Nutrient cycling in agroecosystems: nitrogen cycling in southern Sweden in the 1850s and two Tanzanian villages in the 1990s
(1999)- Abstract
- This study presents a general model for analysing nutrient cycling in agroecosystems. The focus is on food production intensity, human carrying capacity, sustainability and efficiency. The model can be used on systems including different kinds of land uses, which makes it applicable for studies on different scales. Comparisons of all kinds of agroecosystems, independent of time and place, are made possible. Different kinds of nutrients can be studied with the model. Here, nitrogen cycling is used as an example. A region in Scania, southern Sweden, 1858, and two Tanzanian villages, 1989-91, are analysed. The book includes a discussion of ecological principles of how humans can increase their food production, based on nutrient cycling and... (More)
- This study presents a general model for analysing nutrient cycling in agroecosystems. The focus is on food production intensity, human carrying capacity, sustainability and efficiency. The model can be used on systems including different kinds of land uses, which makes it applicable for studies on different scales. Comparisons of all kinds of agroecosystems, independent of time and place, are made possible. Different kinds of nutrients can be studied with the model. Here, nitrogen cycling is used as an example. A region in Scania, southern Sweden, 1858, and two Tanzanian villages, 1989-91, are analysed. The book includes a discussion of ecological principles of how humans can increase their food production, based on nutrient cycling and with concrete examples. Main conclusions in the thesis are: - There exists a conflict between increase of food production and sustainability. - Crop-dominated agroecosystems have higher human carrying capacities and are more efficient, concerning nitrogen losses per unit of nitrogen in the food produced, than livestock-dominated agroecosystems. - Neither the Tanzanian nor the Scanian agroecosystems can be judged as being sustainable. - There were high losses of nitrogen from livestock manure/excreta, especially in the Scanian agroecosystems. - Biological nitrogen fixation on cultivated land was the most important input in the Scanian agroecosystems and has a large potential for improving the negative nitrogen budgets of cultivated land in the Tanzanian systems. (Less)
- Abstract (Swedish)
- Popular Abstract in Swedish
För analys av agroekosystems näringsämnescirkulation presenteras här en generell modell. I centrum står födoproduktionsintensitet, mänsklig bärförmåga, uthållighet och effektivitet. Modellen kan användas på system med flera markanvändningstyper och är därför lämpad för studier i olika skalor. Jämförelser av alla slags agroekosystem, oavsett tid och rum, är möjliga. Olika näringsämnen kan analyseras med modellen. Kvävets cirkulation i Malmöhus län, 1858, och två tanzaniska byar, 1989-91, studeras som exempel. Ekologiska principer för hur människan kan öka sin födoproduktion, utifrån cirkulation av näringsämnen, diskuteras och exemplifieras. Huvudsakliga slutsatser: - Det råder en konflikt mellan... (More) - Popular Abstract in Swedish
För analys av agroekosystems näringsämnescirkulation presenteras här en generell modell. I centrum står födoproduktionsintensitet, mänsklig bärförmåga, uthållighet och effektivitet. Modellen kan användas på system med flera markanvändningstyper och är därför lämpad för studier i olika skalor. Jämförelser av alla slags agroekosystem, oavsett tid och rum, är möjliga. Olika näringsämnen kan analyseras med modellen. Kvävets cirkulation i Malmöhus län, 1858, och två tanzaniska byar, 1989-91, studeras som exempel. Ekologiska principer för hur människan kan öka sin födoproduktion, utifrån cirkulation av näringsämnen, diskuteras och exemplifieras. Huvudsakliga slutsatser: - Det råder en konflikt mellan ökad matproduktion och uthållighet. - Agroekosystem dominerade av grödoproduktion har en högre mänsklig bärförmåga och är mer effektiv, med avseende på kväveförluster per kväveenhet i matproduktionen, jämfört med system dominerade av djurproduktion. - Varken de tanzaniska eller de skånska agroekosystemen kan anses som uthålliga. - Stora kväveförluster konstateras från djurgödsel/exkrement, speciellt i de skånska systemen. - Biologisk kvävefixering på åkermark var den viktigaste införseln av kväve i de skånska agroekosystemen och har en stor potential för att förbättra kväveunderskotten på de tanzaniska åkrarna. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/18996
- author
- Williams, Lars-Erik LU
- supervisor
- opponent
-
- Ebbersten, Sten
- organization
- publishing date
- 1999
- type
- Thesis
- publication status
- published
- subject
- keywords
- nutrient, nutrient model, nutrient cycling, nitrogen fixation, nitrogen budget, mixed system, miombo, manure, livestock, land use, historical system, food production, efficiency, crops, agroecosystem, carrying capacity, phosphorus, Scania, sustainability, Plant ecology, Växtekologi
- pages
- 120 pages
- publisher
- Lund
- defense location
- Ecology Building, Lund University
- defense date
- 1999-09-24 10:15:00
- external identifiers
-
- other:CODEN: SE-LUNBDS/NBBE-99/1052+120pp
- ISBN
- 91-7105-113-9
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Plant Ecology and Systematics (Closed 2011) (011004000)
- id
- db88fc17-75ed-4048-90f5-998c2663b8be (old id 18996)
- date added to LUP
- 2016-04-04 11:39:14
- date last changed
- 2018-11-21 21:06:16
@phdthesis{db88fc17-75ed-4048-90f5-998c2663b8be,
abstract = {{This study presents a general model for analysing nutrient cycling in agroecosystems. The focus is on food production intensity, human carrying capacity, sustainability and efficiency. The model can be used on systems including different kinds of land uses, which makes it applicable for studies on different scales. Comparisons of all kinds of agroecosystems, independent of time and place, are made possible. Different kinds of nutrients can be studied with the model. Here, nitrogen cycling is used as an example. A region in Scania, southern Sweden, 1858, and two Tanzanian villages, 1989-91, are analysed. The book includes a discussion of ecological principles of how humans can increase their food production, based on nutrient cycling and with concrete examples. Main conclusions in the thesis are: - There exists a conflict between increase of food production and sustainability. - Crop-dominated agroecosystems have higher human carrying capacities and are more efficient, concerning nitrogen losses per unit of nitrogen in the food produced, than livestock-dominated agroecosystems. - Neither the Tanzanian nor the Scanian agroecosystems can be judged as being sustainable. - There were high losses of nitrogen from livestock manure/excreta, especially in the Scanian agroecosystems. - Biological nitrogen fixation on cultivated land was the most important input in the Scanian agroecosystems and has a large potential for improving the negative nitrogen budgets of cultivated land in the Tanzanian systems.}},
author = {{Williams, Lars-Erik}},
isbn = {{91-7105-113-9}},
keywords = {{nutrient; nutrient model; nutrient cycling; nitrogen fixation; nitrogen budget; mixed system; miombo; manure; livestock; land use; historical system; food production; efficiency; crops; agroecosystem; carrying capacity; phosphorus; Scania; sustainability; Plant ecology; Växtekologi}},
language = {{eng}},
publisher = {{Lund}},
school = {{Lund University}},
title = {{Nutrient cycling in agroecosystems: nitrogen cycling in southern Sweden in the 1850s and two Tanzanian villages in the 1990s}},
year = {{1999}},
}