Nitrapyrin is a nitrification inhibitor that is co-applied with N-fertilizer in agroecosystems. Over the course of one year (March 2016 to June 2017), 192 water samples from seven streams across Iowa and Illinois were analyzed for nitrapyrin, its degradate 6-chloropicolinic acid (6-CPA), and three widely used herbicides acetochlor, atrazine, and metolachlor. Additional environmental samples were collected and analyzed in spring 2017: 63 water samples from eight subsurface drains, and 33 soil samples from a field in Iowa that received direct application of nitrapyrin (only for nitrapyrin and herbicides). Nitrapyrin was detected in all seven streams (56% detection) with concentrations ranging from 4 to 1,200 ng/L; 6-CPA was detected in six of the seven streams (13% detection) with concentrations ranging from 2 to 13 ng/L. Nitrapyrin was detected in only two of the eight subsurface drains and in 10% of drain samples (10% detection), and with concentrations ranginged from 3 to 12 ng/L; 6-CPA was detected in six of the eight subsurface drains and in (33% of drain samples withdetection), and concentrations ranginged from 2 to 6 ng/L. Nitrapyrin was detected in 67% of the soil samples collected, and concentrations ranged from 0.9 to 42 ng/g. Generally, all three herbicides were detected more frequently and at higher concentrations than nitrapyrin in the streams, subsurface drains, and soils. There are 3 csv datasets related to this data release. Please find in each of the child items the data and metadata.

Nitrapyrin, a nitrification inhibitor, 6-CPA, a nitrapyrin degradate, and three co-applied herbicides (acetochlor, atrazine, and metolachlor) were measured in water samples from seven streams across Iowa and Illinois. Iowa water samples were collected from March 2016 to June 2017, and Illinois water samples were collected from September 2016 to June 2017. The compounds studied are applied to corn, and Iowa and Illinois are the two largest corn producing states in the U.S. The seven stream sites are all adjacent to agricultural fields in corn production. Water samples (1-L) were collected in amber glass bottles using a grab or depth weighted approach. With the exception of one site, Iowa River at Wapello (USGS Site ID 05465500), all water samples were collected using a hydrologic based sampling approach. This means that samples were collected near peak flow during storm events and periodically during base flow conditions. Water samples were filtered (0.7 micrometers), extracted via solid phase extraction (Oasis® MAX cartridge), and analyzed (nitrapyrin and herbicides by gas chromatography with mass-spectrometry; 6-CPA by liquid chromatography tandem mass-spectrometry).

Nitrapyrin, a nitrification inhibitor, 6-CPA, a nitrapyrin degradate, and three co-applied herbicides (acetochlor, atrazine, and metolachlor) were measured in water samples from seven streams across Iowa and Illinois. Iowa water samples were collected from March 2016 to June 2017, and Illinois water samples were collected from September 2016 to June 2017. The compounds studied are applied to corn, and Iowa and Illinois are the two largest corn producing states in the U.S. The seven stream sites are all adjacent to agricultural fields in corn production. Water samples (1-L) were collected in amber glass bottles using a grab or depth weighted approach. With the exception of one site, Iowa River at Wapello (USGS Site ID 05465500), all water samples were collected using a hydrologic based sampling approach. This means that samples were collected near peak flow during storm events and periodically during base flow conditions. Water samples were filtered (0.7 micrometers), extracted via solid phase extraction (Oasis® MAX cartridge), and analyzed (nitrapyrin and herbicides by gas chromatography with mass-spectrometry; 6-CPA by liquid chromatography tandem mass-spectrometry).

Nitrapyrin, a nitrification inhibitor, 6-CPA, a nitrapyrin degradate, and three co-applied herbicides (acetochlor, atrazine, and metolachlor) were measured in surface drains from eights sites in Illinois. Water samples were collected from April to June 2017. The compounds studied are applied to corn, Illinois is one of the largest corn producing states in the U.S. Water samples (1-L) were collected in amber glass bottles using a grab or depth weighted approach. Water samples were filtered (0.7 micrometers), extracted via solid phase extraction (Oasis® MAX cartridge), and analyzed (nitrapyrin and herbicides by gas chromatography with mass-spectrometry; 6-CPA by liquid chromatography tandem mass-spectrometry).

