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| Registros recuperados: 11 | |
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| Chalk,Phillip Michael. |
| Abstract Brazilian scientists have played a pioneering role in developing and applying stable isotope methodologies, in terms of natural abundance and enriched levels, to trace carbon and nutrient flows in terrestrial ecosystems, including natural and agroecosystems. Significant contributions have been made in the areas of biological N2 fixation, carbon dynamics in soil, synthesis and evaluation of labeled fertilizers, and food science. These contributions have originated from several decentralized units of Embrapa, from research institutions, and from federal or state universities. In order to capitalize the existing Brazilian expertise, it is necessary to provide, at an institutional level, analytical facilities for stable isotope research, aiming to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biological N2 fixation; Fertilizer use efficiency; Food science; Labeled fertilizer; Soil carbon; Stable isotopes. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2016000901039 |
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| Gassman, Philip W.; Williams, Jimmy R.; Wang, Xiuying; Saleh, Ali; Osei, Edward; Hauck, Larry M.; Izaurralde, R. Cesar; Flowers, Joan D.. |
| The Agricultural Policy Environmental eXtender (APEX) model was developed by the Blacklands Research and Extension Center in Temple, Texas. APEX is a flexible and dynamic tool that is capable of simulating a wide array of management practices, cropping systems, and other land use across a broad range of agricultural landscapes, including whole farms and small watersheds. The model can be configured for novel land management strategies, such as filter strip impacts on pollutant losses from upslope cropfields, intensive rotational grazing scenarios depicting movement of cows between paddocks, vegetated grassed waterways in combination with filter strip impacts, and land application of manure removal from livestock feedlots or waste storage ponds. A... |
| Tipo: Report |
Palavras-chave: APEX; Best management practices; Farm and watershed simulations; Soil carbon; Water quality; Environmental Economics and Policy. |
| Ano: 2009 |
URL: http://purl.umn.edu/49156 |
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| Gulati, Sumeet; Vercammen, James. |
| In this paper we present the economic determinants of the optimal length of a carbon offset contract. We find that because of a declining capacity of the soil to sequester carbon, the optimal length of the carbon contract is finite (the marginal benefit of remaining in the contract is declining over time, whereas marginal opportunity cost is rising). We also explore the effect of varying key parameter values on the optimal length in the contract. If the contract requires the farmer to sequester at a higher rate, the farmer chooses the contract for a shorter length of time, and this may decrease rather than increase social welfare. If society places a higher value on carbon accumulation, the contract is chosen for a longer length of time. Finally, if both... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Carbon offset contracts; Greenhouse gas policy; Soil carbon; Environmental Economics and Policy; Farm Management; Q200; Q580. |
| Ano: 2005 |
URL: http://purl.umn.edu/37027 |
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| Tirloni,Carolina; Vitorino,Antonio Carlos Tadeu; Bergamin,Anderson Cristian; Souza,Luiz Carlos Ferreira de. |
| Crop-livestock integration represents an interesting alternative of soil management, especially in regions where the maintenance of cover crops in no-tillage systems is difficult. The objective of this study was to evaluate soil physical and chemical properties, based on the hypothesis that a well-managed crop-livestock integration system improves the soil quality and stabilizes the system. The experiment was set up in a completely randomized design, with five replications. The treatments were arranged in a 6 x 4 factorial design, to assess five crop rotation systems in crop-livestock integration, and native forest as reference of soil undisturbed by agriculture, in four layers (0.0-0.05; 0.05-0.10; 0.10-0.15 and 0.15-0.20 m). The crop rotation systems in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Crop rotation; No-tillage system; Soil quality; Soil carbon; Aggregate stability. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832012000400024 |
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| DECKER,KELLY L.M; BOERNER,R.E.J. |
| We measured net nitrogen mineralization, net nitrification, proportional nitrification, and total inorganic nitrogen, available phosphorus, and soil organic carbon in five Andean forested stands in an attempt to resolve the relative influence of elevation and forest canopy composition on soil organic matter and nutrient dynamics in this ecosystem type. Our five forested study sites were within a contiguous Nothofagus forest that ranged from 1,280 to 1,700 m elevation in the central Chilean Andes. The five sites consisted of three single species stands, one each of the low elevation deciduous N. obliqua, the evergreen N. dombeyi, or the high elevation deciduous N. pumilio, as well as two mixed evergreen-deciduous stands. There was no statistically... |
| Tipo: Journal article |
Palavras-chave: Chilean Andes; Leaf lifespan; Nitrogen mineralization; Nitrification; Soil carbon. |
| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2003000300003 |
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| Registros recuperados: 11 | |
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