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1. Impacts of soil abiotic attributes on Fusarium wilt, focusing on bananas

Author:
Nelson, Paul N.,   et al.   ; Orr, Ryan;     Show all 2 Author
Source:
Applied soil ecology 2018 v.132 pp. 20-33
ISSN:
0929-1393
Subject:
Fusarium oxysporum; Fusarium wilt; bananas; boron; calcium; clay; crops; defense mechanisms; disease severity; iron; manganese; nutrient availability; nutrients; organic matter; pH; pathogens; phosphorus; potassium; redox potential; risk; silicon; soil biota; soil temperature; virulent strains; zinc
Abstract:
... 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, redox potential, and extractable iron and mangan ...
DOI:
10.1016/j.apsoil.2018.06.019

2. Image-based quantification of Fusarium wilt severity in banana

Author:
Nelson, Paul N.,   et al.   ; Orr, Ryan; Pattison, Anthony; East, David; Warman, Noeleen; O’Neill, Wayne; Czislowski, Elizabeth;     Show all 7 Authors
Source:
Australasian plant disease notes 2019 v.14 no.1 pp. 14
ISSN:
1833-928X
Subject:
Fusarium wilt; bananas; digital images; image analysis; necrosis; rhizomes
Abstract:
... 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, precision and statistical power. ...
DOI:
10.1007/s13314-019-0344-7

3. Suppressiveness or conduciveness to Fusarium wilt of bananas differs between key Australian soils

Author:
Nelson, Paul N.,   et al.   ; Bowen, Alison; Orr, Ryan; McBeath, Anna V.; Pattison, Anthony;     Show all 5 Authors
Source:
Soil research 2019 v.57 no.2 pp. 158-165
ISSN:
1838-675X
Subject:
Fusarium oxysporum f. sp. cubense; Fusarium wilt; Musa; bananas; beta-glucosidase; clay fraction; discoloration; disease severity; enzyme activity; plant growth; rhizomes; risk; soil enzymes; soil types; soil-borne diseases; soil-plant interactions
Abstract:
... 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 or not with Fusarium oxysporum f.sp. cubense (Foc) ...
DOI:
10.1071/SR18159

4. Impact of oil palm development on the integrity of riparian vegetation of a tropical coastal landscape

Author:
Nelson, Paul N.,   et al.   ; Sheaves, Marcus; Johnston, Ross; Miller, Kelsey;     Show all 4 Authors
Source:
Agriculture, ecosystems & environment 2018 v.262 pp. 1-10
ISSN:
0167-8809
Subject:
Elaeis guineensis; aquatic ecosystems; biodiversity; developing countries; ecological function; financial economics; gardens; landscapes; monitoring; oils; plantations; planting; protocols; remote sensing; riparian areas; riparian vegetation; surveys; villages; Papua New Guinea
Abstract:
... 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 change in riparian zones. Riparian buffer zones were ...
DOI:
10.1016/j.agee.2018.04.011

5. Shifts in prokaryotic communities under forest and grassland within a tropical mosaic landscape

Author:
Nelson, Paul N.,   et al.   ; Morales, Sergio E.; Trouche, Blandine; Wakelin, Steve; Banabas, Murom;     Show all 5 Authors
Source:
Applied soil ecology 2018 v.125 pp. 156-161
ISSN:
0929-1393
Subject:
Anthropocene epoch; community structure; ecological function; ecosystems; forests; genes; grasslands; humans; land use change; landscapes; microbial communities; ribosomal RNA; soil sampling; species diversity; Papua New Guinea
Abstract:
... 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 forest and grassland sites in a humid tropical mosaic ...
DOI:
10.1016/j.apsoil.2017.11.028

6. Temporal variation in abundance of leaf litter beetles and ants in an Australian lowland tropical rainforest is driven by climate and litter fall

Author:
Nelson, Paul N.,   et al.   ; Grimbacher, Peter S.; Edwards, Will; Liddell, Michael J.; Nichols, Cassandra; Wardhaugh, Carl W.; Stork, Nigel E.;     Show all 7 Authors
Source:
Biodiversity and conservation 2018 v.27 no.10 pp. 2625-2640
ISSN:
0960-3115
Subject:
Coleoptera; Formicidae; carbon dioxide; climate; climate change; correlation; insects; invertebrates; plant litter; population size; rain; temperature; temporal variation; tropical rain forests
Abstract:
... 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 seasonality was quantified by sampling a fixed volume of ...
DOI:
10.1007/s10531-018-1558-2

