ABSTRACT It is expected, given the same water source applied to the same soil, that changes in so... more ABSTRACT It is expected, given the same water source applied to the same soil, that changes in soil chemistry would be subtle when comparing furrow and sprinkler irrigation practices. From four paired fields, we collected soil (after similar crops were harvested in September) from the 0-5 cm depth. Samples were analyzed for changes in soil P chemistry due to sprinkler or furrow irrigation using: 1) the Olsen soil test P extraction; 2) the alkaline phosphatase enzyme assay; 3) a sequential extraction technique which fractionated inorganic and organic soil P pools; and 4) a measure of the amorphous soil Al and Fe mineral phases. Olsen-extractable soil P was lower under sprinkler irrigation; however, this was not due to a reduction in microbial phosphatase activity. Soils under sprinkler irrigation contained lower inorganic P concentrations in soluble/Al-bound/Fe-bound and in the occluded phases, lesser amounts of organic P present in the moderately labile and non-labile fractions, and contained lower amorphous Fe concentrations. These results indicate that the method of water application affects soil chemistry and nutrient cycling.
A rising concern with the application of dairy wastes to agricultural fields is the accumulation ... more A rising concern with the application of dairy wastes to agricultural fields is the accumulation of copper (Cu) in the soil. Copper sulfate (CuSO 4) from cattle footbaths is washed out of dairy barns and into wastewater lagoons. The addition of CuSO 4 baths can increase Cu concentration significantly in manure slurry, from approximately 5.0 grams per 1,000 liters to 90.0 grams per 1,000 liters. The Cu-enriched dairy waste is then applied to agricultural crops, thus raising concerns about how soils and plants are impacted by these Cu additions.
The Cities of Littleton and Englewood, Colorado and the Colorado Agricultural Experiment Station ... more The Cities of Littleton and Englewood, Colorado and the Colorado Agricultural Experiment Station (project number 15-2924) funded this project. **Mention of a trademark or proprietary product does not constitute endorsement by the Colorado Agricultural Experiment Station.** Colorado State University is an equal opportunity/affirmative action institution and complies with all Federal and Colorado State laws, regulations, and executive orders regarding affirmative action requirements in all programs. The Office of Equal Opportunity is located in 101 Student Services. In order to assist Colorado State University in meeting its affirmative action responsibilities, ethnic minorities, women, and other protected class members are encouraged to apply and to so identify themselves.
Proceedings of the Water Environment Federation, 2007
The city of Fort Collins, Colorado owns 10,390 ha of semi-arid rangeland for the recycling of mun... more The city of Fort Collins, Colorado owns 10,390 ha of semi-arid rangeland for the recycling of municipal wastes via land application. In 1991, a study was initiated to determine the potential short-term impacts of water treatment residuals-biosolids coapplication on soils and vegetation. Treatments consisted of 10 Mg biosolids ha-1 coapplied with 5, 10, and 21 Mg water treatment residuals (WTR) ha-1 to 15 x 15 m plots. All treatments were replicated four times. In October 2002, the plots were divided in half with one half of each plot receiving rates identical to the 1991 application. Soils data was collected in June 2004 and June 2005, from the 0-8, 8-15, and 15-30-cm depths, to access the short-term impacts of a repeated co-application and the long-term impacts of a single application. Soil pH and electrical conductivity (EC) were relatively unaffected by coapplication. Soil NO 3-N increased with both increasing WTR and with the repeated application, while soil NH 4-N only increased in the soil surface. Total soil C and N increased in the soil surface with increasing co-application rate. Total surface-soil Cu, Cr, and Zn increased with increasing co-application and with repeated co-application. Total surface soil Ni increased with repeated co-application. Downward transport of both Mo and P indicated that these materials are translocated most likely as a WTRparticulate-bound phase.
