Biochars can improve soil health but have been widely shown to reduce plant-available nitrogen(N)owing to their high carbon(C)content,which stimulates microbial N-immobilization.However,because biochars contain large ...Biochars can improve soil health but have been widely shown to reduce plant-available nitrogen(N)owing to their high carbon(C)content,which stimulates microbial N-immobilization.However,because biochars contain large amounts of C that are not microbially available,their total elemental C:N ratio does not correspond well with impacts on soil N.We hypothesized that impacts on soil plant-available N would relate to biochar mineralizable-C(C_(min))content,and that C:N ratios of the mineralizable biochar component could provide a means for predicting conditions of net soil N-mineralization or-immobilization.We conducted two laboratory experiments,the first measuring biochar C_(min)from respiration of isotopically labeled barley biochars manufactured at 300,500,and 750℃,and the second characterizing C_(min)by proxy measurements for ten biochars from six feedstocks at several temperatures.For both experiments,soils were incubated with 2%biochar by mass to determine impacts to soil N-mineralization.Contrary to expectation,all the biochars increased soil N-mineralization relative to unamended soils.Also unexpected,higher temperature(500 and 700℃)barley biochars with less C_(min)stimulated more soil decomposition and more soil N-mineralization than a 350℃barley biochar.However,across diverse biochar feedstocks and production methods,none of the biochar characteristics correlated with soil N-mineralization.The finding of improved soil N-mineralization adds complexity to the range of soil N responses that can be expected in response to biochar amendment.Because of the limited ability to predict soil N responses from biochar properties,users should monitor soil N to manage soil fertility.展开更多
The Oronogo-Duenweg mining belt is a designated United States Environmental Protection Agency Superfund site due to lead-contaminated soil and groundwater by former mining and smelting operations.Sites that have under...The Oronogo-Duenweg mining belt is a designated United States Environmental Protection Agency Superfund site due to lead-contaminated soil and groundwater by former mining and smelting operations.Sites that have undergone remediation-in which the O,A,and B horizons have been removed alongside the lead contamination-have an exposed C horizon and are incalcitrant to revegetation efforts.Soils also continue to contain quantifiable Cd and Zn concentrations.To improve soil conditions and encourage successful site revegetation,our study employed three biochars,sourced from different feedstocks(poultry litter,beef cattle manure,and lodgepole pine),at two rates of application(2.5%,and 5%),coupled with compost(0%,2.5%and 5%application rates).Two plant species-switchgrass(Panicum virgatum)and buffalograss(Bouteloua dactyloides)-were grown in the amended soils.Amendment of soils with poultry litter biochar applied at 5%resulted in the greatest reduction of soil bioavailable Cd and Zn.Above-ground biomass yields were greatest with beef cattle manure biochar applied at 2.5%with 5%compost,or with 5%biochar at 2.5%and 5%compost rates.Maximal microbial biomass was achieved with 5%poultry litter biochar and 5%compost,and microbial communities in soils amended with poultry litter biochar distinctly clustered away from all other soil treatments.Additionally,poultry litter biochar amended soils had the highest enzyme activity rates forβ-glucosidase,N-acetyl-β-D-glucosaminidase,and esterase.These results suggest that soil reclamation using biochar and compost can improve mine-impacted soil biogeophysical characteristics,and potentially improve future remediation efforts.展开更多
In response to increasing concerns over climate change,soil health and wine quality,grape growers are seeking new practices(e.g.,biochar application)to minimize their environmental footprint while increasing productiv...In response to increasing concerns over climate change,soil health and wine quality,grape growers are seeking new practices(e.g.,biochar application)to minimize their environmental footprint while increasing productivity and the quality of their products.To explore the potential of biochar-based amendments to achieve these goals in wine grape production,vineyard trials were established in the fall of 2018.Two Oregon sites were chosen with distinct soil types and climates(Willamette Valley and Rogue Valley)but planted with the same grapevine scion/rootstock Pinot noir combination.Four treatments were applied under vines at each location:no biochar-no tillage(NT);no biochar+tillage(B0);18 tons ha^(−1)biochar+tillage(B18);35 tons ha^(−1)biochar+tillage(B35).In 