Data for the Comparison Of Biofuel Systems (COBS) experiment related to plant measurements, Iowa USA, 2008-2025.

Author(s): M. Stephenson, R. Dietzel, L. English, M. Helmers, R. Horton, Meghann Jarchow, F. Kordbacheh, M. McDaniel, F. Miguez, V. Nichols, M. Osterloh, C. Pederson, D. Sundberg, M. Thompson, A. VanLoocke, M. Woods, M. Liebman

Abstract:

This dataset contains data directly related to measurements of plants for the Comparison Of Biofuel-cropping Systems experiment in Boone County, IA, USA taken between 2008 and 2025. COBS was established to answer questions related to cellulosic bioenergy production and multi-functionality of agricultural landscapes and many studies have been conducted on those and other topics. This dataset contains measurements for corn, soybeans, and prairie harvested by hand and by combine, rye cover crop harvested by hand prior to termination, root biomass within soil cores, and nutrient contents for all of the above. More information on experimental design and management can be found in "Data for the Comparison Of Biofuel Systems (COBS) experiment related to design, management, and weather; Iowa, USA, 2008-2025".

Funder: Leopold Center for Sustainable Agriculture; Iowa Nutrient Research Center; Department of Agronomy, ISU; College of Agriculture and Life Sciences, ISU; Plant Sciences Institute, ISU; ConocoPhillips; NIFA; U.S. EPA

Award Number: E2009-18, E2016-18; NA; NA; NA; NA; 2007-F-01, 2007-F-02; IOW05296; FP917160; E2016-18

Keywords:

COBS, Comparison of Biofuel-cropping Systems, agriculture, bioenergy, biofuel, biomass, cereal rye, cover crop, energy content, fiber content, grassland, intercepted photosynthetically active radiation (IPAR), nutrient balance, perennial agriculture, plant diversity, prairie, stover

Project (Abbreviated name):

COBS_plants

Team: COBS

Geographic Location:

The experiment was conducted at the Iowa State University Agronomy and Agricultural Engineering South Reynoldson Research Farm located in Boone County, Iowa at the corner of 300th St. and Violet Ave.

Families:

Amaranthaceae, Apiaceae, Apocynaceae, Asteraceae, Brassicaceae, Chenopodiaceae, Commelinaceae, Euphorbiaceae, Fabaceae, Lamiaceae, Oxalidaceae, Plantaginaceae, Poaceae, Salicaceae, Solanaceae

Species:

A. retroflexus, A. artemisiifolia, A. canescens, A. gerardi, A. syriaca, A. tuberosa, A. canadensis, B. alba, B. leucantha, B. inermis, C. fasciculata, C. album, C. arvense, D. purpurea, D. illinoensis, D. canadense, E. pallida, E. crushgalli, ...

Full Metadata:

COBS_plants_metadata_v1.0.1.pdf (532.74 KB)

Data Mirror:

Data Table Column Names and Descriptions

Table name	Column name	Data type	Units	Column description
corn yield hand raw	corn yield hand pkey	integer	dimensionless	A unique primary key for this table.
corn yield hand raw	ear sample count	float	number	The count of corn plants selected for sampling.
corn yield hand raw	ear sample field weight g	float	gram	The fresh field weight of the corn ears selected for sampling.
corn yield hand raw	grain moisture percent	float	percent	The percentage of the weight of harvested grain attributable to water. Calculated as fresh grain weight minus dry grain weight divided by fresh grain weight multiplied by 100.
corn yield hand raw	grain plus stover hand dry ton per ac	float	tonPerAcre	The yield of dry grain and stover on a ton per acre basis. Calculated in original Excel workbooks as 1/(harvest_index_dry_pct/100) * (grain_yield_hand_normalized_bu_per_ac560.845)/2000.
corn yield hand raw	grain sample dry weight g	float	gram	The dried weight of the corn kernels from the ears selected for sampling in grams.
corn yield hand raw	grain sample field weight g	float	gram	The fresh field weight of the corn kernels from the ears selected for sampling in grams.
corn yield hand raw	grain yield hand normalized bu per ac	float	bushelPerAcre	Corn grain yield normalized to 15.5% moisture. Calculated in original Excel workbooks as ((remaining_ear_field_weight_g(shell_ratio_field_pct/100)+(grain_sample_field_weight_g/454))/(100/43560)/56)(1-grain_moisture_percent/100)/0.845.
corn yield hand raw	harvest index dry pct	float	percent	The percentage of the total potential biomass attributable to grain weight. Calculated as dry grain weight divided by dry grain weight plus dry stover weight, multiplied by 100. Hand harvest stover yield estimation is extrapolated from grain yield using this ratio.
corn yield hand raw	plot	integer	dimensionless	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
corn yield hand raw	shell ratio field pct	float	percent	The percentage of the fresh weight of corn ears coming from the kernels. Calculated as the grain_sample_field_weight_g divided by ear_sample_field_weight_g multiplied by 100.
corn yield hand raw	stover moisture percent	float	percent	The percentage of the weight of harvested stover attributable to water. Calculated as fresh stover weight minus dry stover weight divided by fresh stover weight multiplied by 100.
corn yield hand raw	stover yield hand dry g	float	gram	The dried weight of the non-grain biomass (stalk, leaves, husks, cobs) from the sample in grams.
corn yield hand raw	stover yield hand dry g per m sq	float	gramPerMeterSquared	The yield of dry stover biomass on a grams per square meter basis. Recalculated in R as (grain_plus_stover_hand_dry_ton_per_ac * lbs.per.ton * g.per.lb * ac.per.sq.m) * (1-(harvest_index_dry_pct/100)).
corn yield hand raw	stover yield hand dry ton per ac	float	tonPerAcre	The yield of dry stover biomass on a grams per square meter basis. Unit conversion in R from original calculation in Excel workbooks: grain_plus_stover_hand_dry_ton_per_ac * (1-(harvest_index_dry_pct/100))
corn yield hand raw	study year	integer	number	The calendar year for this entry. The overall study began in 2008 and various data were collected in every subsequent year. The study was ongoing at the time of publication.
corn yield hand raw	total biomass yield hand g per m sq 0 pct	float	gramPerMeterSquared	The yield of dry grain and stover on a grams per square meter basis. Unit conversion of grain_plus_stover_hand_dry_ton_per_ac.
corn yield hand raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.
corn yield hand raw	yield hand sample area ft sq	float	footSquared	The combined area of belt transects selected for hand sampling in square feet. Belt transects were one row wide (midpoint to midpoint) and length, number, and location varied as described in methods.
grain yield mechanical raw	block	float	dimensionless	This is the block within which treatments were replicated. Numbering begins at one for the North-east site quadrant and continues two through four clockwise around the site. Blocks were separated by mowed grass alleyways.
grain yield mechanical raw	crop	string	NA	The grain species documented in this row.
grain yield mechanical raw	grain yield combine lb per ac 0 pct	float	poundPerAcre	The grain yield from the center area of the plot harvested by a combine and weighed by a weigh wagon in pounds per acre. Normalized to 0% moisture.
grain yield mechanical raw	grain yield combine normalized bu per ac	float	bushelPerAcre	The grain yield from the center area of the plot harvested by a combine and weighed by a weigh wagon in pounds. Normalized to bushels per acre at 15.5% moisture and 56 pounds per bushel for corn and 13% moisture and 60 pounds per bushel for soybeans.
grain yield mechanical raw	grain yield mechanical pkey	integer	dimensionless	A unique primary key for this table.
grain yield mechanical raw	harvest strip length ft	float	foot	Mechanical yield per plot is determined from harvesting a single pass of this length down the center of the plot.
grain yield mechanical raw	harvest strip width ft	float	foot	Mechanical yield per plot is determined from harvesting a single pass of this width down the center of the plot.
