| 1. |
- Weslien, P., et al.
(författare)
-
Nitrogen losses following application of pig slurry to arable land
- 1998
-
Ingår i: Soil use and management. - 0266-0032 .- 1475-2743. ; 14:4, s. 200-208
-
Tidskriftsartikel (refereegranskat)abstract
- Emissions of ammonia (NH3) and nitrous oxide (N2O), and nitrate (NO3/-) leaching were measured in two field experiments following application of pig slurry at rates corresponding to 83-96kg NH4-N ha-1 before sowing. In spring and in autumn 1994, slurry was applied by four methods: trenching (T), shallow injection (S), band spreading immediately followed by harrowing (B/H) and band spreading (B). NH3 emission measurements were made during the first week after application in both experiments. In the spring experiment N2O emissions and NO3/- leaching were measured during 6 and 52 weeks after spreading respectively, and during 11-and 33 weeks after spreading in the autumn experiment. In spring, the increased N2O emissions (i.e. control subtracted) ranged from 0.27% (T) to 0.45% (B/H), and in the autumn study from 0.92% (T) to 1.14% (B/H), of applied NH4-N, although showing no statistically significant differences. In order to validate the chamber measurements, a 'megachamber' (21 m2) was used together with an infrared spectrometer. The emissions agreed well for (B/H), while (B) resulted in lower emissions compared with the smaller chambers. Emissions of NH3 were about one order of magnitude higher. In spring, (B) gave the highest emission, reaching 19.5% of applied NH4-N, whereas (S), and (B/H) gave the lowest emissions, reaching 1.2 and 3.5% of applied NH4-N, respectively. NH3 emissions in autumn were 15-20% lower compared with spring. In spring the increased nitrate leaching ranged from 10.1 (T) to 24.9 kg ha-1 (B/H) and from 29.5 (B) to 37.8 kg ha-1 (T) in the autumn experiment, showing no statistically significant differences. Estimations of indirect N2O emissions due to ammonia deposition and nitrate leaching, suggested that the N2O contribution from NH3 deposition was relatively small, while the indirect N2O emissions from NO3/- leaching were of the same order of magnitude or higher than the direct N2O emissions.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Johansson, Emma, et al.
(författare)
-
Hydrological and meteorological investigations in a periglacial lake catchment near Kangerlussuaq, west Greenland - presentation of a new multi-parameter data set
- 2015
-
Ingår i: Earth System Science Data. - : Copernicus GmbH. - 1866-3508 .- 1866-3516. ; 7:1, s. 93-108
-
Tidskriftsartikel (refereegranskat)abstract
- Few hydrological studies have been conducted in Greenland, other than on glacial hydrology associated with the ice sheet. Understanding permafrost hydrology and hydroclimatic change and variability, however, provides key information for understanding climate change effects and feedbacks in the Arctic landscape. This paper presents a new, extensive, and detailed hydrological and meteorological open access data set, with high temporal resolution from a 1.56 km(2) permafrost catchment, with a lake underlain by a through-talik close to the ice sheet in the Kangerlussuaq region, western Greenland. The paper describes the hydrological site investigations and utilized equipment, as well as the data collection and processing. The investigations were performed between 2010 and 2013. The high spatial resolution, within the investigated area, of the data set makes it highly suitable for various detailed hydrological and ecological studies on catchment scale. The data set is available for all users via the PANGAEA database, http://doi.pangaea.de/10.1594/PANGAEA.836178.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Svanbäck, Annika, et al.
(författare)
-
Reducing agricultural nutrient surpluses in a large catchment - Links to livestock density
- 2019
-
Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 648, s. 1549-1559
-
Tidskriftsartikel (refereegranskat)abstract
- The separation between crop- and livestock production is an important driver of agricultural nutrient surpluses in many parts of the world. Nutrient surpluses can be symptomatic of poor resource use efficiency and contribute to environmental problems. Thus, it is important not only to identify where surpluses can be reduced, but also the potential policy tools that could facilitate reductions. Here, we explored linkages between livestock production and nutrient flows for the Baltic Sea catchment and discuss management practices and policies that influence the magnitude of nutrient surpluses. We found that the majority of nutrients cycled through the livestock sector and that large nitrogen and phosphorus surpluses often occurred in regions with high livestock density. Imports of mineral fertilizers and feed to the catchment increased overall surpluses, which in turn increased the risk of nutrient losses from agriculture to the aquatic environment. Many things can be done to reduce agricultural nutrient surpluses; an important example is using manure nutrients more efficiently in crop production, thereby reducing the need to import mineral fertilizers. Also, existing soil P reserves could be used to a greater extent, which further emphasizes the need to improve nutrient management practices. The countries around the Baltic Sea used different approaches to manage agricultural nutrient surpluses, and because eight of the coastal countries are members in the European Union (EU), common EU policies play an important role in management. We observed reductions in surpluses between 2000 and 2010 in some countries, which suggested the influence of different approaches to management and policy and that there are opportunities for further improvement. However, the separation between crop and livestock production in agriculture appears to be an underlying cause of nutrient surpluses; thus, further research is needed to understand how policy can address these structural issues and increase sustainability in food production.
|
|
| 8. |
|
|
