Paul N. Nelson

Paul N. Nelson
James Cook University Brisbane

PhD

About

140
Publications
95,333
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5,113
Citations
Additional affiliations
January 2004 - present
James Cook University Brisbane

Publications

Publications (140)
Preprint
Clay minerals and metal oxides play an important role in controlling the decomposition of soil organic matter and the mineralization of organic nitrogen. To study the effects of clay content and composition on mineralization of organic nitrogen, an incubation experiment was carried out. In the experiment, mineralization of organic nitrogen from alf...
Article
Full-text available
Mafic igneous rocks, such as basalt, are composed of abundant calcium- and magnesium-rich silicate minerals widely proposed to be suitable for scalable carbon dioxide removal (CDR) by enhanced rock weathering (ERW). Here, we report a detailed characterization of the mineralogy, chemistry, particle size and surface area of six mined basalts being us...
Article
Fusarium wilt of banana, caused by Fusarium oxysporum f.sp. cubense, is a serious threat to banana production, with no effective treatment. Mulches and oils from Eucalyptus have been shown to inhibit the growth of F. oxysporum, and reduce the severity of Fusarium wilt. Eucalyptus cloeziana leaves contain many compounds commonly found in Eucalyptus...
Article
Previous research has shown that application of iron chelates to soil reduces Fusarium wilt in several crop species. The aim of this work was to test the effect for bananas grown in tropical soils. Disease severity and plant characteristics were measured in banana plants (cv. Ducasse, Musa ABB) grown in pots inoculated with Fusarium oxysporum f. sp...
Article
Mineralization of soil organic carbon and CO2 emission from the soil is slowed by interactions between organic matter and minerals. The main minerals involved are clay minerals and oxides but there is limited understanding of their effects when combined, as occurs in soil. We aimed to determine the effects of clay content and composition on organic...
Research
Dissolved inorganic nitrogen (DIN) in runoff from agricultural land is considered to have a significant detrimental impact on the Great Barrier Reef (GBR). Losses of DIN to runoff can be reduced by good agricultural practices, but they cannot be eliminated entirely in the Wet Tropics due to the need for adequate nitrogen supply to crops, the high s...
Article
Naturally occurring and synthetic chelating ligands can act as suppressants for fungal pathogens, nematodes and weeds, based on their ability to alter micronutrient bioavailability in soil, particularly iron. Chelators are also used as detergents, for remediation of heavy metal contamination and for supplying metals as fertiliser. The aim of this w...
Article
Oil palm, Elaeis guineensis Jacq., is currently cultivated on 19 M ha and palm oil represents more than one‐third of the global vegetable oil market. Addition of nitrogen via legume cover crop and fertilizers is a common practice in industrial oil palm plantations. Part of this added nitrogen is prone to loss from the field, contributing significan...
Technical Report
Full-text available
In this technical report, we describe thoroughly the structure and functioning of the agri-environmental indicator IN-Palm, to assess potential N losses in oil palm plantations (Pardon et al. 2019). It includes the user instructions, an explanation of the use of fuzzy decision trees in IN-Palm, the structure and calculation of the 17 modules of t...
Article
The severity of Fusarium wilt of bananas has long been classified based on visual assessment of necrosis in rhizome or pseudostem cross-sections. The improved method proposed here uses digital image analysis to quantify the proportion of rhizome tissue that is necrotic. It agrees well with visual classification, but provides greater reproducibility...
Article
The sorption behaviour of three perfluoroalkyl substances (PFASs), namely perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexane sulfonic acid (PFHxS), was determined on 28 tropical soils. Tropical soils are often highly weathered, richer in sesquioxides than temperate soils and may contain variable charge minerals....
Article
This study investigated the effect of surface charge on the sorption of perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexane sulfonic acid (PFHxS) onto 7 tropical soils as a function of pH. The net surface charge became less negative with decreasing pH (from 7.5 to 3.5) in all soils. The rate of change in net surf...
