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Context Compaction removal and organic amendment application are commonly used to mitigate the compaction-induced declines in crop yield, soil carbon (C) and soil health. However, the response of microbial activities and nutrient pools to the combination of mill-mud amendments and decompaction in the soil profile are not fully understood. Aims A field trial was conducted at Burdekin, Australia, to investigate the effects of different decompaction managements on soil nutrient cycling, associated biological activities and sugarcane yield. Methods This experiment included four treatments: control (CK, without mill-mud), mill-mud shallow furrow (MS), deep trenching without mill-mud (DT) and deep trenching mill-mud application (MD). Key results The MD treatment increased concentrations of hot water extractable organic C by 30–70% and hot water extractable total nitrogen (N) by 30–90% at the application depth. Soil microbial biomass C and N were also higher in mill-mud applied layers. Mill-mud applied treatments increased plant cane yield by 7% (MS treatment) and 14% (MD treatment) compared to CK. The DT treatment also increased plant cane yield by 11% compared to CK. Conclusion The MD treatment increased the supply of organic C and nutrients to the microbial community within the entire soil profile, enhanced nutrient cycling processes, improved soil environmental conditions and soil health for sugarcane growth and thus increased sugarcane productivity. Implications Further research should focus on microbial community composition shifts to further explore the mechanisms responsible for soil microorganism regulation of nutrient cycling in sugarcane farming systems.

High sodicity and Low nutrient retention in bauxite-processing residue sand (BRS) disposal areas restrict sustainable vegetation management in this highly alkaline environment. Although previous investigations have reported the beneficial effect of organic amendments on BRS rehabilitation, little is known about the underlying mechanisms of this complicated process, particularly after supplementary leaching of biochar amended BRS. We have investigated the coupled effect of supplementary leaching process, biochar [aged acidic (AC) vs alkaline pine (PC)] amendment and di-ammonium phosphate (DAP) fertilisation on rhizosphere nutrient dynamic and ryegrass performance in a 116-day glasshouse study. Biochar amendment in DAP + PC and DAP + AC treatments significantly increased and decreased pH (0.3–0.5 units) in all BRS rhizosphere and root-free zones, respectively. The application of alkaline and acidic biochars to BRS have reduced ammonia volatilisation (25–80%) and increased nitrogen retention (9–72%) in comparison with DAP treatment. Supplementary leaching had no significant effect on BRS rhizosphere pH, but reduced the EC values by ca. 62% in biochar-amended treatments. The leachates’ pH remained unchanged (ca. 8) throughout the experiment, while their EC reduced in AC (6 folds) and PC (9 folds) amended treatments, with lower reduction in rhizosphere than root-free zones. The interaction of applied biochars and plant roots generally decreased nutrient leaching from rhizosphere in comparison with root-free zones. Sodium was the dominant cation in the leachate of all treatments and cumulative abundance of exchangeable cations were in the order of Na+ > Ca2+ > K+ > Mg2+ > Al3+. The reduction of BRS salinity has increased plant biomass (ca. 47%) in biochar amended treatments by improving the capacity of fresh BRS rhizosphere for plant establishment.

Low nitrogen (N) content and retention in bauxite-processing residue sand (BRS) disposal areas pose a great challenge to the establishment of sustainable vegetation cover in this highly alkaline environment. The budget and fate of applied N in BRS and its potential environmental impacts are largely unknown. We investigated the effect of combined application of biochars [aged acidic (AC) vs alkaline pine (PC)] and di-ammonium phosphate (DAP) fertiliser on ammonia (NH3) volatilisation, nitrous oxide (N2O) emission and N retention in a 116-day glasshouse study. The application of AC to BRS decreased pH (≈0.5 units) in BRS, while PC biochar increased pH (≈0.3 units). The application of AC reduced NH3 volatilisation by ca. 80%, while PC by ca. 25%. On the other hand, the AC treatment increased N2O emission by 5 folds. However, the N loss via N2O emission in the AC treatment only accounted for ca. 0.4% of applied N. The reduction in BRS pH and increased retention of mineral N due to the presence of oxygen-containing (phenolic and carboxylic) functional groups in AC may be responsible for reduced NH3 volatilisation and increased N2O emission. This study has highlighted the potential of biochar (particularly aged biochar) in improving N retention and minimising environmental impacts in highly alkaline environments.

