Consulta: creatorFacets:"Høgh-Jensen, Henning"
Registros recuperados: 36
Data/hora: 12/06/2024 04:41:16

Organic Agriculture in a Development Policy Perspective
Provedor de dados: 21
Autores: Egelyng, Henrik; Halberg, Niels; Høgh-Jensen, Henning.
Farmers growing food with high eco-efficiency may be seen cultivating peace by reducing competition among nations for oil and as producers of other public goods: biodiverse landscapes and ecosystem services with more soil fertility, less water use and less pollution. How does Organic agriculture (OA) fare globally on eco-efficiency? Are most African farmers eco-efficient – or may eco-efficient farmers be found everywhere? As OA develops throughout the planet, what does Denmark do beyond Europe? Is organic farming part of our development  policy? Do we dilligently share our comparative advantages in this field with developing nations? This article pursues these basic questions.
Tipo: Conference paper, poster, etc.
Palavras-chave: Environmental aspects; Policy environments and social economy; "Organics" in general.
Ano: 2006
URL: http://orgprints.org/7578/1/FinVRSecoconloadheg_nha%2Dhhj.doc

Integrating pigeonpea in maize based farming systems may increase food production and alleviate poverty
Provedor de dados: 21
Autores: Høgh-Jensen, Henning; Odgaard, R.; Myaka, F.A.; Sakala, W.D.; Adu-Gyamfi, J.J.; Vesterager, J.M.
Pressure on natural resources implies that millions of farmers in semi-arid eastern and southern Africa face very low and declining crop yields. Major natural constraints are the nitrogen and phosphorus supply together with insufficient and highly variable rainfall. This article addresses the possibilities for improved soil fertility, increased productivity and income opportunities among smallholders in semi-arid eastern and southern Africa through the integration of improved pigeonpea in maize-based cropping systems. Specifically farmers’ experiences with cultivation and integration of pigeonpea in maize-based cropping systems are discussed. This includes how the integration of pigeonpea affects the livelihood situation of rural smallholders – male as...
Tipo: Conference paper, poster, etc.
Palavras-chave: Crop combinations and interactions; Farm nutrient management; Social aspects; Farm economics.
Ano: 2008
URL: http://orgprints.org/11420/1/Hogh%2DJensen_11420_ed.rtf

Nitrogen transfer from forage legumes to nine neighbouring plants in a multi-species grassland
Provedor de dados: 21
Autores: Pirhofer-Walzl, K.; Rasmussen , Jim; Høgh-Jensen, Henning; Eriksen, Jørgen; Soegaard, Karen; Rasmussen, Jesper.
Legumes play a crucial role in nitrogen supply to grass-legume mixtures for ruminant fodder. To quantify N transfer from legumes to neighbouring plants in multi-species grasslands we established a grass-legume-herb mixture on a loamy-sandy site in Denmark. White clover (Trifolium repens L.), red clover (Trifolium pratense L.) and lucerne (Medicago sativa L.) were leaflabelled with 15N enriched urea during one growing season. N transfer to grasses (Lolium perenne L. and xfestulolium), white clover, red clover, lucerne, birdsfoot trefoil (Lotus corniculatus L.), chicory (Cichorium intybus L.), plantain (Plantago lanceolata L.), salad burnet (Sanguisorba minor L.) and caraway (Carum carvi L.) was measured. Neighbouring plants contained greater amounts of N...
Tipo: Journal paper
Palavras-chave: Crop combinations and interactions.
Ano: 2012
URL: http://orgprints.org/20645/4/20645.pdf

Research in sub-saharan African food systems must address post-sustainability challenges and increase developmental returns
Provedor de dados: 21
Autores: Høgh-Jensen, Henning; Egelyng, Henrik; Oelofse, Myles.
The article argue that the livelihood approach is relevant for Research in sub-saharan African food systems, which must  address post-sustainability challenges and increase  developmental returns
Tipo: Journal paper
Palavras-chave: Environmental aspects; "Organics" in general; Food systems.
Ano: 2009
URL: http://orgprints.org/16350/1/16350.pdf

The impact of organic farming on food security in a regional and global perspective
Provedor de dados: 21
Autores: Halberg, Niels; Sulser, Timothy B.; Høgh-Jensen, Henning; Rosegrant, Mark W.; Knudsen, Marie Trydeman.
The spread of organic and agro-ecological farming (OF) methods in developing countries has raised a debate whether a large scale adoption of OF will increase or decrease global food security. This will however depend on a number of socio-economic factors together with the relative yield levels of OF versus conventional farming systems. Relative yields again depend on a number of agro ecological factors and the characteristics of farming systems before conversion.    In areas with intensive high-input agriculture, conversion to OF will most often lead to a reduction in crop yields per ha by 20-45 % in crop rotations integrated with leguminous forage crops. In many areas with low input agricultural systems farmers have little incentive or access to use...
Tipo: Book chapter
Palavras-chave: Food security; Food quality and human health Food systems.
Ano: 2006
URL: http://orgprints.org/9209/1/9209.pdf

