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| 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 |
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| Chongtham, Imam Raj; de Neergaard, Andreas; Pillot, Didier. |
| Organic agriculture in Uganda is developing at a fast pace and despite this trend Uganda is still unable to produce enough fresh and dry organic fruits mainly pineapple to meet the exporters demand. This current research investigated the strategies of farmers at production level by assessing the pros and cons of fruit growing, organic agriculture and fruit drying in order to understand the underlying causal factor for the low production of organic dry fruits in a major fruit producing district of Uganda. The study was carried out in two separate and distinctive areas; one which only produces and export fresh organic pineapple and the other which exports dried fruits (mainly pineapple and papaya). About 10 % of the farmers in the two study areas were... |
| Tipo: Journal paper |
Palavras-chave: Farm economics; Markets and trade; Produce chain management. |
| Ano: 2010 |
URL: http://orgprints.org/18490/1/18490.pdf |
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| 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 |
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| 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<0.05) and not by the form in which the N was applied (P>0.05). The utilization... |
| Tipo: Journal paper |
Palavras-chave: Crop husbandry. |
| Ano: 2008 |
URL: http://orgprints.org/18305/1/18305.pdf |
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| de Neergaard, Andreas; Hauggaard-Nielsen, Henrik; Jensen, Lars Stoumann; Magid, Jakob. |
| Using data from a decomposition study, we aimed to test the parameterisation of the soil organic matter module of the DAISY model, and link measurable plant litter fractions (lignin, water-soluble) with the model defined plant litter pools. Shoot and root material from perennial ryegrass and white clover was incubated in a sandy loam soil at 9 °C for 94 days. Accumulated CO2 evolution, soil mineral nitrogen (N) and soil microbial biomass-N were measured during the incubation. Marked differences in decomposition rates between above- and below-ground material as well as between the two plant species were observed. The DAISY model was used to interpret the incubation results. Decomposition rates and utilisation efficiencies were modified, under the constraint... |
| Tipo: Journal paper |
Palavras-chave: Crop husbandry. |
| Ano: 2002 |
URL: http://orgprints.org/1333/1/1333.pdf |
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| 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 |
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| Thonar, Cécile; Lekfeldt, Jonas D.S.; Cozzolino, Vincenza; Kundel, Domimika; Kulhánek, Martin; Mosimann, Carla; Neumann, Günter; Piccolo, Alessandro; Rex, Martin; Symanczik, Sarah; Walder, Florian; Weinmann, Markus; de Neergaard, Andreas; Mäder, Paul. |
| Background: Agricultural production is challenged by the limitation of non-renewable resources. Alternative fertilizers are promoted but they often have a lower availability of key macronutrients, especially phosphorus (P). Biological inoculants, the so-called bio-effectors (BEs), may be combined with these fertilizers to improve the nutrient use efficiency. Methods: The goal of this study was to assess the potential of three BEs in combination with alternative fertilizers (e.g., composted manure, biogas digestate, green compost) to promote plant growth and nutrient uptake in soils typical for various European regions. Pot experiments were conducted in Czech Republic, Denmark, Germany, Italy, and Switzerland where the same variety of maize was grown in... |
| Tipo: Journal paper |
Palavras-chave: Composting and manuring; Nutrient turnover. |
| Ano: 2017 |
URL: http://orgprints.org/32920/1/Thonar2017-Potential%20of%20three%20microbial%20bio%E2%80%91effectors%20to%20promote%20maize%20growth%20and%20nutrient%20acquisition%20from%20alternative%20phosphorous%20fertilizers%20in%20contrasting%20soils.pdf |
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