2019,a suite of soil health,plant,and crop variables were measured,and wines were produced after harvest.The incorporation of biochar modified the chemical and physical composition of soils at the two studied locations,increasing the bioavailability of carbon and nitrogen,their gravimetric water content and the concentration of plant available micro and macro nutrients.No responses of plant physiology parameters or productivity at either site were found after biochar incorporation when compared with controls.Conversely,a significant and gradual decrease in the amount of wine tannins was found as a result of biochar application in wines produced from grapes from the Woodhall location.Long-term field experiments are required to assess the effects of biochar on soil properties,vine physiol-ogy,productivity,and grape and wine quality several years after incorporation.展开更多
Meta-analyses have shown that only about half of biochar addition studies report improved plant growth.To improve yield response,here we describe a decision support tool(DST)for selecting a biochar type and amendment ...Meta-analyses have shown that only about half of biochar addition studies report improved plant growth.To improve yield response,here we describe a decision support tool(DST)for selecting a biochar type and amendment rate to meet soil and crop management goals,based on soil and biochar tests values and crop requirements as reported by regional extension recommendations.Using data from a greenhouse wheat trial,we assessed whether this approach could predict changes in soil chemistry and whether it could identify soils in which amendment would stimulate crop yield.These data indicated that the DST could provide semi-quantitative predictions of biochar amendment rates needed to meet target soil pH levels,with recommended rates averaging 25%higher than were needed.The DST was better at predicting biochar application rates to provision P and K.Across six soil types,post-harvest measurements of extractable-K showed an average 104%recovery of the quantities estimated to be provisioned by conifer wood or wheat straw biochars.Extractable-P recovery averaged 101%in two sandy soils with low P-retention but was considerably lower in four soils with higher P-retention capacity.Green-house data also showed that wheat growth improved only when biochar alleviated pH that was substantially below critical thresholds for plant growth,and supported the principle of using crop-specific pH requirements as part of an approach for biochar decision-support.Future field trials that evaluate yield responses in several nutrient-deficient or acidified soils will be needed to provide a robust evaluation of this DST.展开更多
基金the USDA Agricultural Research Service projects in the laboratories of K.M.T(2072-12620-001),C.L.P.(5030-12000-015),C.E.S(3012-11120-001),J.M.N.(6082-12630-001),and M.A.G.(3060-43440-016)a Grant from the Institute for Working Forest Landscapes at Oregon State University.
文摘Biochars can improve soil health but have been widely shown to reduce plant-available nitrogen(N)owing to their high carbon(C)content,which stimulates microbial N-immobilization.However,because biochars contain large amounts of C that are not microbially available,their total elemental C:N ratio does not correspond well with impacts on soil N.We hypothesized that impacts on soil plant-available N would relate to biochar mineralizable-C(C_(min))content,and that C:N ratios of the mineralizable biochar component could provide a means for predicting conditions of net soil N-mineralization or-immobilization.We conducted two laboratory experiments,the first measuring biochar C_(min)from respiration of isotopically labeled barley biochars manufactured at 300,500,and 750℃,and the second characterizing C_(min)by proxy measurements for ten biochars from six feedstocks at several temperatures.For both experiments,soils were incubated with 2%biochar by mass to determine impacts to soil N-mineralization.Contrary to expectation,all the biochars increased soil N-mineralization relative to unamended soils.Also unexpected,higher temperature(500 and 700℃)barley biochars with less C_(min)stimulated more soil decomposition and more soil N-mineralization than a 350℃barley biochar.However,across diverse biochar feedstocks and production methods,none of the biochar characteristics correlated with soil N-mineralization.The finding of improved soil N-mineralization adds complexity to the range of soil N responses that can be expected in response to biochar amendment.Because of the limited ability to predict soil N responses from biochar properties,users should monitor soil N to manage soil fertility.
基金The information in this document has been funded in part by the U.S.Environmental Protection Agency.
