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| Chirinda, N.; Kracher, D.; Porter, J.R.; Olesen, J.E.; Petersen, B.M.; Doltra, J.; Kiese, R.; Butterbach-Bahl, K.. |
| Modelling of soil emissions of nitrous oxide (N2O) and carbon dioxide (CO2) is complicated by complex interactions between processes and factors influencing their production, consumption and transport. In this study N2O emissions and heterotrophic CO2 respiration were simulated from soils under winter wheat grown in three different organic and one inorganic fertilizer-based cropping system using two different models, i.e., MoBiLE-DNDC and FASSET. The two models were generally capable of simulating most seasonal trends of measured soil heterotrophic CO2 respiration and N2O emissions. Annual soil heterotrophic CO2 respiration was underestimated by both models in all systems (about 10−30% by FASSET and 10−40% by MoBiLE-DNDC). Both models overestimated annual... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover; Air and water emissions. |
| Ano: 2010 |
URL: http://orgprints.org/18512/1/Chirinda_et_al_(modelling).pdf |
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| Dalgaard, T.; Halberg, N.; Porter, J.R.. |
| Knowledge about fossil energy use in agricultural systems is needed, because it can improve the understanding of how to reduce the unsustainable use of limited energy resources and the following greenhouse gas emissions. This study describes and validates a model to assess fossil energy use in Danish agriculture; gives an example of how the model can be used to compare organic and conventional farming; and discusses the implications and potentials of using the model to simulate energy use in scenarios of agricultural production. The model is a development of an existing model, which was too coarse to predict measured energy use on Danish farms. The model was validated at the field operational, thecroptype, and the national level, and can supplement the... |
| Tipo: Journal paper |
Palavras-chave: "Organics" in general. |
| Ano: 2001 |
URL: http://orgprints.org/15521/1/15521.pdf |
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| Chirinda, N.; Olesen, J.E.; Porter, J.R.; Schjønning, P.. |
| Organic and conventional farming practices differ in the use of several management strategies, including use of catch crops, green manure, and fertilization, which may influence soil properties, greenhouse gas emissions and productivity of agroecosystems. An 11-yr old field experiment on a sandy loam soil in Denmark was used to compare several crop rotations with respect to a range of physical, chemical and biological characteristics related to carbon (C) and nitrogen (N) flows. Four organic rotations and an inorganic fertilizer-based system were selected to evaluate effects of fertilizer type, catch crops, of grass-clover used as green manure, and of animal manure application. Soil was sampled from winter wheat and spring barley plots in Sept 2007, April... |
| Tipo: Journal paper |
Palavras-chave: Soil biology; Nutrient turnover; Air and water emissions. |
| Ano: 2010 |
URL: http://orgprints.org/18511/1/18511.pdf |
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| Chirinda, N.; Carter, M.S; Albert, K.R.; Ambus, P.; Olesen, J.E.; Porter, J.R.; Petersen, S.O.. |
| Conventional cropping systems rely on targeted short-term fertility management, whereas organic systems depend, in part, on long-term increase in soil fertility as determined by crop rotation and management. Such differences influence soil nitrogen (N) cycling and availability through the year. The main objective of this study was to compare nitrous oxide (N2O) emissions from soil under winter wheat (Triticum aestivum L.) within three organic and one conventional cropping system that differed in type of fertilizer, presence of catch crops and proportion of N2-fixing crops. The study was replicated in two identical long-term crop rotation experiments on sandy loam soils under different climatic conditions in Denmark (Flakkebjerg–eastern Denmark and... |
| Tipo: Journal paper |
Palavras-chave: Farming Systems; Air and water emissions; Environmental aspects. |
| Ano: 2010 |
URL: http://orgprints.org/18510/1/chirinda_et_al_2010_%28N2O%29.pdf |
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| Chirinda, N.; Olesen, Jørgen E.; Porter, J.R.. |
| In agroecosystems, carbon (C) inputs come from applied manures, plant roots and retained shoot residues. Whereas the manure and shoot derived C inputs can be relatively easily determined, high costs associated with root measurements have caused current knowledge of in situ root C input to remain scant, hence it may be considered a "black box". This study aimed at determining root biomass C and nitrogen (N) in response to nutrient management and soil fertility building measures (green manures and catch crops). We made use of one inorganic fertilizer-based and four organic arable cropping systems in an 11-year-old field experiment on a sandy loam soil. Shoots and roots of catch crop mixtures and cereals sampled in 2008 and 2010 were characterized for dry... |
| Tipo: Journal paper |
Palavras-chave: Crop husbandry; Soil. |
| Ano: 2012 |
URL: http://orgprints.org/18757/4/18757.pdf |
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| Chirinda, N.; Olesen, Jørgen E.; Porter, J.R.. |
| In agroecosystems, soil organic carbon (C) inputs come from applied manures, plant roots and retained shoot residues. Several reasons, associated with root measurements, limit current knowledge on root C input.This study aimed at evaluating root responses to nutrient management and fertility building measures (e.g. catch crops). We made use of one inorganic fertilizer-based and two organic systems in an 11-year-old field experiment on sandy loam soil. At anthesis, soil cores (5 cm dia.) were sampled from 0-30 cm depth within and between rows of winter wheat and spring barley. Roots were separated from soil and washed with tap water, the dry matter (DM) biomass was determined. Dry matter biomass was also measured in shoots.The spring barley root DM was at... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Soil quality; Soil. |
| Ano: 2011 |
URL: http://orgprints.org/19499/4/19499.pdf |
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| Chirinda, Ngonidzashe; Olesen, J.E.; Porter, J.R.. |
| Soil denitrifying enzyme activity (DEA) is often assessed after cold storage.Previous studies using the short-term acetylene inhibition method have not considered conditioning time (post-cold storage warming-up time prior to soil analysis) as a factor influencing results. We observed fluctuations in DEA following cold storage, suggesting a need to consider conditioning time when planning and interpreting results. |
| Tipo: Journal paper |
Palavras-chave: Soil biology. |
| Ano: 2011 |
URL: http://orgprints.org/18514/1/18514.pdf |
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