grain yield mechanical raw	harvested area ac	float	acre	Mechanical yield per plot is determined from harvesting a single pass of this area down the center of the plot. Calculated from the harvested_strip_length_ft and harvested_strip_width_ft.
grain yield mechanical raw	harvested weight lb	float	pound	The weight of the harvested grain from the indicated harvested_strip_length_ft and harvested_strip_width_ft, as recorded by a weigh wagon.
grain yield mechanical raw	moisture percent	float	percent	The water moisture content of the mechanically-harvested grain in percent by weight.
grain yield mechanical raw	plot	integer	dimensionless	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
grain yield mechanical raw	study year	integer	number	The calendar year for this entry. The overall study began in 2008 and various data were collected in every subsequent year. The study was ongoing at the time of publication.
grain yield mechanical raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.
intercepted photosynthetically active radiation raw	above canopy par	float	µmolPhotonsPerMeterSquaredPerSecond	The measured photosynthetically active radiation above the canopy.
intercepted photosynthetically active radiation raw	beam fraction	float	proportion	The portion of incoming solar radiation that arrives as direct, unscattered rays rather than diffuse sky light.
intercepted photosynthetically active radiation raw	below canopy par	float	µmolPhotonsPerMeterSquaredPerSecond	The measured photosynthetically active radiation at ground level.
intercepted photosynthetically active radiation raw	block	float	dimensionless	This is the block within which treatments were replicated. Numbering begins at one for the North-east site quadrant and continues two through four clockwise around the site. Blocks were separated by mowed grass alleyways.
intercepted photosynthetically active radiation raw	intercepted photosynthetically active radiation	float	PAR	Calculated by subtracting below canopy PAR from the above canopy PAR to determine the amount of solar radiation intercepted by plant material. No units given beyond "PAR".
intercepted photosynthetically active radiation raw	ipar pkey	integer	dimensionless	A unique primary key for this table.
intercepted photosynthetically active radiation raw	leaf area index	float	dimensionless	Leaf area index calculated from IPAR.
intercepted photosynthetically active radiation raw	plot	integer	dimensionless	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
intercepted photosynthetically active radiation raw	sample date	dateTime	NA	The calendar date the measurement was taken.
intercepted photosynthetically active radiation raw	sample period	integer	number	The sampling window in which this measurement was taken. Measurements were repeated every two weeks during the growing season.
intercepted photosynthetically active radiation raw	sample rep	float	number	The sample replication. Four measurements were taken for each plot and sample_period.
intercepted photosynthetically active radiation raw	sample time	dateTime	NA	The time of the PAR measurement.
intercepted photosynthetically active radiation raw	study year	integer	number	The calendar year for this entry. This dataset contains data from 2009 and 2010.
intercepted photosynthetically active radiation raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.
intercepted photosynthetically active radiation raw	zenith angle	float	degree	The angle between directly overhead and the center of the sun's disc in the sky.
nutrient content raw	aluminum ppm	float	milligramPerKilogram	The concentration of the indicated element in parts per million (e.g., mg/kg).
nutrient content raw	block	string	NA	This is the block within which treatments were replicated. Numbering begins at one for the North-east site quadrant and continues two through four clockwise around the site. Blocks were separated by mowed grass alleyways.
nutrient content raw	boron ppm	float	milligramPerKilogram	The concentration of the indicated element in parts per million (e.g., mg/kg).
nutrient content raw	calcium pct	float	percent	The concentration of the indicated element in percent by weight.
nutrient content raw	carbon pct	float	percent	The concentration of the indicated element in percent by weight.
nutrient content raw	copper ppm	float	milligramPerKilogram	The concentration of the indicated element in parts per million (e.g., mg/kg).
nutrient content raw	crop	string	NA	The grain species documented in this row.
nutrient content raw	iron ppm	float	milligramPerKilogram	The concentration of the indicated element in parts per million (e.g., mg/kg).
nutrient content raw	magnesium pct	float	percent	The concentration of the indicated element in percent by weight.
nutrient content raw	manganese ppm	float	milligramPerKilogram	The concentration of the indicated element in parts per million (e.g., mg/kg).
nutrient content raw	nitrogen pct	float	percent	The concentration of the indicated element in percent by weight.
nutrient content raw	nutrient content pkey	integer	dimensionless	A unique primary key for this table.
nutrient content raw	phosphorus pct	float	percent	The concentration of the indicated element in percent by weight.
nutrient content raw	plot	string	NA	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
nutrient content raw	potassium pct	float	percent	The concentration of the indicated element in percent by weight.
