The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform
A B Mcbratney - One of the best experts on this subject based on the ideXlab platform.
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a small strip approach to empirically determining Management Class yield response functions and calculating the potential financial net wastage associated with whole field uniform rate fertiliser application
Field Crops Research, 2012Co-Authors: B M Whelan, J A Taylor, A B McbratneyAbstract:Abstract Site-specific crop Management requires site-specific information. The amount and pattern of variability in natural resources and production output, the reasons for variability, the agronomic implications and the Management opportunities ultimately need to be identified locally. In this context it is often desirable to obtain information on any variability in production response to different application rates of inputs across a site in order to help identify if worthwhile financial gains can be made by implementing spatially variable application rates. However there has been little development and promotion of practical, considered experimental design and analysis techniques that can be applied at a commercial farm scale to test variability in optimal input rates. Here a stratified, randomised, replicated ‘small strip’ experimental design is proposed for use in commercial-scale cropping systems that employ a Management Class approach. The experimental design considers technical, economic, agronomic and non-spatial statistical constraints and seeks to find a compromise between these constraints such that any one constraint is not limiting to adoption or interpretation. A description and rationale for the experimental design and analysis is presented followed by the results from the application of this experimental design to 15 nitrogen and 18 phosphorus response trials on various types of crops, in 3 different regions of Australia, over 6 seasons. Under these conditions, the results show that optimum response data can be obtained using the experimental technique. A gross margin analysis for each experiment was used to calculate the ‘net wastage’ in fertiliser and yield resulting from the customary, spatially uniform input Management. A median ‘wastage’ of A$39/ha for nitrogen fertiliser and A$48/ha for phosphorus fertiliser was observed. Standardising the individual results to the total, seasonal cost of uniform fertiliser application in each experiment, determined that the median ‘net wastage’ value equated to 99% of the traditional fertiliser budget for phosphorus and 97% for nitrogen. These figures suggest that the potential financial benefit to be gained over a number of seasons by knowing more about the optimum rates of fertiliser for Management Classes within a field could be equal to the amount of money traditionally outlaid on fertiliser. The technique does have some statistical limitations that require a practical, agronomic interpretation to be included in an assessment of the results. Although applied to nutrient response experiments in this study, it could be adapted for any crop input or Management practice experiment.
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A ‘small strip’ approach to empirically determining Management Class yield response functions and calculating the potential financial ‘net wastage’ associated with whole-field uniform-rate fertiliser application
Field Crops Research, 2012Co-Authors: Brett Whelan, J A Taylor, A B McbratneyAbstract:Abstract Site-specific crop Management requires site-specific information. The amount and pattern of variability in natural resources and production output, the reasons for variability, the agronomic implications and the Management opportunities ultimately need to be identified locally. In this context it is often desirable to obtain information on any variability in production response to different application rates of inputs across a site in order to help identify if worthwhile financial gains can be made by implementing spatially variable application rates. However there has been little development and promotion of practical, considered experimental design and analysis techniques that can be applied at a commercial farm scale to test variability in optimal input rates. Here a stratified, randomised, replicated ‘small strip’ experimental design is proposed for use in commercial-scale cropping systems that employ a Management Class approach. The experimental design considers technical, economic, agronomic and non-spatial statistical constraints and seeks to find a compromise between these constraints such that any one constraint is not limiting to adoption or interpretation. A description and rationale for the experimental design and analysis is presented followed by the results from the application of this experimental design to 15 nitrogen and 18 phosphorus response trials on various types of crops, in 3 different regions of Australia, over 6 seasons. Under these conditions, the results show that optimum response data can be obtained using the experimental technique. A gross margin analysis for each experiment was used to calculate the ‘net wastage’ in fertiliser and yield resulting from the customary, spatially uniform input Management. A median ‘wastage’ of A$39/ha for nitrogen fertiliser and A$48/ha for phosphorus fertiliser was observed. Standardising the individual results to the total, seasonal cost of uniform fertiliser application in each experiment, determined that the median ‘net wastage’ value equated to 99% of the traditional fertiliser budget for phosphorus and 97% for nitrogen. These figures suggest that the potential financial benefit to be gained over a number of seasons by knowing more about the optimum rates of fertiliser for Management Classes within a field could be equal to the amount of money traditionally outlaid on fertiliser. The technique does have some statistical limitations that require a practical, agronomic interpretation to be included in an assessment of the results. Although applied to nutrient response experiments in this study, it could be adapted for any crop input or Management practice experiment.
B M Whelan - One of the best experts on this subject based on the ideXlab platform.
