All arable land in Sweden need a proper drainage for an effectively agriculture to take place. Of all arable land in Sweden, about 50% is naturally drained and 50% need artificial drainge. More than half of the tile drained area is in need of new drainage or renewed drainage. A good drainage improves farming and crop growth and increases the opportunity to achieve a high and safe harvest level. Future climate change and agriculture size rationalization will increase the need for good drainage. In this paper, two trials with three drainage distances, performed at Lanna experimental station, were analyzed using a mixed linear model.

Eutrophication is an environmental problem that affects more than ten percent of Swedish lakes. Excess nutrients increase the growth of algae, and cause major problems in the ecosystem through oxygen-free bottoms, fish kills, and at worst dead bottoms. Agriculture accounts for 44% of human emissions of phosphorus to lakes and rivers. Leaching occurs of particle bound phosphorus and of dissolved phosphate. The amount of phosphate in the soil solution that may be leached is partly due to the prevailing pH in the soil solution. The purpose of this study was to investigate how the relationship between phosphate solubility and pH was affected by liming.

Agriculture has to be performed in a sustainable way in order to sustain high yields and to support a globally growing population. Functional soil properties are fundamental for high yields and in order to achieve good soil conditions sustainable management is a key. Loss of soil organic material and increased soil acidity are problems associated with degradation of soils and hence less sustainable agriculture. In this thesis, the effect of different agricultural systems on soil organic matter, pH and yield was examined. The systems examined are a cereal system with straw removal or returning and a ley system, all with different nitrogen levels.

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.