Soil labile organic carbon (C) and nitrogen (N) pools play a central role in nutrient cycling, while fire is a key driver of biogeochemical cycle, shaping ecosystem structure and functioning. However, how soil labile organic C and N responds to the long-term repeated prescribed fire is largely unknown. In this study, a prescribed fire field experiment in a wet sclerophyll forest established in 1972 in southeast Queensland was used to evaluate the long-term impacts of different fire frequency regimes on labile organic C and N measured by different extraction methods. The fire frequency regimes included long unburnt (NB), burnt every two years (2yrB) and burnt every four years (4yrB). Results revealed that the 2yrB treatment had significantly lower C and N concentrations in hot water and K2SO4 extracts and in density fractions (LFD 1.6) compared with the NB treatment. Concentrations of carbohydrate-C in hot water extracts and acid soluble and insoluble organic matter-C in cold-water extracts followed a similar trend. The maximum reduction was observed for carbohydrate‑C (72%) and the hot water extractable N (54%) in the 2yrB treatment compared with the NB treatment, showing these parameters are most sensitive indicators. However, there was no significant difference in most of the above parameters between the 4yrB and the NB treatments, indicating that less frequent fire (4yrB) allows the ecosystem to have sufficient time to recover from fire disturbance and may be a sustainable practice for fire management in this wet sclerophyll forest ecosystem.

Nitrogen (N) bioavailability is one of the main limiting factors for microbial activity and vegetation establishment in bauxite-processing residue sand (BRS). Although beneficial effects of biochar on reducing N loss in the early stages of BRS rehabilitation have been observed previously, the underlying mechanisms of this complicated process, particularly the interactions between applied biochar and the plant rhizosphere is largely unknown. This glasshouse study (116 days), investigated the coupled effects of biochar and water stress on N bioavailability in the rhizosphere of ryegrass (Lolium rigidum) grown in BRS amended with di-ammonium phosphate (DAP) fertiliser (at rates of 0 or 2.7 t ha−1) with and without biochar amendment. The applied biochar was characterised as either aged acidic (AC) or alkaline pine (PC) and was mixed with BRS at a rate of 5% v/v under four moisture regimes (50%, 40%, 20% and 7.5% water holding capacity). Amending BRS with AC and PC biochars increased NH4 + retention and decreased cumulative NH3 volatilization within both the rhizosphere and root-free zones compared with fertiliser only treatment. These effects were more pronounced for the AC than PC biochar, suggesting that aged acidic biochar has the great potential for use in rapid establishment of vegetation in BRS disposal areas. The biochar amendment increased cumulative nitrous oxide emissions compared with DAP only treatment, with no significant differences among different moisture regimes. The Control and 20% water holding capacity (WHC) treatment showed the highest dissolved organic carbon (DOC) concentrations compared with other treatments and moisture regimes in the ryegrass rhizosphere, while the highest dissolved organic N concentration were observed in the DAP + AC treatment. Reducing moisture levels below 20% WHC generally decreased microbial biomass carbon (MBC) concentrations and activity in both the rhizosphere and root-free zones of all treatments, while total N generally decreased as moisture levels decreased from 50% to 7.5% WHC. Plant took up more N in the DAP + AC treatment compared with DAP + PC and DAP only treatments, while increasing water stress generally resulted in decreased aboveground biomass. © 2018

While the ecosystem of the Great Barrier Reef (GBR), north-eastern Australia, is being threatened by the elevated levels of sediments and nutrients discharged from adjacent coastal river systems, the source of these detrimental pollutants are not well understood. Here we used a combined isotopic (δ13C, δ15N) and geochemical (Zn, Pt and S) signatures and stable isotope analysis in R (SIAR) mixing model to estimate the contribution of different land uses to the sediment and associated particulate nitrogen delivered to the Johnstone River. Results showed that rainforest was the largest contributor of suspended and bed sediments in the river estuary (both 33.1%), followed by banana (26.7%, 20.4%), sugarcane (21.5%, 21.4%) and grazing (18.7%, 25.1%). However, bananas and sugarcane land uses had the highest contribution to sediments delivered to the coast per unit of area. This will help land managers to prioritise on-ground activities to improve water quality in the GBR lagoon.