Empirical model for quantification of symbiotic nitrogen fixation in grass-clover mixtures
Provedor de dados: 21
Autores: Høgh-Jensen, Henning; Loges, Ralf; Jensen, Erik Steen; Jørgensen, Finn V.; Vinther, Finn P.
Symbiotically fixed nitrogen (N2) is an important input of nitrogen (N) source in many agricultural systems. In spite of this fact, the input of symbiotically fixed N to a particular cropping system is usually not known and exact measurements are costly and laborious. Consequently, there is a demand for an uncomplicated and reliable tool to estimate symbiotic N2 fixation (SNF) in leguminous crops. A simple emperical model is proposed for quantification of SNF in forage legumes under low external input conditions. The model estimates SNF using dry matter yield as input and parameters for (i)N concentration in dry matter and the (ii) proportion of the N in the legume that is derived from the atmosphere. Further, the model includes fixed N not included in the...
Tipo: Journal paper
Palavras-chave: Pasture and forage crops.
Ano: 2004
URL: http://orgprints.org/3085/1/emperical_model.pdf

Organic Agriculture: A New Field of International Development Policy
Provedor de dados: 21
Autores: Egelyng, Henrik; Høgh-Jensen, Henning; Kledal, Paul Rye; Halberg, Niels.
This paper reviews strategically selected global policy documents and development literature and analyse perspectives on the role of organic agriculture (OA) as a possible vehicle for sustainable development in developing countries. It shows that not only has compliance assessed organics made entry in terms of projects and programmes in many LICs. OA is also gaining position in formal policies and strategies of international donor agencies and organisations. If agriculture is generally “back” in development business, organic farming has certainly “arrived”.
Tipo: Conference paper, poster, etc.
Palavras-chave: Policy environments and social economy; "Organics" in general.
Ano: 2008
URL: http://orgprints.org/12508/1/Egelyng_12508_ed.pdf

Crop responses to 15N-labelled organic and inorganic nitrogen sources
Provedor de dados: 21
Autores: El-Naggar, Ahmed; El-Araby, Ahmed; de Neergaard, Andreas; Høgh-Jensen, Henning.
A major challenge for low¬-external-input farming systems is to secure the N supply. Lack of synchrony between mineralization of organic N sources and plant N requirements is causing many growers to use different techniques to overcome this problem. One of these techniques is the application of soluble water extracts of different farm residues and plants. A field study was conducted to study the crop uptake of applied 15N-labeled alfalfa and clover extracts as compared to the N uptake from15N-glycine and three levels of 15N-(NH4)2SO4. The results show that total N accumulation in the field crops, squash and lettuce, was primarily affected by the amount of added N (P&lt;0.05) and not by the form in which the N was applied (P&gt;0.05). The utilization...
Tipo: Journal paper
Palavras-chave: Crop husbandry.
Ano: 2008
URL: http://orgprints.org/18305/1/18305.pdf

Systems Theory as a Scientific Approach towards Organic Farming
Provedor de dados: 21
Autores: Høgh-Jensen, Henning.
Systems theory differs from classic analytical science by producing statements in the context of a descriptive system rather than seeking to reduce a complex problematic situation to researchable entities. This paper analyses the validity and applicability of systems theory as a scientific approach towards organic farming. The world-views on which organic farming and systems theory build, respectively, are discussed and the methodological consequences of these world views are clarified.  The world-view inherent in organic farming (the ontological level), as reflected in stewardship towards nature, the ethic of animal husbandry, and the cycling processes in nature, is harmonious with the underlying ideas of systems theory as regards a hierarchical structure...
Tipo: Journal paper
Palavras-chave: Research methodology and philosophy.
Ano: 1998
URL: http://orgprints.org/353/1/systems_theory.DOC

To meet future food demands we need to change from annual grain legumes to multipurpose semi-perennial legumes
Provedor de dados: 21
Autores: Høgh-Jensen, Henning.
The last meal of an Iron Age man buried in a Danish bog included at least 60 plant species, including barley, linseed and species we now consider weeds. A modern man relies in contrast on a remarkable small number of crop plants, mostly cereal stables like wheat, rice and maize (Evans, 1998). Both land and people in Sub-Saharan Africa are suffering. Natural resource management is in distress and most rural Africans remain poor and food insecure despite widespread macroeconomic, political and sectorial reforms. Most predictions are that these Africans will remain food insecure in the foreseeable future (Pinstrup-Andersen &amp; Pandya-Lorch, 2001). Innovations are, however, changing this landscape much faster than we could expect.    A market-oriented...
Tipo: Book chapter
Palavras-chave: Production systems Crop combinations and interactions Food security; Food quality and human health.
Ano: 2011
URL: http://orgprints.org/23294/7/23294.pdf