Article
Soils are known to differ in suppressiveness to soil-borne diseases, but the suppressiveness or otherwise to Fusarium wilt of Australian soils used to grow bananas is unknown. In this work we tested the relative suppressiveness of six key soil types. Banana (Musa (AAB group) 'Pome', cultivar 'Lady Finger') was grown in pots of the soils inoculated...
Article
Full-text available
Determining if the seasonality of leaf litter invertebrate populations in tropical rainforests is driven by climate or availability of litter, or both, is important to more accurately predict the vulnerability of litter invertebrates to climate change. Here we used two approaches to disentangle these effects. First, the influence of climatic season...
Article
Palm oil production provides economic benefits in developing countries but its development can drastically alter landscapes. We investigated an oil palm-dominated landscape in New Britain, Papua New Guinea, and developed a simple remote sensing approach, supported by site visits and video surveys, to assess the condition and the extent of recent ch...
Article
Production of many crops, including bananas, is threatened worldwide by the spread of pathogenic strains of Fusarium oxysporum, the causal agent of Fusarium wilt. Severity of the disease is related to soil biotic and abiotic attributes, which influence the plant, the pathogen and the other soil organisms. Across a variety of crops, soil temperature...
Article
Full-text available
In the version of this Perspective originally published, ‘acidification’ was incorrectly spelt as ‘adification’ in Fig. 4. This has now been corrected.
Presentation
Full-text available
We reviewed the available knowledge about measurements and modelling of N fluxes and losses in oil palm plantations.
Presentation
Full-text available
We developed IN-Palm, a model to help managers and scientists to estimate N losses to the environment and identify best management practices.
Article
The magnitude of future climate change could be moderated by immediately reducing the amount of CO2entering the atmosphere as a result of energy generation and by adopting strategies that actively remove CO2from it. Biogeochemical improvement of soils by adding crushed, fast-reacting silicate rocks to croplands is one such CO2-removal strategy. Thi...
Article
The Anthropocene is linked to massive land use changes as a result of human activity. While aboveground changes in biodiversity are well documented, the effects on belowground microbial communities are less understood, yet could impact on many ecosystem functions. Here we aimed to identify differences in belowground microbial diversity between fore...
Article
Full-text available
Understanding the main factors driving fire regimes in grasslands and savannas is critical to better manage their biodiversity and functions. Moreover, improving our knowledge on pyrogenic carbon (PyC) dynamics, including formation, transport and deposition, is fundamental to better understand a significant slow-cycling component of the global carb...
Article
This study aimed to assess the performance of an indigenous arbuscular mycorrhizal fungus (AMF) inoculant isolated from yam rhizosphere on yam (Dioscorea rotundata Poir.) growth and yield in field conditions. For this purpose, a factorial experiment was carried out in two contrasting agricultural soils located in Duokro and INP-HB in Yamoussoukro,...
Article
Oil palm cultivation has environmental impacts, including those associated with nitrogen (N) losses. Improving management practices to optimise yield and N losses is critical. In order to identify the key management and site parameters driving yield and N losses, over a 25-year cycle, we undertook a Morris’s sensitivity analysis of the Agricultural...
Article
Quantification of soil organic carbon (SOC) content is important for sustainable agricultural management and accurate carbon accounting. Infrared (IR) absorbance can be used to estimate SOC content, but the relationship differs between regions due to matrix effects. We developed an IR-based model specific for SOC in Papua New Guinean soils. A total...
Article
Understanding the factors controlling stability against mineralisation of soil organic matter is important for predicting changes in carbon stocks under changed environment or management. Soil carbon dynamics in oil palm plantations are little studied and have some characteristics that are unusual compared with other agricultural soils, such as hig...
Presentation
Full-text available
Soil quality decline has been the major threat for the ecological and agricultural sustainability. This study investigated the effects of biochar and compost, applied individually or together, on soil fertility, crop yield and greenhouse gas (GHG) fluxes in tropical agricultural Ferralsols of North Queensland, Australia. The treatments comprised 1)...
