Chemistry and Bioavailability of Waste Constituents in Soils

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
133	1540	1060	40%
133	0110	2000	40%
133	0699	1060	20%

Progress 10/01/99 to 09/30/04

Outputs
In May 1997, we applied Denver Metro Wastewater District composted biosolids at rates of 0, 5, 10, 20, 40, and 80 Mg/ha to a severely burned, previously forested site near Buffalo Creek, CO. Following treatment over a 4 year period, total biomass of vegetation increased with increasing biosolids application and the percentage of bareground decreased. Higher rates of biosolids application produced higher concentrations of N, P, and Zn in tissue of the dominant plant species (Elymus lanceolatus [Scribn. & J.G. Sm] Gould ssp. lanceolatus) relative to controls. The highest biosolids application rate resulted in elevated C and N content of soils for only two years after application. We compared dryland hard-red winter wheat (Triticum aestivum L., Vona or TAM 107) and soil responses, in a summer fallow rotation system from a 40 dry Mg biosolids/ha rate per cropping (six to nine times larger than the agronomic rate) that we discontinued after five applications, to the control (0 Mg/ha) responses. We applied biosolids from the Littleton/Englewood, CO wastewater treatment plant to a Platner loam (Aridic Paleustoll) and a Weld loam (Aridic Argiustoll) soil. Using a split plot in time design for each site, we found that by the third cropping following cessation the discontinued biosolids treatment produced statistically consistent decreasing trends for grain P, Zn, and Cu concentrations, N, Zn and Cu uptake (grain removal), EC, and surface soil nitrate-N, organic C and total N. We determined if a single surface biosolids application at 0 and 40 Mg/ha to a shrubland site and 0 and 30 Mg/ha to a grassland site affected the percentage of root samples of western wheatgrass (Pascopyrum smithii (Rydb.) A. Love) and blue grama (Bouteloua gracilis (H.B.K.) Lag. ex steud) colonized by arbuscular mycorrhizal (AM) fungi 5 or 6 years later. Western wheatgrass (shrubland site) showed a 33% significant increase and blue grama (grassland site) a 23% significant increase in the percentage of root samples colonized by AM fungi in soils receiving biosolids as compared to unamended soil. Biosolids application produced a significant increase in basal root respiration and metabolic quotient on the shrubland site and created a significant increase (11 to 25%) in active microbial biomass at both sites. We treated water-treatment residuals (WTR) with inorganic P to its adsorption capacity of approximately 10 g P/kg WTR. We followed with desorption of the treated WTR by shaking in 0.01 M calcium chloride for 1d, 2d, 4d, 7d, 14d, 28d, 84 d, and 211d. These batch studies suggested solid octacalcium phosphate formation as the P adsorbing mechanism. X-ray diffraction and electron microprobe analysis using wavelength dispersive spectroscopy results indicated that surface P chemisorption as an amorphous surface mineral phase might occur. Co-application of WTR and sewage biosolids provides municipalities with recycling options. With co-application of WTR and biosolids, we found inconsistent effects on two range grasses grown in the greenhouse. Also, WTR:biosolids of 8:1 adsorbed all of the biosolids available P.

Impacts
Our studies show that long-term recycling of biosolids and water treatment residuals on dryland wheat, rangeland, and wildfire-burn areas is socially, environmentally, and economically sustainable. The wildfire-revegetation study results suggest that the application of biosolids can provide quick establishment of vegetative cover to prevent soil erosion and will affect plant biomass and canopy cover for three years after application. Scientifically, these results provide new information on recovery from biosolids overapplication and on the effects of WTR-biosolids application to shrub- or grassland on soil chemical characteristics.