Organic amendments are mostly carried out on the soil surface layer to mitigate the decline in sugarcane soil health, however, the effects of subsoil application of composts on soil carbon (C) and nutrient dynamics and sugarcane yield are largely unknown. A 4 years field trial was conducted at Maryborough, Australia, to investigate the effects of subsoil application of compost on soil C and N cycling, associated biological processes and sugarcane productivity. The trial included four subsoil (ca. 25 cm) amendment treatments of control (CK, without amendment); gypsum (GP); compost (CP); and mineral fertilizer (FE). Overall, the compost treatment increased concentrations of soil NH4+-N by 30% and NO3−-N by 40% at subsoil (10–25 cm) amendment layer. Soil microbial biomass C and N at the 0–10 cm depth were also significantly higher in the compost treatment than the other treatments. The CO2 respiration in the compost and fertilizer treatments, were significantly higher than in the control and gypsum treatments at the subsoil amendment depth. The compost treatment had greater β–glucosidase activities than other treatments at the 10–25 cm soil depth. In addition, subsoil application of compost increased inputs of hot water extractable organic C (HWEOC) by 30% and N (HWETN) by 70% at the application depth, but did not affect total soil C and N contents. The HWEOC and HWETN pools were positively related to the cumulative sugarcane yield during the 4 years cropping cycle. The subsoil application of compost increased the supply of organic C and N for microbial community, enhanced nutrient cycling processes, improved soil environmental conditions and soil health for sugarcane growth and thus increased sugarcane productivity.

Bauxite residue sand (BRS) is the primary growth medium for rehabilitating Alcoa’s residue storage areas in south-west Western Australia. Successful revegetation of highly alkaline BRS can be hindered by its low nitrogen (N) use efficiency. Biochar, a carbon (C)-rich material, has been suggested to have the potential to improve water and nutrient retention in soil. However, little is still known about the effect of biochar amendment on N use efficiency in the alkaline BRS environment. This incubation study aimed to evaluate the impact of biochars with different characteristics on N retention and dynamics in BRS. The BRS (pH 9.5 after being pre-treated with 1% gypsum and leached with water) was amended with the acidic biochar (pH 3.86; AC, from wild fire) and alkaline biochars (pH 9.58–10.8; greenwaste, GW; Jarrah, JL; mallee, ML) at a rate of 10% (w/w). The N loss via NH 3 volatilization was much lower from the AC treatment (24% of di-ammonia phosphate (DAP)-N added) than the alkaline biochars treatments (76–80% of the DAP-N added). The AC treatment can retain about 73% of N added to BRS, compared with 4 + -N sorption capacity arising from the presence of a high density of the oxygen-containing functional groups on the surface of acidic biochar as revealed by the FTIR spectroscopy. These results imply acidic biochar can be used as an effective amendment for increasing N use efficiency by plants growing in alkaline BRS.

Char as a carbon-rich material, can be produced under pyrolytic conditions, wildfires or prescribed burn offs for fire management. The objective of this study was to elucidate mechanistic interactions of copper (Cu2+) and nickel (Ni2+) with different chars produced by pyrolysis (green waste, GW; blue-Mallee, BM) and forest fires (fresh-burnt by prescribed fire, FC; aged char produced by wild fire, AC). The pyrolytic chars were more effective sorbents of Cu2+ (∼11 times) and Ni2+ (∼5 times) compared with the forest fire chars. Both cross-polarization (CPMAS-NMR) and Bloch decay (BDMAS-NMR) 13C NMR spectroscopies showed that forest fire chars have higher woody components (aromatic functional groups) and lower polar groups (e.g. O-alkyl C) compared with the pyrolytic chars. The polarity index was greater in the pyrolytic chars (0.99–1.34) than in the fire-generated chars (0.98–1.15), while aromaticity was lower in the former than in the latter. Fourier transform infrared (FTIR) and Raman spectroscopies indicated the binding of carbonate and phosphate with both Cu2+ and Ni2+ in all chars, but with a greater extent in pyrolytic than forest fire-generated chars. These findings have demonstrated the key role of char's oxygen-containing functional groups in determining their sorption capacity for the Cu2+ and Ni2+ in contaminated lands.