nutrient content raw	sample date	dateTime	NA	The calendar date the sample was taken.
nutrient content raw	sample label	string	NA	The sample label recorded in the original data table.
nutrient content raw	sample replicate	float	number	The sample replication (place in the sequence of samples taken for this plot or sub-plot location).
nutrient content raw	sample tissue	string	NA	The plant tissue tested in this row.
nutrient content raw	sodium pct	float	percent	The concentration of the indicated element in percent by weight.
nutrient content raw	study year	integer	number	The calendar year for this entry. The overall study began in 2008 and various data were collected in every subsequent year. The study was ongoing at the time of publication.
nutrient content raw	sulfur pct	float	percent	The concentration of the indicated element in percent by weight.
nutrient content raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.
nutrient content raw	zinc ppm	float	milligramPerKilogram	The concentration of the indicated element in parts per million (e.g., mg/kg).
plant energy contents raw	block	string	NA	This is the block within which treatments were replicated. Numbering begins at one for the North-east site quadrant and continues two through four clockwise around the site. Blocks were separated by mowed grass alleyways.
plant energy contents raw	calories per gram	integer	caloriePerGram	The number of calories contained in a gram of sample tissue.
plant energy contents raw	kilojoules per gram	float	kilojoulesPerGram	The number of kilojoules contained in a gram of sample tissue.
plant energy contents raw	moisture correction percent	float	percent	The mean proportion of the sample comprised of water.
plant energy contents raw	plant energy content pkey	integer	dimensionless	A unique primary key for this table.
plant energy contents raw	plot	string	NA	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
plant energy contents raw	sample tissue	string	NA	The plant tissue tested in this row.
plant energy contents raw	study year	integer	number	The calendar year for this entry. The overall study began in 2008 and various data were collected in every subsequent year. The study was ongoing at the time of publication.
plant energy contents raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.
plant fiber contents raw	cellulose percent	float	percent	The estimated percent of the plant material comprised of cellulose.
plant fiber contents raw	ethanol C5 g per kg	float	gramPerKilogram	An estimate of the maximum conversion of C5 sugars to ethanol.
plant fiber contents raw	ethanol C6 g per kg	float	gramPerKilogram	An estimate of the maximum conversion of C6 sugars to ethanol.
plant fiber contents raw	ethanol g per kg	float	gramPerKilogram	An estimate of the maximum conversion of combined C5 and C6 sugars to ethanol.
plant fiber contents raw	grain yield bu per ac normalized corn	float	bushelPerAcre	Corn grain yield in bushels per acre normalized to 15.5% moisture content.
plant fiber contents raw	grain yield bu per ac normalized soybean	float	bushelPerAcre	Soybean yield normalized to 13% moisture.
plant fiber contents raw	hemicellulose percent	float	percent	The estimated percent of the plant material comprised of hemicellulose.
plant fiber contents raw	lignin percent	float	percent	The estimated percent of the plant material comprised of lignin.
plant fiber contents raw	method	string	NA	Method used to quantify fiber content.
plant fiber contents raw	plant fiber content pkey	integer	dimensionless	A unique primary key for this table.
plant fiber contents raw	plot	string	NA	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
plant fiber contents raw	stover remaining percent 0 pct	float	percent	Percentage of stover left in the field after harvest.
plant fiber contents raw	stover remaining ton per ac 0 pct	float	tonPerAcre	Unharvested stover remaining in the field, normalized to 0% moisture.
plant fiber contents raw	stover yield ton per ac 0 pct	float	tonPerAcre	Stover yield normalized to 0% moisture.
plant fiber contents raw	study year	integer	number	The calendar year for this entry. The overall study began in 2008 and various data were collected in every subsequent year. The study was ongoing at the time of publication.
plant fiber contents raw	total dry biomass ton per ac	float	tonPerAcre	Total dry biomass (grain plus stover or prairie biomass).
plant fiber contents raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.
prairie plant point intercepts raw	block	float	dimensionless	This is the block within which treatments were replicated. Numbering begins at one for the North-east site quadrant and continues two through four clockwise around the site. Blocks were separated by mowed grass alleyways.
prairie plant point intercepts raw	common name	string	NA	The common name given for this species. Species that were labeled as "Unknown..." were not positively identified, but should be distinct from other identified species (within that sampling period) and may be appropriate to include in measures of diversity.
prairie plant point intercepts raw	group functional kindscher wells	string	NA	Prairie plant functional groups as defined by Kindscher & Wells (1995) Vegetatio.
prairie plant point intercepts raw	latin name	string	NA	The scientific name for this species. Generally formatted as Genus species, but some observations were recorded at higher taxonomic levels.