Multiple nutrient imbalances in eara-leaves of on-farm cultivated maize in Eastern Africa
Provedor de dados: 21
Autores: Høgh-Jensen, Henning; Kamalongo, D.; Myaka, F.A.; Adu-Gyamfi, J.J.
Maize is a major food crop in eastern and southern Africa and is often cultivated with insufficient supplies of nutrients. The current studies are aimed at diagnosing any potential nutrient limitation in maize under farmers’ conditions using the nutrient content in ear leaf tissue at tasseling stage. The majority of the maize crops were considered below the critical nitrogen (N) content in the ear leaves with mean N content of 1.84%. Phosphorus (P), B and Cu content appeared critically low at three of the four sites. Unique fingerprinting by multivariate statistics was possible for each site when using the proportion of nutrients in the leaf tissue. The content of six macro elements (N, P, K, S, Mg, Ca) at the tasseling stage were found to be able to...
Tipo: Journal paper
Palavras-chave: "Organics" in general; Crop husbandry.
Ano: 2009
URL: http://orgprints.org/18303/1/18303.pdf

Organic farm conventionalisation and farmer practices  in China, Brazil and Egypt
Provedor de dados: 21
Autores: Oelofse, Myles; Høgh-Jensen, Henning; Abreu, Lucimar Santiago de; Almeida, Gustavo Fonseca de; El-Araby, Ahmed; Hui, Qiao Yu; Sultan, Tursinbek; de Neergaard, Andreas.
Certified organic agriculture stipulates a range of principles and standards, which govern farmer practices. The recent global expansion of organic agriculture has raised new challenges for organic agriculture, particularly whether management practices in organic farms are subject to the forces of conventionalisation. We studied changes in agroecological practices in certified organic farms in China,Brazil and Egypt. The study takes departure in the conventionalisation hypothesis and the analysis is framed using organic and agroecological principles. The study focuses on agroecological design principles, inherent to organic agriculture, of diversity in crop production, pest, disease and weed management, and soil fertility management. The research design...
Tipo: Journal paper
Palavras-chave: "Organics" in general; Systems research and participatory research; Food systems; Policy environments and social economy; Research methodology and philosophy; Knowledge management.
Ano: 2011
URL: http://orgprints.org/23292/7/23292.pdf

Robustness in the mineral supply from temporary grasslands
Provedor de dados: 21
Autores: Høgh-Jensen, Henning; Søegaard, K.
The current study examined the capacity of different temporary grassland legume-grass mixtures under different N supply levels to supply similar amounts of elements in systems where the herbage is cut and feed. Mixtures showed a good robustness in supplying equal amounts of mineral elements in the combined herbage as well as equal concentrations in dry matter of mineral elements compared to the same species in monocultures. The reasons for the mixed systems to be able to buffer differences in N supply levels as well as different compositions of the mixtures were that legume leaves and stems had similar concentrations of mineral elements, whether in monocultures or in mixtures with grasses. Grasses in mixture with legumes had however higher N, Ca, S, Zn, Cu...
Tipo: Journal paper
Palavras-chave: Health and welfare Crop health; Quality; Protection.
Ano: 2012
URL: http://orgprints.org/23287/7/23287.pdf

The Bean – Naturally Bridging Agriculture and Human Wellbeing
Provedor de dados: 21
Autores: Høgh-Jensen, Henning; Myaka, Fidelis M; Kamalongo, Donwell; Ngwira, Amos.
Access to a food and a diverse diet are important to secure human wellbeing. A big part of our diet is carbohydrates, which cereals are superior in supplying. The challenge addressed in this chapter is to find appropriate ways to supplement these carbohydrates. Using Phaseolus beans as example, we discuss the focus of our efforts based on variations in yield of the crop and variations in the bean grain’s richness in minerals. Securing an abundant supply of minerals in the daily diet of people is a major challenge for mankind. But acknowledging that farmers cultivate their crops in very different environments may be a first important premise to re-establish the bridge between agriculture and human well-being. If the farmers are helped to address the...
Tipo: Book chapter
Palavras-chave: Farming Systems; Crop husbandry; Food systems; Research methodology and philosophy; Environmental aspects.
Ano: 2013
URL: http://orgprints.org/23295/7/23295.pdf

