1. Reaction on burial depth and nitrogen availability and placement in competition with a crop In this trial it was investigated how couch grass (Elymus repens) changes its ability to compete in stands of wheat and barley with different burial depth and different amounts and placement of nitrogen. More knowledge in this area can be valuable in the attempt to decrease the use of herbicides and still keep the weeds under control. The trial was carried out in the summer of 2004 as an outdoor pot experiment. The pots contained 15 litres of soil with a surface of 0,06 m2.

The objective of this thesis is to explore opportunities to enhance the phosphorus use efficiencyof inorganic fertilizers in crop production, with techniques available today and in thefuture. Phosphorus is a finite resource of declining quality; therefore a phosphorus use efficiencyin crop production of only 15-30 % is unacceptable. The main reason for low efficiencyis the retention by Ca and Mg in calcareous soils and Fe and Al in non-calcareoussoils. Due to the low mobility of phosphorus, plant uptake is mainly dependent on root growthrather than diffusion. Therefore, measurements need to be taken that benefit contact betweenroot and fertilizer, before fertilizer phosphorus becomes unavailable to the plant.

This thesis aims to present the essential background on how to perform climate changeimpact assessments, and to present the results from a climate impact assessment on waterbalance and nitrate leaching for an arable Swedish soil. The soil is a sandy soil in southwesternSweden, grown with spring cereals. This study is meant to be a benchmark example,and cannot be seen as a regional or national assessment for Sweden, rather as an approachto present and analyze the most important parts of these kinds of assessments.A dynamical simulation model (COUP, Jansson and Karlberg, 2004) was used for thisstudy. The model was parameterized and calibrated against data from an experimental site,located in Mellby in Hallands county, south western Sweden. Measurements were carriedout between 1st of April 1988 and 1st of April 1991.

The eutrophication of inshore seas, lakes and watercourses is mainly due to leaching of nitrogen and phosphorus (P) from agriculture. Many efforts are made to reduce the lea-kage of phosphorus in Sweden and the Baltic Sea countries. Phosphorus is also a finite resource and the mining of good quality raw material gets more and more difficult. Se-dimentation dams in combination with filters is one relatively new method to separate P from run-off and drainage water from agricultural land. This study was a part of an IVL Swedish Environmental Research Institute?s project which tests the capacity and func-tion for separation of phosphorus in four phosphorus filters.

Hunger is a problem in some parts of the world (www, FAO 1, 2012). The lack of food is often a result of insufficient knowledge in soil fertility management (Röing de Nowina, 2012). Ongoing hunger and malnourishment are quite prevalent in Sub-Saharan Africa and are often combined with poverty (www, FAO 1, 2012). Farming is the most common occupation in this area and the farms are often small-scale farms with subsistence crops and a few cattle. The farmers who operate these small-scale farms are economically a weak group.

Corn is an important food and feed crop in the world, in Sweden it?s up till now grown on limited acreages mainly for silage. But I think it can get more important if you can grow it also for grain, because it?s a good animal feed for example, for life stock-, pigsand poultry. On of corns advantage is that it can produce the same amount of dry matter as for example wheat, barley and rise but with 25% less water. I will examine if it possible to grow corn for grain production in the south of Sweden.

In order to produce grain in an economically rational manner numerous decisions have to be made. One of these decisions is what tillage system to use. The cost of the tillage system is a large part of the total cost in grain production. Different tillage systems result in different distribution of fixed costs, operating costs and timeliness costs. The price of the produced grain and cost of inputs also affect the best way to produce grain.

Crop efficiency in utilizing available nutrients is an important factor in increasing produc-tivity and reducing the environmental impact of agriculture. Nitrogen is the nutrient that plants need in the largest quantity and wheat, along with maize and rice, is the world's most cultivated crop. In this work, the Nitrogen Use Efficiency, NUE, during the major growth period, HTP, of twelve different spring wheat varieties, were examined. The NUE was calculated as the product of uptake efficiency of nitrogen, UN, and the conversion effi-ciency of nitrogen to biomass, EN. The purpose of this work was to find if there are varietal differences in NUE and its components among the twelve varieties and to link a high NUE to specific characteristics of the varieties.

