Some biochars produced by pyrolysis of biomass have the potential to sequester C and enhance nutr... more Some biochars produced by pyrolysis of biomass have the potential to sequester C and enhance nutrient supplies in agricultural soils. A 28-day lab incubation was used to assess the potential effects of biochars derived from pine chips (PC) or poultry litter (PL) applied at five application rates (0, 22.5, 45.0, 67.5, and 90 Mg ha−1 equivalent). Biochars were applied to two acidic Ultisols, a Cecil sandy loam and a Tifton loamy sand, found in Georgia, USA. Cumulative basal soil respiration was measured over the 28-day incubation. Other soil properties measured before and after incubation were soil pH, total soil organic carbon (SOC), total soil N, soluble organic C (OC), soil mineral nitrogen (NH4+-N and NO3−-N), and microbial biomass C (MBC). Before incubation, addition of both PC and PL biochars increased soil pH, total SOC, and C:N ratio in both soils. Addition of the PL biochar increased total soil N, soluble OC, and NO3−-N in both soils, MBC in Tifton soil, and NH4+-N in Cecil s...
<p>Flower coverage time (%t), pollinator visitation time (pvt), pollinator visitiation inte... more <p>Flower coverage time (%t), pollinator visitation time (pvt), pollinator visitiation intensity (pvt %t<sup>−1</sup>), sum of flowers produced per hectare (∑f ha<sup>−1</sup>), sucrose per hectare per year (s h<sup>−1</sup> y<sup>−1</sup>), and ratio of pollinator visitation time to flower coverage time (pvt %t<sup>−1</sup>).</p
a<p>SRC, Stepwise regression coefficient.</p><p>Stepwise multiple regression mo... more a<p>SRC, Stepwise regression coefficient.</p><p>Stepwise multiple regression model of anthesis duration using days to flower (DTF), anthesis rainfall (ARF), and vegetative rainfall (VRF). R<sup>2</sup> = 0.77.</p
Abstract Biochar, used as a soil amendment, arose from the influx of new understanding of the ori... more Abstract Biochar, used as a soil amendment, arose from the influx of new understanding of the origin of the “Terra Preta” soils rediscovered in the Amazon. Current theory assumes that active measures were taken centuries ago (CE 450–950) to enrich soils with burnt biomass (char), bone, and manure. These active measures over time resulted in extremely fertile soils rich in plant nutrients, microbial activity, and reactive functional groups that influence cation exchange capacity and a host of other physicochemical soil properties. A wealth of research resulting from this rediscovery has demonstrated that laboratory and commercial grade biochar may enhance soil health and plant growth and can be used as a soil amendment in forestry, agriculture, degraded landscapes, and contaminated soils. However, not all biochars are alike or have the same uses, as variable feedstocks and thermoconversion conditions influence biochar properties. Similarly, the landscape to which they are applied will express variable reactions due to differences in soil type, climate, vegetation, and management. In this chapter the occurrence, production and properties of biochar, and how these properties influence specific soil conditions and reactions is described. We then discuss the proposed, prescribed, and applied uses for biochar on the landscape. We finish with mention of potential hazards from biochar use and gaps in our knowledge.
