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- Bölenius, Elisabeth, et al.
(författare)
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Within field cereal yield variability as affected by soil physical properties and weather variations - A case study in east central Sweden
- 2017
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Ingår i: Geoderma Regional. - : Elsevier BV. - 2352-0094. ; 11, s. 96-103
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Tidskriftsartikel (refereegranskat)abstract
- Yield variations within fields can be substantial and soil physical properties are important as explanatory factors. However, correlations between yield and soil physical properties change between years, mainly depending on weather conditions. This study examined yield variations within a field and the explanatory power of interactions with soil physical factors. It also examined whether soil penetration resistance measurements can indicate areas where soil physical properties are potentially yield-limiting. Field measurements and soil sampling were carried out at 20 locations spread across a 7.5 ha area on a Eutric Cambisol within a 28 ha field at Kvarnbo farm in Uppsala, Sweden (59 degrees 50'N, 17 degrees 32'E). Yield was monitored in 1996-2000 and 2004. Soil sampling was performed in spring 2004 for measurement of soil texture, organic matter content, saturated hydraulic conductivity, bulk density and water-holding capacity at two matric tensions, 0.5 kPa and 10 kPa. Penetration resistance was measured on three separate occasions in 2004 and 2005, to cover any changes within and between seasons. "Simple" regression and principal component analysis (PCA) was used to test for significant differences in the data. Texture proved to be the main factor explaining the overall variation between sampling points, but penetration resistance was the most influential factor for yield variations. Yield in 2000 differed from that in other years due to excess water in lower-lying parts of the field (r=-0.70 between yield in 2000 and water-holding capacity in the subsoil, compared with r=0.6 in dry years). Since penetration resistance was correlated to several other measured soil properties it could be suitable as a screening tool to identify areas with poorer soil physical status for further investigations. Soil physical properties and their effects on yield were highly dependent on the weather. In high-yielding years, when water was not the limiting factor, soil physical status mattered less.
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| 2. |
- Eriksson, Jan, et al.
(författare)
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Spatial patterns of essential trace element concentrations in Swedish soils and crops
- 2017
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Ingår i: Geoderma Regional. - : Elsevier BV. - 2352-0094. ; 10, s. 163-174
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Tidskriftsartikel (refereegranskat)abstract
- Trace element (TE) concentrations in topsoil of Swedish arable soils and grain of winter wheat, spring barley and oats are regularly monitored. Data on Co, Cr, Cu, Mn, Mo, Ni and Zn were analysed in this study, in order to determine spatial patterns of geographical variation in concentrations and their correlations with soil parent material and bedrock geology, and to identify areas with possible TE deficiency or excess with regard to crop and livestock production and product quality. The results showed that pseudo-total (7 M HNO3extraction) concentrations of Co, Cr, Cu, Ni and Zn were elevated in heavy clay soils. Areas influenced by sedimentary rock containing alum shale clearly showed elevated concentrations of various TEs, but otherwise it was difficult to find a clear correlation between soil TE concentration and bedrock geology. This may be because in the recently glaciated Swedish landscape, the ice sheet itself and the melt water from the declining ice sheet have transported soil material over large distances and/or because of low sampling density in many parts of the country. Despite weak correlations for individual elements, there was a general correlation between concentration in soil and concentration in cereal grain for many of the elements studied. One exception was Mn, for which pH was much more important than the concentration in soil. However, there was large variation in TE concentrations within short distances, indicating that soils with high and low concentrations can exist side by side. Nevertheless, for most TE, the risk of low concentrations in crop plants appeared to be greatest on coarse-textured soils on felsic rock and on soils on sedimentary rock (other than alum shale) in southern Sweden. While soils in this region generally have lower concentrations of Co, Cr, Cu, Mn, Ni and Zn than soils in most of western and central Europe, it was difficult to find documented deficiency of elements other than Cu and Mn among those that are essential to plants. Comparing the data on cereal grain presented on this study with suggested critical values indicates possible Cu and Ni deficiency. For the cationic TEs, the generally lower pH in arable soils in Sweden may be one explanation for the modest deficiency problems observed despite rather low soil concentrations. No excessive TE concentrations in crops were recorded, but on clayey soils in eastern Sweden the concentrations were higher than the national average.
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