The discovery of elevated fertility of the Amazonian The discovery of elevated fertility of the A... more The discovery of elevated fertility of the Amazonian The discovery of elevated fertility of the Amazonian The discovery of elevated fertility of the Amazonian The discovery of elevated fertility of the Amazonian Terra Preta Terra Preta Terra Preta Terra Preta soils was widely reported in the news soils was widely reported in the news soils was widely reported in the news soils was widely reported in the news media starting in 2006, coinciding with the initial public awareness of the existential threat of climate media starting in 2006, coinciding with the initial public awareness of the existential threat of climate media starting in 2006, coinciding with the initial public awareness of the existential threat of climate media starting in 2006, coinciding with the initial public awareness of the existential threat of climate change. Small groups of people worldwide seized on the idea of change. Small groups of people worldwide seized on the idea of change. Small groups of people worldwide seized on the idea of change. Small groups of people worldwide seized on the idea of Terra Preta Terra Preta Terra Preta Terra Preta and biochar as a climate and biochar as a climate and biochar as a climate and biochar as a climate solution, and began to publicize and act on the promise of biochar. Recently, a few individuals in Seattle, solution, and began to publicize and act on the promise of biochar. Recently, a few individuals in Seattle, solution, and began to publicize and act on the promise of biochar. Recently, a few individuals in Seattle, solution, and began to publicize and act on the promise of biochar. Recently, a few individuals in Seattle, WA (USA) started a group called "SeaChar" to inform the public about biochar and encourage its use. WA (USA) started a group called "SeaChar" to inform the public about biochar and encourage its use. WA (USA) started a group called "SeaChar" to inform the public about biochar and encourage its use. WA (USA) started a group called "SeaChar" to inform the public about biochar and encourage its use. Initially, they encountered skepticism about adding what most people considered to be fuel to soil. With Initially, they encountered skepticism about adding what most people considered to be fuel to soil. With Initially, they encountered skepticism about adding what most people considered to be fuel to soil. With Initially, they encountered skepticism about adding what most people considered to be fuel to soil. With no existing biochar trials in the region to point to, SeaChar decided to set up a scientific field trial at a no existing biochar trials in the region to point to, SeaChar decided to set up a scientific field trial at a no existing biochar trials in the region to point to, SeaChar decided to set up a scientific field trial at a no existing biochar trials in the region to point to, SeaChar decided to set up a scientific field trial at a local college as a way to learn for themselves whether biochar was valuable as a soil additive. This article local college as a way to learn for themselves whether biochar was valuable as a soil additive. This article local college as a way to learn for themselves whether biochar was valuable as a soil additive. This article local college as a way to learn for themselves whether biochar was valuable as a soil additive. This article reports on the results of that trial and some of the challenges encountered along the way. reports on the results of that trial and some of the challenges encountered along the way. reports on the results of that trial and some of the challenges encountered along the way. reports on the results of that trial and some of the challenges encountered along the way.
ABSTRACT Irrigated agriculture is an essential part of stable food and fiber production. However,... more ABSTRACT Irrigated agriculture is an essential part of stable food and fiber production. However, water returning from irrigated watersheds can contain excess sediment, nutrients and salts. Applying polyacrylamide to furrow irrigated fields reduces erosion 60 to 90%. Converting from furrow irrigation to sprinkler irrigation eliminates planned irrigation runoff necessary for uniform water application. Installing sediment ponds removes 50 to 80% of the suspended sediment from water before it flows back to major water bodies. In southern Idaho, irrigation watershed monitoring showed that implementing these conservation practices has reduced average suspended sediment loss from 460 kg/ha in 1970 to less than 100 kg/ha in 2005. These practices, however, have had less effect on soluble nutrients. Median nitrate concentrations have almost doubled from 1970 to 2005. Current research is focusing on identifying practices to reduce soluble nutrient losses.
This case study addresses where geographically soil addition of municipal organic wastes occurs a... more This case study addresses where geographically soil addition of municipal organic wastes occurs and how this addition affects soil profile development and the use of soils as a sustainable resource. Goal The goal of this application is for students to understand geographically where soil addition of municipal organic wastes occurs and how this addition affects soil profile development and the use of soils as a sustainable resource. Objectives Identify which constituents in organic wastes are of concern in terms of environmental pollution. Identify which constituents may lead to an improvement in profile development and soil sustainability Identify the effects of biota/organisms on soil formation. [Lesson map of application scenario on agroecosystems. Highlighted in red on the map are concepts addressed in this application lesson. Image courtesy of UNL, 2006.] Modules: Lesson home Learning Objectives The Situation The Problem Soil Horizons Soil Forming Processes Soil Orders Soil Function Recommendation Summar
Treatment Plant, Colorado and the Colorado Agricultural Experiment Station (project number 15-292... more Treatment Plant, Colorado and the Colorado Agricultural Experiment Station (project number 15-2924) funded this project.