For many years, sugar beets have been the most profitable crop for farmers with suitable growing prerequisites. During year 2007 when the grain prices increased and the EU reform decreased the payment for sugarbeets, it was no longer obvious to grow sugar beets in the crop sequence. With the latest agricultural reform in mind, farming has turned to a more open market and that is important for the independent farmer to adjust to the prevailing market presumptions. In the theory, scientists distinguish between unique and repetitive decisions. Unique decisions can be described as decisions made ones or not often. The opposite, repetitive decisions are decisons that have been made several times before.

A severe profitability decline in sugar beet production in all of Europe is one of the consequences of the latest reform of the EU sugar regime. In south of Sweden, sugar beets is the crop that has been the most profitable by far for the last decade. The high profitability has contributed to the high rate of increase in the price of land and has restrained the structural change towards a more effective agriculture. Because of the reform, all sugar beet producers are facing diminishing income and must find ways to compensate this. The aim of this master thesis is to study how Swedish farmers adapt to the sugar beet reform. A questionnaire was sent to 354 randomly selected sugar beet producers.

The trend towards increasingly large farming units raises questions regarding how to better monitor production. Larger units make the impact from possible errors more severe, which increases the pressure on management supervision. To cope with management issues, prevent errors and handle increased demands on traceability and documentation, the Real Time Location Systems (RTLS) concept is making its way into various parts of agriculture. In sectors outside agriculture, RTLS are already being used successfully to track and locate items through nodes at different levels of accuracy, such as room level or the relative or absolute position. Empirical data can be received in real time from the nodes.

This study investigated potato growing in beds as an alternative to conventional ridges.It was based on results from field trials on bed-grown potatoes carried out by Halland Rural Economy and Agricultural Society in 2007, studies of literature and interviews with farmers with experience of bed growing of potatoes. Due to their shallow root system, potatoes are one of the most drought-sensitive crops. Potatoes are often grown on sandy soils with poor water-holding capacity. Factors such as total yield, tuber size distribution and quality defects are negatively affected when water becomes insufficient. Wide beds have a more flat top which leads to more uniform water infiltration. Further on, beds have lower soil surface area due to its shape, and therefore, retain water more efficient. In the field trials, which were carried out at the Stjärnarp Estate near Halmstad, potatoes were grown in beds alongside a conventional ridge-grown crop.

The aim of this study was to increase the knowledge about whooper swan (Cygnus cygnus) ecology to enhance the ability to predict and also to prevent the crop damage they cause. The largest proportion of damage in Sweden has been reported at stopover sites during spring migration in February, March and April. Therefore, this study focused on an important stopover site, Lake Tysslingen, situated in south-central Sweden. Specifically, the relation between the duration and period migrating swans stage at the stopover site and mean temperature (measured at three different weather stations) for the years 2001-2010 was studied. Furthermore, the swans´ selection for certain fields in relation to field type, distance to roosting site, a supplemental feeding site and forest edge within agricultural land surrounding the lake was analyzed.

The price trend on rapeseed the latest years has led to an increasing interest to grow the crop among many farmers in Sweden. The price trend has resulted in more than a doubling of the oilseed area since the early 2000s. For many farmers it is an advantage to increase cultivation of rapeseed because of the high proportion of cereals in the crop rotation on many farms, but it is not just benefits. The risk of the fields being infected by clubroot increases within frequent rapeseed cultivation and it often leads to subtantial economic losses. Clubroot is caused by Plasmodiophora brassicae that is a soilborne pathogen in genus Protozoa and its resting spores can be found in the soil for up to 18 years.

The corn plant came to Europe with Christopher Columbus in the 14th century and have ever since bin cropped here, but corn haven?t bin very common in Scandinavia until recently. The mainly use for this crop silage but even corn for grain is cropped in Europe. Corn for grain is a common part of feed in beef and chicken farming. In Sweden corn for grain is pretty rare but almost 1000 hectares are used for this crop, Lantmännen Sverige is the biggest buyer of corn at the moment.