Nitrapyrin, a nitrification inhibitor, 6-CPA, a nitrapyrin degradate, and three co-applied herbicides (acetochlor, atrazine, and metolachlor) were measured in surface drains from eights sites in Illinois. Water samples were collected from April to June 2017. The compounds studied are applied to corn, Illinois is one of the largest corn producing states in the U.S. Water samples (1-L) were collected in amber glass bottles using a grab or depth weighted approach. Water samples were filtered (0.7 micrometers), extracted via solid phase extraction (Oasis® MAX cartridge), and analyzed (nitrapyrin and herbicides by gas chromatography with mass-spectrometry; 6-CPA by liquid chromatography tandem mass-spectrometry).

Nitrapyrin, a nitrification inhibitor, and three co-applied herbicides (acetochlor, atrazine, and metolachlor) were measured in soil samples from an agricultural field in Iowa. Samples were collected from three locations in the field before and after nitrapyrin application in April-May 2017. Soils were collected using a 5-inch pipe that was hammered into the ground. Soil samples were extracted using pressurized solvent extraction (with dichloromethane), clean-up via solid phase extraction (carbon and alumina sorbents), and analyzed by gas chromatography with mass-spectrometry.

Nitrapyrin, a nitrification inhibitor, and three co-applied herbicides (acetochlor, atrazine, and metolachlor) were measured in soil samples from an agricultural field in Iowa. Samples were collected from three locations in the field before and after nitrapyrin application in April-May 2017. Soils were collected using a 5-inch pipe that was hammered into the ground. Soil samples were extracted using pressurized solvent extraction (with dichloromethane), clean-up via solid phase extraction (carbon and alumina sorbents), and analyzed by gas chromatography with mass-spectrometry.

Four dichloroacetamide herbicide safeners (AD-67, benoxacor, dichlormid, and furilazole) and two co-applied herbicides (acetochlor and metolachlor) were measured in water samples from 7 streams across Iowa and Illinois. Iowa water samples were collected from March 2016 to June 2017, and Illinois water samples were collected from September 2016 to June 2017. The compounds studied are applied to corn, and Iowa and Illinois are the two largest corn producing states in the U.S. The seven stream sites are all adjacent to agricultural fields in corn production. Water samples (1-L) were collected in amber glass bottles using a grab or depth weighted approach. With the exception of one site, Iowa River at Wapello (USGS Site ID 05465500), all water samples were collected using a hydrologic based sampling approach. This means that samples were collected near peak flow during storm events and periodically during base flow conditions. Water samples were filtered (0.7 micrometers), extracted via solid phase extraction (Oasis® MAX cartridge), and analyzed for each herbicide and safener by gas chromatography with mass-spectrometry.

Four dichloroacetamide herbicide safeners (AD-67, benoxacor, dichlormid, and furilazole) and two co-applied herbicides (acetochlor and metolachlor) were measured in water samples from 7 streams across Iowa and Illinois. Iowa water samples were collected from March 2016 to June 2017, and Illinois water samples were collected from September 2016 to June 2017. The compounds studied are applied to corn, and Iowa and Illinois are the two largest corn producing states in the U.S. The seven stream sites are all adjacent to agricultural fields in corn production. Water samples (1-L) were collected in amber glass bottles using a grab or depth weighted approach. With the exception of one site, Iowa River at Wapello (USGS Site ID 05465500), all water samples were collected using a hydrologic based sampling approach. This means that samples were collected near peak flow during storm events and periodically during base flow conditions. Water samples were filtered (0.7 micrometers), extracted via solid phase extraction (Oasis® MAX cartridge), and analyzed for each herbicide and safener by gas chromatography with mass-spectrometry.

These data were collected to determine the effect of nitrapyrin, a commercial nitrification inhibitor, on nitrification by a diverse nitrifier-enriched microbial (NEM) community. The NEM community was originally collected from an aquaculture pond in Columbia, Missouri and cultured in HEPES-buffered, minimal mineral salts media, supplemented with a nominal dose of 2 milligrams per liter ammonia-nitrogen, added as ammonium-sulfate. NEM were exposed to nitrapyrin (0 to 32 micrograms per liter) for 192 hours. Before dosing, the nitrapyrin was dissolved in dimethyl sulfoxide (DMSO). After dosing, the DMSO concentration in the flasks was 0.1 percent volume to volume. Ammonia, nitrite, nitrate, pH, dissolved oxygen, temperature, water hardness, conductivity, alkalinity, turbidity, and nitrapyrin were monitored at intervals during the experiment.