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.
2010
Authors
Ingrid Nesheim Per Stålnacke Sekhar Udaya Nagothu Eva Skarbøvik Line Johanne Barkved Håkon ThaulowAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
The water quality in the western part of Lake Vansjø in south eastern Norway is classified as very poor due to excessive growth of blue green algae. It has been shown that phosphorus (P) losses are high from a subcatchment where potatoes and vegetables are grown on 25 % of the agricultural area. The water quality of the lake is of great concern because it is the drinking water reservoir of 60.000 inhabitants and an important recreation area for people living in the area. An integrated project funded by the government was started in 2008 in order to improve the water quality of the lake. Within this project, the public agricultural management, agricultural advisors, farmers and the Norwegian Institute for Agricultural and Environmental Research (Bioforsk) collaborate to attain the target of improved water quality. The farmers are encouraged to sign a contract where they will receive a financial support for covering extra costs for committing to a set of restrictions and mitigation options aiming at reduced P losses. Vegetable- and potato fields give large challenges when aiming at reduced P losses. A large part of the research activity is therefore related to possible mitigation options on these fields, e.g. effect of reduced P fertilization on yields and quality of bulb onion (Allium cepa), carrots (Daucus carota) and white cabbage (Brassica oleracea var. capitata alba), and evaluation of catch crops as a mitigation option for reduced soil erosion from these fields. Development of constructed wetlands to include filters that adsorb P and measurement of P losses through tile drains are also included in the project.
Abstract
In Scandinavia, high losses of soil and particulate-bound phosphorus (PP) have been shown to occur from tine-cultivated and mouldboard-ploughed soils in clay soil areas, especially in relatively warm, wet winters. Omitting primary tillage (not ploughing)in autumn and continuous crop cover are generally used to control soil erosion. In Norway, ploughing and shallow cultivation of sloping fields in spring instead of ploughing in autumn has been shown to reduce particle transport by up to 89% on soils with high erodibility. Particle erosion from clay soils can be reduced by 79% by direct drilling in spring compared with autumn ploughing. Hence, field experiments in Scandinavia on ploughless tillage of clay loams and clay soils compared with conventional ploughing in autumn usually show reductions in total P losses of 10-80%, via both surface runoff and subsurface runoff (lateral movements to drains). However, the effects of not ploughing during autumn on losses of dissolved reactive P (DRP) are frequently negative, since the proportion of DRP losses without ploughing compared conventional ploughing has increased up to fourfold in field experiment. In a comprehensive Norwegian field experiment at a site with high erosion risk the proportion of DRP compared to total P has increased twice in water after direct drilling compared to ploughing before winter wheat. Therefore erosion control measures should be further evaluated for fields with a low erosion risk since reduction in PP losses may be low and DRP losses still high. Ploughless tillage systems have potential side-effects, including an increased need for pesticides to control weeds (e.g. Elytrigia repens (L.) Desv. ex Nevski) and plant diseases (e.g. Fusarium spp.) harboured by crop residues on the soil surface. Overall, soil tillage systems should be appraised for their positive and negative environmental effects before they are widely used for all conditions of soil, management practices, climate and landscape.
Abstract
No abstract has been registered
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No abstract has been registered
Abstract
No abstract has been registered
Abstract
Peatland drainage results in several environmental impacts such as release of greenhouse gas to the atmosphere and leaching of nutrients to watercourses. These hazardous environmental effects can partly be controlled with soil management, and different drainage and remediation practices. Grading is a new method developed for soils with low conductivity suffering from poor drainage, water logging and ice. The soil surface is graded towards the ditch to increase surface runoff and drainage. The present study compares environmental effects of peatland grading compared to traditional intense pipe drainage. Detailed measurements of hydrology, climate, leaching and gas emissions were carried out at adjacent drainage areas with grass cultivation. Additional measurements were made at plots that were abandoned, cultivated with perennial crops, and remained as pristine peatlands. The results show that the leaching of nutrients is highest from pipe drainage. Climate gas emission was considerably higher at all managed sites than from the reference pristine site. Drainage, soil hydrology and soil nutrient status seemed to control gas emissions. The gas emissions were higher than assumed for Norwegian cold conditions. The results confirm observations made on peat soils in other climatic regions. The highest emissions of CO2 was observed when the soil temperature was high and groundwater table low. The N2O emission showed a large variation with no clear pattern. However, at some locations it peaked after a dry period when NO3-N was leached. More CH4 was emitted from the intensively drained site than the graded site, but more CO2 was emitted from the graded site. The difference in leaching and emission properties is partly due to differences in near surface hydrology. At grade sites, a faster runoff response to rainfall occur probably due to shallow throughfall or overland flow which provides better drainage. Also, the graded site was prepared recently, and this can have exposed fresh peat for decay. Therefore the drainage history must be well known in peatland studies as peat change in time due to drainage and cultivation. Abandoned peat field continue to leach greenhouse gases in a same way as cultivated sites.
Abstract
This report presents results from a field trial evaluating the effect of iSeed® coating on turf quality and nitrogen and phosphorus leaching during the grow-in of athletic fields on sand-based rootzones.
Authors
Gunnhild Riise Tore Krogstad Inggard Blakar Elin L. Gjengedal Ståle Haaland Johnny Kristiansen Kristine Naas Torgeir Reierstad Aleksandra Trnic Romarheim Johnson Rutsinda Sara ZambonAbstract
No abstract has been registered