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Dissertation
Shifting cultivation and forest resources in Nagaland, N.-E. India
(2010-06-17)
Die vorliegende Studie befasst sich mit der Ressourcennachhaltigkeit der traditionellen, auf Wanderfeldbau beruhenden Subsistenzwirtschaft in zwei Dörfern (Hongphoy und Minyakshu) in Nagaland im Nordosten Indiens. Hierbei werden die Cerealien Produktion, der Feuerholz Konsum und auch die Folgen der intensivierten Bewirtschaftung (Forstdegradation und Bodenverarmung) im Hinblick auf das Bevölkerungswachstum diskutiert. Während das traditionelle System des Wanderfeldbaus (Jhum) seit Jahrzehnten die Bedürfnisse der ...
Aufsatz
Effects of manure quality and application forms on soil C and N turnover of a subtropical oasis soil under laboratory conditions
(2003)
Our knowledge of the agricultural sustainability of the millennia-old mountain oases in northern Oman is restricted in particular with respect to C and N turnover. A laboratory study was conducted (1) to analyse the effects of rewetting and drying on soil microorganisms after adding different manures, (2) to investigate the effects of mulching or incorporating of these manures, and (3) to evaluate the relationships between C and N mineralisation rates and manure quality indices. During the first 9-day rewetting and ...
Dissertation
Geospatial crop yield modeling for climate change risk transfer, impact assessment, and adaptation strategies
(2023)
Changing climate and weather patterns increase the pressure on food production systems worldwide, significantly impacting livelihoods and economies at various scales. Understanding and adapting/mitigating climate change are essential to cope with the adverse effects of climate change. Biophysical crop modeling offers a unique way to assess the pros and cons of different adaptation strategies because they integrate physical and biological principles to simulate the use and allocation of captured resources mechanistically. ...
Dissertation
Sustainability of traditional cocoa agroforests in Ghana
(2022)
Cocoa (Theobroma cacao L.) is an important agricultural commodity that is important to the economies of many countries in the world. Due to cocoa’s dependence on fertile forests soils, its production is a major cause of deforestation and soil degradation in producing countries. When grown in agroforestry systems it can conserve biodiversity, sequester carbon (C), and maintain soil fertility. There are many cocoa agroforests which are managed without synthetic agrochemicals. Because organic cocoa certification is now ...
Dissertation
Der Einfluss von Befahrung alter Rückegassen mit einem schweren Rückezug auf mechanische, strukturelle und funktionelle Eigenschaften eines mit Fichten bestockten Lössbodens in Abhängigkeit von der Fahrwerkkonfiguration
(2023)
Bei der maschinellen Holzernte mit schweren Holzerntefahrzeugen wird der befahrene Waldboden deformiert und damit potenziell in seiner forstwirtschaftlichen Produktivität eingeschränkt. Mögliche Lösungsansätze für diese unerwünschte Nebenwirkung des Technikeinsatzes sind die Beschränkung der Befahrung des Waldbodens auf permanenten Rückegassen und die Verwendung tragender Bogiebänder. Es besteht jedoch eine Forschungslücke zur Veränderung der physikalischen Eigenschaften von vorverdichtetem Boden bestehender Rückegassen ...
Aufsatz
The ‘forma specialis’ issue in Fusarium: A case study in Fusarium solani f. sp. pisi
(2018-01-19)
The Fusarium solani species complex (FSSC) has been studied intensively but its association with legumes, particularly under European agro-climatic conditions, is still poorly understood. In the present study, we investigated phylogenetic relationships and aggressiveness of 79 isolates of the FSSC collected from pea, subterranean clover, white clover and winter vetch grown under diverse agro-climatic and soil conditions within Temperate and Mediterranean Europe. The isolates were characterized by sequencing tef1 and ...
Aufsatz
Roots of symptom-free leguminous cover crop and living mulch species harbor diverse Fusarium communities that show highly variable aggressiveness on pea (Pisum sativum)
(2018-02-14)
Leguminous cover crop and living mulch species show not only great potential for providing multiple beneficial services to agro-ecosystems, but may also present pathological risks for other crops in rotations through shared pathogens, especially those of the genus Fusarium. Disease severity on roots of subterranean clover, white clover, winter and summer vetch grown as cover crop and living mulch species across five European sites as well as the frequency, distribution and aggressiveness to pea of Fusarium spp. ...
Aufsatz
Soil organic carbon management for sustainable land use in Sudano-Sahelian West Africa
(2001)
Judged by their negative nutrient balances, low soil cover and low productivity, the predominant agro-pastoral farming systems in the Sudano-Sahelian zone of West Africa are highly unsustainable for crop production intensification. With kaolinite as the main clay type, the cation exchange capacity of the soils in this region, often less than 1 cmol_c kg^-1 soil, depends heavily on the organic carbon (Corg) content. However, due to low carbon sequestration and to the microbe, termite and temperature-induced rapid ...
Aufsatz
Multi-site time-trend analysis of soil fertility management effects on crop production in sub-Saharan West Africa
(2002)
Soil fertility constraints to crop production have been recognized widely as a major obstacle to food security and agro-ecosystem sustainability in sub-Saharan West Africa. As such, they have led to a multitude of research projects and policy debates on how best they should be overcome. Conclusions, based on long-term multi-site experiments, are lacking with respect to a regional assessment of phosphorus and nitrogen fertilizer effects, surface mulched crop residues, and legume rotations on total dry matter of cereals ...
Aufsatz
Phosphorus placement an acid arenosols of the West African Sahel
(2003)
Phosphorus (P) deficiency is a major constraint to pearl millet (Pennisetum glaucum L.) growth on acid sandy soils of the West African Sahel. To develop cost-effective fertilization strategies for cash poor farmers, experiments with pearl millet were conducted in southwestern Niger. Treatments comprised single superphosphate hill-placed at rates of 1, 3, 5 or 7 kg P ha^−1 factorially combined with broadcast P at a rate of 13 kg ha^−1. Nitrogen was applied as calcium ammonium nitrate at rates of 30 and 45 kg ha^−1. ...