Research has suggested that biochar soil amendments have the ability to improve soil water retention, but results have not been consistent or predictable across soil types. The objective of this project was to evaluate the potential for biochar soil amendments to mitigate agricultural drought by characterizing their impacts on soil hydraulics and plant growth across a range of agricultural soil conditions. This data set contains soil moisture retention curves and unsaturated hydraulic conductivities for four Oregon agricultural soils amended with biochar. Gasified biochars made from wheat straw (AgEnergy, Spokane, WA) and conifer wood (BioLogical, Philomath, OR) were tilled into soils at experimental stations in Madras (loam), Pendleton (silt loam), Aurora (sandy loam), and Klamath Falls (loamy sand). The biochars were incorporated by tillage in the fall to a depth of 12 cm at rates equating to 0, 9, 18, and 36 Mg/ha, with three replicate plots per treatment. Soil cores were collected the following spring and used to construct moisture retention curves using a combination of pressure plates, a WP4 water potentiameter instrument, and a HYPROP instrument.

Research has suggested that biochar soil amendments have the ability to improve soil water retention, but results have not been consistent or predictable across soil types. The objective of this project was to evaluate the potential for biochar soil amendments to mitigate agricultural drought by characterizing their impacts on soil hydraulics and plant growth across a range of agricultural soil conditions. This data set contains soil moisture retention curves and unsaturated hydraulic conductivities for four Oregon agricultural soils amended with biochar. Gasified biochars made from wheat straw (AgEnergy, Spokane, WA) and conifer wood (BioLogical, Philomath, OR) were tilled into soils at experimental stations in Madras (loam), Pendleton (silt loam), Aurora (sandy loam), and Klamath Falls (loamy sand). The biochars were incorporated by tillage in the fall to a depth of 12 cm at rates equating to 0, 9, 18, and 36 Mg/ha, with three replicate plots per treatment. Soil cores were collected the following spring and used to construct moisture retention curves using a combination of pressure plates, a WP4 water potentiameter instrument, and a HYPROP instrument.

The objective of this project was to evaluate the potential for biochar soil amendments to mitigate agricultural drought by characterizing their impacts on soil hydraulics and plant growth across a range of agricultural soil conditions. This data set contains soil water infiltration measurements using Beerkan infiltration rings in four Oregon agricultural soils amended with biochar. Gasified biochars made from wheat straw (AgEnergy, Spokane, WA) and conifer wood (BioLogical, Philomath, OR) were tilled into soils at experimental stations in Madras (loam), Pendleton (silt loam), Aurora (sandy loam), and Klamath Falls (loamy sand). The biochars were incorporated by tillage in fall 2016 to a depth of 12 cm at rates equating to 0, 9, 18, and 36 Mg/ha (about 0.5, 1, 2, and 4% by mass in the tillage zone), with three replicate plots per treatment. In April and May 2017 infiltration was measured by inserting small rings into the soil surface and determining the time required for repeated 10 0mL volumes of water to infiltrate. From each infiltration experiment we estimated steady-state infiltration rate, and where possible we also estimated field saturated soil hydraulic conductivity (Kfs). Diagnostic plots demonstrated that in about half of the measurements sets, Kfs could be estimated by modeling infiltration as a two-term function of sorptivity and Kfs. In the remaining plots, additional unknown factors that influenced infiltration prevented estimation of Kfs, possibly due to air entrapment, soil layering, or ring insertion effects in the remaining experiments. Increasing biochar amendment rates led to an increase in infiltration rate only for the CW biochar at the silt loam site. For all other soil-biochar combinations no patterns in infiltration rate were detectable.

The objective of this project was to evaluate the potential for biochar soil amendments to mitigate agricultural drought by characterizing their impacts on soil hydraulics and plant growth across a range of agricultural soil conditions. This data set contains soil water infiltration measurements using Beerkan infiltration rings in four Oregon agricultural soils amended with biochar. Gasified biochars made from wheat straw (AgEnergy, Spokane, WA) and conifer wood (BioLogical, Philomath, OR) were tilled into soils at experimental stations in Madras (loam), Pendleton (silt loam), Aurora (sandy loam), and Klamath Falls (loamy sand). The biochars were incorporated by tillage in fall 2016 to a depth of 12 cm at rates equating to 0, 9, 18, and 36 Mg/ha (about 0.5, 1, 2, and 4% by mass in the tillage zone), with three replicate plots per treatment. In April and May 2017 infiltration was measured by inserting small rings into the soil surface and determining the time required for repeated 10 0mL volumes of water to infiltrate. From each infiltration experiment we estimated steady-state infiltration rate, and where possible we also estimated field saturated soil hydraulic conductivity (Kfs). Diagnostic plots demonstrated that in about half of the measurements sets, Kfs could be estimated by modeling infiltration as a two-term function of sorptivity and Kfs. In the remaining plots, additional unknown factors that influenced infiltration prevented estimation of Kfs, possibly due to air entrapment, soil layering, or ring insertion effects in the remaining experiments. Increasing biochar amendment rates led to an increase in infiltration rate only for the CW biochar at the silt loam site. For all other soil-biochar combinations no patterns in infiltration rate were detectable.

