SLU long-term field experiments: The Swedish soil fertility experiments (R3-9001), crop and soil data from 1962 and onwards

The SLU long-term agricultural field experiments are a nationwide research infrastructure consisting of experiments in hydrological management, tillage, landscape ecology, plant nutrition, weed biology and control, cropping systems, and cropping systems in northern Sweden. They are used to study how crop rotations and cultivation measures in agriculture affect soil properties and crop yields in the long term, and the effect of weather and climate on the efficacy of these treatments. The experimental sites and the data collected in the long-term experiments are a valuable resource for research, teaching and consulting. The experiments are open for those who want to use data already collected or who want to do their own sampling. All long term experiments are funded by the NJ faculty and administered by an academic department, with the activities coordinated by a committee.  Twenty four long-term field experiments in plant nutrition and soil fertility are currently managed by the Department of Soil and Environment at the Swedish University of Agricultural Sciences. These experiments, starting as early as 1936 or as recently as 2010, are grouped into eight different experimental series that focus on themes such as agronomically-relevant factors including liming, long-term soil fertility, soil organic matter and soil biology. Plant and soil samples have been collected, measured for standard parameters, and archived since the start of the experiments, forming the basis of over 200 theses and papers across a broad range of disciplines. The Swedish long-term soil fertility experiments (R3-9001) were established at twelve different locations between 1957 and 1966, and nine of these experiments are on-going at present. These long-term experiments (LTEs) were designed to investigate how much the productivity of an agricultural soil could be increased by the use of mineral fertilisers. The focus was on the influence of natural site conditions (climate, soil type, etc.) compared to the influence of management practices. Which factors are most important for long-term productivity: fertilisation, crop rotation or natural conditions? In addition, the resilience of soils to nutrient depletion and intensive cash crop production was to be tested. This data collection include yield, crop and soil data from the nine currently active experiments from the year 1962 (when the current experimental design were established) to 2022. Yield and crop data has been collected every year, and soil data has been collected at regular intervals depending on time period and location. The data has been checked for obvious outliers or faulty values, but cation is advised since this collection spans many years and has been collected and compiled by different persons during this time period. Please contact soilnutrientcycling@slu.se if there are any questions regarding the data, or regarding the design and management of the long-term experiments. Links to metadata records in the GLTEN (Global Long-Term Agricultural Experiment Network) platform are provided under Relations.