The continuing pollinator crisis is due, in part, to the lack of year-round floral resources. In ... more The continuing pollinator crisis is due, in part, to the lack of year-round floral resources. In intensive farming regions, such as the Upper Midwest (UMW) of the USA, natural and pastoral vegetation largely has been replaced by annual crops such as maize (Zea mays L.), soyabean (Glycine max L.) and wheat (Triticum spp.). Neither the energy (nectar) nor protein (pollen) needs of pollinating and other beneficial insects are being met sufficiently by the new, high-intensity, agricultural landscape. Several potentially useful oilseed crops can be grown in the UMW, and many of these oilseeds are highly attractive to beneficial insects. Prior research showed that some of these oilseeds produced abundant nectar, but their corresponding values for pollen production are unknown. Accordingly, the aim of our research was to document pollen (and protein) production per unit area of twelve oilseed crops grown in Minnesota and associate these values with levels of beneficial insect visitation during anthesis. Our results show that oilseed crops such as camelina (Camelina sativa L.), flax (Linum usitatissimum L.) and pennycress (Thlaspi arvense L.) produce relatively little pollen (≤40 kg/ha); borage (Borago officinalis L.), calendula (Calendula officinalis L.), canola (Brassica napus L.), crambe (Crambe abyssianica Hochst) and cuphea (Cuphea viscosissima Jacq. × Cuphea lanceolata W. T. Aiton) produce bountiful pollen resources (50-150 kg/ha); and oilseed echium (Echium plantagineum L.) generates massive amounts of pollen (>400 kg/ha), about 50% of which is protein. Our study is unique in presenting a season-long perspective of pollen production in alternative oilseed crops, a resource valuable to pollen-feeding insects such as managed and wild bees. Diversification of UMW landscapes that includes alternative oilseed crops such as oilseed echium and cuphea can potentially provide a ready source of pollen and protein to help combat pollinator decline.
The introduction, establishment and spread of non-native earthworm species in North America have ... more The introduction, establishment and spread of non-native earthworm species in North America have been ongoing for centuries. These introductions have occurred across the continent and in some ecosystems have resulted in considerable modifications to ecosystem processes and functions associated with above-and belowground foodwebs. However, many areas of North America have either never been colonized by introduced earthworms, or have soils that are still inhabited exclusively by native earthworm fauna. Although several modes of transport and subsequent proliferation of non-native earthworms have been identified, little effort has been made to interrupt the flow of new species into new areas. Examples of major avenues for introduction of earthworms are the fish-bait, horticulture, and vermicomposting industries. In this paper we examine land management practices that influence the establishment of introduced species in several ecosystem types, and identify situations where land management may be useful in limiting the spread of introduced earthworm species. Finally, we discuss methods to regulate the importation of earthworms and earthworm-containing media so that introduction of new exotic species can be minimized or avoided. Although our focus in this paper is necessarily North American, many of the management and policy options presented here could be applicable to the problem of earthworm invasions in other parts of the world.
Echium (Echium plantagineum L.) is an alternative oilseed crop in summer-wet temperate regions th... more Echium (Echium plantagineum L.) is an alternative oilseed crop in summer-wet temperate regions that provides floral resources to pollinators. Its seed oil is rich in omega-3 fatty acids, such as stearidonic acid, which is desired highly by the cosmetic industry. Seeds were sown in field plots over three years in western Minnesota in spring (early-sown) or early summer (late-sown), and flower abundance, pollinator visitation, and seed yields were studied. Initial flowering commenced 41 to 55 d after sowing, and anthesis duration (first flowering to harvest) was 34 to 70 d. Late sowing dates delayed anthesis, but increased the intensity of visitation by pollinators. Cumulative flower densities ranged from 1 to 4.5 billion ha21. Flowers attracted numerous honey bees (Apis mellifera L.), as many as 35 per minute of observation, which represented about 50 % of all insect visitors. Early-sown echium produced seed yields up to 750 kg ha21, which were 2–29 times higher than those of late-so...
Nitrogen management is an important issue for economic and environmental sustainability. We desig... more Nitrogen management is an important issue for economic and environmental sustainability. We designed an experiment in two phases 1) the growth phase to determine the impact of herbivore pressure on N uptake, and 2) the decomposition phase to determine recovery in a second crop from separately decomposing above and below ground residue. Canopy enclosures and insecticides were used to exclude herbivorous insects. We used 15N labeled ammonium sulfate as the initial fertilizer source of N for the first corn crop. 15N uptake and %N of plant tissue were greater under canopy exclosures than under open conditions; however, yields were still substantially higher under open conditions. During the decomposition phase greater %N in the decomposing tissue had an impact on final yield and net N mineralized during the growing season.
