Richard Doyle | University of Tasmania (original) (raw)
Papers by Richard Doyle
Applied and Environmental Soil Science, 2015
Soils treated with lime-amended biosolids (LAB), poppy seed waste (PSW), anaerobically digested b... more Soils treated with lime-amended biosolids (LAB), poppy seed waste (PSW), anaerobically digested biosolids (ADB) and poppy mulch (PM) and incubated at 12.5°C for 56 days released 45%, 36%, 25%, and −8%, respectively, of total applied N as plant available nitrogen (PAN) by the end of the incubation. The mineralisation rates were contrary to expectations based on the C : N ratios of the four products: LAB (5 : 1), PSW (7 : 1), ADB (3 : 1), and PM (16 : 1). PM showed a significant negative priming effect over the incubation period. These results have implications for production agriculture in temperate regions where application and incorporation of bio-resources traditionally occurs in autumn and spring when soil and air temperatures are relatively low. Current application times may not be suitable for nitrogen release to satisfy crop demand.
I International Symposium on Organic Matter Management and Compost Use in Horticulture, 2014
ABSTRACT This paper reviews available literature on vegetable production systems in Papua New Gui... more ABSTRACT This paper reviews available literature on vegetable production systems in Papua New Guinea (PNG), including the role of composted organic matter in sustaining the practice of shifting cultivation. The implications for commercial temperate vegetable production in Central Province (CP), PNG, are discussed, taking into consideration the similarities and differences between CP and the traditional highland vegetable production regions.
Soil resources of the Eastern Highlands Province and Central Province of Papua New Guinea are out... more Soil resources of the Eastern Highlands Province and Central Province of Papua New Guinea are outlined, with particular emphasis on the implications of their characteristics for agronomic practice and soil management under conditions of increasing demand for food because of population increase. Implications for crop options are also examined. Key areas of irrigation and drainage, acid soil infertility, organic matter based farming and nutrient management, with particular emphasis on nitrogen, phosphorus and potassium supply and availability in soils, are examined in a sustainability context. Cation balance, micronutrient and sulphur supply are also considered. The risk of soil degradation is examined briefly, and the need to select appropriate sites for sustainable intensive production highlighted. Introduction Soil resources and climatic conditions interact strongly influence crop options and agronomic practices. This interaction is particularly important in developing countries wh...
suitability analysis has been undertaken for potential vegetable producing areas surrounding Port... more suitability analysis has been undertaken for potential vegetable producing areas surrounding Port Moresby, PNG. We have used high resolution radar based imagery to produce 10 m resolution outputs. This will later be combined with an updated geology and climatic information (layers) from PNGRIS and other map sources. This analysis will clearly identify areas most suitable for an intensification of agricultural production on a sustainable basis. Discussions were held with local coop members on soil and crop management strategies. Soil profiles are described and sampled for analysis at NARI laboratories in Port Moresby. GEOSAR X Band Radar P Band 10m Radar Elevation Model Topographic Position Index High Fertility Lower Slopes (purple) Inundation (Blue) within High Fertility Lower Slopes Using a 10 m Digital Elevation Model (DEM) derived from GEOSAR Radar data a four class Topographic Position Index was generated using Land Facet Tools Extension for ArcGIS (Jenness et. al 2011). This ex...
ABSTRACT This paper reviews available literature on vegetable production systems in Papua New Gui... more ABSTRACT This paper reviews available literature on vegetable production systems in Papua New Guinea (PNG), including the role of composted organic matter in sustaining the practice of shifting cultivation. The implications for commercial temperate vegetable production in Central Province (CP), PNG, are discussed, taking into consideration the similarities and differences between CP and the traditional highland vegetable production regions.
Soil Use and Management, 2006
Organic carbon (C) was measured in the silt + clay fraction of 78 soils from agricultural areas i... more Organic carbon (C) was measured in the silt + clay fraction of 78 soils from agricultural areas in Tasmania, and the relationship between C in the silt + clay fraction and the percentage by weight of particles in this fraction was compared with similar data for soils from other regions and climates. Most of the cropping soils from Tasmania followed a previously published linear relationship, which is considered an indication of the capacity of soils to store C. The soils which fell the greatest distance below this relationship were sandy soils, consistent with previous evidence that these soils in Tasmania have been degraded. Soils which showed a major positive departure from the relationship were clay loams with >60% silt + clay. Most were also pasture soils. Tasmania's cool-temperate climate would promote plant growth and C inputs and slow C breakdown, while the high clay content would help protect C. The results for the clay loam soils are consistent with earlier observations that these soils are generally in good health.