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a small strip approach to empirically determining Management Class yield response functions and calculating the potential financial net wastage associated with whole field uniform rate fertiliser application
Field Crops Research, 2012Co-Authors: B M Whelan, J A Taylor, A B McbratneyAbstract:Abstract Site-specific crop Management requires site-specific information. The amount and pattern of variability in natural resources and production output, the reasons for variability, the agronomic implications and the Management opportunities ultimately need to be identified locally. In this context it is often desirable to obtain information on any variability in production response to different application rates of inputs across a site in order to help identify if worthwhile financial gains can be made by implementing spatially variable application rates. However there has been little development and promotion of practical, considered experimental design and analysis techniques that can be applied at a commercial farm scale to test variability in optimal input rates. Here a stratified, randomised, replicated ‘small strip’ experimental design is proposed for use in commercial-scale cropping systems that employ a Management Class approach. The experimental design considers technical, economic, agronomic and non-spatial statistical constraints and seeks to find a compromise between these constraints such that any one constraint is not limiting to adoption or interpretation. A description and rationale for the experimental design and analysis is presented followed by the results from the application of this experimental design to 15 nitrogen and 18 phosphorus response trials on various types of crops, in 3 different regions of Australia, over 6 seasons. Under these conditions, the results show that optimum response data can be obtained using the experimental technique. A gross margin analysis for each experiment was used to calculate the ‘net wastage’ in fertiliser and yield resulting from the customary, spatially uniform input Management. A median ‘wastage’ of A$39/ha for nitrogen fertiliser and A$48/ha for phosphorus fertiliser was observed. Standardising the individual results to the total, seasonal cost of uniform fertiliser application in each experiment, determined that the median ‘net wastage’ value equated to 99% of the traditional fertiliser budget for phosphorus and 97% for nitrogen. These figures suggest that the potential financial benefit to be gained over a number of seasons by knowing more about the optimum rates of fertiliser for Management Classes within a field could be equal to the amount of money traditionally outlaid on fertiliser. The technique does have some statistical limitations that require a practical, agronomic interpretation to be included in an assessment of the results. Although applied to nutrient response experiments in this study, it could be adapted for any crop input or Management practice experiment.
Rachel Zyirek - One of the best experts on this subject based on the ideXlab platform.
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Massasoit Libraries: BUSN125: Small Business Management - Mariano: Getting Started
2018Co-Authors: Rachel ZyirekAbstract:This guide support student research in Professor Mariano's Small Business Management Class.
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Massasoit Libraries: BUSN125: Small Business Management - Mariano: Finding Numbers
2018Co-Authors: Rachel ZyirekAbstract:This guide support student research in Professor Mariano's Small Business Management Class.
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Massasoit Libraries: BUSN112: Principles of Management - Peterson: Getting Started
2016Co-Authors: Rachel ZyirekAbstract:This guide supports the research project in Professor Rob Peterson's Principles of Management Class.
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Massasoit Libraries: BUSN112: Principles of Management - Peterson: Bias in the News Media
2016Co-Authors: Rachel ZyirekAbstract:This guide supports the research project in Professor Rob Peterson's Principles of Management Class.
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Massasoit Libraries: BUSN112: Principles of Management - Peterson: APA Style
2016Co-Authors: Rachel ZyirekAbstract:This guide supports the research project in Professor Rob Peterson's Principles of Management Class.
J A Taylor - One of the best experts on this subject based on the ideXlab platform.
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a small strip approach to empirically determining Management Class yield response functions and calculating the potential financial net wastage associated with whole field uniform rate fertiliser application
Field Crops Research, 2012Co-Authors: B M Whelan, J A Taylor, A B McbratneyAbstract:Abstract Site-specific crop Management requires site-specific information. The amount and pattern of variability in natural resources and production output, the reasons for variability, the agronomic implications and the Management opportunities ultimately need to be identified locally. In this context it is often desirable to obtain information on any variability in production response to different application rates of inputs across a site in order to help identify if worthwhile financial gains can be made by implementing spatially variable application rates. However there has been little development and promotion of practical, considered experimental design and analysis techniques that can be applied at a commercial farm scale to test variability in optimal input rates. Here a stratified, randomised, replicated ‘small strip’ experimental design is proposed for use in commercial-scale cropping systems that employ a Management Class approach. The experimental design considers technical, economic, agronomic and non-spatial statistical constraints and seeks to find a compromise between these constraints such that any one constraint is not limiting to adoption or interpretation. A description and rationale for the experimental design and analysis is presented followed by the results from the application of this experimental design to 15 nitrogen and 18 phosphorus response trials on various types of crops, in 3 different regions of Australia, over 6 seasons. Under these conditions, the results show that optimum response data can be obtained using the experimental technique. A gross margin analysis for each experiment was used to calculate the ‘net wastage’ in fertiliser and yield resulting from the customary, spatially uniform input Management. A median ‘wastage’ of A$39/ha for nitrogen fertiliser and A$48/ha for phosphorus fertiliser was observed. Standardising the individual results to the total, seasonal cost of uniform fertiliser application in each experiment, determined that the median ‘net wastage’ value equated to 99% of the traditional fertiliser budget for phosphorus and 97% for nitrogen. These figures suggest that the potential financial benefit to be gained over a number of seasons by knowing more about the optimum rates of fertiliser for Management Classes within a field could be equal to the amount of money traditionally outlaid on fertiliser. The technique does have some statistical limitations that require a practical, agronomic interpretation to be included in an assessment of the results. Although applied to nutrient response experiments in this study, it could be adapted for any crop input or Management practice experiment.