7. Estimating organic carbon content of soil in Papua New Guinea using infrared spectroscopy

Author:
Nelson, Paul N.,   et al.   ; Orr, Ryan; McBeath, Anna V.; Dieleman, Wouter I. J.; Bird, Michael I.;     Show all 5 Authors
Source:
Soil research 2017 v.55 no.8 pp. 735-742
ISSN:
1838-675X
Subject:
absorbance; agricultural management; carbon footprint; combustion; infrared spectroscopy; model validation; models; regression analysis; soil; soil organic carbon; spectral analysis; wavelengths; Papua New Guinea
Abstract:
... 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 of 437 samples from 0.0–0.3m depth were analysed ...
DOI:
10.1071/SR16227

8. The effects of biochar, compost and their mixture and nitrogen fertilizer on yield and nitrogen use efficiency of barley grown on a Nitisol in the highlands of Ethiopia

Author:
Nelson, Paul N.,   et al.   ; Agegnehu, Getachew; Bird, Michael I.;     Show all 3 Authors
Source:
The Science of the total environment 2016 v.569-570 pp. 869-879
ISSN:
0048-9697
Subject:
Nitisols; barley; biochar; composts; crops; fertilizer rates; grain yield; highlands; nitrogen; nitrogen fertilizers; nutrient use efficiency; nutrients; nutrition; Ethiopia
Abstract:
... The effects of organic amendments and nitrogen (N) fertilizer on yield and N use efficiency of barley were investigated on a Nitisol of the central Ethiopian highlands in 2014. The treatments were factorial combinations of no organic amendment, biochar (B), compost (Com), Com+B and co-composted biochar (COMBI) as main plots and five N fertilizer levels as sub-plots, with three replicates. Applicat ...
DOI:
10.1016/j.scitotenv.2016.05.033

9. Crop yield, plant nutrient uptake and soil physicochemical properties under organic soil amendments and nitrogen fertilization on Nitisols

Author:
Nelson, Paul N.,   et al.   ; Agegnehu, Getachew; Bird, Michael I.;     Show all 3 Authors
Source:
Soil & tillage research 2016 v.160 pp. 1-13
ISSN:
0167-1987
Subject:
Nitisols; barley; biochar; biomass; cation exchange capacity; chlorophyll; composts; farms; fertilizer rates; food production; grain yield; highlands; nitrogen; nitrogen content; nitrogen fertilizers; nutrient uptake; organic soils; soil amendments; soil fertility; soil organic carbon; soil pH; soil water; soil water content; tillers; Sub-Saharan Africa
Abstract:
... Sustaining soil fertility and enhancing food production on smallholder farms is a great challenge in sub-Saharan Africa. The effects of organic amendments and nitrogen fertilizer on soil physicochemical properties and barley yield were investigated in the central Ethiopian highlands. The treatments were factorial combinations of no organic amendment (control), 10tha−1 biochar only (B), 10tha−1 com ...
DOI:
10.1016/j.still.2016.02.003

10. The distributed-order fractional diffusion-wave equation of groundwater flow: Theory and application to pumping and slug tests

Author:
Nelson, Paul N.,   et al.   ; Su, Ninghu; Connor, Sarah;     Show all 3 Authors
Source:
Journal of hydrology 2015 v.529 pp. 1262-1273
ISSN:
0022-1694
Subject:
aquifers; equations; field experimentation; groundwater flow; saturated hydraulic conductivity
Abstract:
... We present a distributed-order fractional diffusion-wave equation (dofDWE) to describe radial groundwater flow to or from a well, and three sets of solutions of the dofDWE for flow from a well for aquifer tests: one for pumping tests, and two for slug tests. The dofDWE is featured by two temporal orders of fractional derivatives, β1 and β2, which characterise small and large pores, respectively. B ...
DOI:
10.1016/j.jhydrol.2015.09.033

11. A native arbuscular mycorrhizal fungus inoculant outcompetes an exotic commercial species under two contrasting yam field conditions