Soil Research, 2013
ABSTRACT The effects of environmental parameters, land-use history, and management practices on s... more ABSTRACT The effects of environmental parameters, land-use history, and management practices on soil organic carbon (SOC) concentrations, nitrogen, and bulk density were determined in agricultural soils of four soil types in Tasmania. The sites sampled were Dermosols, Vertosols, Ferrosols, and a group of texture-contrast soils (Chromosol and Sodosol) each with a 10-year management history ranging from permanent perennial pasture to continuous cropping. Rainfall, Soil Order, and land use were all strong explanatory variables for differences in SOC, soil carbon stock, total nitrogen, and bulk density. Cropping sites had 29-35% less SOC in surface soils (0-0.1m) than pasture sites as well as greater bulk densities. Clay-rich soils contained the greatest carbon stocks to 0.3m depth under pasture, with Ferrosols containing a mean of 158MgCha(-1), Vertosols 112MgCha(-1), and Dermosols 107MgCha(-1). Texture-contrast soils with sandier textured topsoils under pasture had a mean of 69MgCha(-1). The range of values in soil carbon stocks indicates considerable uncertainty in baseline values for use in soil carbon accounting. Farmers can influence SOC more by their choice of land use than their day-to-day soil management. Although the influence of management is not as great as other inherent site variables, farmers can still select practices for their ability to retain more SOC.
Geomorphology, 2012
ABSTRACT Many Tasmanian deposits previously described as ‘periglacial’ have been described in mor... more ABSTRACT Many Tasmanian deposits previously described as ‘periglacial’ have been described in more detail, re-interpreted and dated. We suggest that ‘periglacial’ has little meaning when applied locally and the term ‘relict cold-climate deposits’ is more appropriate. In this paper we examine the origin and age of relict cold-climate slope deposits, fan alluvium and aeolian sediments in Tasmania, and infer the conditions under which they accumulated.Fan alluvium dating from the penultimate Glacial (OIS 6) and capped by a prominent palaeosol deduced to date to the Last Interglacial (OIS 5e) is present at Woodstock, south of Hobart. Many fan deposits formed before 40 ka or in a period c. 30–23 ka; only a few deposits date to the Last Glacial Maximum in Tasmania, which is defined as spanning the period 23.5–17.5 ka.Slope deposits indicate widespread instability down to present-day sea level throughout the Last Glacial, probably as a result of freeze–thaw in a sparsely vegetated landscape. Layered fine gravel and coarse sand colluvial deposits resembling grèzes litées, produced both by dry deposition and by the action of water, are locally common where jointed siltstone bedrock outcrops. These deposits occur from altitudes of 500 m to near sea level and also in caves and must have formed under sparse vegetation cover, probably by freeze–thaw in extremely dry conditions. They have been radiocarbon dated from 35 to 17.5 cal. ka.Relict dunes and sandsheets are widespread at the margin of the Bassian Plain that once provided a land bridge between Tasmania and the mainland. They are also found in western Tasmania and in areas of inland southern Tasmania that now support wet eucalypt forest and rainforest and receive mean annual rainfall > 1500 mm. In the south they have been dated > 87.5–19 ka and attest to a long period of semi-arid climate in an area extending well to the west and south of the present semiarid zone.We deduce that during most of the Last Glacial anticyclones dominated Tasmania's climate and rain-bearing depressions generally passed south of the land mass. However in the east prominent palaeosols in aeolian deposits, dated between 26.4 ka and 16 ka at different locations, and palaeosols with morphology indicating formation under humid conditions, indicate periods of wetter climate in eastern Tasmania during or close to the LGM, deduced to be the result of easterlies associated with near-coastal depressions in the western Tasman Sea. Such easterlies may also be responsible for short Last Glacial wet periods noted at mainland coastal sites.A plot of ages of all dated deposits reveals an increase of erosion and deposition between 35 and 20 ka, and greater prevalence of aeolian deposits in the 35–15 ka period than earlier in the Last Glacial. There are two possible explanations for this pattern: (1) that aeolian activity increased as the result of climatic effects (e.g. increased windiness); or (2) that shrubland biomass increased after the megafauna were hunted to extinction following human arrival c. 40 ka, causing increased fire frequency, and in the cold dry climate of the late Last Glacial such fires caused increased erosion and increased aeolian accumulation.