Consequences of including adapted white clover in northern European grassland: transfer and deposition of nitrogen
Provedor de dados: 21
Autores: Gylfadóttir, Thórey; Helgadóttir, Áslaug; Høgh-Jensen, Henning.
The interspecific transfer of nitrogen (N) between white clover (Trifolium repens) and smooth meadow grass (Poa pratensis) in legume-based grasslands was assessed under North European field conditions using 15N individual plant leaf labelling. On average 50% of N in the grass was transferred from the white clover and about 6% of N in white clover was transferred from the grass. This corresponds to 2.5 and 0.3 g N m-2 being transferred over the growing season between the two species respectively and demonstrates that a significant part of the total N of the grass is coming through interspecific transfer. The majority of the 15N transferred was within a period of 20 days at relatively low soil temperatures. This implies that there is a need for a new focus...
Tipo: Journal paper
Palavras-chave: Landscape and recreation; Farm nutrient management; Biodiversity and ecosystem services.
Ano: 2007
URL: http://orgprints.org/11466/1/11466.pdf

In situ carbon and nitrogen dynamics in ryegrass-clover mixtures: Transfers, deposition and leaching
Provedor de dados: 21
Autores: Rasmussen, Jim; Eriksen, Jørgen; Jensen, Erik Steen; Esbensen, Kim H.; Høgh-Jensen, Henning.
Carbon (C) and nitrogen (N) dynamics in ryegrass-clover mixtures were investigated in field mezotrons installed to depths of 20, 40 and 60 cm and equipped with suction cups to collect percolating pore water. Ryegrass and clover leaves were cross-labelled with 14C- and 15N-enriched urea and the fate of the two tracers was studied for three months during summer. Transfer of 14C occurred mainly from ryegrass to clover, whereas the largest transfer of 15N was in the opposite direction. The average transfer of N from clover was 40% (±3.1, n=9) of N in ryegrass, whereas the fraction of N in clover donated by ryegrass was 5% (±1.2, n=9). The amount of 14C transferred from ryegrass to clover was 1.7% (±0.1, n=9) of the 14C-activity in the total aboveground biomass...
Tipo: Journal paper
Palavras-chave: Nutrient turnover; Air and water emissions.
Ano: 2007
URL: http://orgprints.org/10390/1/10390.pdf

Globalisation as a challenge or opportunity for organic farming
Provedor de dados: 21
Autores: El-Nagger, Ahmed; Ounmaa, Andres; Muukka, Eija; Zaleckas, Ernestas; Abraityté, Gerda; Jansons, Imants; Rasmussen, Jim; Ahnström, Johan; Pirhofer-Walzl, Karin; Jensen, Katherine O’Doherty; Jørgensen, Kirstine F.; Sarunaite, Lina; Bleidere, Mara; Knudsen, Marie Trydeman; Pugliese, Massimo; Nielsen, Merete Højrup Møller; Mugurerza, Natalia Bellostas; Bakewell-Stone, Petra; Hansen, Preben Klarskov; Al-Kufaishi, Sermed Adil Abed-Ali; Kobayashi, Sofie; Rydberg, Torbjörn; Klubova, Vera; Liorancas, Viktoras; Høgh-Jensen, Henning.
During one intensive week in October 2005, the authors were gathered to discuss the impact that globalisation has on the Organic Food Systems and the opportunities that globalisation opens up for developing these systems. The meeting took place as a Ph.D. course under the auspices of the Research School of Organic Farming and Food Systems (SOAR; www.soar.dk). All participants research within Organic Agriculture and Food Production in one way or another.
Tipo: Journal paper
Palavras-chave: Food security; Food quality and human health "Organics" in general Food systems Markets and trade Values; Standards and certification.
Ano: 2006
URL: http://orgprints.org/9333/1/9333.pdf

A comparative study of farm nutrient budgets and nutrients flows of certified organic and non-organic farms in China, Brazil and Egypt
Provedor de dados: 21
Autores: Oelofse, Myles; Høgh-Jensen, Henning; de Abreu, L.S.; de Almeira, G.F.; Hui, Q.Y.; de Neergaard, Andreas.
Increased demand for certified organic products has led to  an increase in the number of certified organic farms in developing countries. Knowledge of farmer nutrient management practices on certified organic farms in developing countries is limited. Thus, the aim of this study was to investigate the impact of the adoption of certified organic agriculture on farm nutrient flows and nutrient budgets, and evaluate to which degree organic farms comply with organic principles relating to nutrient   management. The study is based on five case studies of different types of certified organic farming systems in Brazil, Egypt and China. Farm nutrient flows and nutrient budgets for nitrogen, phosphorous and potassium were created for each farm. Four of the five...
Tipo: Journal paper
Palavras-chave: Farm nutrient management.
Ano: 2010
URL: http://orgprints.org/18298/1/18298.pdf