Conference Paper
Full-text available
Soil quality decline has been the major threat for the ecological and agricultural sustainability. This study investigated the effects of biochar and compost, applied individually or together, on soil fertility, crop yield and greenhouse gas (GHG) fluxes in tropical agricultural Ferralsols of North Queensland, Australia. The treatments comprised 1)...
Article
Full-text available
Oil palm is the most rapidly expanding tropical perennial crop. Its cultivation raises environmental concerns, notably related to the use of nitrogen (N) fertilisers and the associated pollution and greenhouse gas emissions. While numerous and diverse models exist to estimate N losses from agriculture, very few are currently available for tropical...
Data
Oral presentation. Conference: International Environmental Modelling and Software Society (iEMSs) 8th International Congress on Environmental Modelling and Software, At Toulouse, France
Conference Paper
Full-text available
Oil palm cultivation area is expected to increase until at least 2050. This expansion raises environmental concerns, not only regarding land-use change and its consequences, but also concerning potential impacts of losses of nitrogen such as ammonia volatilisation, nitrous oxide emission and nitrate leaching and runoff. The prerequisite to any work...
Article
Full-text available
Oil palm is the most rapidly expanding tropical perennial crop. Its cultivation raises environmental concerns, notably related to the use of nitrogen (N) fertilisers and the associated pollution and greenhouse gas emissions. While numerous and diverse models exist to estimate N losses from agriculture, very few are currently available for tropical...
Presentation
Full-text available
N2O emissions from agriculture greatly contribute to climate change. In palm plantations on mineral soils, these emissions are mostly due to fertiliser inputs. This raises environmental concerns as oil palm is the most rapidly expanding tropical perennial crop. There is hence a critical need to quantify and model N2O emissions in order to explore s...
Data
Conference paper. 5th International Conference on Oil Palm and Environment (ICOPE), 16-18th Mar 2016, Bali, Indonesia
Data
Oral presentation. Conference: 5th International Conference on Oil Palm and Environment (ICOPE), 16-18th Mar 2016, Bali, Indonesia
Article
Nitrogen (N) losses in agroecosystems are a major environmental and economic issue. This issue is particularly pronounced in oil palm cultivation because oil palm production area is expected to increase to 12 Mha by 2050. N fertilization in oil palm plantations is mainly provided by mineral fertilizers, palm oil mill by-products, and biological fix...
Article
The conversion of grassland to oil palm is expected to increase throughout tropical regions where oil palm grows. Given the extent of land use change, there are concerns associated with impacts on ecosystem function and nutrient cycling. For this work, soil samples were collected in Papua New Guinea from 15 sites with oil palm (planted on grassland...
Article
Tropical forests play a key role in the global carbon cycle. However, little is known about carbon cycling in the substantial portion of tropical forests that are low-lying, with shallow and fluctuating water tables. This study aimed to determine what factors control emissions of CO 2 from soil in a riparian rainforest in Queensland, Australia. Emi...
Article
Full-text available
Soil carbon fluxes are highly variable in space and time under tree crops such as oil palm, and attempts to model such fluxes must incorporate an understanding of this variability. In this work, we measured soil CO2 emission, root biomass and pruned frond deposition rates and calculated carbon fluxes into and out of the soil in a mature (20-year-ol...
Article
In tropical dairy production systems, where high rates of urea fertiliser are applied, little is known about nitrogen (N) fertiliser response, fertiliser-use efficiency and losses to the environment. This study aimed to determine the effects of N fertiliser (urea) application rate and a nitrification inhibitor (3, 4-dimethylpyrazole phosphate, DMPP...
Article
Full-text available
Soil pH buffering capacity (pHBC) plays a crucial role in predicting acidification rates, yet its large-scale patterns and controls are poorly understood, especially for neutral-alkaline soils. Here, we evaluated the spatial patterns and drivers of pHBC along a 3600 km long transect (1900 km sub-transect with carbonate-containing soils and 1700 km...
