The data comprise water quality measurements taken from streams and rivers in the Conwy catchment and its estuary from March 2013 to October 2016. Depending on water type and sampling location the data consist of concentrations of major cations and anions, pH, conductivity, alkalinity, suspended material and coliforms. Samples were collected manually or by automatic sampler. Analysis was carried out at the Centre for Ecology & Hydrology (CEH) Bangor, CEH Lancaster and Bangor University laboratories. The data were collected provide information on the relationship between stream water quality, primarily macronutrient concentrations, and catchment and hydrological characteristics. The data are used to drive a catchment scale water quality model, and to investigate nutrient ratios and limitation with respect to land cover and management. All sampling and analysis was carried out by trained members of staff from the Centre for Ecology & Hydrology and Bangor University. This data was assembled under the NERC project 'The Multi-Scale Response of Water quality, Biodiversity and Carbon Sequestration to Coupled Macronutrient Cycling from Source to Sea (NE/J011991/1). The project is also referred to as Turf2Surf. Full details about this dataset can be found at https://doi.org/10.5285/32392c33-8cbe-434a-a582-ab8425a5062c

General soil chemical, physical and microbial properties are presented for soil samples at six depths collected from a field experiment in the Conwy catchment. Samples were collected in May 2015. Core samples were taken along three transects by trained members of staff the Centre for Ecology & Hydrology and Bangor University. General soil chemical, physical and microbial properties were measured at six depths by trained members of staff, using recognised procedures at the laboratories of the School of Environment, Natural Resources and Geography, Bangor University. The samples were taken to provide supporting information for assessing the relationship between soil microbial populations and soil properties. The data were collected for the NERC project 'The Multi-Scale Response of Water quality, Biodiversity and Carbon Sequestration to Coupled Macronutrient Cycling from Source to Sea' (NE/J011991/1). The project is also referred to as Turf2Surf. Full details about this dataset can be found at https://doi.org/10.5285/f7b2beaa-08cf-48db-9b07-c55118d11506

The data consist of general physical, biological and chemical parameters for soil samples taken in the Conwy catchment in North West Wales. Samples were collected between 2013 and 2014 across a land use intensification gradient ranging from semi-natural peatlands, acid grasslands to improved grasslands and arable fields. Soil cores were taken to a depth of 1 metre and divided into 15 centimetre (cm) depth increments. General soil physical and chemical parameters were measured at each depth increment for most of the sites. Biological (root and fine root biomass) parameters were assessed in the topsoil 0-15 cm in 5 cm intervals. Soil parameters were tested across a land use intensification gradient to detect parameters that can predict aboveground biomass production across different land management types. Data were used to enhance the predictions of biomass production in the Joint UK Land Environment Simulator model (JULES). Measurements informed the improvement of the nitrogen cycle component in the model. Measurements were undertaken by trained members of staff from Bangor University, the Centre for Ecology & Hydrology and Exeter University. This data was collected for the NERC project 'The Multi-Scale Response of Water quality, Biodiversity and Carbon Sequestration to Coupled Macronutrient Cycling from Source to Sea' (NE/J011991/1). The project is also referred to as Turf2Surf. Full details about this dataset can be found at https://doi.org/10.5285/6566a706-9c55-4f7f-b33d-27bc29c73274

Data are presented of tensiometer measurements as centimetres of water from a field experiment in the Conwy catchment. The data were collected between October 2013 and January 2015 using tensiometers inserted into boreholes. The data were collected by trained members of staff from Bangor University and the Centre for Ecology & Hydrology. The samples were taken to provide supporting information for assessing the relationship between soil microbial populations and soil moisture status. The data were collected for the NERC project 'The Multi-Scale Response of Water quality, Biodiversity and Carbon Sequestration to Coupled Macronutrient Cycling from Source to Sea' (NE/J011991/1). The project is also referred to as Turf2Surf. Full details about this dataset can be found at https://doi.org/10.5285/875ca233-ffaa-45c2-b4d2-db7d21bc0e61