prairie plant point intercepts raw	observer	string	NA	The person conducting the survey and identifying the plant. Field surveys were led by Meghann Jarchow in 2009-2015 and Lydia English in 2017, but plant identification may have been conducted by a different observer if none was recorded.
prairie plant point intercepts raw	pin drops	float	number	The number of pin drops represented by this line of data.
prairie plant point intercepts raw	pin hit count	float	number	The number of times this plant species touched the sampling pin. This can be used as a measure of relative abundance or biomass. Missing values have been replaced as zeros (the plant was not present, and so it did not touch the pin). Plot-years that have already been aggregated represent the average number of hits across all pins dropped.
prairie plant point intercepts raw	pin number	string	NA	The sequence in the sampling frame where the pin was dropped and hits recorded.
prairie plant point intercepts raw	plot	integer	dimensionless	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
prairie plant point intercepts raw	prairie plant point intercept pkey	integer	dimensionless	A unique primary key for this table.
prairie plant point intercepts raw	quadrant	string	NA	The area within the plot targeted for sampling.
prairie plant point intercepts raw	replicate	string	NA	The replicate for the sampling transect in this sampling period and plot. Some years have pin-level observations, and also replicates, and some have already been averaged up to the plot level.
prairie plant point intercepts raw	sample date	dateTime	NA	The calendar date the sample was taken.
prairie plant point intercepts raw	sample period	string	NA	The sampling window in which this measurement was taken. Measurements were targeted for mid-June and mid-August.
prairie plant point intercepts raw	sampling method	string	NA	In all years except 2024, a 1 m2 quadrat was used to locate pin drops. In 2024, pins were dropped every 6 meters along a transect.
prairie plant point intercepts raw	sampling method unit	string	NA	The units for 'sampling_method_value'.
prairie plant point intercepts raw	sampling method value	float	number	The value of the sampling area (e.g., square meters for quadrats or linear meters for transects)
prairie plant point intercepts raw	species code	string	NA	This is the code for the species written on the paper datasheet. Observers had a key with them of common and scientific names for expected plant species and established species codes which were used to link the recorded data to scientific and common names.
prairie plant point intercepts raw	study year	integer	number	The calendar year for this entry. The overall study began in 2008 and various data were collected in every subsequent year. The study was ongoing at the time of publication.
prairie plant point intercepts raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.
prairie yield hand harvest raw	hay dry g	float	gram	The weight of the hay collected from the sample quadrat after drying at 60 degrees C for at least two days.
prairie yield hand harvest raw	litter g per 1000 cm sq	float	gram	The weight of the litter collected from the 0.1 m^2 sample quadrat in 2008.
prairie yield hand harvest raw	litter plus stubble g	float	gram	The weight of the litter plus stubble collected from the sample quadrat after drying at 60 degrees C for at least six days.
prairie yield hand harvest raw	plot	integer	dimensionless	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
prairie yield hand harvest raw	prairie yield hand harvest pkey	integer	dimensionless	A unique primary key for this table.
prairie yield hand harvest raw	quadrat area m sq	float	meterSquared	The area over which the sample was collected in square meters.
prairie yield hand harvest raw	sample date	dateTime	NA	The calendar date the sample was taken.
prairie yield hand harvest raw	sample label	string	NA	The sample label recorded in the original data table.
prairie yield hand harvest raw	stubble g	float	gram	The weight of the stubble collected from the sample quadrat after drying at 60 degrees C for at least 48 hours.
prairie yield hand harvest raw	study year	integer	number	The calendar year for this entry. The overall study began in 2008 and various data were collected in every subsequent year. The study was ongoing at the time of publication.
prairie yield hand harvest raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.
prairie yield hand harvest raw	weigh date	dateTime	NA	The calendar date the sample was weighed.
prairie yield mechanical harvest raw	dry weight lb per ac	float	poundPerAcre	The biomass yield for the plot year expressed in pounds per acre on a dry weight (0% moisture) basis.
prairie yield mechanical harvest raw	harvested area ac	float	acre	The area of the plot harvested for yield determination, expressed in acres.
prairie yield mechanical harvest raw	harvested weight lb	integer	pound	The weight of the harvested and baled prairie hay. 2014 data was not collected due to a scale malfunction.
prairie yield mechanical harvest raw	moisture percent	float	percent	The water moisture content of the mechanically-harvested grain in percent by weight.
prairie yield mechanical harvest raw	plot	integer	dimensionless	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