Interest in the use of biochar as a soil amendment to increase soil fertility and sequester carbo... more Interest in the use of biochar as a soil amendment to increase soil fertility and sequester carbon is increasing. However, the effects of biochar on the survival and reproduction of earthworms are unknown. The toxicity of two different biochars (pine chip and poultry litter char) on Eisenia fetida applied to an artificial soil (70% sand, 20% kaolin, and 10% sphagnum) was investigated at five different application rates of 0, 22.5, 45, 67.5, and 90 Mg ha -1 . Earthworm mortality and weight loss reached 100% at the two highest application rates of poultry litter biochar, whereas mortality and weight loss with pine chip biochar did not differ from control treatments. Soil pH, which also increased in controls and pine chip biochar treatments over the course of the incubation, was the most likely cause of earthworm mortality in all treatments. However, it was apparent that poultry litter biochar provided a more stressful environment to earthworms since many worms died in the first five d...
The material in this chapter covers the concepts of “low-input” and “intensified” production syst... more The material in this chapter covers the concepts of “low-input” and “intensified” production systems in the context of input intensity and sustainability. Research-based case studies are presented that draw out the practicalities of implementing production practices on an input intensity gradient from external inputs to captured inputs. Captured inputs are those generated from natural capital such as N fixation, and biological control. The discussion focuses on how management strategies along this gradient support soil health and crop productivity. Farm-based case studies are used to explore how individual producers have employed or adapted low-input and agroecosystem approaches to build viable environmentally sound farming systems. A national case study, focused on Cuba, furthers understanding of generating a national food system under a constrained input environment that is capable of meeting food security needs. Conclusions are drawn on the practicality of adopting low-input or a...
Organic dairy cows were used to evaluate the effect of two organic pasture production systems (te... more Organic dairy cows were used to evaluate the effect of two organic pasture production systems (temperate grass species and warm-season annual grasses and cool-season annuals compared with temperate grasses only) across two grazing seasons (May to October of 2014 and 2015) on milk production, milk components (fat, protein, milk urea nitrogen (MUN), somatic cell score (SCS)), body weight, body condition score (BCS), and activity and rumination (min/day). Cows were assigned to two pasture systems across the grazing season at an organic research dairy in Morris, Minnesota. Pasture System 1 was cool-season perennials (CSP) and Pasture System 2 was a combination of System 1 and warm-season grasses and cool-season annuals. System 1 and System 2 cows had similar milk production (14.7 and 14.8 kg d−1), fat percentage (3.92% vs. 3.80%), protein percentage (3.21% vs. 3.17%), MUN (12.5 and 11.5 mg dL−1), and SCS (4.05 and 4.07), respectively. Cows in System 1 had greater daily rumination (530 m...
Biochar is a material created from the thermoconversion of biomass through pyrolysis for the prod... more Biochar is a material created from the thermoconversion of biomass through pyrolysis for the production of bio-energy. The use of biochar as a soil amendment has been proposed as a means to sequester carbon, thus offsetting the release of CO2. Management strategies for the use of biochar as a soil amendment are still in development, and the effect of adding biochar to soil on soil organisms, in particular earthworms, is virtually unknown. We studied the effect of two different biochars, pine chip biochar and poultry litter biochar, on earthworm growth and survival in incubated mesosocoms in two different field soils, as well as the effect of the two biochars and earthworms on soil microbial carbon biomass. The poultry litter char adversely affected earthworm survival, but resulted in higher levels of microbial carbon, especially at the higher rates of application. The pine char had a higher survival rate, and did not show any change in the microbial carbon levels.