Effects of including chicory in perennial ryegrass-white clover leys on production and health in organic lambs
Provedor de dados: 21
Autores: Nielsen, Bea; Thamsborg, Stig Milan; Hansen, Hanne; Ranvig, Hans; Høgh-Jensen, Henning.
Two trials were conducted to examine the effect of chicory  included in or as additional plots of the ryegrass–white clover pastures on growth, naturally acquired nematode infections and selectivity of chicory by lambs. In Experiment 1, 31 weaned Texel lambs (36±7 kg) grazed either ryegrass–white clover (CTRL) or ryegrass–white clover–hicory pastures (CHIC). In Experiment 2, 30 weaned Shropshire lambs (32±7 kg) grazed either ryegrass–white clover (CTRL) or ryegrass–white clover with access to small additional chicory plots, which corresponded to 3% (CHIC-LO) or 6% of the total grazing area (CHIC-HI). No consistent differences in live weight gain and nematode faecal egg counts were observed in lambs grazing the different pasture types. Sward height on the...
Tipo: Journal paper
Palavras-chave: Feeding and growth.
Ano: 2009
URL: http://orgprints.org/18302/1/Nielsen_2009_Livestock-Science.pdf

DOC and DON from grass-clover - results from a field experiment
Provedor de dados: 21
Autores: Rasmussen, Jim; Høgh-Jensen, Henning.
The C and N dynamics in perennial grass-clover mixtures are not fully understood although such mixtures dominate temperate grassland. The co-existence of clover and grass involves both competition for and transfer of nutrients between the species. The nutrients that are competed for and transferred may originate from leaky root systems, from a rapid turnover of the fine root systems, or from degradation of more stabile organic material.    The aim of the present study was to investigate the origin of dissolved organic C and N in perennial grass-clover mixtures. In an existing grass-clover ley, field mezotrons (cylinders with a diameter 30 cm) were installed in the spring of 2003 to depths of 20, 40 and 60 cm. Suction cups was installed beneath the...
Tipo: Conference paper, poster, etc.
Palavras-chave: Air and water emissions.
Ano: 2005
URL: http://orgprints.org/9128/1/9128.pdf

The Circular Economy of a Local Organic Food Chain: Xiedao in Beijing
Provedor de dados: 21
Autores: Liu, Yuexian; Høgh-Jensen, Henning; Egelyng, Henrik.
The local organic food market in China is growing and socalled leisure agriculture has been widely accepted and advocated in urban areas as a positive means of relaxation. This paper presents an analysis of a local organic food chain based on leisure agriculture and seeks to explain development of organic food in Urban China using the theoretical frame of the Circular Economy. The study uses a local organic food chain involving Xiedao as a case. In conclusion, the paper provides an estimate of the energy use efficiency of the chain.
Tipo: Conference paper, poster, etc.
Palavras-chave: Recycling; Balancing and resource management.
Ano: 2008
URL: http://orgprints.org/11548/1/Liu_11548_ed.doc

Effect of deep-rooted plant species on 15Nitrogen uptake and herbage yield in temporary agricultural grasslands
Provedor de dados: 21
Autores: Pirhofer-Walzl, K.; Eriksen, Jørgen; Rasmussen , Jim; Soegaard, Karen; Høgh-Jensen, Henning; Rasmussen, Jesper.
Aim is to ncrease of plant diversity has been suggested to enhance grassland productivity and resource use efficiency. Most studies on agricultural grasslands have focused on functional diversity of mixtures comprising legumes and non-legumes, but there is little knowledge of plant nutrient acquisition from deep- and shallow-rooted grassland plant species. To investigate whether deep-rooted (chicory: Cichorium intybus L.; Lucerne: Medicago sativa L.) and shallow-rooted (perennial ryegrass: Lolium perenne L.; white clover: Trifolium repens L.) grassland plant species  differ in herbage yield and depth dependent soil N-access, we investigated in the field if 1) a mixture comprising shallow- and deep-rooted grassland plant species has greater herbage yields...
Tipo: Journal paper
Palavras-chave: Crop combinations and interactions.
Ano: 2012
URL: http://orgprints.org/20647/4/20647.pdf

Energy use in organic, green and conventional pear producting systems - cases from China
Provedor de dados: 21
Autores: Liu, Yuexian; Langer, Vibeke; Høgh-Jensen, Henning; Egelyng, Henrik.
The objective of this study was to evaluate the differences in the energy consumption between the production of certified organic pear, green food certified pear, and conventional pear in two areas in China. Data were collected from interviews with farmers during 2007 and 2008. Energy inputs were significantly higher in organic systems compared with conventional and green systems. Fertilizer was the most important contributor to energy consumption in all three farming systems. Three calculation methods for energy value of manure have been found in the literature: substitution method, by-product method, and thermal method. The choise of various calculation methods for estimating the energy value of manure turns out to have great influence on the results in...
Tipo: Journal paper
Palavras-chave: Environmental aspects.
Ano: 2010
URL: http://orgprints.org/18297/1/18297.pdf