provides equal opportunity in education and employment on the basis of race, color, national orig... more provides equal opportunity in education and employment on the basis of race, color, national origin, religion, sex, sexual orientation, age, disability, or status as a disabled veteran or Vietnam-era veteran, as required by state and federal laws.
The objective of this experiment was to evaluate the effects of Mo source (feed or water) on perf... more The objective of this experiment was to evaluate the effects of Mo source (feed or water) on performance and mineral status of cows and calves fed a forage-based diet for two years (DM basis: 6.6% CP; 0.14% S, 6.7 mg Cu/kg, 2.4 mg Mo/kg). Fifty-four cow-calf pairs were stratified by cow age, BW, and liver Cu and Mo status, and randomly assigned to one of six treatments. Treatments consisted of: 1) Negative control (NC; no supplemental Mo or Cu); 2) Positive control [PC: NC + Cu (3 mg Cu/kg diet DM from CuSO4·5H2O)]; 3) NC + 500 µg Mo/L from MoNa2O4·2H2O in drinking water (Mo 500-water); 4) NC + 1000 µg Mo/L of MoNa2O4·2H2O in drinking water (Mo 1000-water); 5) Mo 1000-water + 3 mg Cu/kg diet DM from CuSO4·5H2O (Mo 1000-water+Cu); and 6) NC + 3 mg Mo/kg diet DM from MoNa2O4·2H2O (3.0 Mo-diet). Cattle were allowed ad-libitum access to feed, water, and a protein supplement throughout the experiment. During the winter months animals were housed in three replicate pens per treatment and during the summer months animals were housed in separate pastures by treatment where cow and calf feed and water intake could be measured separately. Data were analyzed as a completely randomized block design. Throughout the experiment no signs of molybdenosis were observed. There was a treatment x time (P < 0.01) interaction for cow liver Cu concentrations. Cows not receiving supplemental Cu had lower (P < 0.01) liver Cu concentrations than cows receiving supplemental Cu. Cow and calf performance, calf mineral status, cow liver Mo, and plasma and milk Mo and Cu concentrations were similar across treatments. These data indicate that Mo supplemented in water or feed at concentrations used in this experiment had minimal impact on Cu status and overall animal performance.
Mineralized terranes (areas enriched in metal-bearing minerals) occur throughout the Western US, ... more Mineralized terranes (areas enriched in metal-bearing minerals) occur throughout the Western US, and are characterized by highly variable soil trace metal concentrations across small spatial scales. Assuming that non-lithologic (extrinsic) soil forming factors are relatively constant between mineralized and unmineralized zones, these mineralized areas allowed us to evaluate the effect of lithology on soil microbial activity. We established the following study sites: 1) sage-grassland on a Mo/Cu deposit (Battle Mountain, NV); 2) pine-chaparral on Ni/Cr bearing rocks (Chinese Camp, CA); and 3) two pine woodland sites on acid-sulfate altered rocks (Reno, NV; Bridgeport, CA). Microbial, physical and chemical measurements were performed on soils from undisturbed mineralized areas and adjacent unmineralized areas to determine baseline conditions for comparison to sites disturbed by mining. A host of abiotic soil parameters, along with bioavailable (diethylenetriaminepentaacetic acid (DTPA)-extractable) and total metals, were measured to examine their correlation with the following measures of microbial activity: enzyme assays (arylsulfatase, phosphatase, fluorescein diacetate hydrolysis), C/N mineralization potential, C substrate utilization (Biolog Ecoplate), and microbial biomass and community structure (phospholipid fatty acid analysis). Within the Battle Mountain study area, both microbial activity and structure were statistically similar between mineralized and unmineralized soils. Nutrient and metal concentrations were also similar; the only differences being higher Cu and lower P in the mineralized soils. Within the Chinese Camp study area, soil organic carbon and total nitrogen concentrations were similar between the serpentine (Ni/Cr bearing) and adjacent andesite soils, while differences were noted for other nutrients (S, P, Ca, Mg). For the serpentine soils, Co, Fe, Mn, and Ni showed the strongest correlations with microbial activity, where Cr, Mn showed the strongest correlations in the andesite soils. Measures of microbial activity were statistically similar, except for arylsulfatase and Biolog C substrate utilization, which were greater in the andesite soils. Biolog substrate utilization richness was greater for the andesite soils, which also