Organic matter mitigates biotic impact of copper in fruit orchard soil.

Inorganic copper (Cu) fungicides and bactericides are widely used to control disease in fruit and vegetable crops and has led to widespread accumulation of the metal in soil beyond regulatory thresholds. We aimed to elucidate the impacts of Cu on soil health within cherry orchard soils in New Zealand, focusing on three biological indicators: earthworm behaviour, soil respiration, and plant growth. We sampled soils from four blocks of different ages within a single orchard, varying in amounts of accumulated soil Cu (7-263 mg kg) but also in Soil Organic Matter (SOM) content (3-10 %).

Revealing the Complex Interplay of Biostimulant Applications.

Some biostimulant products provide proven benefits to plant production, potentially offering more environmentally friendly, sustainable, and natural inputs into production systems. However, the transference and predictability of known benefits between different growth environments, application protocols, and management systems are fraught with difficulty. In this study, we carried out carefully controlled glasshouse and in vitro assays with applications of humic acids, protein hydrolysates, and seaweed extract to compare the variability of biostimulant effects and dosage-dependent variations across diverse conditions, encompassing a sufficient range to comprehensively assess their full spectrum of impacts.

Grasses procure key soil nutrients for clovers.

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 pool.

Plant Species Complementarity in Low-Fertility Degraded Soil.

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 low to deficient in P, Mn, S, Fe, and B.

The ecological importance of moss ground cover in dry shrubland restoration within an irrigated agricultural landscape matrix.

Kānuka (, Myrtaceae) dryland shrubland communities of the lowland plains of South Island (Te Wai Pounamu), New Zealand (Aoteoroa), contain a ground cover largely consisting of mosses, predominantly . There has been no previous study of the role of mosses in this threatened habitat which is currently being restored within a contemporary irrigated and intensively farmed landscape that may be incompatible with this component of the ecosystem.The aim of the present study was to investigate the influence of moss ground cover on hydrology, nitrogen (N) availability and vascular plant interactions, and in relation to nutrient spillover from adjacent farmland.

Chemical Elements and the Quality of Mānuka () Honey.

Soil properties in the foraging range of honeybees influence honey composition. We aimed to determine relationships between the antimicrobial properties of New Zealand mānuka () honey and elemental concentrations in the honey, plants, and soils. We analyzed soils, plants, and fresh mānuka honey samples from the Wairarapa region of New Zealand for the chemical elements and the antimicrobial activity of the honey as indicated by methylglyoxal (MGO) and dihydroxyacetone (DHA).

Response of a Pioneering Species ( J.R.Forst. & G.Forst.) to Heterogeneity in a Low-Fertility Soil.

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 determine the characteristics of root foraging by a pioneering species, , using pot trials and rhizobox experiments with patches of biosolids.

Host Plant Selection by the Wheat Bug, Nysius huttoni (Hemiptera: Lygaeidae) on a Range of Potential Trap Plant Species.

The wheat bug, Nysius huttoni L. is an endemic New Zealand pest. The seedlings of forage brassicas are highly susceptible to direct feeding damage by this insect, and this can reduce plant establishment.

Lithium as an emerging environmental contaminant: Mobility in the soil-plant system.

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 by food and fodder species.

Potential Environmental Benefits from Blending Biosolids with Other Organic Amendments before Application to Land.

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 (NO-N) leaching and residual contamination from pathogens, heavy metals, and xenobiotics. This paper evaluates evidence that these concerns can be reduced significantly by blending biosolids with organic materials to reduce the environmental impact of biosolids application to soils.

Impacts of Endemic Earthworms (Megascolecidae) in Biosolids-Amended Soil.

Biosolids can be a valuable fertilizer for agriculture and in ecological restoration, although there are concerns about contaminants. Earthworm activity, including vermicomposting of biosolids, may influence the efficacy of their use. We investigated how two New Zealand endemic anecic species of (cf.

Biowaste Mixtures Affecting the Growth and Elemental Composition of Italian Ryegrass ().

Biosolids (sewage sludge) can be beneficially applied to degraded lands to improve soil quality. Plants grown on biosolids-amended soils have distinct concentrations of macronutrients and trace elements, which can be beneficial or present a risk to humans and ecosystems. Potentially, biosolids could be blended with other biowastes, such as sawdust, to reduce the risks posed by rebuilding soils using biosolids alone.

Effect of Pine Waste and Pine Biochar on Nitrogen Mobility in Biosolids.

Humanity produces ∼27 kg of dry matter in biosolids per person per year. Land application of biosolids can improve crop production and remediate soils but may result in excessive nitrate N (NO-N) leaching. Carbonaceous materials can reduce the environmental impact of biosolids application.

The effect of lignite on nitrogen mobility in a low-fertility soil amended with biosolids and urea.

Lignite has been proposed as a soil amendment that reduces nitrate (NO3(-)) leaching from soil. Our objective was to determine the effect of lignite on nitrogen (N) fluxes from soil amended with biosolids or urea. The effect of lignite on plant yield and elemental composition was also determined.

The phytoremediation potential of native plants on New Zealand dairy farms.

