I den här studien har granskning gjorts av skördekartering och markkartering på Bjertorp Egendom, Lantmännen SW Seed, i Västergötland. Bakgrunden till detta arbete är att ta till vara på information om fälten på gården i form av inlagrade skördekarteringsdata. Detta för att sedan kunna koppla dem samman med markkartering och kunna få bättre förståelse för fältens avkastning och dess potentiella avkastningsförmåga. Utifrån detta ska man i framtiden kunna anpassa val av odlingsåtgärder ur ekonomiskt och miljömässigt perspektiv. En litteraturstudie har gjorts för att ge bättre förståelse för teknikerna som används vid mark- och skördekartering. Den inledande delen av litteraturstudien handlar om Precisionsodling för att skapa bättre förståelse för vad det begreppet innebär. För skördekartering även en mer ingående förklaring till hur man från rådata omvandlar detta till skördekartor och sedan beskrivning av olika tekniker för markkartering. Avslutande handlar den om hur skörden påverkas av olika faktorer såsom väder, näringstillgång och jordart. Skördedata som på gården samlats in under ett flertal år har använts tillsammans med befintlig markkartering.

GPS is perhaps the future in agriculture. The next years will show it but the precision becomes only better and better and the number of users becomes only more and more. This work shows experiences from today's users and how the profitability can be improved on a farm with normal plant cultivation. The aim is to show how big the actual advantage can be to have a GPS and how good precision there is with the equipment. John Deere and Trimble are the big producers of GPS equipment to the agriculture.

The Yara N-Tester is a handheld chlorophyll meter which can be used in several different crops as an aid to determine if there is a need of complementary fertilization with nitrogen (N) or not. If the crop requires more N the N-Tester will recommend an amount in kg per ha. The possibility to assess the need of N depends on the strong relation that exists between chlorophyll- and N-concentration in the leaves of plants. In the multiannual trial series ?Nitrogen to winter wheat at different soil conditions? measurements with the N-Tester was carried out at flag leaf emergence (GS 37). In this work the result of measurements, the NTesters ability to estimate the need of N in winter wheat, will be presented for the years 2008-2011.

I denna studie har jag tittat närmare på värdena för rådata i skörd av spannmål, genom att utvärdera skördekartering från tre olika fält, två fält på Sannarps egendom och ett fält på Nya Fjällalunda gård. Gårdarna ligger i Halland utanför Falkenberg och Sannarp AB står för driften av båda enheterna. De skördekarterade grödor som ingår i studien är foderkorn, rågvete samt höstvete. Studien har gått till på det viset att i de tre fälten har två provytor belägna nära en markarteringspunkt valts ut. I provytorna har rådata lästs ut från skördedata och sedan jämförts med medelvärdet för fältet.

Different techniques for precision agriculture have been available during the last decade. Some of them are more widely used than others. The main purpose of this thesis was to investigate the different attitudes to precision agriculture that exists among farmers and advisors in Sweden. Eight advisors and sixteen farmers were asked for their opinion of a number of specific techniques for precision agriculture, such as yield-mapping, precision liming, the Yara Nitrogen Sensor and site-specific fertilization with phosphorous and potassium. They were also asked to describe the way in which the counselling in Swedish agriculture is used and also about it's importance for the adaptation of new techniques. The high costs are mentioned to be one of the most important reasons why precision agriculture hasn't been more widely spread. Several farmers refer to their farms as too small to bear the costs that come with the techniques. The individual interest for technique among the potential users plays an important role.

Variation in tuber quality within a single field was one of the motives for a pilot study in Halland, in south-western Sweden conducted during 2002. Quality problems in potatoes have been increasing due to the aggregation of several small fields with different land use history into larger farm units, which are heterogeneous in soil properties and fertility. The study in Halland indicated that both the uniformity and the mean size of tubers may increase from site-specific K fertilization, whereas total yields may be unaffected. The results from this pilot-study with site-specific fertilization showed that tubers reached a more uniform quality and gave a more uniform mean size, while the total yield wasn't affected at all. Site-specific K-fertilization has been applied for some years in Halland with good results. The aim of this study was to test this technique in another potato growing area.

Due to excess precipitation that cause runoff, all soils in Sweden naturally leaches nitrogen.High leaching from arable land is an environmental problem when the runoff reacheswaters. In the international agreement, Baltic Sea Action Plan, the aim is to reduce therunoff of nutrients. Sweden has agreed to reduce its load of e.g. nitrogen to the Baltic Sea.One of the proposed measures is an increased use of site-specific N-fertilization, which hasbeen shown to increase nitrogen use efficiency and therefore also reduce the nitrogen runoff.Either yields are increased with the same total amount of nitrogen, or the total quantityof nitrogen is reduced with preserved yield levels, which is profitable for the farmers.The dynamics of nitrogen leaching differs between top dressing applications above orbelow the economical optimum. There is a consensus about a difference in the dynamics,but not about its magnitude.