showed greater fungal biomass compared to the serpentine soils. In the acid sulfate systems, most measures of microbial activity were reduced in the acid sulfate soils compared to the adjacent andesite soils. Lower pH and P, and greater Al concentrations in the acid sulfate soils are potential inhibitors of microbial activity, while greater concentrations of inorganic N suggest that N is not limiting in the acid sulfate soils. Biolog substrate utilization richness was much lower in the acid sulfate soils, which also exhibited a greater proportion of polymer and carbohydrate use compared to the andesite soils. Impacts on microbial activity and microbial community structure are depend on a combination of trace metal and nutrient concentrations within a given mineralization type. Improving our understanding of biotic/abiotic relationships in undisturbed systems should increase our understanding of these relationships in areas disturbed by mining.
Biochar is a fine-grained, carbon enriched product created when biomass (e.g. wood waste, manures... more Biochar is a fine-grained, carbon enriched product created when biomass (e.g. wood waste, manures) is bumed at relatively low temperatures (less than 1300°F) and under an anoxic (lack of oxygen) atmosphere. The process itself is called pyrolysis and is similar to the production of charcoal, yet the intent is generally to create biofuel with the concomitant production of the secondary product, biochar. Benefits of biochar addition to soils are recognized. Arnazonian dark earth soils, also known as terra preta, are charcoalenriched soils containing a high nutrient content from reduced leaching, likely a response of human-induced biochar accumulation. These soils, dating to between 450 BC and 950 AD, are unique to the Figure 1. Blochar product Continued on page 2 '.
ABSTRACT It is expected, given the same water source applied to the same soil, that changes in so... more ABSTRACT It is expected, given the same water source applied to the same soil, that changes in soil chemistry would be subtle when comparing furrow and sprinkler irrigation practices. From four paired fields, we collected soil (after similar crops were harvested in September) from the 0-5 cm depth. Samples were analyzed for changes in soil P chemistry due to sprinkler or furrow irrigation using: 1) the Olsen soil test P extraction; 2) the alkaline phosphatase enzyme assay; 3) a sequential extraction technique which fractionated inorganic and organic soil P pools; and 4) a measure of the amorphous soil Al and Fe mineral phases. Olsen-extractable soil P was lower under sprinkler irrigation; however, this was not due to a reduction in microbial phosphatase activity. Soils under sprinkler irrigation contained lower inorganic P concentrations in soluble/Al-bound/Fe-bound and in the occluded phases, lesser amounts of organic P present in the moderately labile and non-labile fractions, and contained lower amorphous Fe concentrations. These results indicate that the method of water application affects soil chemistry and nutrient cycling.
A rising concern with the application of dairy wastes to agricultural fields is the accumulation ... more A rising concern with the application of dairy wastes to agricultural fields is the accumulation of copper (Cu) in the soil. Copper sulfate (CuSO 4) from cattle footbaths is washed out of dairy barns and into wastewater lagoons. The addition of CuSO 4 baths can increase Cu concentration significantly in manure slurry, from approximately 5.0 grams per 1,000 liters to 90.0 grams per 1,000 liters. The Cu-enriched dairy waste is then applied to agricultural crops, thus raising concerns about how soils and plants are impacted by these Cu additions.
The Cities of Littleton and Englewood, Colorado and the Colorado Agricultural Experiment Station ... more The Cities of Littleton and Englewood, Colorado and the Colorado Agricultural Experiment Station (project number 15-2924) funded this project. **Mention of a trademark or proprietary product does not constitute endorsement by the Colorado Agricultural Experiment Station.** Colorado State University is an equal opportunity/affirmative action institution and complies with all Federal and Colorado State laws, regulations, and executive orders regarding affirmative action requirements in all programs. The Office of Equal Opportunity is located in 101 Student Services. In order to assist Colorado State University in meeting its affirmative action responsibilities, ethnic minorities, women, and other protected class members are encouraged to apply and to so identify themselves.
