Pub Date : 1983-02-01DOI: 10.1016/0304-3746(83)90006-9
R.L. Burt, W.T. Williams, D.J. Abel
The problems of analysing genetic resources data are reviewed, with particular reference to the use of graph-theoretic methods and to the concept of “validation”. A taxonomically difficult set of Stylosanthes (Leguminosae) accessions is subjected to classification, a minimum spanning tree, and a two-neighbour network. It is then subjected to a novel multiple-nearest-neighbour approach (program NEBALL) which provides a more detailed and exact summary of the configuration; this is validated by appeal to phytochemical, provenance and performance data. The results suggest that, providing the assumptions implicit in the model are met, the new technique may well be the most powerful yet available for the study of genetic resources data.
{"title":"A new graph-theoretic technique for the analysis of genetic resources data","authors":"R.L. Burt, W.T. Williams, D.J. Abel","doi":"10.1016/0304-3746(83)90006-9","DOIUrl":"10.1016/0304-3746(83)90006-9","url":null,"abstract":"<div><p>The problems of analysing genetic resources data are reviewed, with particular reference to the use of graph-theoretic methods and to the concept of “validation”. A taxonomically difficult set of <em>Stylosanthes</em> (Leguminosae) accessions is subjected to classification, a minimum spanning tree, and a two-neighbour network. It is then subjected to a novel multiple-nearest-neighbour approach (program NEBALL) which provides a more detailed and exact summary of the configuration; this is validated by appeal to phytochemical, provenance and performance data. The results suggest that, providing the assumptions implicit in the model are met, the new technique may well be the most powerful yet available for the study of genetic resources data.</p></div>","PeriodicalId":100066,"journal":{"name":"Agro-Ecosystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-3746(83)90006-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88229322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-02-01DOI: 10.1016/0304-3746(83)90015-X
M.J. Frissel
{"title":"Nitrogen cycling in west African ecosystems","authors":"M.J. Frissel","doi":"10.1016/0304-3746(83)90015-X","DOIUrl":"10.1016/0304-3746(83)90015-X","url":null,"abstract":"","PeriodicalId":100066,"journal":{"name":"Agro-Ecosystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-3746(83)90015-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"102057642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-02-01DOI: 10.1016/0304-3746(83)90017-3
A. ban Diest
{"title":"Proceedings o f a symposium on paddy soil","authors":"A. ban Diest","doi":"10.1016/0304-3746(83)90017-3","DOIUrl":"https://doi.org/10.1016/0304-3746(83)90017-3","url":null,"abstract":"","PeriodicalId":100066,"journal":{"name":"Agro-Ecosystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-3746(83)90017-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137439014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-02-01DOI: 10.1016/0304-3746(83)90009-4
G. Singh, Z. Singh, I.S. Dahiya, R.S. Malik
The simultaneous movement of surface-applied phorate and water was studied in laboratory columns containing, initially, moist and dry sandy loam soil. Phorate was applied onto the soil and leached with water under ponded and controlled infiltration conditions. Phorate and water distribution profiles were determined by destructive sampling at two stages: (1) immediately following infiltration and (2) after matching total infiltration, redistribution and evaporation time for two water-application rates. Regardless of the initial soil water content, just after the termination of infiltration, phorate was displaced more efficiently and its concentration peak formed at deeper depth with the slower than with the faster application rate. Following redistribution, this trend was reversed. Phorate movement was also found to be dependent on the initial soil water content. The higher the initial soil water content, the deeper and more complete was the displacement of phorate during infiltration and redistribution.
{"title":"Movement of surface-applied phorate and water through unsaturated soil","authors":"G. Singh, Z. Singh, I.S. Dahiya, R.S. Malik","doi":"10.1016/0304-3746(83)90009-4","DOIUrl":"10.1016/0304-3746(83)90009-4","url":null,"abstract":"<div><p>The simultaneous movement of surface-applied phorate and water was studied in laboratory columns containing, initially, moist and dry sandy loam soil. Phorate was applied onto the soil and leached with water under ponded and controlled infiltration conditions. Phorate and water distribution profiles were determined by destructive sampling at two stages: (1) immediately following infiltration and (2) after matching total infiltration, redistribution and evaporation time for two water-application rates. Regardless of the initial soil water content, just after the termination of infiltration, phorate was displaced more efficiently and its concentration peak formed at deeper depth with the slower than with the faster application rate. Following redistribution, this trend was reversed. Phorate movement was also found to be dependent on the initial soil water content. The higher the initial soil water content, the deeper and more complete was the displacement of phorate during infiltration and redistribution.</p></div>","PeriodicalId":100066,"journal":{"name":"Agro-Ecosystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-3746(83)90009-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88467495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-02-01DOI: 10.1016/0304-3746(83)90012-4
P. Jacquard
{"title":"Physiological processes in plant ecology. Toward a synthesis with atriplex","authors":"P. Jacquard","doi":"10.1016/0304-3746(83)90012-4","DOIUrl":"https://doi.org/10.1016/0304-3746(83)90012-4","url":null,"abstract":"","PeriodicalId":100066,"journal":{"name":"Agro-Ecosystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-3746(83)90012-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137439016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-02-01DOI: 10.1016/0304-3746(83)90018-5
K.J. Murphy
{"title":"Elsevier's dictionary of weeds of western Europe","authors":"K.J. Murphy","doi":"10.1016/0304-3746(83)90018-5","DOIUrl":"10.1016/0304-3746(83)90018-5","url":null,"abstract":"","PeriodicalId":100066,"journal":{"name":"Agro-Ecosystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-3746(83)90018-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72813469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-02-01DOI: 10.1016/0304-3746(83)90016-1
J.W. Sturrock
{"title":"Grassland in the British economy","authors":"J.W. Sturrock","doi":"10.1016/0304-3746(83)90016-1","DOIUrl":"https://doi.org/10.1016/0304-3746(83)90016-1","url":null,"abstract":"","PeriodicalId":100066,"journal":{"name":"Agro-Ecosystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-3746(83)90016-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137439013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1982-07-01DOI: 10.1016/0304-3746(82)90002-6
Stephen M. Freedman
Human labor requirements for rice production practices in the developing world are assessed in terms of baseline worker hours and energy costs per hectare. Modifications of traditional cultivation systems are analyzed with respect to agricultural techniques (the methods by which inputs are powered) and technologies (the applications of knowledge to the production system) used. Human labor, animal labor and mechanical sources of energy are compared within traditional, improved and modern modes of technology. Nine different technique/technology options are examined in terms of energy efficiency for land preparation and seeding, harvesting and threshing, as well as auxilliary intercultivation procedures. Specific employment planning strategies are suggested, based on the results of the operational analysis.
{"title":"Human labor as an energy source for rice production in the developing world","authors":"Stephen M. Freedman","doi":"10.1016/0304-3746(82)90002-6","DOIUrl":"10.1016/0304-3746(82)90002-6","url":null,"abstract":"<div><p>Human labor requirements for rice production practices in the developing world are assessed in terms of baseline worker hours and energy costs per hectare. Modifications of traditional cultivation systems are analyzed with respect to agricultural techniques (the methods by which inputs are powered) and technologies (the applications of knowledge to the production system) used. Human labor, animal labor and mechanical sources of energy are compared within traditional, improved and modern modes of technology. Nine different technique/technology options are examined in terms of energy efficiency for land preparation and seeding, harvesting and threshing, as well as auxilliary intercultivation procedures. Specific employment planning strategies are suggested, based on the results of the operational analysis.</p></div>","PeriodicalId":100066,"journal":{"name":"Agro-Ecosystems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1982-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-3746(82)90002-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91502638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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