breast height (DBH), leaf mass per area (LMA) and leaf concentration of 13C. (DOCX)

Total concentration (mean ±SE) of nine TEs at the seven study sites of the Guadiamar Valley. Maximum and minimum values are indicated between brackets. (DOCX)

Available concentrations of S and five trace elements at each sampling site (mg kg-1; mean values ± SE). Range for each element in parenthesis. Abbreviation dl means detection limit. (DOCX)

Macronutrient concentrations in leaves and flower buds at each sampling site (g 100g-1; mean values ± SE). Range for each element in parenthesis. (DOCX)

General soil parameters analyzed at two depths (0–20 and 20-40cm) of the seven sampling sites with specific location indicated below. Mean values ± SE; n = 3 except for N, Org. C and texture with a single value from a composite sample. (DOCX)

Trace element concentrations in leaves and flower buds at each sampling site (mg kg-1; mean values ± SE). Range for each element in parenthesis. (DOCX)

Cadmium and Zn concentrations (mg kg-1) of Eucalyptus camaldulensis and Salix viminalix at sites S1 and S2. Significant differences per species at each site and organ are marked with and asterisk (p<0.05). (DOCX)

Silvopastoral systems aim to enhance economic, cultural and social principles by sustainably combining forest management with agriculture. In these typically high-nitrogen (N) environments, plant species selection can profoundly influence N fluxes. For grazed pastures, plants may be exposed to urine patches that have received the equivalent of up t...

Biosolids disposal to landfill or through incineration is wasteful of a resource that is rich in organic matter and plant nutrients. Land application can improve soil fertility and enhance crop production but may result in excessive nitrate N (NO3⁻–N) leaching and residual contamination from pathogens, heavy metals, and xenobiotics. This paper eval...

Numerous studies have shown that urban soils can contain elevated concentrations of heavy metals (HMs). Christchurch, New Zealand, is a relatively young city (150 years old) with a population of 390,000. Most soils in Christchurch are sub-urban, with food production in residential gardens a popular activity. Earthquakes in 2010 and 2011 have result...

Important knowledge gaps remain with regards to the ecology and the systematics of New Zealand’s native earthworms. With many putative new species yet to be described, often specimens cannot be named, which makes species inventory, monitoring and community comparisons dif cult. Our work aimed to identify new putative taxa of New Zealand native spec...

Attempts to restore native biodiversity into agricultural landscapes in New Zealand appear to be compromised both by soil nitrogen enrichment from farming and N-leakage to the wider environment. We investigated whether interactions between native earthworms and a native rhizobium-inoculated leguminous shrub (Sophora microphylla) have a measurable e...