Proceedings of the Water Environment Federation, 2007
The city of Fort Collins, Colorado owns 10,390 ha of semi-arid rangeland for the recycling of mun... more The city of Fort Collins, Colorado owns 10,390 ha of semi-arid rangeland for the recycling of municipal wastes via land application. In 1991, a study was initiated to determine the potential short-term impacts of water treatment residuals-biosolids coapplication on soils and vegetation. Treatments consisted of 10 Mg biosolids ha-1 coapplied with 5, 10, and 21 Mg water treatment residuals (WTR) ha-1 to 15 x 15 m plots. All treatments were replicated four times. In October 2002, the plots were divided in half with one half of each plot receiving rates identical to the 1991 application. Soils data was collected in June 2004 and June 2005, from the 0-8, 8-15, and 15-30-cm depths, to access the short-term impacts of a repeated co-application and the long-term impacts of a single application. Soil pH and electrical conductivity (EC) were relatively unaffected by coapplication. Soil NO 3-N increased with both increasing WTR and with the repeated application, while soil NH 4-N only increased in the soil surface. Total soil C and N increased in the soil surface with increasing co-application rate. Total surface-soil Cu, Cr, and Zn increased with increasing co-application and with repeated co-application. Total surface soil Ni increased with repeated co-application. Downward transport of both Mo and P indicated that these materials are translocated most likely as a WTRparticulate-bound phase.
The discovery of elevated fertility of the Amazonian The discovery of elevated fertility of the A... more The discovery of elevated fertility of the Amazonian The discovery of elevated fertility of the Amazonian The discovery of elevated fertility of the Amazonian The discovery of elevated fertility of the Amazonian Terra Preta Terra Preta Terra Preta Terra Preta soils was widely reported in the news soils was widely reported in the news soils was widely reported in the news soils was widely reported in the news media starting in 2006, coinciding with the initial public awareness of the existential threat of climate media starting in 2006, coinciding with the initial public awareness of the existential threat of climate media starting in 2006, coinciding with the initial public awareness of the existential threat of climate media starting in 2006, coinciding with the initial public awareness of the existential threat of climate change. Small groups of people worldwide seized on the idea of change. Small groups of people worldwide seized on the idea of change. Small groups of people worldwide seized on the idea of change. Small groups of people worldwide seized on the idea of Terra Preta Terra Preta Terra Preta Terra Preta and biochar as a climate and biochar as a climate and biochar as a climate and biochar as a climate solution, and began to publicize and act on the promise of biochar. Recently, a few individuals in Seattle, solution, and began to publicize and act on the promise of biochar. Recently, a few individuals in Seattle, solution, and began to publicize and act on the promise of biochar. Recently, a few individuals in Seattle, solution, and began to publicize and act on the promise of biochar. Recently, a few individuals in Seattle, WA (USA) started a group called "SeaChar" to inform the public about biochar and encourage its use. WA (USA) started a group called "SeaChar" to inform the public about biochar and encourage its use. WA (USA) started a group called "SeaChar" to inform the public about biochar and encourage its use. WA (USA) started a group called "SeaChar" to inform the public about biochar and encourage its use. Initially, they encountered skepticism about adding what most people considered to be fuel to soil. With Initially, they encountered skepticism about adding what most people considered to be fuel to soil. With Initially, they encountered skepticism about adding what most people considered to be fuel to soil. With Initially, they encountered skepticism about adding what most people considered to be fuel to soil. With no existing biochar trials in the region to point to, SeaChar decided to set up a scientific field trial at a no existing biochar trials in the region to point to, SeaChar decided to set up a scientific field trial at a no existing biochar trials in the region to point to, SeaChar decided to set up a scientific field trial at a no existing biochar trials in the region to point to, SeaChar decided to set up a scientific field trial at a local college as a way to learn for themselves whether biochar was valuable as a soil additive. This article local college as a way to learn for themselves whether biochar was valuable as a soil additive. This article local college as a way to learn for themselves whether biochar was valuable as a soil additive. This article local college as a way to learn for themselves whether biochar was valuable as a soil additive. This article reports on the results of that trial and some of the challenges encountered along the way. reports on the results of that trial and some of the challenges encountered along the way. reports on the results of that trial and some of the challenges encountered along the way. reports on the results of that trial and some of the challenges encountered along the way.