prairie yield mechanical harvest raw	prairie yield mechanical harvest pkey	integer	dimensionless	A unique primary key for this table.
prairie yield mechanical harvest raw	sample dry weight g	float	gram	The weight of the prairie hay sample taken to determine percent moisture after drying.
prairie yield mechanical harvest raw	sample field weight g	float	gram	The weight of the prairie hay sample taken to determine percent moisture.
prairie yield mechanical harvest raw	study year	integer	number	The calendar year for this entry. The overall study began in 2008 and various data were collected in every subsequent year. The study was ongoing at the time of publication.
prairie yield mechanical harvest raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.
relative growth rates raw	biomass mean g per sq m	float	gramPerMeterSquared	Biomass per unit area in grams per square meter.
relative growth rates raw	biomass sample 1 g	float	gram	The dry weight of the first of two biomass samples taken from a 0.28 sq m quadrat.
relative growth rates raw	biomass sample 2 g	float	gram	The dry weight of the second of two biomass samples taken from a 0.28 sq m quadrat.
relative growth rates raw	biomass sample mean g	float	gram	The mean dry weight of two biomass samples taken from 0.28 sq m quadrats.
relative growth rates raw	block	float	dimensionless	This is the block within which treatments were replicated. Numbering begins at one for the North-east site quadrant and continues two through four clockwise around the site. Blocks were separated by mowed grass alleyways
relative growth rates raw	julian date	integer	number	The day of the year.
relative growth rates raw	plot	integer	dimensionless	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
relative growth rates raw	relative growth rate pkey	integer	dimensionless	A unique primary key for this table.
relative growth rates raw	sample date	dateTime	NA	The calendar date the measurement was taken.
relative growth rates raw	sample period	integer	number	The sampling window in which this measurement was taken. Measurements were repeated every two weeks during the growing season.
relative growth rates raw	study year	float	number	The calendar year for this entry. This dataset contains data from 2009 and 2010.
relative growth rates raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.
root biomass raw	block	float	dimensionless	This is the block within which treatments were replicated. Numbering begins at one for the North-east site quadrant and continues two through four clockwise around the site. Blocks were separated by mowed grass alleyways.
root biomass raw	core area cm sq	float	centimeterSquared	The surface area of the circular soil core, expressed in square centimeters.
root biomass raw	core diameter cm	float	centimeter	The diameter of the soil sampling core, in centimeters. Probe diameter varied primarily by maximum depth.
root biomass raw	crop	string	NA	The grain species documented in this row.
root biomass raw	plot	integer	dimensionless	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
root biomass raw	root biomass pkey	integer	dimensionless	A unique primary key for this table.
root biomass raw	root dry weight g	float	gram	The mass of the roots in the soil core after cleaning and drying in an oven, in grams.
root biomass raw	root dry weight g per m sq	float	gramPerMeterSquared	The mass of the roots in the soil core after cleaning and drying in an oven divided by the surface area of the core, expressed in grams per square meter.
root biomass raw	sample date	dateTime	NA	The calendar date the sample was taken.
root biomass raw	sample replicate	string	NA	The sample replication (place in the sequence of samples taken for this plot or sub-plot location).
root biomass raw	sample volume cm cubed	float	centimeterCubed	The volume of the soil core calculated as the maximum depth minus the minimum depth, multiplied by the surface area, expressed in cubic centimeters.
root biomass raw	section depth max cm	float	centimeter	The depth of the bottom of the soil core segment, in centimeters.
root biomass raw	section depth min cm	float	centimeter	The depth of the top of the soil core segment, in centimeters.
root biomass raw	section depth range cm	string	NA	The depth range of the soil core segment, in centimeters.
root biomass raw	study year	integer	number	The calendar year for this entry. The overall study began in 2008 and various data were collected in every subsequent year. The study was ongoing at the time of publication.
root biomass raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.
rye biomass sample hand raw	block	float	dimensionless	This is the block within which treatments were replicated. Numbering begins at one for the North-east site quadrant and continues two through four clockwise around the site. Blocks were separated by mowed grass alleyways.
rye biomass sample hand raw	moisture percent	float	percent	The moisture content of the sample at the time of harvest, calculated by subtracting the dry weight from the field weight and dividing by the field weight. Expressed in percent water by weight.
rye biomass sample hand raw	plot	integer	dimensionless	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
rye biomass sample hand raw	rye biomass sample pkey	integer	dimensionless	A unique primary key for this table.