Research
Soil pH buffering capacity (pHBC) plays a crucial role in predicting acidification rates,yet its large-scale patterns and controlsare poorly understood, especially for neutral-alkaline soils. Here, we evaluated the spatial patternsand drivers of pHBC along a 3600-km long transect (1900km sub-transect with carbonatecontaining soils and 1700km sub-tr...
Article
A common approach for estimating water-table depth simply and reliably is using seismic refraction. Typical layered solutions from seismic refraction are successful in areas where the water table does not fluctuate rapidly. However, there are many areas around the world where water tables rise and fall rapidly in response to intense rainfall events...
Article
Full-text available
The provision of farmers with proper and balanced fertilizer recommendations is becoming increasingly important, for reasons of crop productivity, food security and sustainability. Phosphorus (P) response trials with wheat were conducted on Nitisols at 14 sites in the central Ethiopian highlands during the 2010 and 2011 cropping seasons. The treatm...
Article
Full-text available
Soil pH buffering capacity (pHBC) plays a crucial role in predicting acidification rates, yet its large-scale patterns and controls are poorly understood, especially for neutral-alkaline soils. Here, we evaluated the spatial patterns and drivers of pHBC along a 3600 km long transect (1900 km sub-transect with carbonate containing soils and 1700 km...
Article
Full-text available
This study investigated the effects of biochar and compost, applied individually or together, on soil fertility, peanut yield and greenhouse gas (GHG) emissions on a Ferralsol in north Queensland, Australia. The treatments were (1) inorganic fertilizer only (F) as a control; (2) 10 t ha-1 biochar + F (B + F); (3) 25 t compost + F (Com + F) ha-1; (4...
Poster
Full-text available
Palm oil represents 38% of the world plant oil production. Nitrogen losses are the main cause of pollution during the cultivation period of oil palm. We need to better estimate losses to reduce them. The main challenges that we identified for modelling are: to adapt emission factors to tropical context, to take into account important internal fluxe...
Article
Full-text available
Aims The aim was to devise a practical soil sampling design for oil palm plantations that takes into account tree-scale variability, thus facilitating detection of trends in soil properties over time. Methods We geometrically evaluated the ability of linear sampling transects to represent the distribution of typical management zones and radial p...
Article
Full-text available
Widespread burning of mixed tree–grass ecosystems represents the major natural locus of pyrogenic carbon (PyC) production. PyC is a significant, pervasive and yet poorly understood "slow-cycling" form of carbon present in the atmosphere, hydrosphere, soils and sediments. We conducted 16 experimental burns on a rainfall transect through northern Aus...
Conference Paper
Full-text available
The productivity and quality of malting barley (Hordeum vulgare L.) were evaluated using factorial combinations of four precursor crops [faba bean (Vicia faba L.), field pea (Pisum sativum L., rapeseed (Brassica napus L.) and barley] as main plots and four nitrogen (N) fertilizer rates (0, 18, 36 and 54 kg N ha-1) as sub-plots at two sites on Nitis...
Article
Full-text available
Deteriorating soil fertility and the concomitant decline in agricultural productivity are major concerns in many parts of the world. A pot experiment was conducted with a Ferralsol to test the hypothesis that application of biochar improves soil fertility, fertiliser-use efficiency, plant growth and productivity, particularly when combined with com...
Article
Full-text available
Our paper makes no claims regarding the general stability of the Great Divide but asserts that locally, the divide has migrated. Such a change is not surprising given a series of large Pliocene to Pleistocene volcanic eruptions on, or immediately next to, the drainage divide. There are many examples elsewhere of rivers being diverted from their ori...
Article
Full-text available
Widespread burning of mixed tree-grass ecosystems represents the major natural locus of pyrogenic carbon (PyC) production. PyC is a significant, pervasive, and yet poorly understood "slow-cycling" form of carbon present in the atmosphere, hydrosphere, soils and sediments. We conducted sixteen experimental burns on a rainfall transect in northern Au...