Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2006
Authors
Liv Sognnes Gustav Fystro Samson Øpstad Arve Arstein Trond BørresenAbstract
In terms of agricultural use, peat soils have weak structure, high water content, insufficient soil aeration and poor thermal properties resulting in suboptimal physical properties and yields of grass. During the period 1978 - 1995, a long-term field trial was conducted on highly decomposed peat soil in order to investigate the impact of adding mineral materials to improve soil characteristics and increase grass yield. Shell sand or moraine soil (200, 400 or 800 m(3) ha(-1)) was incorporated into peat soil. Generally, addition of both shell sand and moraine soil improved the physical properties of the soil and grass production. During the first nine years, shell sand ( 400 m 3 ha(-1)) was the most efficient. Thereafter, moraine soil ( 400 and 800 m(3) ha(-1)) seemed most beneficial. This study indicates that additions of shell sand or moraine soil to peat are appropriate methods to improve and conserve the physical properties and cropping potential of these vulnerable soils.
Authors
Ingvald Røsberg Jon Frank Arne O. StuanesAbstract
Soil uptake of N, P, and K from the unfertilized plots leads to a depletion of these elements, but also very little leaching. Upon addition of N, P, K, Mg, Ca, and S, soil uptake and nutrient accumulation in the soil usually increased at the same time. The high doses of N, P, K, and S in the "optimal" treatment gave a distinct response with higher uptake from the soil and higher accumulation in the soil. No P was leached from the soil, while about one fourth to one third of the applied N, K, and Mg were leached. The treatment induced an unacceptably high nitrate leaching, and must therefore be regarded as "suboptimal". (c) 2006 Elsevier B.V All rights reserved. Tree growth and nutrient cycling of N, P, K, Mg, Ca, S, and B were examined after four growing seasons in a pine ecosystem in southern Norway. The Scots pine (Pinus sylvestris L.) stand, growing on a Cambic Arenosol, was 33 years old and had a medium site index class. The randomized block experiment had six treatments and three replicates: (1) control, (2) 3000 kg per hectare lime, (3) 3000 kg per hectare dolomite, (4) 3000 kg per hectare dolomite and (5) 6000 kg per hectare dolomite, both treatments (4 and 5) with the fertilizers KCl and superphosphate, and (6) 3000 kg per hectare dolomite with KCl, superphosphate, NH4NO3, kieserite, and borax, and denoted as "optimal" treatment. The "optimal" treatment gave a significantly higher annual increase in tree height and diameter, stand basal area and volume than the control and lime treatments. The dry mass of needles and branches increased slightly for the treatments nos. 3-5 compared to the control and lime treatments, with the most distinct increase for the "optimal" treatment. Highest dry mass of stem wood + bark was found for the treatments nos. 3-6. The nutrient contents in needles were highest for the "optimal" treatment, while dolomite without fertilizer elevated the Mg content in both needles and branches. The nutrient concentrations in the current year's needles increased the most for the "optimal" treatment, except for Ca and Mg. The addition of lime gave the highest concentration of Ca in needles compared to the other treatments. The amounts of N, P, S, and B in the forest floor were also highest for the "optimal" treatment. Soil uptake of N, P, and K from the unfertilized plots leads to a depletion of these elements, but also very little leaching. Upon addition of N, P, K, Mg, Ca, and S, soil uptake and nutrient accumulation in the soil usually increased at the same time. The high doses of N, P, K, and S in the "optimal" treatment gave a distinct response with higher uptake from the soil and higher accumulation in the soil. No P was leached from the soil, while about one fourth to one third of the applied N, K, and Mg were leached. The treatment induced an unacceptably high nitrate leaching, and must therefore be regarded as "suboptimal".