The USDA Agricultural Research Service (ARS) organized a workshop entitled, “Collaborative Resear... more The USDA Agricultural Research Service (ARS) organized a workshop entitled, “Collaborative Research and Data Networking: Leveraging GRACEnet-REAP Successes,” that was held on June 14 to 16, 2016, in Fort Collins, Colorado. One of the primary workshop goals was to create and encourage development of multi-location database teams that can provide meaningful networks to collect, store, and make ARS data and other data more accessible to stakeholders, research partners, technology transfer personnel, and other users. This workshop was intended to be aligned with but not duplicate actions associated with the ARS big data effort or National Program (NP) goals. In fact, the workshop was organized to help advance cross-location activities associated with NP-212 (Soil and Air) and its 2016 to 2020 Action Plan. A direct workshop outcome was the decision to create a national Nutrient Uptake and Outcome Network (NUOnet), which had been under discussion by ARS scientists from several different national programs for several months. The Fort Collins workshop brought together an initial invited group of members, which was subsequently expanded during and after the meeting to develop a NUOnet steering committee. The steering committee has now developed a flexible roadmap outlining how to jumpstart coordinated, multi-location NUOnet efforts. The…
Impacts of biochar application at laboratory scales are routinely studied, but impacts of biochar... more Impacts of biochar application at laboratory scales are routinely studied, but impacts of biochar application on decomposition of crop residues at field scales have not been widely addressed. The priming or hindrance of crop residue decomposition could have a cascading impact on soil processes, particularly those influencing nutrient availability. Our objectives were to evaluate biochar effects on field decomposition of crop residue, using plots that were amended with biochars made from different plant-based feedstocks and pyrolysis platforms in the fall of 2008. Litterbags containing wheat straw material were buried in July of 2011 below the soil surface in a continuous-corn cropped field in plots that had received one of seven different biochar amendments or a uncharred wood-pellet amendment 2.5 yr prior to start of this study. Litterbags were collected over the course of 14 weeks. Microbial biomass was assessed in treatment plots the previous fall. Though first-order decomposition rate constants were positively correlated to microbial biomass, neither parameter was statistically affected by biochar or wood-pellet treatments. The findings indicated only a residual of potentially positive and negative initial impacts of biochars on residue decomposition, which fit in line with established feedstock and pyrolysis influences. Overall, these findings indicate that no significant alteration in the microbial dynamics of the soil decomposer communities occurred as a consequence of the application of plant-based biochars evaluated here.
Some biochars produced by pyrolysis of biomass have the potential to sequester C and enhance nutr... more Some biochars produced by pyrolysis of biomass have the potential to sequester C and enhance nutrient supplies in agricultural soils. A 28-day lab incubation was used to assess the potential effects of biochars derived from pine chips (PC) or poultry litter (PL) applied at five application rates (0, 22.5, 45.0, 67.5, and 90 Mg ha−1 equivalent). Biochars were applied to two acidic Ultisols, a Cecil sandy loam and a Tifton loamy sand, found in Georgia, USA. Cumulative basal soil respiration was measured over the 28-day incubation. Other soil properties measured before and after incubation were soil pH, total soil organic carbon (SOC), total soil N, soluble organic C (OC), soil mineral nitrogen (NH4+-N and NO3−-N), and microbial biomass C (MBC). Before incubation, addition of both PC and PL biochars increased soil pH, total SOC, and C:N ratio in both soils. Addition of the PL biochar increased total soil N, soluble OC, and NO3−-N in both soils, MBC in Tifton soil, and NH4+-N in Cecil s...
