uid=KBS,o=lter,dc=ecoinformatics,dc=orgalluid=sbohm,o=lter,dc=ecoinformatics,dc=orgallpublicreadhttps://lter.kbs.msu.edu/datasets/36.emlG.RobertsonMichigan State University

3700 East Gull Lake DriveHickory CornersMI49060US

(269) 760-8364(269)671-2351robert30@msu.edu0000-0001-9771-9895JosephSimmonsMichigan State University

3700 East Gull Lake DriveHickory CornersMI49060

(269) 671-2528(269)671-2104simmonsj@kbs.msu.eduprincipal contactClaireMcSwineyMichigan State University

3700 East Gull Lake DriveHickory CornersMI49060USA

(269) 671-2212(269)671-2351cmcswiney@kbs.msu.eduoriginal investigatorNevilleMillarMichigan State University

3700 E Gull Lake DrHickory CornersMI49060US

millarn@msu.edu0000-0003-0297-0804principal contactStaceyVanderWulpMichigan State University

3700 East Gull Lake DriveHickory CornersMI49060US

(269) 671-2339(269) 671-2333vanderws@msu.eduprincipal contact2026-05-13

This dataset contains the agronomic yields and soil properties of the LTER Resource Gradient Experiment, which applies nine different rates of nitrogen fertilization (F1-F9) to annual row crops under rainfed (since 1999) and irrigated (since 2003) conditions. Since 2006, row crops have followed the same rotation as the LTER Main Cropping System Experiment (MCSE; corn-soybean-wheat); continuous corn was grown from 1999-2005. Nitrogen fertilization rates differ by crop (since 2008) and are given on the plot map. The experiment moved to its current location in the LTER Main Site in 2005; previous experimental designs and locations are given here original data source http://lter.kbs.msu.edu/datasets/36