The construction and operation of the Three Gorges Reservoir (TGR), the largest hydropower dam in the world, has had significant consequences for the hydrology of riparian zones along the Yangtze river. Little is known about how such changes in hydrology might affect the levels of nutrients and organic matter (OM) in riparian soils. We conducted a nine-year study on the spatio-temporal dynamics and dominant environmental correlates of nutrients and OM in riparian soils along a 600 km section of the Yangtze. These soils have been exposed to a disrupted hydrological regime since the TGR's establishment in 2008. Vegetation surveys were also conducted from 2012 to 2016 to assess relationships between soil chemical properties and vegetation community properties under altered hydrology. Across the stream gradient, concentrations of total potassium (K) increased by 54% since the TGR's establishment. The opposite occurred for SOM and available K, concentrations of which were 35% and 33% lower in 2016, respectively, than those of 2008. The rate of increase in total K tended to be more rapid at the middle section of the stream gradient. Moreover, concentrations of SOM, total N, total K, and available phosphorus (P) and K tended to be particularly high at the middle section. The spatio-temporal distributions of nutrients were strongly positively related to the contents of fine soil particles (i.e., silt and clay). Moreover, the aboveground biomass was negatively correlated with the nutrient dynamics. Our results indicate that the control of the nutrient release in the middle reaches and lower elevations where fine particles tend to accumulate, will be essential for maintaining the health of aquatic and riparian ecosystems upstream of the TGR.

Soil organic matter (SOM) formation involves microbial transformation of plant materials of various quality with physico-chemical stabilisation via soil aggregation. Land use and vegetation type can affect the litter chemistry and bioavailability of organic carbon (OC), and consequently influence the processing and stabilisation of OC into SOM. We used 13C nuclear magnetic resonance (13C NMR) and hot-water extraction to assess the changes in chemical composition and labile OC fractions during the transformation processes from leaf to litter to SOM depending on land use and vegetation type. The hot-water-extractable OC (HWEOC) decreased from leaf (43–65 g kg−1) to litter (19–23 g kg−1) to SOM (8–16 g kg−1) similar in four land use types: grassland, sugarcane, forest and banana. These trends demonstrated the uniform converging pathways of OC transformation and increasing stability by SOM formation. The preferential decomposition and decrease of labile OC fractions (∑% di-O-alkyl, O-alkyl and methoxyl) from leaf (54–69%) to SOM (41–43%) confirmed the increasing stability of the remaining compounds. Despite differences in the biochemical composition of the leaf tissues among the vegetation types, the proportions of labile OC fractions in SOM were similar across land uses. The OC content of soil was higher in forest (7.9%) and grassland (5.2%) compared to sugarcane (2.3%) and banana (3.0%). Consequently, the HWEOC per unit of soil weight was higher in forest and grassland (2.0 and 1.2 g kg−1 soil, respectively) compared to sugarcane and banana (0.3 and 0.4 g kg soil−1, respectively). The availability of labile SOM is dependent on the quantity of SOM not the chemical composition of SOM. In conclusion, labile OC fractions in SOM, as identified by 13C NMR, were similar across land use regardless of vegetation type and consequently, SOM formation leads to convergence of chemical composition despite diversity of OC sources.

Determining the source of sediments and associated nutrients from terrestrial to aquatic environments is critical for managing the detrimental impacts of soil erosion and loss of nutrients from terrestrial into aquatic environment. However, tracing the source of particulate nutrients from different land uses has not been adequately carried out due to methodological difficulties in separating sources, particularly in the Great Barrier Reef (GBR) catchment. The objective of this study was to develop a method to differentiate the sources of particulate nutrients from soils collected from different land uses (combination of beef and dairy grazing, sugarcane, forest and banana) using both geochemical and isotopic signatures. In order to select a discriminative group of signatures, all soil samples collected from each of the land use areas were fractionated to

