Experimental Site of the ‘Ecology of Arable Land’ Project

Abstract

In 1979 a major integrated research project ‘The Ecology of Arable Land’ was initiated, in which recent trends in Swedish crop husbandry are reflected. These trends include less carbon input through crop residues, a higher nitrogen input through fertilizers, less biological fixation of nitrogen, through growing of legumes and simpler crop rotations. Nitrogen is the major limiting nutrient in modern agriculture. Crop uptake efficiency of nitrogen is low and pollution of waters and the atmosphere by nitrogen from fertilizer use is becoming increasingly evident. The project aims at quantitatively determining the fate of fertilizer and biologically-fixed nitrogen in four cropping systems (barely with 0 kg N ha⁻¹ yr⁻¹ barley with 120 kg N ha⁻¹ yr⁻¹, meadow fescue grass ley with 200 kg N ha⁻¹ yr⁻¹, lucerne ley with biological nitrogen fixation), with special attention to the role of soil organisms (microorganisms, fauna and roots) in regulating the biogeochemical nitrogen cycle. The experimental site of the project is situated 40 km north of Uppsala. A detailed description of the site is given with regard to geology, hydrology, climate and site history. Important soil characteristics of the site are stated such as texture, water characteristics, pH and carbon, total nitrogen, nitrate, phosphorus, potassium and magnesium contents. The plan of the field experiments, the drainage system and the equipment and instruments installations are also described.