LTERKBSKellogg Biological StationHickory CornersMichiganGreat LakesyieldsnitrogenfertilizerirrigationPrimary ProductionDisturbanceInorganic NutrientsLTER Core Research Areazea mays fertilizer corn yields irrigation nitrous oxide nitrogenfarmingbiotahttps://apps.usgs.gov/thesaurus/thesaurus-full.php?thcode=15Data in the KBS LTER core database may not be published without written permission of the lead investigator or project director. These restrictions are intended mainly to preserve the primary investigators' rights to first publication and to ensure that data users are aware of the limitations that may be associated with any specific data set. These restrictions apply to both the baseline data set and to the data sets associated with specific LTER-supported subprojects.All publications of KBS data and images must acknowledge KBS LTER support.The areas around the Kellogg Biological Station in southwest Michigan-85.404699-85.36685742.42026542.3910191999-10-132025-07-24Kellogg Biological StationData Managerlter.data.manager@kbs.msu.eduhttp://lter.kbs.msu.edu02vkce854KBS LTERSampling Frequency: minimum of once per year Harvestable biomass in each cropped plot is measured at the time of crop harvest. For grains, the agricultural grain harvester is fitted with a GPS-referenced yield monitoring system to provide yield maps for each 1 ha treatment plot. Additionally, grain is off-loaded into weigh wagons and weighed at the KBS dairy . Alfalfa and wheat straw is measured on a gravimetric basis per plot after it has been cut and baled. Gravimetric moisture content is measured and subtracted from the biomass and the harvestable biomass estimate presented as dry weight alfalfa or straw per area.Data Managerhttp://lter.kbs.msu.edu/protocols/29Agronomic yields are defined as the crop grain and non-grain biomass harvested in a given growing cycle and serve as the basic measurement for comparing production differences among treatments. For annual row-cropping systems of corn, soybean and wheat, yield is determined as the grain biomass collected during harvest; for annual sorghum, yield is determined as the non-grain biomass harvested. For perennial crops, including monoculture systems, such as switchgrass and miscanthus, and polyculture systems that are harvested annually, such as restored prairie, native grasses,and early successional (GLBRC only), yield is determined as the biomass harvested at the end of the growing season. For alfalfa, harvested several times per year, yield is the sum of biomass harvested over the growing season. For woody cropping systems of short-rotation poplar, annual yield is determined as the biomass collected at clear-cutting divided by the number of years of growth. Crops are harvested using commercial sized equipment; for the specific harvesters and equipment used see the Agronomic Activity Report (KBS004-012) or search the Ag-log at https://aglog.kbs.msu.edu/ for Harvest under the Observations tab. Data Managerhttp://lter.kbs.msu.edu/protocols/194The amount of water or moisture in a given mass of soil is highly variable and is important to measure in field studies because it affects microbial activity, nutrient movement, and plant growth. To measure soil moisture content by the gravimetric method, a subsample of a fresh, sieved composite sample or a fresh soil core is weighed, oven dried until there is no further mass loss, and then reweighed. The moisture content is expressed as mass of water per mass of dry soil. Sampling frequency: Depends on experiment and research objective. Soil moisture is routinely measured as part of our LTER core soil sampling for inorganic N, N mineralization, and greenhouse gas fluxes.Data Managerhttp://lter.kbs.msu.edu/protocols/24The Alpkem 3550 Flow analyzer is an automated continuous-flow colorimetric analyzer used for the analysis of NO 3 - , NO 2 - , NH 4 + , and PO 4 = in soil extracts and water samples . Our configuration consists of the Model 501 XYZ sampler, Model 502 pump, Model 503 Cartridge heater, Model 504 Power Supply, Model 505 Filter Photometer, Model 509 Power Distribution Module, Model 510 Monochromator Detector, Model 511 Dilutor, Model 512 Valve Module, New Analyzer Program (NAP) Software, and Super Cartridges (2 for NO 3 - , 2 for NH 4 + , 1 for Phos/orthoPhos, 1 for Silicates) . Further information about the analyzer can be obtained from OI Analytical (OI Analytical, 151 Graham Road, P.O . Box 9010, College Station, TX 77842 or www.oico.com) .Data Managerhttp://lter.kbs.msu.edu/protocols/30Surface (0-25 cm) soil samples are typically collected in the fall, composited by plot, and sent to an analytical laboratory for analysis and for nutrient and liming recommendations for field crops. Analyses include pH, lime index, phosphorus, potassium, calcium, magnesium, and cation exchange capacity. Samples collected in the fall provide liming and fertilizer recommendations for the following year. Deep cores (0-100 cm) are collected every 5-10 years and samples are analyzed separately by depth interval to monitor longer-term changes in composition with depth. Sampling frequency: Depends on experiment and research objective. Data Managerhttp://lter.kbs.msu.edu/protocols/178Soil pH is a measure of the hydrogen ion activity in soil solution; high hydrogen activity (low pH) is an index of soil acidity which can affect nutrient availability and plant growth. To measure the pH of fresh soil, duplicate subsamples (15 g fresh weight) from a sieved soil sample are suspended in solution by adding deionized water in a soil:water ratio of 1:2. The pH of the suspension is measured with a glass electrode pH meter standardized with standard buffer solutions of pH 7 and pH 4. Sampling frequency: Depends on experiment, time of year, and research objective. Soil pH is often taken to inform liming recommendations.Data Managerhttp://lter.kbs.msu.edu/protocols/163The O.I. Analytical Flow Solution IV analyzer is an automated continuous-flow colorimetric analyzer used for the analysis of NO3^- , NO2^- , NH4^+ , and PO4^= in soil extracts and water samples . Our configuration