Author:
Nelson, Paul N.,   et al.   ; Kouadio, Aka Niangoran Marie-Stéphanie; Nandjui, Jacob; Krou, Serge Martial; Séry, Drolet Jean-Marc; Zézé, Adolphe;     Show all 6 Authors
Source:
Rhizosphere 2017 v.4 pp. 112-118
ISSN:
2452-2198
Subject:
Acaulospora; Dioscorea rotundata; Paraglomeraceae; Rhizophagus intraradices; Rhizophagus irregularis; agricultural soils; cassava; codominance; commercialization; mycorrhizal fungi; nutrient content; rhizosphere; sand; sandy loam soils; tubers; yams; Cote d'Ivoire; Spain
Abstract:
... 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, Côte d’Ivoire. The Duokro soil was neutral sandy l ...
DOI:
10.1016/j.rhisph.2017.10.001

12. Cropping sequence and nitrogen fertilizer effects on the productivity and quality of malting barley and soil fertility in the Ethiopian highlands

Author:
Nelson, Paul N.,   et al.   ; Agegnehu, Getachew; Lakew, Berhane;     Show all 3 Authors
Source:
Archiv für Acker- und Pflanzenbau und Bodenkunde 2014 v.60 no.9 pp. 1261-1275
ISSN:
1476-3567
Subject:
Nitisols; barley; break crops; carbon; cropping sequence; faba beans; fertilizer rates; grain yield; highlands; malting barley; malting quality; nitrogen; nitrogen content; nitrogen fertilizers; peas; protein content; rapeseed; seeds; soil fertility
Abstract:
... The productivity and quality of malting barley were evaluated using factorial combinations of four preceding crops (faba bean, field pea, rapeseed, and barley) as main plots and four nitrogen fertilizer rates (0, 18, 36, and 54 kg N ha ⁻¹) as sub-plots with three replications at two sites on Nitisols of the Ethiopian highlands in 2010 and 2011 cropping seasons. Preceding crops other than barley an ...
DOI:
10.1080/03650340.2014.881474

13. Benefits of biochar, compost and biochar–compost for soil quality, maize yield and greenhouse gas emissions in a tropical agricultural soil

Author:
Nelson, Paul N.,   et al.   ; Agegnehu, Getachew; Bass, Adrian M.; Bird, Michael I.;     Show all 4 Authors
Source:
The Science of the total environment 2016 v.543 pp. 295-306
ISSN:
0048-9697
Subject:
Ferralsols; aboveground biomass; agricultural soils; ammonium nitrogen; biochar; carbon dioxide; cation exchange capacity; chlorophyll; composts; corn; exchangeable cations; grain yield; greenhouse gas emissions; greenhouse gases; leaves; nitrate nitrogen; nitrogen; nitrous oxide; phosphorus; seeds; soil fertility; soil nutrients; soil organic carbon; soil quality; soil water; soil water content; stable isotopes; tropics
Abstract:
... Soil quality decline represents a significant constraint on the productivity and sustainability of agriculture in the tropics. In this study, the influence of biochar, compost and mixtures of the two on soil fertility, maize yield and greenhouse gas (GHG) emissions was investigated in a tropical Ferralsol. The treatments were: 1) control with business as usual fertilizer (F); 2) 10tha−1 biochar (B ...
DOI:
10.1016/j.scitotenv.2015.11.054

14. Tree-scale spatial variability of soil carbon cycling in a mature oil palm plantation

Author:
Nelson, Paul N.,   et al.   ; Goodrick, Iain; Nake, Steven; Webb, Michael J.; Bird, Michael I.; Huth, Neil;     Show all 6 Authors
Source:
Soil research 2016 v.54 no.4 pp. 397-406
ISSN:
1838-675X
Subject:
Elaeis guineensis; biomass; carbon; carbon cycle; carbon dioxide; fronds; greenhouse gas emissions; mineralization; oil crops; planting; roots; soil heterogeneity; soil water; soil water content; space and time; temperature; trees; Papua New Guinea
Abstract:
... 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-old, second planting cycle) oil palm plantation in P ...
DOI:
10.1071/SR15211

15. Development of an oil palm cropping systems model: Lessons learned and future directions

Author:
Nelson, Paul N.,   et al.   ; Huth, Neil I.; Banabas, Murom; Webb, Michael;     Show all 4 Authors
Source:
Environmental modelling & software 2014 v.62 pp. 411-419
ISSN:
1364-8152
Subject:
Elaeis guineensis; climate; computer software; cropping systems; crops; environmental models; environmental sustainability; meteorological data; production technology; soil; Papua New Guinea
Abstract:
... Oil palm has become one of the most important crops in the world with questions being raised about its economic and environmental sustainability. Agricultural systems models are regularly employed in studying sustainable crop management but no detailed model is currently available for oil palm systems.We developed a production systems model for oil palm within the Agricultural Production Systems S ...
DOI:
10.1016/j.envsoft.2014.06.021