The amounts and forms of soil phosphorus (P) follow predictable patterns during long-term pedogenesis, but have rarely been examined along subtropical chronosequences. We quantified changes in soil nutrient stocks, foliar nutrient concentrations, and the chemical forms of soil P along the Cooloola chronosequence, a series of coastal dunes spanning ca. 500,000 years of pedogenesis in subtropical Queensland. The total P stock in the upper 30 cm of the soil profile declined continuously with soil age, from 229–237 kg ha − 1 on the youngest soils (40 years old) to 24–28 kg ha − 1 on the oldest soils (195–> 460 ka). In contrast, total carbon (C) and nitrogen (N) stocks increased initially along the chronosequence and then declined in the oldest soils. As a consequence, soil N:P ratios increased continually throughout the sequence, from ≤ 4 on the youngest soils to 27–30 on the oldest soils. This indication of increasing biological P stress and ultimately P limitation was further supported by a decline in foliar P concentrations and increasing foliar N:P ratios of two common plant genera along the chronosequence. Sequential P fractionation revealed that although all forms of P declined during pedogenesis, young soils contained low concentrations of primary mineral P and relatively high concentrations of occluded P associated with secondary minerals, suggesting that the parent sand originated from strongly-weathered continental soils. We conclude that the Cooloola chronosequence is an important example of long-term ecosystem development under a subtropical climate, although the pre-weathered nature of the parent sand indicates that the sequence represents a modification of the Walker and Syers model of P transformations during pedogenesis.

Tree and grass species coexist in many ecosystems worldwide and support multiple ecosystem functions and services. However, the distribution of bacterial communities and factors driving coexistence in tree–grass associations and their ecosystem functions remain poorly understood. In this study, the distribution of soil bacteria and their link to changes in abiotic factors were investigated in adjacent montane grassland (C4 plants) and pine forest (bunya pine and hoop pine; C3 plants) sites in the Bunya Mountains, subtropical Australia. Different vegetation (grassy balds and forest) had a substantial effect on terrestrial ecosystem properties, with higher levels of soil nutrients (e.g. total nitrogen (N), total phosphorus (P)) and electrical conductivity (EC), and lower δ13C values and pH under forests compared with grassland. Bacterial α-diversity (total species per operational taxonomic unit richness) did not differ between grassland and pine forest sites, whereas strong shifts in the bacterial community composition and structure were evident. Patterns in bacterial community structure were strongly associated with changes in soil pH, EC, total P and δ13C. Different bacterial groups associated with pine forest (Gammaproteobacteria and Alphaproteobacteria) and grassland (Acidobacteria and Verrucomicrobia) were identified as key groups contributing to the segregation of these two ecosystems in the Bunya Mountains. These findings suggest that heterogeneity in soil edaphic properties (e.g. key nutrients) likely contributed to variation in bacterial β-diversity of grassland and pine forest, which has potential implications for species coexistence and ecosystem function in montane eastern Australia.

Cadmium (Cd) is a critical environmental chemical in which sorption reactions control its entry into soil solution. The aim of the present study was to evaluate Cd sorption characteristics of some soils of the northern part of Iran with a wide range of physicochemical properties. Duplicates of each sample were equilibrated with solutions containing 5 to 500 mg Cd L−1 with 0.01 M CaCl2 as background solution. The quantity of Cd retention was calculated as the difference between initial and equilibrated Cd concentration. Sorption isotherms including Freundlich, Langmuir, Temkin, Dubinin-Radushkevich, and Redlich-Peterson were used to evaluate the behavior of Cd sorption. Cadmium sorption data were well fitted to Langmuir, Freundlich, and Redlich-Peterson isotherms. The constant of Freundlich equation (kF ) and adsorption maxima (bL ) of Langmuir equation were related to pH and cation exchange capacity (CEC). The maximum buffering capacity (Kd ) was significantly correlated with pH (R2 = 0.52, p ≤ 0.001) and...

Liming has been widely used to decrease soil acidity, but its effects on soil nitrogen (N) availability and microbial processes in sugarcane fields are largely unknown. Adjacent sugarcane soils at 26 months after liming (26ML), 14 months after liming (14ML) and with no lime amendment (CK) in Bundaberg, Australia, were selected to investigate the effect of liming on soil N bioavailability and microbial activity in a long-term subtropical sugarcane cropping system. Liming in both 14ML and 26ML treatments significantly increased soil pH (by 1.2–1.4 units) and exchangeable Ca2+ (>2-fold) compared with the CK treatment. The lower concentrations of hot water extractable organic carbon (C) and total N and ammonium-N in the 14ML, compared with the CK and 26ML treatments, can be attributed to the absence of trash blanket placement in the former. Enhanced microbial immobilisation due to improved soil pH by liming (14ML and 26ML treatments) led to increased soil microbial biomass C and N, particularly in the presence of a trash blanket (26 ML treatment), but decreased soil respiration and metabolic quotient indicated that acidic stress conditions were alleviated in the liming treatments. Soil pH was the main factor governing soil enzyme activities, with an overall decrease in all enzyme activities in response to liming. Overall, liming and trash blanket practices improved sugarcane soil fertility. Further study is warranted to investigate the shifts in soil microbial community composition and the diversity and abundance of N-associated functional genes in response to liming in sugarcane fields.