<p>Flower coverage time (%t), pollinator visitation time (pvt), pollinator visitiation inte... more <p>Flower coverage time (%t), pollinator visitation time (pvt), pollinator visitiation intensity (pvt %t<sup>−1</sup>), sum of flowers produced per hectare (∑f ha<sup>−1</sup>), sucrose per hectare per year (s h<sup>−1</sup> y<sup>−1</sup>), and ratio of pollinator visitation time to flower coverage time (pvt %t<sup>−1</sup>).</p
a<p>SRC, Stepwise regression coefficient.</p><p>Stepwise multiple regression mo... more a<p>SRC, Stepwise regression coefficient.</p><p>Stepwise multiple regression model of anthesis duration using days to flower (DTF), anthesis rainfall (ARF), and vegetative rainfall (VRF). R<sup>2</sup> = 0.77.</p
Abstract Biochar, used as a soil amendment, arose from the influx of new understanding of the ori... more Abstract Biochar, used as a soil amendment, arose from the influx of new understanding of the origin of the “Terra Preta” soils rediscovered in the Amazon. Current theory assumes that active measures were taken centuries ago (CE 450–950) to enrich soils with burnt biomass (char), bone, and manure. These active measures over time resulted in extremely fertile soils rich in plant nutrients, microbial activity, and reactive functional groups that influence cation exchange capacity and a host of other physicochemical soil properties. A wealth of research resulting from this rediscovery has demonstrated that laboratory and commercial grade biochar may enhance soil health and plant growth and can be used as a soil amendment in forestry, agriculture, degraded landscapes, and contaminated soils. However, not all biochars are alike or have the same uses, as variable feedstocks and thermoconversion conditions influence biochar properties. Similarly, the landscape to which they are applied will express variable reactions due to differences in soil type, climate, vegetation, and management. In this chapter the occurrence, production and properties of biochar, and how these properties influence specific soil conditions and reactions is described. We then discuss the proposed, prescribed, and applied uses for biochar on the landscape. We finish with mention of potential hazards from biochar use and gaps in our knowledge.
The continuing pollinator crisis is due, in part, to the lack of year-round floral resources. In ... more The continuing pollinator crisis is due, in part, to the lack of year-round floral resources. In intensive farming regions, such as the Upper Midwest (UMW) of the USA, natural and pastoral vegetation largely has been replaced by annual crops such as maize (Zea mays L.), soyabean (Glycine max L.) and wheat (Triticum spp.). Neither the energy (nectar) nor protein (pollen) needs of pollinating and other beneficial insects are being met sufficiently by the new, high-intensity, agricultural landscape. Several potentially useful oilseed crops can be grown in the UMW, and many of these oilseeds are highly attractive to beneficial insects. Prior research showed that some of these oilseeds produced abundant nectar, but their corresponding values for pollen production are unknown. Accordingly, the aim of our research was to document pollen (and protein) production per unit area of twelve oilseed crops grown in Minnesota and associate these values with levels of beneficial insect visitation during anthesis. Our results show that oilseed crops such as camelina (Camelina sativa L.), flax (Linum usitatissimum L.) and pennycress (Thlaspi arvense L.) produce relatively little pollen (≤40 kg/ha); borage (Borago officinalis L.), calendula (Calendula officinalis L.), canola (Brassica napus L.), crambe (Crambe abyssianica Hochst) and cuphea (Cuphea viscosissima Jacq. × Cuphea lanceolata W. T. Aiton) produce bountiful pollen resources (50-150 kg/ha); and oilseed echium (Echium plantagineum L.) generates massive amounts of pollen (>400 kg/ha), about 50% of which is protein. Our study is unique in presenting a season-long perspective of pollen production in alternative oilseed crops, a resource valuable to pollen-feeding insects such as managed and wild bees. Diversification of UMW landscapes that includes alternative oilseed crops such as oilseed echium and cuphea can potentially provide a ready source of pollen and protein to help combat pollinator decline.
The introduction, establishment and spread of non-native earthworm species in North America have ... more The introduction, establishment and spread of non-native earthworm species in North America have been ongoing for centuries. These introductions have occurred across the continent and in some ecosystems have resulted in considerable modifications to ecosystem processes and functions associated with above-and belowground foodwebs. However, many areas of North America have either never been colonized by introduced earthworms, or have soils that are still inhabited exclusively by native earthworm fauna. Although several modes of transport and subsequent proliferation of non-native earthworms have been identified, little effort has been made to interrupt the flow of new species into new areas. Examples of major avenues for introduction of earthworms are the fish-bait, horticulture, and vermicomposting industries. In this paper we examine land management practices that influence the establishment of introduced species in several ecosystem types, and identify situations where land management may be useful in limiting the spread of introduced earthworm species. Finally, we discuss methods to regulate the importation of earthworms and earthworm-containing media so that introduction of new exotic species can be minimized or avoided. Although our focus in this paper is necessarily North American, many of the management and policy options presented here could be applicable to the problem of earthworm invasions in other parts of the world.