16. Biochar and biochar-compost as soil amendments: Effects on peanut yield, soil properties and greenhouse gas emissions in tropical North Queensland, Australia

Author:
Nelson, Paul N.,   et al.   ; Agegnehu, Getachew; Bass, Adrian M.; Muirhead, Brian; Wright, Graeme; Bird, Michael I.;     Show all 6 Authors
Source:
Agriculture, ecosystems & environment 2015 v.213 pp. 72-85
ISSN:
0167-8809
Subject:
Ferralsols; biochar; carbon dioxide; chlorophyll; composts; correlation; greenhouse gas emissions; greenhouse gases; leaves; mineral fertilizers; nitrous oxide; nodulation; nutrient availability; nutrient content; peanuts; principal component analysis; seed yield; soil amendments; soil fertility; soil nutrients; soil organic carbon; soil water; soil water content; Queensland
Abstract:
... 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) 10tha−1 biochar+F (B+F); (3) 25t compost+F (Com+F)ha−1; (4) 2.5t Bha−1+25t Comha−1 mixed on site+F; and (5) 25tha−1 co-c ...
DOI:
10.1016/j.agee.2015.07.027

17. Phosphorus Response and Fertilizer Recommendations for Wheat Grown on Nitisols in the Central Ethiopian Highlands

Author:
Nelson, Paul N.,   et al.   ; Agegnehu, Getachew; Bird, Michael I.; van Beek, Christy;     Show all 4 Authors
Source:
Communications in soil science and plant analysis 2015 v.46 no.19 pp. 2411-2424
ISSN:
1532-2416
Subject:
NPK fertilizers; Nitisols; climate; farmers; fertilizer rates; field experimentation; food security; grain yield; highlands; phosphorus; phosphorus fertilizers; planting; seasons; soil properties; wheat
Abstract:
... 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 treatments, comprising six levels of P fertilizer (0, 1 ...
DOI:
10.1080/00103624.2015.1081922

18. Soil sampling in oil palm plantations: a practical design that accounts for lateral variability at the tree scale

Author:
Nelson, Paul N.,   et al.   ; Banabas, Murom; Goodrick, Iain; Webb, Michael J.; Huth, Neil I.; O’Grady, Damien;     Show all 6 Authors
Source:
Plant and soil 2015 v.394 no.1-2 pp. 421-429
ISSN:
0032-079X
Subject:
Elaeis guineensis; bulk density; crops; plantations; soil properties; soil sampling; trees
Abstract:
... 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 patterns known to influence soil properties. The eff ...
DOI:
10.1007/s11104-015-2490-9

19. The ameliorating effects of biochar and compost on soil quality and plant growth on a Ferralsol

Author:
Nelson, Paul N.,   et al.   ; Agegnehu, Getachew; Bird, Michael I.; Bass, Adrian M.;     Show all 4 Authors
Source:
Soil research 2015 v.53 no.1 pp. 1-12
ISSN:
1838-675X
Subject:
Acacia; Ferralsols; biochar; biomass; chlorophyll; composts; corn; fertilizer rates; harvesting; leaching; leaves; mineral fertilizers; nitrogen; nutrient content; nutrients; phosphorus; plant growth; potassium; principal component analysis; shoots; soil fertility; soil nutrients; soil quality; soil water content; synergism; variance; water uptake
Abstract:
... 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 compost. Treatments comprised: untreated control; min ...
DOI:
10.1071/SR14118

20. Soil pH buffering capacity: a descriptive function and its application to some acidic tropical soils

Author:
Nelson, Paul N.,   et al.   ; Su, Ninghu;     Show all 2 Author
Source:
Soil research 2010 v.48 no.3 pp. 201-207
ISSN:
0004-9573
Subject:
acidification; buffering capacity; calcium chloride; risk; soil acidification; soil organic matter; soil pH; titration; tropical soils; variable charge
Abstract:
... Calculation of soil acidification rates requires knowledge of pH buffering capacity (pHBC), which is measured using titration methods. The pHBC is often quoted as a single value for a particular soil, implying a linear relationship between pH and the amount of acid or alkali added. However, over its whole range, the relationship is sigmoid rather than linear, and in many soils pH is low or high en ...
DOI:
10.1071/SR09150