ABSTRACT Irrigated agriculture is an essential part of stable food and fiber production. However,... more ABSTRACT Irrigated agriculture is an essential part of stable food and fiber production. However, water returning from irrigated watersheds can contain excess sediment, nutrients and salts. Applying polyacrylamide to furrow irrigated fields reduces erosion 60 to 90%. Converting from furrow irrigation to sprinkler irrigation eliminates planned irrigation runoff necessary for uniform water application. Installing sediment ponds removes 50 to 80% of the suspended sediment from water before it flows back to major water bodies. In southern Idaho, irrigation watershed monitoring showed that implementing these conservation practices has reduced average suspended sediment loss from 460 kg/ha in 1970 to less than 100 kg/ha in 2005. These practices, however, have had less effect on soluble nutrients. Median nitrate concentrations have almost doubled from 1970 to 2005. Current research is focusing on identifying practices to reduce soluble nutrient losses.
This case study addresses where geographically soil addition of municipal organic wastes occurs a... more This case study addresses where geographically soil addition of municipal organic wastes occurs and how this addition affects soil profile development and the use of soils as a sustainable resource. Goal The goal of this application is for students to understand geographically where soil addition of municipal organic wastes occurs and how this addition affects soil profile development and the use of soils as a sustainable resource. Objectives Identify which constituents in organic wastes are of concern in terms of environmental pollution. Identify which constituents may lead to an improvement in profile development and soil sustainability Identify the effects of biota/organisms on soil formation. [Lesson map of application scenario on agroecosystems. Highlighted in red on the map are concepts addressed in this application lesson. Image courtesy of UNL, 2006.] Modules: Lesson home Learning Objectives The Situation The Problem Soil Horizons Soil Forming Processes Soil Orders Soil Function Recommendation Summar
Treatment Plant, Colorado and the Colorado Agricultural Experiment Station (project number 15-292... more Treatment Plant, Colorado and the Colorado Agricultural Experiment Station (project number 15-2924) funded this project.
provides equal opportunity in education and employment on the basis of race, color, national orig... more provides equal opportunity in education and employment on the basis of race, color, national origin, religion, sex, sexual orientation, age, disability, or status as a disabled veteran or Vietnam-era veteran, as required by state and federal laws.
The objective of this experiment was to evaluate the effects of Mo source (feed or water) on perf... more The objective of this experiment was to evaluate the effects of Mo source (feed or water) on performance and mineral status of cows and calves fed a forage-based diet for two years (DM basis: 6.6% CP; 0.14% S, 6.7 mg Cu/kg, 2.4 mg Mo/kg). Fifty-four cow-calf pairs were stratified by cow age, BW, and liver Cu and Mo status, and randomly assigned to one of six treatments. Treatments consisted of: 1) Negative control (NC; no supplemental Mo or Cu); 2) Positive control [PC: NC + Cu (3 mg Cu/kg diet DM from CuSO4·5H2O)]; 3) NC + 500 µg Mo/L from MoNa2O4·2H2O in drinking water (Mo 500-water); 4) NC + 1000 µg Mo/L of MoNa2O4·2H2O in drinking water (Mo 1000-water); 5) Mo 1000-water + 3 mg Cu/kg diet DM from CuSO4·5H2O (Mo 1000-water+Cu); and 6) NC + 3 mg Mo/kg diet DM from MoNa2O4·2H2O (3.0 Mo-diet). Cattle were allowed ad-libitum access to feed, water, and a protein supplement throughout the experiment. During the winter months animals were housed in three replicate pens per treatment and during the summer months animals were housed in separate pastures by treatment where cow and calf feed and water intake could be measured separately. Data were analyzed as a completely randomized block design. Throughout the experiment no signs of molybdenosis were observed. There was a treatment x time (P < 0.01) interaction for cow liver Cu concentrations. Cows not receiving supplemental Cu had lower (P < 0.01) liver Cu concentrations than cows receiving supplemental Cu. Cow and calf performance, calf mineral status, cow liver Mo, and plasma and milk Mo and Cu concentrations were similar across treatments. These data indicate that Mo supplemented in water or feed at concentrations used in this experiment had minimal impact on Cu status and overall animal performance.
