Effect of cattle slurry on soil and herbage chemical properties, yield, nutrient balance and plant species composition of moderately dry Arrhenatherion grassland

There is increasing pressure to apply cattle slurry on Arrhenatherion grasslands in Central Europe, but intensive manuring can decrease their natural value. We searched for an N application rate which represents an acceptable compromise between farming requirements for high soil fertility and adequate herbage production, environmental protection requirements for balanced applications of nutrients and nature conservation requirements for species-rich grasslands. We applied different annual rates of cattle slurry (0, 60, 120, 180, 240 kg N ha(-1)) on moderately dry Arrhenatherion grasslands over six years. Slurry application positively affected soil fertility by increasing pH, as well as P, K and Mg availability, without any effect on organic C and the total N content. The mean annual herbage yield was 2.58, 3.56, 4.40, 5.75 and 6.09 t ha(-1) in 0, 60,120, 180 and 240 treatments, respectively. Concentrations of N, P and K in herbage slightly increased with slurry application, while the concentration of Ca decreased. There was no surplus of N, K and Ca up to an N application rate of 120 kg ha(-1), and there was only a slight surplus of P and Mg. In S3 and S4 treatments, the main change in vegetation was an increase in graminoids cover, accompanied by a decrease in the cover of legumes and short forbs, without any significant effect on the species richness of vascular plants. Slurry application at annual rates up to 120 Nha seems to be an acceptable compromise, and we recommend setting this limit for application of cattle slurry on Arrhenatherion grasslands. (C) 2015 Elsevier B.V. All rights reserved.