文摘The Oronogo-Duenweg mining belt is a designated United States Environmental Protection Agency Superfund site due to lead-contaminated soil and groundwater by former mining and smelting operations.Sites that have undergone remediation-in which the O,A,and B horizons have been removed alongside the lead contamination-have an exposed C horizon and are incalcitrant to revegetation efforts.Soils also continue to contain quantifiable Cd and Zn concentrations.To improve soil conditions and encourage successful site revegetation,our study employed three biochars,sourced from different feedstocks(poultry litter,beef cattle manure,and lodgepole pine),at two rates of application(2.5%,and 5%),coupled with compost(0%,2.5%and 5%application rates).Two plant species-switchgrass(Panicum virgatum)and buffalograss(Bouteloua dactyloides)-were grown in the amended soils.Amendment of soils with poultry litter biochar applied at 5%resulted in the greatest reduction of soil bioavailable Cd and Zn.Above-ground biomass yields were greatest with beef cattle manure biochar applied at 2.5%with 5%compost,or with 5%biochar at 2.5%and 5%compost rates.Maximal microbial biomass was achieved with 5%poultry litter biochar and 5%compost,and microbial communities in soils amended with poultry litter biochar distinctly clustered away from all other soil treatments.Additionally,poultry litter biochar amended soils had the highest enzyme activity rates forβ-glucosidase,N-acetyl-β-D-glucosaminidase,and esterase.These results suggest that soil reclamation using biochar and compost can improve mine-impacted soil biogeophysical characteristics,and potentially improve future remediation efforts.
基金USDA National Institute of Food and Agriculture[2018-67012-28080]U.S.Department of Agriculture,Agricultural Research Service(2072-12620-001)Oregon Wine Research Institute.
文摘In response to increasing concerns over climate change,soil health and wine quality,grape growers are seeking new practices(e.g.,biochar application)to minimize their environmental footprint while increasing productivity and the quality of their products.To explore the potential of biochar-based amendments to achieve these goals in wine grape production,vineyard trials were established in the fall of 2018.Two Oregon sites were chosen with distinct soil types and climates(Willamette Valley and Rogue Valley)but planted with the same grapevine scion/rootstock Pinot noir combination.Four treatments were applied under vines at each location:no biochar-no tillage(NT);no biochar+tillage(B0);18 tons ha^(−1)biochar+tillage(B18);35 tons ha^(−1)biochar+tillage(B35).In 2019,a suite of soil health,plant,and crop variables were measured,and wines were produced after harvest.The incorporation of biochar modified the chemical and physical composition of soils at the two studied locations,increasing the bioavailability of carbon and nitrogen,their gravimetric water content and the concentration of plant available micro and macro nutrients.No responses of plant physiology parameters or productivity at either site were found after biochar incorporation when compared with controls.Conversely,a significant and gradual decrease in the amount of wine tannins was found as a result of biochar application in wines produced from grapes from the Woodhall location.Long-term field experiments are required to assess the effects of biochar on soil properties,vine physiol-ogy,productivity,and grape and wine quality several years after incorporation.
基金This work was supported by the USDA Agricultural Research Service project in the laboratory of K.T(2072-12620-001-00D)the U.S.Department of the Interior under award JVA#16-JV-11261944-089 to C.P.and K.T.
文摘Meta-analyses have shown that only about half of biochar addition studies report improved plant growth.To improve yield response,here we describe a decision support tool(DST)for selecting a biochar type and amendment rate to meet soil and crop management goals,based on soil and biochar tests values and crop requirements as reported by regional extension recommendations.Using data from a greenhouse wheat trial,we assessed whether this approach could predict changes in soil chemistry and whether it could identify soils in which amendment would stimulate crop yield.These data indicated that the DST could provide semi-quantitative predictions of biochar amendment rates needed to meet target soil pH levels,with recommended rates averaging 25%higher than were needed.The DST was better at predicting biochar application rates to provision P and K.Across six soil types,post-harvest measurements of extractable-K showed an average 104%recovery of the quantities estimated to be provisioned by conifer wood or wheat straw biochars.Extractable-P recovery averaged 101%in two sandy soils with low P-retention but was considerably lower in four soils with higher P-retention capacity.Green-house data also showed that wheat growth improved only when biochar alleviated pH that was substantially below critical thresholds for plant growth,and supported the principle of using crop-specific pH requirements as part of an approach for biochar decision-support.Future field trials that evaluate yield responses in several nutrient-deficient or acidified soils will be needed to provide a robust evaluation of this DST.