Geoderma, 2004
Soil genesis has been examined using field description, particle size distributions, chemical pro... more Soil genesis has been examined using field description, particle size distributions, chemical properties, mineralogy and elemental distributions of five soil profiles developed on dolerite on Mt Nelson and Tolmans Hill near Hobart in Tasmania. The soils form a sequence ranging from a Black Vertosol (P8) to four texture contrast soils namely a Eutrophic Brown Chromosol (P5), two Mottled-Subnatric Grey Sodosols a Corresponding author.
Page 1. Richard Barry Doyle Bachelor of Science (honours) Master of Science (distinction) Submitt... more Page 1. Richard Barry Doyle Bachelor of Science (honours) Master of Science (distinction) Submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy University of Tasmania, March 2005 Mount Orlikos ...
Historical water quality data from stations at Baden, downstream of the Craigbourne Dam, Richmond... more Historical water quality data from stations at Baden, downstream of the Craigbourne Dam, Richmond and White Kangaroo Rivulet collected between 1999 and 2008 were obtained from DPIPWE. Riparian land use within one kilometre of the river was assessed and digitised using 2005/7 colour aerial photographs and water quality data for that period were examined and possible linkages investigated. The historical data demonstrates complex spatial patterns of in-stream water quality parameters in the Coal River Valley. There was ...
Changes in the soil structure and hydraulic conductivity of an Acidic Red Ferrosol were measured ... more Changes in the soil structure and hydraulic conductivity of an Acidic Red Ferrosol were measured in a long-term (1968-2003) fertiliser experiment on pasture in north-western Tasmania, Australia. Studies were initiated following observations of both softer soil surface and cracking on plots that had received 15 t/ha of ground agricultural limestone. Liming decreased penetration resistance and increased hydraulic conductivity. These structural improvements were associated with increased mean dry aggregate size, a small increase in wet aggregate stability, higher exchangeable calcium levels, and increased plant growth, but a 9% decrease in total soil organic carbon in the surface 50 mm. This decrease in organic carbon was not associated with deterioration in soil structure, as may have been anticipated. This was probably because total organic C was still 82 g/kg on unlimed plots. Decreases in soil penetration resistance due to liming increased the likelihood of pugging from livestock but may improve ease of tillage.
It is estimated that sodic soils (ESP>G) occupy at least 23% of Tasmania's land area based on the... more It is estimated that sodic soils (ESP>G) occupy at least 23% of Tasmania's land area based on the present limited soil data set. Sodic soils are mostly restricted to lower rainfall areas (<800 mm/y) of eastern Tasmania, occurring primarily in the Launceston Tertiary Basin, the Derwent, Coal, Jordan and Huon River Valleys and on Flinders Island.
Site-species matching is vital for successful reforestation. This study examined the site conditi... more Site-species matching is vital for successful reforestation. This study examined the site conditions for seedling growth and development of Hopea odorata Roxb. in a secondary natural evergreen dipterocarp forest in South Vietnam and in artificial gaps in an Acacia hybrid plantation on degraded land in Central Vietnam. The per cent transmitted incident daily photosynthetically active radiation (PAR) near the forest floor of around 11% was necessary for active seedling development in the natural forest. In the plantation, a positive response of seedling growth and photosynthetic rate up to a transmitted PAR level of around 60% was observed. This suggests that while H. odorata is shade-adapted, higher light levels are required to maximise its potential growth rate. Soils with low nutrient concentration associated with low clay and high sand contents appeared not to constrain the growth of H. odorata seedlings given adequate light conditions. Vigorous growth of seedlings in soils ranging from slightly acidic in the natural forest to very acidic in the plantation indicates that this species can adapt to a wide range of soil acidity. Successful re-establishment of H. odorata on degraded sites using nurse crops should be possible provided that high levels of shading are avoided.
