||Long-term forest fertilization experiments in Finland and Sweden - their use for vitality and nutrient balance studies.
Helmisaari, H. ;
Helmisaari, H. S. ;
||Swedish Environmental Protection Agency, Solna.
Experimental Data ;
Field Tests ;
Research Programs ;
Soil Chemistry ;
Foreign technology ;
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
||The aim of this survey was to compile and describe long-term forest fertilization experiments on mineral soils in Finland and Sweden, to evaluate the usefulness of these experiments in providing information about changes in nutrient balance in trees and soil and to give recommendations concerning the future use of these experiments in forest vitality research. In total, 52 FFRI (Finnish Forest Research Institute), 62 IFI (Institute for Forest Improvement, Sweden) and 21 SUAS (Swedish University of Agricultural Sciences) fertilization experiments are described in a tabular form. The sites and stand characteristics, treatments, samplings and measurements presented in the tables give a comprehensive overview of the experiments included. All experiments described here are situated on mineral soils. A comparison of the analysed soil variables in control and fertilized plots will give information about changes in soil nutrient status after long-term fertilization. The relationship between soil variables and stand and tree variables, (e.g. needle loss, needle nutrient concentrations, needle discolouration, needle nutrient ratios) in stands showing nutrient imbalances should also be studied in all experiments (both Finnish and Swedish). An analysis of vegetation date are available only from a few experiments, the data from them should be analysed. Nutrient budgets should be developed for the stands in those experiments that have received high amounts of nitrogen for a long time. Nutrient budgets can provide information about the distribution of the excess nitrogen inputs in forest ecosystems as well as the possible leaching losses of different nutrients. (86 refs., 2 figs., 3 apps.) (au).
||With summary in Swedish and Finnish.
||PC A07/MF A02