New challenges in underprivileged regions calls for people-centred research for development
Provedor de dados: 21
Autores: Høgh-Jensen, Henning; Oelofse, Myles; Egelyng, Henrik.
The need for enhancing food production and availability in underprivileged regions of the world requires the attention of scientists. This paper explores the possibilities for rethinking Agricultural Research for Development (AR4D) in the light of new challenges characterized by a high degree of scientific uncertainty and associated with intense political differences of interest. New challenges that particularly influence food production in underprivileged regions include global climate change, globalisation of food chains, and emerging low-carbon energy systems. We argue that by applying the people-centred Sustainable Livelihoods Approach as a research paradigm in AR4D, researchers may be more successful in producing knowledge that is useful to...
Tipo: Journal paper
Palavras-chave: Community development; "Organics" in general; Research methodology and philosophy.
Ano: 2010
URL: http://orgprints.org/18300/1/18300.pdf

Empirical model for quantification of symbiotic nitrogen fixation in leguminous crops
Provedor de dados: 21
Autores: Høgh-Jensen, Henning; Loges, Ralf; Jensen, Erik Steen; Jørgensen, Finn V.; Vinther, Finn P.
Symbiotically fixed N2 (SNF) is an important input of nitrogen (N) in many cropping systems. In spite of this fact, the input of fixed N to a particular cropping system is usually not known, and an exact estimation of the amount of N2 fixed requires laborious measurements. Consequently, there is a demand for a simple and reliable tool to estimate N2 fixation in leguminous crops. A model is here proposed for quantification of SNF in leguminous crops in different arable systems. The model estimates SNF using dry matter yield as input and cropping system specific values for the parameters: N concentration in dry matter and the proportion of the N in the legume that is derived from the atmosphere. Further, the model includes fixed N not included in the...
Tipo: Journal paper
Palavras-chave: Production systems.
Ano: 2003
URL: http://orgprints.org/316/1/Emperical_N2%2Dfixation_eng_v6.doc

Certified organic agriculture in China and Brazil: Market accessibility and outcomes following adoption
Provedor de dados: 21
Autores: Oelofse, Myles; Høgh-Jensen, Henning; Abreu, L.S.; Almeida, Gustavo Fonseca de; Hui, Qiao Yu; Sultan, Tursinbek; de Neergaard, Andreas.
Based on three case studies in China and Brazil, this paper explores the terms of access for farmers' participation in certified organic agriculture (OA) and investigates the influence of adoption on productivity, nutrient budgets, income and labour use. Small-scale farmers converting to OA require substantial external production-related, marketing and certification support. Access to OA was strongly dependent upon the type of support available to farmers. Organization based on a contract-farming model resulted in OA only being an option available to a narrow group of farmers, whilst OA initiated by a farmer cooperative provided better access. Gross output was significantly higher for oranges, whilst for the other crops gross output was similar. However,...
Tipo: Journal paper
Palavras-chave: "Organics" in general; Quality and evaluation of inputs.
Ano: 2010
URL: http://orgprints.org/18301/1/Oelofse_et_al_Ecological_Economics_2010_In_press.pdf

Variations in the natural abundance of 15N in ryegrass/white clover shoot material as influenced by cattle grazing.
Provedor de dados: 21
Autores: Eriksen, Jørgen; Høgh-Jensen, Henning.
Biological N2 fixation in clover is an important source of N in low external-N input farming systems. Using the natural 15N-abundance method, variations in N2 fixation were investigated in grazed and mowed plots of a ryegrass/white clover field. Ryegrass 15N varied considerably, from 0.2 to 5.6‰ under mowed conditions and from -3.3 to 11.6‰ under grazed conditions. Variations in 15N in white clover were lower than in ryegrass, especially in the mowed plots (SE = 0.05‰, n = 20). The variations in the percentage of nitrogen derived from the atmosphere (%Ndfa) in white clover were highest in the grazed plots where it ranged from 12 to 96% (mean = 64%) compared with the mowed plots where it ranged from 64 to 92% (mean = 79%). Thus, the N2 fixation per unit...
Tipo: Journal paper
Palavras-chave: Nutrient turnover.
Ano: 1998
URL: http://orgprints.org/139/1/PLSO7762.doc