Authors
Aksel GranhusAbstract
No abstract has been registered
Abstract
Organic farmers are often advised to plough shallowly (<15 cm) in order to optimise nutrient turnover and to promote the activity of soil biota, but deeper for better control of perennial weeds. Different ploughing depths (13 vs 25 cm) had minor effects on decomposition rate of barley straw and earthworm activity in the decomposing straw when using a light tractor (2 and 4 Mg). However, different burying depths (13 vs 25 cm) of barley straw had some important effects on decomposition and earthworm activity.
Authors
Jørgen Aleksander Mølmann Olavi Junttila Øystein Johnsen Jorunn Elisabeth OlsenAbstract
Seedlings of trees with a free growth pattern cease growth when night-lengths become shorter than a critical value, and this critical night-length (CNL) decreases with increasing latitude of origin. In northern populations, the light quality also appears to play an important role and a clinal variation in requirement for far-red (FR) light has been documented. In this study we dissected the light quality requirements for maintaining growth in different latitudinal populations of Norway spruce (Picea abies (L.) H. Karst.) using light emitting diodes for red (R), FR and blue (B) light, as 12 h day extension to provide 24 h photoperiod. At equal spectral photon flux, FR light was more effective than R light in maintaining growth, and the requirement of both R and FR increased with northern latitude of origin. One-to-one mixtures of R and FR light were more effective in maintaining growth than either FR or R light alone, indicating a possible interaction between R and FR light maintaining growth. Using the blue light as day extension could not prevent growth cessation in any of the populations, but delayed the bud set slightly in all populations. Our results suggest that phytochrome(s) are the primary photoreceptors in high irradiance responses maintaining growth in Norway spruce seedlings.
Abstract
No abstract has been registered
Editors
Gro HylenAbstract
The Intergovernmental Panel on Climate Change under the UN finalised in 2004 the report “Good Practice Guidance for Estimating and Reporting of Emissions and Removals from Land Use, Land-use Change and Forestry”. The present report describes the data material and the methods used to provide estimates for Norway for the period from 1990 to 2004 in accordance with the good practice guidance. Land-use changes cause changes in carbon storage, thus indirectly emissions and removals of CO2. Removals of CO2 in Norway due to land-use change are relatively insignificant compared to sequestration in existing forest. For 2004, the net sequestration of CO2 from this sector has been estimated at 26 million tonnes, which correspond to about 48% of the total anthropogenic greenhouse gas emissions in Norway. The net sequestration increased by approximately 81 per cent from 1990 to 2004.
Abstract
No abstract has been registered
Abstract
Agricultural policy has in the last 50 years taken much of the risk and the initiative away from Norwegian farm forest owners. Subsidies in agriculture have guaranteed an acceptable income and there has been neither need nor incentives for starting up new activities at the farms. This situation is now gradually changing. The income both from agriculture and forestry is decreasing and farm forest owners have either to move, to find job opportunities outside the farm or to start up new activity at the farm using the farm's resources. Entrepreneurship theory is used to study the question why some farm forest owners choose to start up some new activity based on the forest resources they have. We identify two main elements of entrepreneurship; the ability to recognise business opportunities and the ability to take calculated risk. In a survey to 500 forest owners in southern Norway (response rate 45%), we included questions about opportunity recognition and risk aversion. From the answers, we were able to split the forest owners in two groups, those with entrepreneurial attitudes and those without. Using logistic regression we found a significantly higher probability for start-up of new activities in the group with entrepreneurial attitudes. This result has very interesting policy implications. Many studies show that entrepreneurial attitudes to a large degree can be learnt. The first way of learning about entrepreneurship is through the education system and through courses and training of forest owners. The other way is 'learning by doing', which is most probably the most efficient way to learn about entrepreneurship. Public policy should stimulate more owners to 'do', by that they will 'learn' and that will again lead to more entrepreneurial activities at the holdings. (c) 2005 Elsevier B.V. All rights reserved.
Authors
Ian K. Toth L Moleleki Leighton Pritchard H Liu Sonia Humphris L Hyman Gunnhild W. Axelsen May Bente Brurberg M Ravensdale E Gilroy Paul R.J. BirchAbstract
No abstract has been registered