Time series data of carbon release in disintegrations per minute are presented for different nitrogen and phosphorus treatments with a low glucose concentration substrate added as a carbon source to soil samples from six depths (0-15, 15-30, 50-100, 100-150, 150-200 and 250-300 centimetres). Soil cores were collected from a field experiment in the Conwy catchment in July 2016 and returned the laboratories of the School of Environment, Natural Resources and Geography, Bangor University. A high molecular weight substrate was added as a carbon source to the samples and the rate of 14C-substrate mineralization measured. All the work was carried out by trained members of staff from Bangor University and the Centre for Ecology & Hydrology. The measurements were taken to improve understanding of the relationship between microbial activity and soil properties and depth of sampling, under differing nutrient availability. The data were collected for the NERC project 'The Multi-Scale Response of Water quality, Biodiversity and Carbon Sequestration to Coupled Macronutrient Cycling from Source to Sea' (NE/J011991/1). The project is also referred to as Turf2Surf. Full details about this dataset can be found at https://doi.org/10.5285/c29d2ce1-0295-439b-adf1-98ed59f73fae

Data are presented showing grass productivity as grammes per 100 square centimetres under four different nutrient treatments (water, nitrogen, phosphorus and nitrogen & phosphorus combined). An experimental hillslope in the Conwy catchment was selected in August 2016. Three transects, were identified across the hillslope. Along each transect, a 1 x 1 square metre quadrat was used to delineate randomly selected sampling areas. Within each quadrat 5 individual 10 x 10 x 10 centimetre (cm) swards were collected using a spade and transported to the laboratory in Bangor University for the nutrient addition. Three different harvests at different stages (initial cut, first harvest, second harvest) were conducted in order to measure grass productivity. Harvest included removal of all vegetation within the quadrat down to approximately 1 cm in height. The data were collected to identify the nutrient limitations within the hillslope by trained members of staff from Bangor University and the Centre for Ecology & Hydrology. The data were collected for the NERC project 'The Multi-Scale Response of Water quality, Biodiversity and Carbon Sequestration to Coupled Macronutrient Cycling from Source to Sea' (NE/J011991/1). The project is also referred to as Turf2Surf. Full details about this dataset can be found at https://doi.org/10.5285/6e395915-ab5c-43f4-b4de-c9a3c5c1b956

Time series data of carbon release in disintegrations per minute are presented for different nitrogen and phosphorus treatments with a high molecular weight substrate added as a carbon source to soil samples from six depths (0-15, 15-30, 50-100, 100-150, 150-200 and 250-300 centimetres). Soil cores were collected from a field experiment in the Conwy catchment in July 2016 and returned the laboratories of the School of Environment, Natural Resources and Geography, Bangor University. A high molecular weight substrate was added as a carbon source to the samples and the rate of 14C-substrate mineralization measured. All the work was carried out by trained members of staff from Bangor University and the Centre for Ecology & Hydrology. The measurements were taken to improve understanding of the relationship between microbial activity and soil properties and depth of sampling, under differing nutrient availability. The data were collected for the NERC project 'The Multi-Scale Response of Water quality, Biodiversity and Carbon Sequestration to Coupled Macronutrient Cycling from Source to Sea' (NE/J011991/1). The project is also referred to as Turf2Surf. Full details about this dataset can be found at https://doi.org/10.5285/4a8fedf4-a572-4d95-ac41-087974169af1

The data consists of plant physiological measurements from 15 sites located in the Conwy catchment (North Wales) and from 2 sites in North West England. Plant photosynthetic parameters for the maximum rate of carboxylation (Vcmax), the maximum rate of electron transport (Jmax) and the maximum light saturated photosynthesis (Asat) were measured on the dominant plant species as were foliar nitrogen (Foliar N) and phosphorus (Foliar P). Leaf mass area (LMA) and specific leaf area (SLA) were recorded on the same leaves. Data were collected in 2013, 2014 and 2016. The sites were chosen to represent habitat types and the terrestrial productivity gradient in Britain from intensive agriculturally managed lowland grasslands through to montane heath. Plots within the sites were located using a stratified random sampling design. Plant parameters were tested across a land use intensification gradient to detect parameters that can predict aboveground biomass production across different land management types. Data were used to enhance the predictions of biomass production in the Joint UK Land Environment Simulator model (JULES). Measurements informed the improvement of the nitrogen cycle component in the model. Measurements were undertaken by trained members of staff from Bangor University, the Centre for Ecology & Hydrology and Exeter University. This data was collected for the NERC project 'The Multi-Scale Response of Water quality, Biodiversity and Carbon Sequestration to Coupled Macronutrient Cycling from Source to Sea' (NE/J011991/1). The project is also referred to as Turf2Surf. Full details about this dataset can be found at https://doi.org/10.5285/a9226e79-d4da-4d4d-bd39-3a6b4a7a327d