,This is digital research metadata corresponding to a published manuscript in Energies (MDPI) entitled "Biochar stability in a highly weathered sandy soil under four years of continuous corn production", Volume 14, Issue 19, 6157. Dataset may be accessed via the included link at the Dryad data repository.,Biochar is being considered a climate change mitigation tool by increasing soil organic carbon contents (SOC), however, questions remain concerning its longevity in soil. We applied 30,000 kg ha−1 of biochars to plots containing a Goldsboro sandy loam (Fine-loamy, siliceous, sub-active, thermic Aquic Paleudults) and then physically disked all plots. Thereafter, the plots were agronomically managed under 4 years (Y) of continuous corn (Zea mays, L.) planting. Annually, incremental soil along with corresponding bulk density samples were collected and SOC concentrations were measured in topsoil (down to 23-cm). The biochars were produced from Lodgepole pine (Pinus contorta) chip (PC) and Poultry litter (PL) feedstocks. An untreated Goldsboro soil (0 biochar) served as a control. After four years, SOC contents in the biochar treated plots were highest in the top 0–5 and 5–10 cm depth suggesting minimal deeper movement. Declines in SOC contents varied with depth and biochar type. After correction for SOC declines in controls, PL biochar treated soil had a similar decline in SOC (7.9 to 10.3%) contents. In contrast, the largest % SOC content decline (20.2%) occurred in 0–5 cm deep topsoil treated with PC biochar. Our results suggest that PC biochar had less stability in the Goldsboro soil than PL biochar after 4 years of corn grain production.,Methods are described in the manuscript: https://doi.org/10.3390/en14196157. Descriptions corresponding to each figure and table in the manuscript are placed on separate tabs in the Excel file to clarify abbreviations and summarize the data headings and units.,,

Data describes the impact of biochar amendments on soil lead bioaccessibility. It contains the raw soil bioaccessibility information. This dataset is associated with the following publication: Plunkett, S., C. Eckley, T. Luxton, and M. Johnson. The effects of biochar and redox conditions on soil Pb bioaccessibility to people and waterfowl. CHEMOSPHERE. Elsevier Science Ltd, New York, NY, USA, 294: 133675, (2022).

,Biochars are charcoals used as soil amendments, and they have many beneficial effects on soil health. However, one negative effect is biochars often reduce concentrations of soil nitrogen that are available to plants. This is believed to be due to the high carbon and low nitrogen contents of biochars, which deprive soil microbes of nitrogen as they decompose the biochar, and cause microbes to tie up nitrogen from soil. We tested whether we could predict biochar impacts on soil nitrogen from the quantities of carbon and nitrogen in biochar that can be consumed soil microbes. Because biochars are mostly composed of carbon in molecules that can not be consumed by microbes, the microbially-available portion is generally small. We measured the microbially-available carbon and nitrogen in ten biochars, and measured how they impacted nitrogen concentrations in two soils from Oregon.,This dataset includes characteristics of ten biochars and two soils, and measurements from two incubation experiments. In the first experiment we incubated 13C-labeled biochars with two soil for 101 days, and measured production of biochar- and soil-respired CO2 and soil dissolved inorganic nitrogen. In the second experiment we expanded to study ten biochar types, including seven biochars that were not isotopically-labeled. We measured how much dissolved inorganic nitrogen was produced by amended soils over 28 days.,Surprisingly, we found all ten biochars increased rather than decreased soil nitrogen concentrations one month after application. We also found that biochars produced at high temperatures, which were more difficult for soil microbes to consume than low-temperature biochars, stimulated more soil decomposition and released more soil nitrogen. It appeared that microbes increased soil decomposition in response to additions of biochar, and this then increased plant-available nitrogen at least temporarily. These unexpected results show that biochar can sometimes have beneficial impacts on soil nitrogen, and that biochar impacts cannot be readily predicted from the qualities of the biochars themselves. These results are relevant to biochar users, and to biochar producers interested in how to make biochars more beneficial for plant growth. These results indicate that biochar users cannot predict nitrogen impacts, and should therefore monitor soil nitrogen concentrations to ensure levels are sufficient for plant growth.,,