Applied and Environmental Soil Science, 2015
Soils treated with lime-amended biosolids (LAB), poppy seed waste (PSW), anaerobically digested b... more Soils treated with lime-amended biosolids (LAB), poppy seed waste (PSW), anaerobically digested biosolids (ADB) and poppy mulch (PM) and incubated at 12.5°C for 56 days released 45%, 36%, 25%, and −8%, respectively, of total applied N as plant available nitrogen (PAN) by the end of the incubation. The mineralisation rates were contrary to expectations based on the C : N ratios of the four products: LAB (5 : 1), PSW (7 : 1), ADB (3 : 1), and PM (16 : 1). PM showed a significant negative priming effect over the incubation period. These results have implications for production agriculture in temperate regions where application and incorporation of bio-resources traditionally occurs in autumn and spring when soil and air temperatures are relatively low. Current application times may not be suitable for nitrogen release to satisfy crop demand.
I International Symposium on Organic Matter Management and Compost Use in Horticulture, 2014
ABSTRACT This paper reviews available literature on vegetable production systems in Papua New Gui... more ABSTRACT This paper reviews available literature on vegetable production systems in Papua New Guinea (PNG), including the role of composted organic matter in sustaining the practice of shifting cultivation. The implications for commercial temperate vegetable production in Central Province (CP), PNG, are discussed, taking into consideration the similarities and differences between CP and the traditional highland vegetable production regions.
Soil resources of the Eastern Highlands Province and Central Province of Papua New Guinea are out... more Soil resources of the Eastern Highlands Province and Central Province of Papua New Guinea are outlined, with particular emphasis on the implications of their characteristics for agronomic practice and soil management under conditions of increasing demand for food because of population increase. Implications for crop options are also examined. Key areas of irrigation and drainage, acid soil infertility, organic matter based farming and nutrient management, with particular emphasis on nitrogen, phosphorus and potassium supply and availability in soils, are examined in a sustainability context. Cation balance, micronutrient and sulphur supply are also considered. The risk of soil degradation is examined briefly, and the need to select appropriate sites for sustainable intensive production highlighted. Introduction Soil resources and climatic conditions interact strongly influence crop options and agronomic practices. This interaction is particularly important in developing countries wh...
suitability analysis has been undertaken for potential vegetable producing areas surrounding Port... more suitability analysis has been undertaken for potential vegetable producing areas surrounding Port Moresby, PNG. We have used high resolution radar based imagery to produce 10 m resolution outputs. This will later be combined with an updated geology and climatic information (layers) from PNGRIS and other map sources. This analysis will clearly identify areas most suitable for an intensification of agricultural production on a sustainable basis. Discussions were held with local coop members on soil and crop management strategies. Soil profiles are described and sampled for analysis at NARI laboratories in Port Moresby. GEOSAR X Band Radar P Band 10m Radar Elevation Model Topographic Position Index High Fertility Lower Slopes (purple) Inundation (Blue) within High Fertility Lower Slopes Using a 10 m Digital Elevation Model (DEM) derived from GEOSAR Radar data a four class Topographic Position Index was generated using Land Facet Tools Extension for ArcGIS (Jenness et. al 2011). This ex...
ABSTRACT This paper reviews available literature on vegetable production systems in Papua New Gui... more ABSTRACT This paper reviews available literature on vegetable production systems in Papua New Guinea (PNG), including the role of composted organic matter in sustaining the practice of shifting cultivation. The implications for commercial temperate vegetable production in Central Province (CP), PNG, are discussed, taking into consideration the similarities and differences between CP and the traditional highland vegetable production regions.
Soil Use and Management, 2006
Organic carbon (C) was measured in the silt + clay fraction of 78 soils from agricultural areas i... more Organic carbon (C) was measured in the silt + clay fraction of 78 soils from agricultural areas in Tasmania, and the relationship between C in the silt + clay fraction and the percentage by weight of particles in this fraction was compared with similar data for soils from other regions and climates. Most of the cropping soils from Tasmania followed a previously published linear relationship, which is considered an indication of the capacity of soils to store C. The soils which fell the greatest distance below this relationship were sandy soils, consistent with previous evidence that these soils in Tasmania have been degraded. Soils which showed a major positive departure from the relationship were clay loams with >60% silt + clay. Most were also pasture soils. Tasmania's cool-temperate climate would promote plant growth and C inputs and slow C breakdown, while the high clay content would help protect C. The results for the clay loam soils are consistent with earlier observations that these soils are generally in good health.