consists of the RA Sampler (X-Y-Z random access autosampler), Model 502 pump, Expanded Range (ER) Detector, and ALPKEM WinFLOW V4 software. Further information about the analyzer can be obtained from OI Analytical (OI Analytical, 151 Graham Road, P.O. Box 9010, College Station, TX 77842 or www.oico.com)Data Managerhttp://lter.kbs.msu.edu/protocols/103programNational Science Foundationhttp://dx.doi.org/10.13039/100000001DEB 2224712https%3A%2F%2Fnsf.gov%2Fawardsearch%2FshowAward%3FAWD_ID%3D2224712%26HistoricalAwards%3Dfalsehttps://lter.kbs.msu.edu/datatables/77Kellogg Biological Station LTER: Agronomic Yields (KBS033-001)Agronomic grain yields of corn, soybean, and wheat harvested from rainfed and irrigated plots using a plot combine and expressed at standard moisture.Agronomic+Yields.csvNone331\ncolumn,no"\https://lter.kbs.msu.edu/datatables/77.csvdateharvest dateYYYY-MM-DD11987-4-18plotplot numberplot numberlocationStudy location. Please refer to the field location sketch. Study location. Please refer to the field location sketch. treatmenttreatment numbertreatment numberreplicatereplicate that the sample was taken from replicate that the sample was taken from irrigatedtrue if the plot is irrigated, false if it is not.true if the plot is irrigated, false if it is not.fertilizer_rate_kg_hathe fertilizer rate appliedkilogramsPerHectarerealcropcrop growncrop grownyield_kg_hagrain yield at standard moisture (15.5% for corn, 13% for soybean and wheat)kilogramsPerHectare10.0realyearharvest yearYYYY11987-4-18https://lter.kbs.msu.edu/datatables/148Kellogg Biological Station LTER: Soil Inorganic Nitrogen, Moisture and Temperature (KBS033-004)Soil inorganic nitrogen (nitrate and ammonium), temperature, and moisture content over the 2002 growing season in association with greenhouse gas sampling.Soil+Inorganic+Nitrogen,+Moisture+and+Temperature.csvNone251\ncolumn,no"\https://lter.kbs.msu.edu/datatables/148.csvsample_datesample dateYYYY-MM-DD11987-4-18plotN rate plotN rate plotno3soil nitrate as nitrogenmicrogramsPerGramrealnh4soil ammonium as nitrogenmicrogramsPerGramrealmoisturesoil moisture (dry weight basis)gramsPerHectogramrealtemperaturesoil temperature at 5 cmcelsiusrealhttps://lter.kbs.msu.edu/datatables/354Kellogg Biological Station LTER: Agronomic Soil Chemistry (KBS033-005)Agronomic chemistry of surface (0-25 cm) soils occasionally collected in the fall (usually after harvest) for fertilizer and liming recommendations and analyzed for pH, lime index, phosphorus, potassium, calcium, magnesium, and cation exchange capacity by an analytical service laboratory.Agronomic+Soil+Chemistry.csvNone441\ncolumn,no"\https://lter.kbs.msu.edu/datatables/354.csvsiteexperimental site that was sampledexperimental site that was sampledsample_datedate the sample was takenYYYY-MM-DD11987-4-18plotplot numberplot numbertreatmenttreatment where the sample was taken fromtreatment where the sample was taken fromreplicatereplicate plot the sample was taken fromreplicate plot the sample was taken fromtop_depth_cmthe top depth of the soil samplecentimeterrealbottom_depth_cmthe bottom of the soil corecentimeterrealirrigatedtrue if the plot is irrigated, false if it is nottrue if the plot is irrigated, false if it is notphpH measureddimensionlessrealpBray P1 phosphorus in ppmmilligramsPerKilogramrealkpotassium in ppmmilligramsPerKilogramrealcacalcium in ppmmilligramsPerKilogramrealmgmagnesium in ppmmilligramsPerKilogramreallime_indexthe lime indexthe lime indexcecestimated cation exchange capacity meq/100gestimated cation exchange capacity meq/100gz_ppmzinc in ppmmilligramsPerKilogramreals_ppmsulfur in ppmmilligramsPerKilogramrealb_ppmboron in ppmmilligramsPerKilogramreallabthe lab that performed the anlysisthe lab that performed the anlysisom_loipercentage of soil organic matter measured by loss on ignitiongramsPerHectogramrealhttps://lter.kbs.msu.edu/datatables/357Kellogg Biological Station LTER: Soil pH (KBS033-006)Soil pH of surface (0-25 cm) soils collected periodically in the fall to monitor the need for soil liming.Soil+pH.csvNone271\ncolumn,no"\https://lter.kbs.msu.edu/datatables/357.csvsitesite that was sampledsite that was sampledsample_datedate the sample was taken from the fieldYYYY-MM-DD11987-4-18plotplot id that was sampledplot id that was sampledtreatmenttreatment the sample was taken fromtreatment the sample was taken fromreplicatereplicate the sample was taken fromreplicate the sample was taken fromirrigatedtrue if the plot was irrigated, false if it was rainfedtrue if the plot was irrigated, false if it was rainfedphpH measureddimensionlessrealsample_typetype of sample measured, whether it was field moist or dired soil.type of sample measured, whether it was field moist or dired soil.https://lter.kbs.msu.edu/datatables/503Kellogg Biological Station LTER: Soil Bulk Density (KBS033-008)Bulk density of surface soils (0-25 cm) collected in fall 2016 from treatments F1, F5, and F8 under both rainfed and irrigated conditions and divided into 0-10 and 10-25 cm intervals. For 2007 samples, core dimensions were 14 cm height x 7.9 cm diameter.Soil+Bulk+Density.csvNone311\ncolumn,no"\https://lter.kbs.msu.edu/datatables/503.csvsample_datedate the sample was takenYYYY-MM-DD11987-4-18treatmentthe treatment sampledthe treatment sampledreplicatethe replicate sampledthe replicate sampledplotthe plot sampledthe plot sampledcoreThe core numberThe core numbertop_depth_cmtop of the depth of the sample (cm)centimeterrealbottom_depth_cmbottom depth of the sample (cm)centimeterrealgravel_free_bulk_densitybulk density of the gravel free soil fraction (gravel >4 mm removed)gramsPerCubicCentimeterrealtotal_bulkt_density_g_cm3total bulk density (including any gravel)gramsPerCubicCentimeterrealmoisturesoil moisture at sampling (dry weight basis)gramsPerGramreal@article{citation_3423, author = {I Gelfand and G P Robertson}, title = {A reassessment of the contribution of soybean biological nitrogen fixation to reactive N in the environment}, year = {2015}, journal = {Biogeochemistry}, pages = {175-184}, volume = {123}, doi = {10.1007/s10533-014-0061-4} }