| 1. |
- Hoffmann, M., et al.
(author)
-
Leaching of nitrogen in Swedish agriculture - A historical perspective
- 2000
-
In: Agriculture, Ecosystems & Environment. - 0167-8809 .- 1873-2305. ; 80:3, s. 277-290
-
Journal article (peer-reviewed)abstract
- There is a need to examine long-term changes in nitrogen leaching from arable soils. The purpose of this study was to analyse variations in specific leaching rates (kg ha-1 per year) and gross load (Mg per year) of N from arable land to watercourses in Sweden from a historical perspective. The start of the study was set to 1865 because information on crop distribution, yield and livestock has been compiled yearly since then. The SOIL/SOILN model was used to calculate nitrogen leaching. Calculations were done for cereals, grass and bare fallow for three different soil types in nine agricultural regions covering a range of climatic conditions. Results indicate that both specific leaching rates and gross load of nitrogen in the middle of 19th century were approximately the same as they are today for the whole of south and central Sweden. Three main explanations for this were (1) large areas of bare fallow typical for the farming practice at the time, (2) enhanced mineralisation from newly cultivated land, and (3) low yield. From 1865, i.e. the start of the calculations, N leaching rates decreased and were at their lowest around 1930. During the same period, gross load was also at its lowest despite the fact that the acreage of arable land was at its most extensive. After 1930, average leaching increased by 60% and gross load by 30%, both reaching a peak in the mid-1970s to be followed by a declining trend. The greatest increase in leaching was in regions where the increase in animal density was largest and these regions were also those where the natural conditions for leaching such as mild winters and coarse-textured soils were found. Extensive draining projects occurred during the period of investigation, in particular an intensive exploitation of lakes and wetlands. This caused a substantial drop in nitrogen retention and the probable increase in net load to the sea might thus have been more affected by this decrease in retention than the actual increase in gross load. (C) 2000 Elsevier Science B.V.
|
|
| 2. |
- Berndes, Göran, 1966, et al.
(author)
-
Cadmium accumulation and Salix-based phytoextraction on arable land in Sweden
- 2004
-
In: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 103:1, s. 207-223
-
Journal article (peer-reviewed)abstract
- Cadmium accumulation in arable soils causes concern due to possible direct environmental effects and health risks associated with exposure of humans to cadmium through agricultural products. This paper discusses the problem of cadmium accumulation in Swedish arable land, and evaluates Salix (Salix vinimalis) cultivation as a tool for addressing the problem. It is found that Salix cultivation offers an effective option for addressing the cadmium accumulation, especially when the topsoil has high cadmium content due to anthropogenic inflows, and the subsoil naturally contains little cadmium. The estimated practical potential for Salix-based cadmium management (ca. 490 000 ha) is very large compared to the present Salix plantation area in Sweden (ca. 15 000 ha). However, the estimates of the net economic value of cadmium removal from arable land indicate that the economics of Salix production will not improve dramatically due to an induced cadmium removal. Salix-based cadmium management will therefore most likely take place in counties where Salix cultivation can be expected to expand as a response to an unfilled biomass demand in the energy sector. © 2003 Elsevier B.V. All rights reserved.
|
|
| 3. |
- Piikki, Kristin, 1975, et al.
(author)
-
The impact of tropospheric O3 on leaf number duration and tuber yield of the potato (Solanum tuberosum L.) cultivars Bintje and Kardal
- 2004
-
In: Agriculture, Ecosystems & Environment. - : Elsevier BV. - 0167-8809. ; 104:3, s. 483-492
-
Journal article (peer-reviewed)abstract
- Ozone (O3) is a major phytotoxic air pollutant with the potential to cause severe yield losses in potato (Solanum tubersosum L.) and in other crops. The present study was aimed (i) to investigate the O3 sensitivity of two potato cultivars (Bintje and Kardal) in relation to their earliness in maturation, and (ii) to analyse possible O3 effects on potato tuber dry mass (DM) production in relation to leaf duration. The experiment was performed in the southwest of Sweden using open-top chamber (OTC) technique. The crops were exposed to three levels of O3: charcoal-filtered air (CF), non-filtered air (NF) and non-filtered air + 26 nmol mol−1 O3 (NF+). In addition, ambient air plots were used to monitor the impact of the OTC enclosure. Leaf number duration (LND) was calculated as the number of leaves integrated over the temperature sum accumulation during the season. In the present study, the O3 effects on potato were characterised by visible injury of the leaves and earlier leaf senescence. The haulm/plant DM ratio was significantly lower in NF+ compared to CF and NF. The conclusions were (i) that the early to intermediate maturing cultivar Bintje tended to suffer more from O3 injury than the late maturing cultivar Kardal, (ii) that this was due to a difference in the ability to compensate for haulm damage by the development of new leaves rather than to a difference in leaf O3 sensitivity, and (iii) that a rather low O3 exposure can induce a significant reduction in LND in potato. The O3 effects on tuber DM (−2% in NF+ and +31% increase in CF, both compared to NF) could not be statistically demonstrated, although there was a strong correlation between LND and tuber DM.
|
|
| 4. |
- Smith, Henrik G., et al.
(author)
-
The effect of pasture on starling (Sturnus vulgaris) breeding success and population density in a heterogenous agricultrual landscape in Southern Sweden
- 2002
-
In: Agriculture, Ecosystems & Environment. - 1873-2305. ; 92:1, s. 107-114
-
Journal article (peer-reviewed)abstract
- Populations of European starlings have declined over large parts of northern and western Europe during the last 20 years. It has been suggested that reduced availability of pasture in the agricultural landscape was one reason for this decline. To investigate this, breeding colonies for starlings were established in southern Sweden, in agricultural landscapes with different availabilities of pasture. Agricultural land-use was classified in a circular area of 500 m around each colony. Production of young per nest was positively related to the availability of pasture close to the breeding colony, not because the availability of pasture affected clutch size or hatchability of eggs, but because nestling survival was higher in colonies surrounded by pasture. The growth rate of an offspring feather character, but not offspring final mass or tarsus length, tended to be related to the availability of pasture. When availability of pasture was low, the variability of breeding success between years was high. Breeding density was also positively related to the availability of pasture near colonies. The combined trends in reproductive success and breeding density in this study support the contention that the reduction of pasture in modern agricultural landscape may be one reason why starling population size has declined.
|
|