rye biomass sample hand raw	rye shoot carbon pct	float	percent	The percent carbon of the aboveground rye biomass expressed as percent by weight.
rye biomass sample hand raw	rye shoot carbon sequestered lb per acre	float	poundPerAcre	An estimate of the amount of carbon within the aboveground rye biomass expressed as pounds carbon per acre.
rye biomass sample hand raw	rye shoot dry weight g	float	gram	The weight of the aboveground biomass after drying, expressed in grams.
rye biomass sample hand raw	rye shoot dry weight g per m sq	float	gramPerMeterSquared	The dry weight of aboveground rye per unit area, expressed in grams per square meter.
rye biomass sample hand raw	rye shoot field weight g	float	gram	The weight of the aboveground biomass before drying, expressed in grams.
rye biomass sample hand raw	rye shoot nitrogen pct	float	percent	The percent nitrogen of the aboveground rye biomass expressed as percent by weight.
rye biomass sample hand raw	rye shoot nitrogen sequestered lb per acre	float	poundPerAcre	An estimate of the amount of nitrogen within the aboveground rye biomass expressed as pounds carbon per acre.
rye biomass sample hand raw	sample area m sq	float	meterSquared	The area over which all rye shots were collected for measurement expressed in meters squared.
rye biomass sample hand raw	sample date	dateTime	NA	The calendar date the sample was taken.
rye biomass sample hand raw	sample number	float	dimensionless	For measurements where multiple samples were taken, this is a unique identifier for each sample.
rye biomass sample hand raw	study year	integer	number	The calendar year for this entry. The overall study began in 2008 and various data were collected in every subsequent year. The study was ongoing at the time of publication.
rye biomass sample hand raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.
soybean yield hand raw	abscised leaves yield hand dry weight g	float	gram	The dry weight of abscised (dropped) leaves within the yield_hand_sample_area_ft_sq.
soybean yield hand raw	abscised leaves yield hand g m sq 0 pct	float	gramPerMeterSquared	The dry weight basis of abscised (dropped) leaves.
soybean yield hand raw	block	float	dimensionless	This is the block within which treatments were replicated. Numbering begins at one for the North-east site quadrant and continues two through four clockwise around the site. Blocks were separated by mowed grass alleyways.
soybean yield hand raw	grain moisture percent	float	percent	The percentage of the weight of harvested grain attributable to water. Calculated as fresh grain weight minus dry grain weight divided by fresh grain weight multiplied by 100.
soybean yield hand raw	grain sample dry weight g	float	gram	The dried weight of the corn kernels from the ears selected for sampling in grams.
soybean yield hand raw	grain sample field weight g	float	gram	The fresh field weight of the corn kernels from the ears selected for sampling in grams.
soybean yield hand raw	grain yield hand g	float	gram	The combined fresh field weight in grams of the soybean grain the yield_hand_sample_area_ft_sq.
soybean yield hand raw	grain yield hand normalized bu per ac	float	bushelPerAcre	Corn grain yield normalized to 15.5% moisture. Calculated in original Excel workbooks as ((remaining_ear_field_weight_g(shell_ratio_field_pct/100)+(grain_sample_field_weight_g/454))/(100/43560)/56)(1-grain_moisture_percent/100)/0.845.
soybean yield hand raw	harvest index field pct	float	percent	The percentage of the total potential biomass attributable to grain weight. Calculated as fresh grain weight divided by fresh grain weight plus dry stover weight, multiplied by 100. Hand harvest stover yield estimation is extrapolated from grain yield using this ratio.
soybean yield hand raw	plot	integer	dimensionless	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
soybean yield hand raw	soybean yield hand pkey	integer	dimensionless	A unique primary key for this table.
soybean yield hand raw	stover moisture percent	float	percent	The percentage of the weight of harvested stover attributable to water. Calculated as fresh stover weight minus dry stover weight divided by fresh stover weight multiplied by 100.
soybean yield hand raw	stover sample dry weight g	float	gram	The dry weight of a subsample of the hand harvested stover for determination of moisture percent.
soybean yield hand raw	stover sample field weight g	float	gram	The fresh weight of a subsample of the hand harvested stover for determination of moisture percent.
soybean yield hand raw	stover stems plus pods yield hand lb per ac 0 pct	float	poundPerAcre	The weight of stover (stems and pods, not grain or abscised leaves) with zero percent moisture. Calculated as whole plant weight minus grain weight multiplied by one minus the stover moisture proportion.
soybean yield hand raw	stover yield hand g	float	gram	The combined weight in grams of the stems and pods (no grain or abscised leaves) in the area indicated in yield_hand_sample_area_ft_sq. Calculated by subtracting grain_yield_hand_g from whole_plant_yield_hand_g.
soybean yield hand raw	study year	integer	number	The calendar year for this entry. The overall study began in 2008 and various data were collected in every subsequent year. The study was ongoing at the time of publication.