Soil Research, 2013
ABSTRACT The effects of environmental parameters, land-use history, and management practices on s... more ABSTRACT The effects of environmental parameters, land-use history, and management practices on soil organic carbon (SOC) concentrations, nitrogen, and bulk density were determined in agricultural soils of four soil types in Tasmania. The sites sampled were Dermosols, Vertosols, Ferrosols, and a group of texture-contrast soils (Chromosol and Sodosol) each with a 10-year management history ranging from permanent perennial pasture to continuous cropping. Rainfall, Soil Order, and land use were all strong explanatory variables for differences in SOC, soil carbon stock, total nitrogen, and bulk density. Cropping sites had 29-35% less SOC in surface soils (0-0.1m) than pasture sites as well as greater bulk densities. Clay-rich soils contained the greatest carbon stocks to 0.3m depth under pasture, with Ferrosols containing a mean of 158MgCha(-1), Vertosols 112MgCha(-1), and Dermosols 107MgCha(-1). Texture-contrast soils with sandier textured topsoils under pasture had a mean of 69MgCha(-1). The range of values in soil carbon stocks indicates considerable uncertainty in baseline values for use in soil carbon accounting. Farmers can influence SOC more by their choice of land use than their day-to-day soil management. Although the influence of management is not as great as other inherent site variables, farmers can still select practices for their ability to retain more SOC.
Geomorphology, 2012
ABSTRACT Many Tasmanian deposits previously described as ‘periglacial’ have been described in mor... more ABSTRACT Many Tasmanian deposits previously described as ‘periglacial’ have been described in more detail, re-interpreted and dated. We suggest that ‘periglacial’ has little meaning when applied locally and the term ‘relict cold-climate deposits’ is more appropriate. In this paper we examine the origin and age of relict cold-climate slope deposits, fan alluvium and aeolian sediments in Tasmania, and infer the conditions under which they accumulated.Fan alluvium dating from the penultimate Glacial (OIS 6) and capped by a prominent palaeosol deduced to date to the Last Interglacial (OIS 5e) is present at Woodstock, south of Hobart. Many fan deposits formed before 40 ka or in a period c. 30–23 ka; only a few deposits date to the Last Glacial Maximum in Tasmania, which is defined as spanning the period 23.5–17.5 ka.Slope deposits indicate widespread instability down to present-day sea level throughout the Last Glacial, probably as a result of freeze–thaw in a sparsely vegetated landscape. Layered fine gravel and coarse sand colluvial deposits resembling grèzes litées, produced both by dry deposition and by the action of water, are locally common where jointed siltstone bedrock outcrops. These deposits occur from altitudes of 500 m to near sea level and also in caves and must have formed under sparse vegetation cover, probably by freeze–thaw in extremely dry conditions. They have been radiocarbon dated from 35 to 17.5 cal. ka.Relict dunes and sandsheets are widespread at the margin of the Bassian Plain that once provided a land bridge between Tasmania and the mainland. They are also found in western Tasmania and in areas of inland southern Tasmania that now support wet eucalypt forest and rainforest and receive mean annual rainfall > 1500 mm. In the south they have been dated > 87.5–19 ka and attest to a long period of semi-arid climate in an area extending well to the west and south of the present semiarid zone.We deduce that during most of the Last Glacial anticyclones dominated Tasmania's climate and rain-bearing depressions generally passed south of the land mass. However in the east prominent palaeosols in aeolian deposits, dated between 26.4 ka and 16 ka at different locations, and palaeosols with morphology indicating formation under humid conditions, indicate periods of wetter climate in eastern Tasmania during or close to the LGM, deduced to be the result of easterlies associated with near-coastal depressions in the western Tasman Sea. Such easterlies may also be responsible for short Last Glacial wet periods noted at mainland coastal sites.A plot of ages of all dated deposits reveals an increase of erosion and deposition between 35 and 20 ka, and greater prevalence of aeolian deposits in the 35–15 ka period than earlier in the Last Glacial. There are two possible explanations for this pattern: (1) that aeolian activity increased as the result of climatic effects (e.g. increased windiness); or (2) that shrubland biomass increased after the megafauna were hunted to extinction following human arrival c. 40 ka, causing increased fire frequency, and in the cold dry climate of the late Last Glacial such fires caused increased erosion and increased aeolian accumulation.