Echium (Echium plantagineum L.) is an alternative oilseed crop in summer-wet temperate regions th... more Echium (Echium plantagineum L.) is an alternative oilseed crop in summer-wet temperate regions that provides floral resources to pollinators. Its seed oil is rich in omega-3 fatty acids, such as stearidonic acid, which is desired highly by the cosmetic industry. Seeds were sown in field plots over three years in western Minnesota in spring (early-sown) or early summer (late-sown), and flower abundance, pollinator visitation, and seed yields were studied. Initial flowering commenced 41 to 55 d after sowing, and anthesis duration (first flowering to harvest) was 34 to 70 d. Late sowing dates delayed anthesis, but increased the intensity of visitation by pollinators. Cumulative flower densities ranged from 1 to 4.5 billion ha21. Flowers attracted numerous honey bees (Apis mellifera L.), as many as 35 per minute of observation, which represented about 50 % of all insect visitors. Early-sown echium produced seed yields up to 750 kg ha21, which were 2–29 times higher than those of late-so...
Nitrogen management is an important issue for economic and environmental sustainability. We desig... more Nitrogen management is an important issue for economic and environmental sustainability. We designed an experiment in two phases 1) the growth phase to determine the impact of herbivore pressure on N uptake, and 2) the decomposition phase to determine recovery in a second crop from separately decomposing above and below ground residue. Canopy enclosures and insecticides were used to exclude herbivorous insects. We used 15N labeled ammonium sulfate as the initial fertilizer source of N for the first corn crop. 15N uptake and %N of plant tissue were greater under canopy exclosures than under open conditions; however, yields were still substantially higher under open conditions. During the decomposition phase greater %N in the decomposing tissue had an impact on final yield and net N mineralized during the growing season.
Interest in the use of biochar as a soil amendment to increase soil fertility and sequester carbo... more Interest in the use of biochar as a soil amendment to increase soil fertility and sequester carbon is increasing. However, the effects of biochar on the survival and reproduction of earthworms are unknown. The toxicity of two different biochars (pine chip and poultry litter char) on Eisenia fetida applied to an artificial soil (70% sand, 20% kaolin, and 10% sphagnum) was investigated at five different application rates of 0, 22.5, 45, 67.5, and 90 Mg ha -1 . Earthworm mortality and weight loss reached 100% at the two highest application rates of poultry litter biochar, whereas mortality and weight loss with pine chip biochar did not differ from control treatments. Soil pH, which also increased in controls and pine chip biochar treatments over the course of the incubation, was the most likely cause of earthworm mortality in all treatments. However, it was apparent that poultry litter biochar provided a more stressful environment to earthworms since many worms died in the first five d...
The material in this chapter covers the concepts of “low-input” and “intensified” production syst... more The material in this chapter covers the concepts of “low-input” and “intensified” production systems in the context of input intensity and sustainability. Research-based case studies are presented that draw out the practicalities of implementing production practices on an input intensity gradient from external inputs to captured inputs. Captured inputs are those generated from natural capital such as N fixation, and biological control. The discussion focuses on how management strategies along this gradient support soil health and crop productivity. Farm-based case studies are used to explore how individual producers have employed or adapted low-input and agroecosystem approaches to build viable environmentally sound farming systems. A national case study, focused on Cuba, furthers understanding of generating a national food system under a constrained input environment that is capable of meeting food security needs. Conclusions are drawn on the practicality of adopting low-input or a...