To predict the environmental fate and mobility of contaminants, it is critical to study desorption behaviour of contaminants in soil system. Cadmium (Cd) desorption kinetics studies were conducted in ten sub-tropical soils of the northern part of Iran, with a wide range of physico-chemical properties. Treatments consisted of two levels of cadmium (15 and 30 mg kg(-1) as CdCl2). Soils were incubated at 20% moisture (w/w) level and 25 +/- 1 degrees C. After weeks, cadmium desorption pattern was investigated by Diethylene Triamine Pentaacetic Acid (DTPA) extraction with equilibration periods from 30 to 960 min. Results showed that two constant rate, parabolic diffusion and simple Elovich equations best described Cd desorption in these soils. The coefficients of kinetic equations had significant correlation with each other. The findings of this investigation indicated that pH, cation exchange capacity, organic matter, and oxalate extractable Fe are the most important soil characteristics in controlling Cd desorption behaviour in sub-tropical soils. Refereed/Peer-reviewed

Over the centuries, opium has been the most frequent substance abused in the Middle East. There are many controversial aspects about the effects of opioids on the atherosclerosis process, which is still unclear.All patients who were candidates for coronary artery bypass graft in Tehran Heart Center were registered and evaluated for risk factors such as diabetes mellitus, hypertension, smoking status and duration, opium abuse, involved coronary arteries and left main branch lesion50%, carotid stenosisor = 70%.A total of 1,339 patients were enrolled in the study, of whom 400 (29.9%) were female and the other 939 (70.1%) male. Female patients were omitted from analysis due to the low numbers of female opium addicts. Our study revealed that in the addicted population, the risk of diabetes and hypertension was lower than in the non-addicted group (p0.05 for each variable) and fasting blood sugar tended to be less in addicted ones, but the number of involved coronary arteries, left main stenosis50% and extent of carotid stenosis was not significantly different between the two groups.Our investigations demonstrate that opium is not cardioprotective, as has been claimed by some previous studies, and does not even decelerate atherosclerosis of carotid arteries in opium-addicted patients, but more evidence is still needed to completely prove the case.

To evaluate the prevalence of abdominal aortic aneurysm in Iranian candidates for coronary artery bypass graft surgery and its associated factors.Totally, 2843 consecutive candidates for coronary artery bypass graft surgery underwent ultrasonography of abdominal aorta. The relation between abdominal aortic aneurysm with gender, age, smoking, dyslipidemia, hypertension, diabetes, and carotid and coronary stenosis was evaluated.The prevalence of abdominal aortic aneurysm was 2.7% and 0.7% in men and women subgroups, respectively. The prevalence was 3.8% in men older than 65 years. The largest diameter of abdominal aortic aneurysm was 61.7 mm. Only two men had aneurysm larger than 55 mm, which led to changing their surgery schedule to stenting. Gender, age, smoking, smoking more than 40 years, diabetes , hypertension, and significant carotid stenosis were associated factors of abdominal aortic aneurysm.Compared with the results sited in Western studies, the prevalence of abdominal aortic aneurysm is lower in Iran (P0.0001). Its associated factors in our study were similar to previously published studies. Significant carotid stenosis, a factor not reported previously, was an associated factor in our study. Because of the low prevalence of abdominal aortic aneurysm in our population, screening the candidates for coronary artery bypass graft surgery is not recommended.

The application of biochar technology for soil amendment is largely based on evidence about soil fertility and crop productivity gains made in the Amazonian Black Earth (terra preta). However, the uncertainty of production gains at realistic application rates of biochars and lack of knowledge about other benefits and other concerns may have resulted in poor uptake of biochar technology in Australia so far. In this review, we identify important opportunities as well as challenges in the adoption of biochar technology for broadacre farming and other sectors in Australia. The paper highlights that for biochar technology to be cost-effective and successful, we need to look beyond carbon sequestration and explore other opportunities to value-add to biochar. Therefore, some emerging and novel applications of biochar are identified. We also suggest some priority research areas that need immediate attention in order to realise the full potential of biochar technology in agriculture and other sectors in Australia.