soybean yield hand raw	total biomass yield hand g per m sq 0 pct	float	gramPerMeterSquared	The yield of dry grain and stover on a grams per square meter basis. Unit conversion of grain_plus_stover_hand_dry_ton_per_ac.
soybean yield hand raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.
soybean yield hand raw	whole plant yield hand g	float	gram	The summed mass of the entire soybean plants hand harvested within the area indicated in yield_hand_sample_area_ft_sq.
soybean yield hand raw	yield hand sample area ft sq	float	footSquared	The combined area of belt transects selected for hand sampling in square feet. Belt transects were 4 ft wide and length and number varied by year as described in methods.
stand counts raw	crop	string	NA	The grain species documented in this row.
stand counts raw	plants per ft	float	countPerFoot	The density of plants (corn or soybean) for this transect, expressed as individuals per foot.
stand counts raw	plot	integer	dimensionless	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
stand counts raw	sample rep	float	number	The sample replication (place in the sequence of samples taken for this plot or sub-plot location).
stand counts raw	stand count	float	number	A count of the individual plants (corn or soybean) in this row in the indicated length.
stand counts raw	stand count pkey	integer	dimensionless	A unique primary key for this table.
stand counts raw	study year	integer	number	The calendar year for this entry. The overall study began in 2008 and various data were collected in every subsequent year. The study was ongoing at the time of publication.
stand counts raw	transect length ft	float	foot	The length over which plants were counted. The width was a single row.
stand counts raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.
stover yield mechanical raw	bale number	float	number	For plot-years in which individual bale weights were recorded, an individual number for bales.
stover yield mechanical raw	block	float	dimensionless	This is the block within which treatments were replicated. Numbering begins at one for the North-east site quadrant and continues two through four clockwise around the site. Blocks were separated by mowed grass alleyways.
stover yield mechanical raw	plot	integer	dimensionless	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
stover yield mechanical raw	stover moisture percent	float	percent	The water moisture content of the mechanically-harvested grain in percent by weight.
stover yield mechanical raw	stover sample dry weight g	float	gram	The mass of the stover sample taken post-harvest after drying in grams, used to determine percent moisture of stover at the time of harvest (baling).
stover yield mechanical raw	stover sample field weight g	float	gram	The mass of the stover sample taken post-harvest to determine percent moisture, in grams.
stover yield mechanical raw	stover yield combine dry lb per bale	float	pound	The weight of the harvested and baled stover in pounds per bale on a dry weight basis.
stover yield mechanical raw	stover yield combine kg per ha 0 pct	float	kilogramPerHectare	The weight of the harvested and baled stover in kilograms per hectare on a dry weight basis. For 2008-2014 per-bale numbers should be summed across all bales in the plot to find the plot yield per acre.
stover yield mechanical raw	stover yield combine lb per ac 0 pct	float	poundPerAcre	The weight of the harvested and baled stover in pounds per acre on a dry weight basis. For 2008-2014 per-bale numbers should be summed across all bales in the plot to find the plot yield per acre.
stover yield mechanical raw	stover yield combine lb per bale	float	pound	The fresh weight of the harvested and baled stover in pounds per bale.
stover yield mechanical raw	stover yield combine ton per ac 0 pct	float	tonPerAcre	The weight of the harvested and baled stover in tons per acre on a dry weight basis. For 2008-2014 per-bale numbers should be summed across all bales in the plot to find the plot yield per acre.
stover yield mechanical raw	stover yield mechanical pkey	integer	dimensionless	A unique primary key for this table.
stover yield mechanical raw	study year	integer	number	The calendar year for this entry. The overall study began in 2008 and various data were collected in every subsequent year. The study was ongoing at the time of publication.
stover yield mechanical raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.
unharvested litter raw	litter g	float	gram	The mass of litter (unattached plant material) left after harvesting, expressed in grams.
unharvested litter raw	litter pkey	integer	dimensionless	A unique primary key for this table.
unharvested litter raw	plot	integer	dimensionless	The name of the plot. The tens digit indicates the block and the numbering for the ones digit goes from one to six within each block.
unharvested litter raw	quadrat area m sq	float	meterSquared	The area over which the litter_g value was sampled.
unharvested litter raw	sample date	dateTime	NA	The calendar date the measurement was taken.
unharvested litter raw	sample label	string	NA	The sample replication. Four measurements were taken for each plot and year.
unharvested litter raw	study year	integer	number	The calendar year for this entry. This dataset contains data from 2008 through 2011.
unharvested litter raw	treatment	string	NA	The treatment for the plot the data was collected in during the year indicated.