Organic dairy cows were used to evaluate the effect of two organic pasture production systems (te... more Organic dairy cows were used to evaluate the effect of two organic pasture production systems (temperate grass species and warm-season annual grasses and cool-season annuals compared with temperate grasses only) across two grazing seasons (May to October of 2014 and 2015) on milk production, milk components (fat, protein, milk urea nitrogen (MUN), somatic cell score (SCS)), body weight, body condition score (BCS), and activity and rumination (min/day). Cows were assigned to two pasture systems across the grazing season at an organic research dairy in Morris, Minnesota. Pasture System 1 was cool-season perennials (CSP) and Pasture System 2 was a combination of System 1 and warm-season grasses and cool-season annuals. System 1 and System 2 cows had similar milk production (14.7 and 14.8 kg d−1), fat percentage (3.92% vs. 3.80%), protein percentage (3.21% vs. 3.17%), MUN (12.5 and 11.5 mg dL−1), and SCS (4.05 and 4.07), respectively. Cows in System 1 had greater daily rumination (530 m...
Biochar is a material created from the thermoconversion of biomass through pyrolysis for the prod... more Biochar is a material created from the thermoconversion of biomass through pyrolysis for the production of bio-energy. The use of biochar as a soil amendment has been proposed as a means to sequester carbon, thus offsetting the release of CO2. Management strategies for the use of biochar as a soil amendment are still in development, and the effect of adding biochar to soil on soil organisms, in particular earthworms, is virtually unknown. We studied the effect of two different biochars, pine chip biochar and poultry litter biochar, on earthworm growth and survival in incubated mesosocoms in two different field soils, as well as the effect of the two biochars and earthworms on soil microbial carbon biomass. The poultry litter char adversely affected earthworm survival, but resulted in higher levels of microbial carbon, especially at the higher rates of application. The pine char had a higher survival rate, and did not show any change in the microbial carbon levels.
The USDA Agricultural Research Service (ARS) organized a workshop entitled, “Collaborative Resear... more The USDA Agricultural Research Service (ARS) organized a workshop entitled, “Collaborative Research and Data Networking: Leveraging GRACEnet-REAP Successes,” that was held on June 14 to 16, 2016, in Fort Collins, Colorado. One of the primary workshop goals was to create and encourage development of multi-location database teams that can provide meaningful networks to collect, store, and make ARS data and other data more accessible to stakeholders, research partners, technology transfer personnel, and other users. This workshop was intended to be aligned with but not duplicate actions associated with the ARS big data effort or National Program (NP) goals. In fact, the workshop was organized to help advance cross-location activities associated with NP-212 (Soil and Air) and its 2016 to 2020 Action Plan. A direct workshop outcome was the decision to create a national Nutrient Uptake and Outcome Network (NUOnet), which had been under discussion by ARS scientists from several different national programs for several months. The Fort Collins workshop brought together an initial invited group of members, which was subsequently expanded during and after the meeting to develop a NUOnet steering committee. The steering committee has now developed a flexible roadmap outlining how to jumpstart coordinated, multi-location NUOnet efforts. The…
Impacts of biochar application at laboratory scales are routinely studied, but impacts of biochar... more Impacts of biochar application at laboratory scales are routinely studied, but impacts of biochar application on decomposition of crop residues at field scales have not been widely addressed. The priming or hindrance of crop residue decomposition could have a cascading impact on soil processes, particularly those influencing nutrient availability. Our objectives were to evaluate biochar effects on field decomposition of crop residue, using plots that were amended with biochars made from different plant-based feedstocks and pyrolysis platforms in the fall of 2008. Litterbags containing wheat straw material were buried in July of 2011 below the soil surface in a continuous-corn cropped field in plots that had received one of seven different biochar amendments or a uncharred wood-pellet amendment 2.5 yr prior to start of this study. Litterbags were collected over the course of 14 weeks. Microbial biomass was assessed in treatment plots the previous fall. Though first-order decomposition rate constants were positively correlated to microbial biomass, neither parameter was statistically affected by biochar or wood-pellet treatments. The findings indicated only a residual of potentially positive and negative initial impacts of biochars on residue decomposition, which fit in line with established feedstock and pyrolysis influences. Overall, these findings indicate that no significant alteration in the microbial dynamics of the soil decomposer communities occurred as a consequence of the application of plant-based biochars evaluated here.
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Papers by Sharon Weyers