Biochar is being evaluated as an amendment to improve soil characteristics to increase crop yields, revitalize degraded soils and facilitate the establishment of plant cover. Unfortunately, there are few rapid tests to determine potential effects of biochar on soil and associated plant responses. Seed germination (emergence of hypocotyl) is a critical parameter for plant establishment and may be a rapid indicator of biochar effects. We adapted Oregon State University Seed Laboratory procedures to develop a “rapid-test” to screen for effects of biochar on seed germination and soil characteristics. Soils were amended with 1% biochar by weight and placed in 11.0 cm square x 3.5 cm deep containers fitted with premoistened blotter paper. Seeds were placed in a uniform 5 x 5 pattern and covered with 15 g of the soil-biochar mixtures. Two South Carolina Coastal Plain soils, the Norfolk (Fine-loamy, kaolinitic, thermic Typic Kandiudults) and Coxville (Fine, kaolinitic, thermic Typic Paleaquults), were used. Eighteen biochars were evaluated produced from 6 feedstocks [pine chips (PC), poultry litter (PL), swine solids (SS), switchgrass (SG); and two blends of PC and PL, 50% PC/50% PL (55), and 80% PC/20% PL (82). For each feedstock biochars were made by pyrolysis at 350, 500 and 700°C for 1-2 hours. Percent germination and shoot dry weight were evaluated for cabbage, carrot, cucumber, lettuce, oat, onion, perennial ryegrass and tomato. Soil pH, electrical conductivity (EC) and extractable phosphorus (EP), factors which can affect seed germination and early seedling growth, were determined after plant harvests. Germination primarily was affected by soil type with few biochar effects. Shoot dry weight was increased for carrot, lettuce, oat and tomato; primarily with biochars containing PL. Soil pH and EC increased with PL, SS, 55 and most 82 treatments across soil types and plant species. Soil EP increased substantially with SS and PL and to a lesser extent with 55 and 82 for both soils across species, and with SG pyrolyzed at 550 and 750°C soil for the Norfolk soil across species. Thus, this rapid-test method can be an early indicator of the effects of biochar on seed germination and important soil health characteristics which can be affected by biochar and effect seed germination. This dataset is associated with the following publication: Olszyk, D.M., T. Shiroyama, J.M. Novak, and M.G. Johnson. A Rapid-Test for Screening Biochar Effects on Seed Germination. Communications in Soil Science and Plant Analysis. Taylor & Francis Group, London, UK, 49(16): 2025-2041, (2018).

Biochar is being evaluated as an amendment to improve soil characteristics to increase crop yields, revitalize degraded soils and facilitate the establishment of plant cover. Unfortunately, there are few rapid tests to determine potential effects of biochar on soil and associated plant responses. Seed germination (emergence of hypocotyl) is a critical parameter for plant establishment and may be a rapid indicator of biochar effects. We adapted Oregon State University Seed Laboratory procedures to develop a “rapid-test” to screen for effects of biochar on seed germination and soil characteristics. Soils were amended with 1% biochar by weight and placed in 11.0 cm square x 3.5 cm deep containers fitted with premoistened blotter paper. Seeds were placed in a uniform 5 x 5 pattern and covered with 15 g of the soil-biochar mixtures. Two South Carolina Coastal Plain soils, the Norfolk (Fine-loamy, kaolinitic, thermic Typic Kandiudults) and Coxville (Fine, kaolinitic, thermic Typic Paleaquults), were used. Eighteen biochars were evaluated produced from 6 feedstocks [pine chips (PC), poultry litter (PL), swine solids (SS), switchgrass (SG); and two blends of PC and PL, 50% PC/50% PL (55), and 80% PC/20% PL (82). For each feedstock biochars were made by pyrolysis at 350, 500 and 700°C for 1-2 hours. Percent germination and shoot dry weight were evaluated for cabbage, carrot, cucumber, lettuce, oat, onion, perennial ryegrass and tomato. Soil pH, electrical conductivity (EC) and extractable phosphorus (EP), factors which can affect seed germination and early seedling growth, were determined after plant harvests. Germination primarily was affected by soil type with few biochar effects. Shoot dry weight was increased for carrot, lettuce, oat and tomato; primarily with biochars containing PL. Soil pH and EC increased with PL, SS, 55 and most 82 treatments across soil types and plant species. Soil EP increased substantially with SS and PL and to a lesser extent with 55 and 82 for both soils across species, and with SG pyrolyzed at 550 and 750°C soil for the Norfolk soil across species. Thus, this rapid-test method can be an early indicator of the effects of biochar on seed germination and important soil health characteristics which can be affected by biochar and effect seed germination. This dataset is associated with the following publication: Olszyk, D.M., T. Shiroyama, J.M. Novak, and M.G. Johnson. A Rapid-Test for Screening Biochar Effects on Seed Germination. Communications in Soil Science and Plant Analysis. Taylor & Francis Group, London, UK, 49(16): 2025-2041, (2018).

The BOREAS HYD-01 team made several measurements related to soil moisture and soil properties. These soil hydraulic properties were determined at the flux tower sites based on analysis of in situ tension infiltrometer tests and laboratory determined water retention from soil cores collected during the 1994-95 field campaigns. Results from this analysis are saturated hydraulic conductivity, and fitting parameters for the van Genuchten-Mualem soil hydraulic conductivity and water retention function at flux tower sites.