Ecological restoration of marginal land and riparian zones in agricultural landscapes in New Zealand enhances the provision of above-ground ecosystem services. We investigated whether native endemic plant assemblages have remediation potential, through modifying soil nutrient and trace element mobility. Analysis of native plant foliage in situ indicated that selective uptake of a range of commonly deficient trace elements including Zn, B, Cu, Mn and Co could provide a browse crop to avoid deficiencies of these elements in livestock, although some native plants may enhance the risk of Mo and Cd toxicity.

Planting woody crops on dredged contaminated sediment provides both positive and negative effects in terms of remediation.

There is currently a requirement for studies focusing on the long-term sustainability of phytoremediation technologies. Trace element uptake by Salix, Populus and Alnus species planted in dredged contaminated canal sediment and concentrations in sediment and pore waters were investigated, eight years after a phytoremediation trial was initiated in NW England. Soil biological activity was also measured using invertebrate and microbial assays to determine soil quality improvements.

Field sampling of soil pore water to evaluate trace element mobility and associated environmental risk.

Monitoring soil pollution is a key aspect in sustainable management of contaminated land but there is often debate over what should be monitored to assess ecological risk. Soil pore water, containing the most labile pollutant fraction in soils, can be easily collected in situ offering a routine way to monitor this risk. We present a compilation of data on concentration of trace elements (As, Cd, Cu, Pb, and Zn) in soil pore water collected in field conditions from a range of polluted and non-polluted soils in Spain and the UK during single and repeated monitoring, and propose a simple eco-toxicity test using this media.

Arsenic mobility and speciation in a contaminated urban soil are affected by different methods of green waste compost application.

Application of green waste compost (GWC) to brownfield land is now common practice in soil restoration. However, previous studies have demonstrated both beneficial and detrimental effects on arsenic and metal mobility. In this paper, trace element behaviour was investigated following GWC application, either as surface mulch to, or mixed into soil from a previously described brownfield site in the U.

Trace element mobility in a contaminated soil two years after field-amendment with a greenwaste compost mulch.

Application of greenwaste compost to brownfield land is increasingly common in soil and landscape restoration. Previous studies have demonstrated both beneficial and detrimental effects of this material on trace element mobility. A pot experiment with homogenised soil/compost investigated distribution and mobility of trace elements, two years after application of greenwaste compost mulch to shallow soils overlying a former alkali-works contaminated with Pb, Cu and As (approximately 900, 200 and 500 mg kg(-1), respectively).

Exposure of an anoxic and contaminated canal sediment: mobility of metal(loid)s.

A derelict canal contains an estimated 9800 tonnes of anoxic sediment with highly elevated concentrations of trace elements. Lack of maintenance, reduced water levels and vegetation colonization threaten the stability of pollutants by removing existing waterlogged reduced conditions. A column leaching study of the sediment under increasingly oxidized conditions showed reductions in As mobility but increased heavy metal concentrations.

Mobility of arsenic, cadmium and zinc in a multi-element contaminated soil profile assessed by in-situ soil pore water sampling, column leaching and sequential extraction.

Three methods for predicting element mobility in soils have been applied to an iron-rich soil, contaminated with arsenic, cadmium and zinc. Soils were collected from 0 to 30 cm, 30 to 70 cm and 70 to 100 cm depths in the field and soil pore water was collected at different depths from an adjacent 100 cm deep trench. Sequential extraction and a column leaching test in the laboratory were compared to element concentrations in pore water sampled directly from the field.

Arsenic mobility in brownfield soils amended with green waste compost or biochar and planted with Miscanthus.

Degraded land that is historically contaminated from different sources of industrial waste provides an opportunity for conversion to bioenergy fuel production and also to increase sequestration of carbon in soil through organic amendments. In pot experiments, As mobility was investigated in three different brownfield soils amended with green waste compost (GWC, 30% v/v) or biochar (BC, 20% v/v), planted with Miscanthus. Using GWC improved crop yield but had little effect on foliar As uptake, although the proportion of As transferred from roots to foliage differed considerably between the three soils.

PHYTOREMEDIATION OF INORGANICS: REALISM AND SYNERGIES.

There are very few practical demonstrations of the phytoextraction of metals and metalloids from soils and sediments beyond small-scale and short-term trials. The two approaches used have been based on using 1) hyperaccumulator species, such as Thlaspi caerulescens (Pb, Zn, Cd, Ni), Alyssum spp. (Ni, Co), and Pteris vittata (As) or 2) fast-growing plants, such as Salix and Populus spp.

Arsenic stability and mobilization in soil at an amenity grassland overlying chemical waste (St. Helens, UK).

A 6.6 ha grassland, established on a former chemical waste site adjacent to a residential area, contains arsenic (As) in surface soil at concentrations 200 times higher than UK Soil Guideline Values. The site is not recognized as statutory contaminated land, partly on the assumption that mobility of the metalloid presents a negligible threat to human health, groundwater and ecological receptors.

Phytoremediation trials on metal- and arsenic-contaminated pyrite wastes (Torviscosa, Italy).

At a site in Udine, Italy, a 0.7m layer of As, Co, Cu, Pb and Zn contaminated wastes derived from mineral roasting for sulphur extraction had been covered with an unpolluted 0.15m layer of gravelly soil.