| 1. |
- Hedwall, Per-Ola, et al.
(författare)
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Effects of clear-cutting and slash removal on soil water chemistry and forest-floor vegetation in a nutrient optimised Norway spruce stand
- 2013
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Ingår i: Silva Fennica. - : Finnish Society of Forest Science. - 0037-5330 .- 2242-4075. ; 47
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Tidskriftsartikel (refereegranskat)abstract
- Fertilisation with nutrient optimisation has in Sweden resulted in large increases in volume growth in young stands of Norway spruce. There are, however, environmental concerns about repeated fertilisation and one is the risk of nutrient leakage to ground water resources and aquatic ecosystems after clear-cutting of such forests. The present study followed soil-water chemistry in optimised fertilised stands after clear-cutting, as well as effects of harvest of slash on nutrient leakage. Parts of a 30-year-old stand of Norway spruce, which had been subject to a nutrient optimisation experiment for 17 years, were clear-cut. A split-plot design with whole-tree harvesting as the sub-plot treatment was applied. Lysimeters were installed and soil-water sampled at nine occasions during the following four years. No significant effects of fertilisation on nitrate leaching were found, while harvest of slash affected the concentration of Ca, DOC, DON, K, Mg, ammonium and nitrate, as well as pH in the soil solution. While no effects of fertilisation could be seen on the soil water concentration of N, the results indicate an interaction between fertilisation and harvest of slash on the concentration of nitrate in the soil solution. The results indicate that forest-floor vegetation plays an important role in the retention of N after clear-cutting of fertilised forests.
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| 2. |
- Lövdahl, Lars, et al.
(författare)
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Effects of mulching and catch cropping on soil temperature, soil moisture and wheat yield on the Loess Plateau of China
- 2009
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Ingår i: Soil and Tillage Research. - : Elsevier BV. - 0167-1987 .- 1879-3444. ; 102, s. 78-86
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Tidskriftsartikel (refereegranskat)abstract
- Soil management can notably influence crop production under dryland farming in semiarid areas. Field experiments were conducted, from October 2001 to September 2004, with an attempt to evaluate the effects of field management regimes on thermal status at an upland site; and soil water and wheat production in a winter wheat (Triticum aestivum L) system at upland, terrace land and bottom land sites on the Loess Plateau, China. The field management regimes tested were: (i) the conventional practice (winter wheat followed by a ploughed summer bare fallow); (ii) conventional management, but a catch crop growing for certain time during fallow period used as green manure (after the wheat harvest, a catch crop were directly sown. instead of ploughing, and then incorporated into the soil roughly one month before wheat sowing); and (iii) wheat straw mulch (0.8 kg m(-2)), covering the soil throughout the year during the experimental period (no summer ploughing, straw was removed during wheat sowing). Soil temperature under catch cropping was lower during certain period of its growing by about 2 degrees C, slightly higher for short spells after incorporation and before wheat harvest, no observed effects during the rest time of a year relative to conventional practice at the upland site. Moreover, soil water storage levels under catch cropping were comparable with those of the conventional practice for all three years, but wheat yield substantially declined in the last year. Mulching showed different responses for the three land sites. At the upland site, daily mean soil temperatures under mulching at 10 cm depth were decreased in the warmer period by 0-4 degrees C, and increased in the colder period by 0-2 degrees C when compared to those of non-mulched soil. At upland and bottom land sites, mulching conserved an average of 28 and 20 mm more water in the upper 100 cm soil layer at the time of wheat sowing, respectively, than conventional practice. However, at the terrace, mulching had little effect on soil water storage, nor on wheat grain yield, relative to conventional practice. Therefore, considering the limited availability of mulch material in this region and the economic benefits, it is recommended that mulching may be beneficial to upland or bottom land, but not to terraced land. In addition, the application of catch cropping in this study did not show positive effects, the more comprehensive evaluation of this approach would be further needed. (C) 2008 Elsevier B.V. All rights reserved.
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| 3. |
- Zhang, Shulan, et al.
(författare)
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Soil Management Practice Effect on Water Balance of a Dryland Soil during Fallow Period on the Loess Plateau of China
- 2016
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Ingår i: Soil and Water Research. - 1801-5395. ; 11, s. 64-73
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Tidskriftsartikel (refereegranskat)abstract
- To understand the mechanisms affecting water balance partitioning during fallow on drylands could improve the fallow management practices in arable land ecosystems. A three-year field experiment was conducted to evaluate the effects of field management regimes on water balance partitioning and fallow efficiency during the fallow periods under a winter wheat (Triticum aestivum L.) fallow system on the Loess Plateau, China. The fallow management regimes tested were: (i) conventional practice, (ii) catch cropping, and (iii) no tillage with wheat straw mulching. A process-oriented ecosystem model (CoupModel) was calibrated with field measurements and then used to generate comparative simulations of the water balance partitioning. The simulations indicated that mulching increased the soil water storage change by 38-71 mm during the three fallow periods, thus resulting in higher fallow efficiency by 9-12%, and decreased soil evaporation by 22-72 mm, compared with the conventional practice. Furthermore, water reached deeper horizons, resulting in 7 mm deep percolation in a wet year under mulching but not under conventional practice or catch cropping. The simulation results also showed that the catch cropping decreased the soil water storage change by 13-21 mm, although it lowered soil evaporation by 11-51 mm, and altogether reduced the fallow efficiency by 3-9%, compared to conventional practice. On the Loess Plateau of China mulching proved to be a sound measure for ensuring certain fallow efficiency and possibly benefit to the water cycle, while catch cropping negatively partitioned the water balance. The catch cropping under mulching might be another management regime to be considered.
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