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A ‘small strip’ approach to empirically determining Management Class yield response functions and calculating the potential financial ‘net wastage’ associated with whole-field uniform-rate fertiliser application
Field Crops Research, 2012Co-Authors: Brett Whelan, J A Taylor, A B McbratneyAbstract:Abstract Site-specific crop Management requires site-specific information. The amount and pattern of variability in natural resources and production output, the reasons for variability, the agronomic implications and the Management opportunities ultimately need to be identified locally. In this context it is often desirable to obtain information on any variability in production response to different application rates of inputs across a site in order to help identify if worthwhile financial gains can be made by implementing spatially variable application rates. However there has been little development and promotion of practical, considered experimental design and analysis techniques that can be applied at a commercial farm scale to test variability in optimal input rates. Here a stratified, randomised, replicated ‘small strip’ experimental design is proposed for use in commercial-scale cropping systems that employ a Management Class approach. The experimental design considers technical, economic, agronomic and non-spatial statistical constraints and seeks to find a compromise between these constraints such that any one constraint is not limiting to adoption or interpretation. A description and rationale for the experimental design and analysis is presented followed by the results from the application of this experimental design to 15 nitrogen and 18 phosphorus response trials on various types of crops, in 3 different regions of Australia, over 6 seasons. Under these conditions, the results show that optimum response data can be obtained using the experimental technique. A gross margin analysis for each experiment was used to calculate the ‘net wastage’ in fertiliser and yield resulting from the customary, spatially uniform input Management. A median ‘wastage’ of A$39/ha for nitrogen fertiliser and A$48/ha for phosphorus fertiliser was observed. Standardising the individual results to the total, seasonal cost of uniform fertiliser application in each experiment, determined that the median ‘net wastage’ value equated to 99% of the traditional fertiliser budget for phosphorus and 97% for nitrogen. These figures suggest that the potential financial benefit to be gained over a number of seasons by knowing more about the optimum rates of fertiliser for Management Classes within a field could be equal to the amount of money traditionally outlaid on fertiliser. The technique does have some statistical limitations that require a practical, agronomic interpretation to be included in an assessment of the results. Although applied to nutrient response experiments in this study, it could be adapted for any crop input or Management practice experiment.
M. Balzarini - One of the best experts on this subject based on the ideXlab platform.
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subfield Management Class delineation using cluster analysis from spatial principal components of soil variables
Computers and Electronics in Agriculture, 2013Co-Authors: Mario Cordoba, Cecilia Bruno, Jose Luis Costa, M. BalzariniAbstract:Understanding spatial variation within a field is essential for site-specific crop Management, which requires the delineation of Management areas. Several soil and terrain variables are used to Classify the field points into Classes. Fuzzy k-means cluster analysis is a widely used tool to delineate Management Classes in the multivariate context. However, this clustering method does not consider the presence of spatial correlations in the data. The MULTISPATI-PCA algorithm is an extension of principal component analysis that considers spatial autocorrelation in the original variables to produce synthetic variables. We propose and illustrate the implementation of a new method (KM-sPC) for subfield Management Class delineation based on the joint use of MULTISPATI-PCA and fuzzy k-means cluster. To assess the performance of KM-sPC, we performed clustering of the original soil variables and of both spatial and Classical principal components on three field data sets. KM-sPC algorithm improved the non-spatial clustering in the formation of within-field Management Classes. Mapping of KM-sPC Classification shows a more contiguous zoning. KM-sPC showed the highest yield differences between delineated Classes and the smallest within-Class yield variance.
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Subfield Management Class delineation using cluster analysis from spatial principal components of soil variables
Computers and Electronics in Agriculture, 2013Co-Authors: Mario Cordoba, J Costa, Claudio Bruno, M. BalzariniAbstract:Understanding spatial variation within a field is essential for site-specific crop Management, which requires the delineation of Management areas. Several soil and terrain variables are used to Classify the field points into Classes. Fuzzy k-means cluster analysis is a widely used tool to delineate Management Classes in the multivariate context. However, this clustering method does not consider the presence of spatial correlations in the data. The MULTISPATI-PCA algorithm is an extension of principal component analysis that considers spatial autocorrelation in the original variables to produce synthetic variables. We propose and illustrate the implementation of a new method (KM-sPC) for subfield Management Class delineation based on the joint use of MULTISPATI-PCA and fuzzy k-means cluster. To assess the performance of KM-sPC, we performed clustering of the original soil variables and of both spatial and Classical principal components on three field data sets. KM-sPC algorithm improved the non-spatial clustering in the formation of within-field Management Classes. Mapping of KM-sPC Classification shows a more contiguous zoning. KM-sPC showed the highest yield differences between delineated Classes and the smallest within-Class yield variance. © 2013 Elsevier B.V.