Mineralized terranes (areas enriched in metal-bearing minerals) occur throughout the Western US, ... more Mineralized terranes (areas enriched in metal-bearing minerals) occur throughout the Western US, and are characterized by highly variable soil trace metal concentrations across small spatial scales. Assuming that non-lithologic (extrinsic) soil forming factors are relatively constant between mineralized and unmineralized zones, these mineralized areas allowed us to evaluate the effect of lithology on soil microbial activity. We established the following study sites: 1) sage-grassland on a Mo/Cu deposit (Battle Mountain, NV); 2) pine-chaparral on Ni/Cr bearing rocks (Chinese Camp, CA); and 3) two pine woodland sites on acid-sulfate altered rocks (Reno, NV; Bridgeport, CA). Microbial, physical and chemical measurements were performed on soils from undisturbed mineralized areas and adjacent unmineralized areas to determine baseline conditions for comparison to sites disturbed by mining. A host of abiotic soil parameters, along with bioavailable (diethylenetriaminepentaacetic acid (DTPA)-extractable) and total metals, were measured to examine their correlation with the following measures of microbial activity: enzyme assays (arylsulfatase, phosphatase, fluorescein diacetate hydrolysis), C/N mineralization potential, C substrate utilization (Biolog Ecoplate), and microbial biomass and community structure (phospholipid fatty acid analysis). Within the Battle Mountain study area, both microbial activity and structure were statistically similar between mineralized and unmineralized soils. Nutrient and metal concentrations were also similar; the only differences being higher Cu and lower P in the mineralized soils. Within the Chinese Camp study area, soil organic carbon and total nitrogen concentrations were similar between the serpentine (Ni/Cr bearing) and adjacent andesite soils, while differences were noted for other nutrients (S, P, Ca, Mg). For the serpentine soils, Co, Fe, Mn, and Ni showed the strongest correlations with microbial activity, where Cr, Mn showed the strongest correlations in the andesite soils. Measures of microbial activity were statistically similar, except for arylsulfatase and Biolog C substrate utilization, which were greater in the andesite soils. Biolog substrate utilization richness was greater for the andesite soils, which also showed greater fungal biomass compared to the serpentine soils. In the acid sulfate systems, most measures of microbial activity were reduced in the acid sulfate soils compared to the adjacent andesite soils. Lower pH and P, and greater Al concentrations in the acid sulfate soils are potential inhibitors of microbial activity, while greater concentrations of inorganic N suggest that N is not limiting in the acid sulfate soils. Biolog substrate utilization richness was much lower in the acid sulfate soils, which also exhibited a greater proportion of polymer and carbohydrate use compared to the andesite soils. Impacts on microbial activity and microbial community structure are depend on a combination of trace metal and nutrient concentrations within a given mineralization type. Improving our understanding of biotic/abiotic relationships in undisturbed systems should increase our understanding of these relationships in areas disturbed by mining.
Biochar is a fine-grained, carbon enriched product created when biomass (e.g. wood waste, manures... more Biochar is a fine-grained, carbon enriched product created when biomass (e.g. wood waste, manures) is bumed at relatively low temperatures (less than 1300°F) and under an anoxic (lack of oxygen) atmosphere. The process itself is called pyrolysis and is similar to the production of charcoal, yet the intent is generally to create biofuel with the concomitant production of the secondary product, biochar. Benefits of biochar addition to soils are recognized. Arnazonian dark earth soils, also known as terra preta, are charcoalenriched soils containing a high nutrient content from reduced leaching, likely a response of human-induced biochar accumulation. These soils, dating to between 450 BC and 950 AD, are unique to the Figure 1. Blochar product Continued on page 2 '.
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