Energy efficiency of organic pear production in greenhouses in China
Provedor de dados: 21
Autores: Liu, Y.; Langer, Vibeke; Høgh-Jensen, Henning; Egelyng, Henrik.
The development of organic protected cultivation taking place in densely populated areas has raised the question whether it is an environmentally friendly production system. The present study investigated energy consumption of organic pear production in two production systems, namely in traditional Chinese solar greenhouse and in the open field. In both production systems, energy output/input ratio and energy productivity were used as indicators to determine the energy efficiency; yield, cost of production, net economic return pear land area unit and benefit/cost ratio were used to evaluate economic productivity. The analysis results indicated that energy input and energy output in the solar greenhouse were higher than in open field per land area; whereas...
Tipo: Journal paper
Palavras-chave: Farm economics; Greenhouses and coverings; Biodiversity and ecosystem services; Environmental aspects.
Ano: 2010
URL: http://orgprints.org/18294/1/Linda_Renew_Agric_Food_Syst.pdf

Forage herbs improve mineral composition of grassland herbage
Provedor de dados: 21
Autores: Pirhofer-Walzl , K.; Søegaard, Karen; Høgh-Jensen, Henning; Eriksen, Jørgen; Sanderson, M.A.; Rasmussen , Jim; Rasmussen, Jesper.
Provision of an adequate mineral supply in the diets of  ruminants fed mainly on grassland herbage can present a challenge if mineral concentrations are suboptimal for animal nutrition. Forage herbs may be included in grassland seed mixtures to improve herbage mineral content, although there is limited information about mineral concentrations in forage herbs. To determine whether herbs have greater macro- and micromineral concentrations than forage legumes and grasses, we conducted a 2-year experiment on a loamy-sand site in Denmark sown with a multi-species mixture comprised of three functional groups (grasses, legumes and herbs). Herb species included chicory (Cichorium intybus L.), plantain (Plantago lanceolata L.), caraway (Carum carvi L.) and salad...
Tipo: Journal paper
Palavras-chave: Crop combinations and interactions.
Ano: 2011
URL: http://orgprints.org/19333/1/19333.pdf

Effect of four plant species on soil 15N-access and herbage yield in temporary agricultural grasslands
Provedor de dados: 21
Autores: Pirhofer-Walzl, Karin; Eriksen, Jørgen; Rasmussen , Jim; Høgh-Jensen, Henning; Søegaard, Karin; Rasmussen, Jesper.
Positive plant diversity-productivity relationships have been reported for experimental semi-natural grasslands (Cardinale et al. 2006; Hector et al. 1999; Tilman et al. 1996) as well as temporary agricultural grasslands (Frankow-Lindberg et al. 2009; Kirwan et al. 2007; Nyfeler et al. 2009; Picasso et al. 2008). Generally, these relationships are explained, on the one hand, by niche differentiation and facilitation (Hector et al. 2002; Tilman et al. 2002) and, on the other hand, by greater probability of including a highly productive plant species in high diversity plots (Huston 1997). Both explanations accept that diversity is significant because species differ in characteristics, such as root architecture, nutrient acquisition and water use efficiency,...
Tipo: Journal paper
Palavras-chave: Crop husbandry; Biodiversity and ecosystem services; Environmental aspects.
Ano: 2013
URL: http://orgprints.org/23296/1/PLANT%20AND%20sOIL.pdf

Productivity and quality, competition and facilitation of chicory in ryegrass/legume-based pastures under various nitrogen supply levels
Provedor de dados: 21
Autores: Høgh-Jensen, Henning; Nielsen, Bea; Thamsborg, Stig Milan.
Traditional perennial ryegrass-white clover mixtures have limitations in combined productivity and quality that herbs like chicory may alleviate. This study examined the consequences on productivity and quality of as well as competition and facilitation after introducing chicory into varies ryegrass-legume-based pastures in a field study over 3 consecutive growing seasons. A cultivar of chicory, suitable for grazing, in pure stand was found to out-yield a pure stand ryegrass in terms of dry matter and nitrogen (N) accumulation but was found to yield similar to mixture of chicory and ryegrass. The inclusion of chicory, increased N accumulation per area unit irrespective of associated leguminous species but had no effect (P&gt;0.05) on the combined dry...
Tipo: Journal paper
Palavras-chave: Crop combinations and interactions.
Ano: 2006
URL: http://orgprints.org/7661/1/7661.pdf