Geoderma, 2004
Soil genesis has been examined using field description, particle size distributions, chemical pro... more Soil genesis has been examined using field description, particle size distributions, chemical properties, mineralogy and elemental distributions of five soil profiles developed on dolerite on Mt Nelson and Tolmans Hill near Hobart in Tasmania. The soils form a sequence ranging from a Black Vertosol (P8) to four texture contrast soils namely a Eutrophic Brown Chromosol (P5), two Mottled-Subnatric Grey Sodosols a Corresponding author.
Page 1. Richard Barry Doyle Bachelor of Science (honours) Master of Science (distinction) Submitt... more Page 1. Richard Barry Doyle Bachelor of Science (honours) Master of Science (distinction) Submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy University of Tasmania, March 2005 Mount Orlikos ...
Historical water quality data from stations at Baden, downstream of the Craigbourne Dam, Richmond... more Historical water quality data from stations at Baden, downstream of the Craigbourne Dam, Richmond and White Kangaroo Rivulet collected between 1999 and 2008 were obtained from DPIPWE. Riparian land use within one kilometre of the river was assessed and digitised using 2005/7 colour aerial photographs and water quality data for that period were examined and possible linkages investigated. The historical data demonstrates complex spatial patterns of in-stream water quality parameters in the Coal River Valley. There was ...
Changes in the soil structure and hydraulic conductivity of an Acidic Red Ferrosol were measured ... more Changes in the soil structure and hydraulic conductivity of an Acidic Red Ferrosol were measured in a long-term (1968-2003) fertiliser experiment on pasture in north-western Tasmania, Australia. Studies were initiated following observations of both softer soil surface and cracking on plots that had received 15 t/ha of ground agricultural limestone. Liming decreased penetration resistance and increased hydraulic conductivity. These structural improvements were associated with increased mean dry aggregate size, a small increase in wet aggregate stability, higher exchangeable calcium levels, and increased plant growth, but a 9% decrease in total soil organic carbon in the surface 50 mm. This decrease in organic carbon was not associated with deterioration in soil structure, as may have been anticipated. This was probably because total organic C was still 82 g/kg on unlimed plots. Decreases in soil penetration resistance due to liming increased the likelihood of pugging from livestock but may improve ease of tillage.
It is estimated that sodic soils (ESP>G) occupy at least 23% of Tasmania's land area based on the... more It is estimated that sodic soils (ESP>G) occupy at least 23% of Tasmania's land area based on the present limited soil data set. Sodic soils are mostly restricted to lower rainfall areas (<800 mm/y) of eastern Tasmania, occurring primarily in the Launceston Tertiary Basin, the Derwent, Coal, Jordan and Huon River Valleys and on Flinders Island.
Site-species matching is vital for successful reforestation. This study examined the site conditi... more Site-species matching is vital for successful reforestation. This study examined the site conditions for seedling growth and development of Hopea odorata Roxb. in a secondary natural evergreen dipterocarp forest in South Vietnam and in artificial gaps in an Acacia hybrid plantation on degraded land in Central Vietnam. The per cent transmitted incident daily photosynthetically active radiation (PAR) near the forest floor of around 11% was necessary for active seedling development in the natural forest. In the plantation, a positive response of seedling growth and photosynthetic rate up to a transmitted PAR level of around 60% was observed. This suggests that while H. odorata is shade-adapted, higher light levels are required to maximise its potential growth rate. Soils with low nutrient concentration associated with low clay and high sand contents appeared not to constrain the growth of H. odorata seedlings given adequate light conditions. Vigorous growth of seedlings in soils ranging from slightly acidic in the natural forest to very acidic in the plantation indicates that this species can adapt to a wide range of soil acidity. Successful re-establishment of H. odorata on degraded sites using nurse crops should be possible provided that high levels of shading are avoided.