Biological nitrogen fixation and nitrogen and phosphorus budgets in farmer-managed intercrops of maize-pigeonpea in semi-arid southern and eastern Africa
Provedor de dados: 21
Autores: Adu-Gyamfi, J. J.; Myaka, F.A.; Sakala, W.D.; Odgaard, R.; Vesterager, J. M.; Høgh-Jensen, Henning.
Maize (Zea mays L.) is a major staple food in Sub-Saharan Africa but low soil fertility, limited resources and droughts keep yields low. Cultivation of maize intercropped with pigeonpea (Cajanus cajan L. Millsp.) is common in some areas of eastern and southern Africa. The objectives of this study were (1) to investigate dry matter, nitrogen (N) and phosphorus (P) accumulation in different plant components of maize-pigeonpea intercropping systems and (2) to report the effects of the intercrops on soil fertility. Maize-pigeonpea intercrops were compared to sole maize grown using farmers’ practices. Intercropping maize and pigeonpea increased (P&lt;0.05) total system yield compared to sole maize in terms of biomass, N and P accumulation. Pigeonpea planted in...
Tipo: Journal paper
Palavras-chave: Farming Systems.
Ano: 2007
URL: http://orgprints.org/18306/1/18306.pdf

Towards a global research programme for organic farming
Provedor de dados: 21
Autores: Egelyng, Henrik; Høgh-Jensen, Henning.
The first half of this chapter theoretically explores, from a development policy perspective, the nature of institutional environments for certified organic agriculture. The aims are to understand the conditions required, and the prospects, for organic agriculture to thrive, to present a view of global initiatives for research on organic production, and the current degree of institutionalization of organic farming and organic research at the global level. Through institutional analysis of social incentive structures, or game rules, the chapter analyses how certified organics in the North has been operationalized into a single policy instrument through which multiple development benefits are pursued, i.e. institutionalized in a way that enables and...
Tipo: Book chapter
Palavras-chave: Policy environments and social economy; Regulation; History of organics; Knowledge management; Consumer issues; Biodiversity and ecosystem services; Technology assessment.
Ano: 2006
URL: http://orgprints.org/15401/1/15401.pdf

Origin and composition of Dissolved Organic C and N from grass-clover mixtures
Provedor de dados: 21
Autores: Rasmussen, Jim; Høgh-Jensen, Henning.
The C and N dynamics in perennial grass-clover mixtures are not fully understood although such mixtures dominate temperate grassland. The co-existence of clover and grass involves both competition for and transfer of nutrients between the species. The nutrients may originate from leaky root systems, from a rapid turnover of the fine root systems, or from degradation of more stabile organic material.     The aim of the study is  - to determine the origin of DOC and DON in grass-clover mixtures  - to determine the composition of DOC and DON from the species  - to investigate the transfer of C and N between grass and clover    Method:  In a third year grass-clover ley at the KVL research fields, mezotrons were installed to depths of 20, 40 and 60 cm in...
Tipo: Conference paper, poster, etc.
Palavras-chave: Nutrient turnover; Specific methods.
Ano: 2004
URL: http://orgprints.org/3542/1/3542.ppt

Carbon sequestration potential of organic agriculture in northern Europe - a modelling approach
Provedor de dados: 21
Autores: Foereid, Bente; Høgh-Jensen, Henning.
Decline in carbon content in agricultural soils contributes both to climate change and to soil fertility problems. The CENTURY element dynamics simulation model was tested and adapted for Northern European agricultural conditions using long-term datasets from Askov experimental farm in southern Denmark. The part of the model dealing with decomposition was tested in isolation using a bare fallow experiment and it could predict soil organic matter levels with high accuracy. In the cropping experiments predictions were less accurate. The crop production was not accurately predicted. Predictions were more accurate on loamy than on sandy soils. The model was used to predict the effect of conversion to organic agriculture on carbon sequestration as soil organic...
Tipo: Journal paper
Palavras-chave: Environmental aspects.
Ano: 2004
URL: http://orgprints.org/18304/1/18304.pdf

Source and temperature determine the releases of multiple amino acids from plant materials
Provedor de dados: 21
Autores: El-Naggar, Ahmed; Rasmussen , Jim; de Neergaard, Andreas; El-Araby, Ahmed; Høgh-Jensen, Henning.
Agricultural crop production is largely dependent on inputs of mineral fertilizers. Mineral fertilizer prices are expected to rise as the competition for fossil energy increases. In order to increase the sustainability of crop production, alternatives to commercial mineral fertilizers are needed. Organic residues and fresh biomass are potentially important sources of nitrogen (N) in crop production. A study was conducted to investigate the impact of temperature on the release rate and profile of amino acids from soybean seeds (Glycine max L.) and fresh young shoots of chicory (Cichorium intybus), alfalfa (Medicago sativa) and red clover (Trifolium pratense) under anaerobic conditions. Plant material was incubated in water at either 15 ◦C or 35 ◦C, and the...
Tipo: Journal paper
Palavras-chave: Composting and manuring; Nutrient turnover; Farm nutrient management.
Ano: 2010
URL: http://orgprints.org/18293/1/18293.pdf