Publications

Barbarick, K. A. 2004. Lecture Notes for Introductory Soil Science. Eighth Edition. Pearson Publishing Co., Boston, MA.
Barbarick, K.A., and Ippolito, J.A. 2004. An Infiltration Exercise for Introductory Soil Science. Agronomy Abstracts. American Society of Agronomy. Madison, WI.
Barbarick, K.A., Doxtader, K.G., Redente, E.F., and Brobst, R.B. 2004. Biosolids effects on microbial activity in shrubland and grassland soils. Soil Sci. 169:176-187.
Barbarick, K.A., Ippolito, J.A., and Peterson, G.A. 2004. Biosolids application to no-till dryland crop rotations: 2002 results. Colorado Agricultural Experiment Station Technical Report. TR04-4.
Barbarick, K.A., Ippolito, J.A., and Peterson, G.A. 2004. Biosolids application to no-till dryland cropping systems. Sustainable Land Application Conference. Lake Buena Vista, FL. January 4-8, 2004.
Bayley, R.M., Ippolito, J.A., Stromberger, M.E. ,and Barbarick, K.A. 2004. The Effect of Long-Term Water Treatment Residuals-Biosolids Co-Applications on Native Rangeland Soil Phosphorus. Agronomy Abstracts. American Society of Agronomy. Madison, WI.
Brobst, R.B., Meyer, V.F., Redente, E.F, Barbarick, K.A., Paschke, M.W., Miller, A.L. 2004. Ecosystem responses to biosolids application following forest fire. Sustainable Land Application Conference. Lake Buena Vista, FL. January 4-8, 2004.
Brobst, R.B., Meyer, V.F., Redente, E.F., Barbarick, K.A., Paschke, M.W., Miller, A.L. 2004. Vegetation Responses to Biosolids Application Following Forest Fire. 18th Annual Residuals and Biosolids Management Conference. Water Environment Federation. Salt Lake City, UT, USA,. February 22-25, 2004.
Freeman, C.L., Ippolito, J.A., Barbarick, K.A., and Brooks, K.R. 2004. Mobility and Fate of Metals in Long-Term Biosolids Field Experiments. American Society of Agronomy. Madison, WI.
Green, C.H. 2004. Phosphorus Impact on Vegetative Filter Strips and Water Treatment Residuals. Ph.D. Thesis, Colorado State University.
Ippolito, J., Barbarick, K.A., and Gourd, T. 2004. Application of anaerobically digested biosolids to dryland winter wheat. Colorado Agricultural Experiment Station Technical Report. TR04-6.
Ippolito, J.A., Barbarick, K.A., and Stromberger, M.E. 2004. Effects of Long-Term Biosolids Applications on Soil Carbon and Nitrogen Dynamics. Agronomy Abstracts. American Society of Agronomy. Madison, WI.
Meyer, V.F., Redente, E.F., Barbarick, K. A., Brobst, R.B., Paschke, M.W., and Miller, A.L. 2004. Plant and soil responses to biosolids application following forest fire. J. Environ. Qual. 33:873-881.
Ippolito, J., Bayley, R., Stromberger, M., and Barbarick, K. 2004. The effect of Long-Term Water Treatment Residuals/Biosolids Co-Application on Rangeland Soil Phosphorus RMSAWWA/RMWEA Joint Annual Conference. Grand Junction, CO. Sept. 12-15, 2004.

Progress 01/01/03 to 12/31/03

Outputs
We studied the sorption of selenate and selenite by water treatment residuals (WTR) with respect to pH. Experiments were conducted in 0.05 M NaCl with a Se concentration comparable to that found in contaminated soils. Solution pH was varied from 5 to 9. In addition, we conducted the selenite experiment under a nitrogen gas atmosphere to control redox. We found selenate sorption decreased with increasing pH, most likely due to increasing net negative charge on WTR. However, the selenite sorption increased with increasing pH, and may be due to the possible presence of calcium carbonate in WTR. In May 1997, we applied Denver Metro Wastewater District composted biosolids at rates of 0, 5, 10, 20, 40, and 80 Mg ha(-1) to a severely burned, previously forested site near Buffalo Creek, CO. Vegetation and soils data were collected for four years following treatment. Following treatment, total biomass of vegetation increased with increasing biosolids application and the percentage of bareground decreased. Higher rates of biosolids application were associated with increased concentrations of N, P, and Zn in tissue of the dominant plant species (Elymus lanceolatus [Scribn. & J.G. Sm] Gould ssp. lanceolatus) relative to controls. The highest biosolids application rate resulted in elevated C and N content of soils for only two years after application. In another study, our overall goal is to determine the long-term distribution, extractability, mobility, and accountability of biosolids-borne metals applied to both an agricultural and rangeland system. We will utilize a sequential extraction procedure to identify labile through resistant trace metal pools. In addition, we will separate the clay fraction and identify trace metal mineral phases using SEM-EDS. In a greenhouse study using simulated buffer strips, we determined the efficacy of WTR to increase the removal of P in surface runoff. Modeling using OPUS2 indicated that about a 10 mm soil-cover thickness of WTR was needed to remove P in an overland-flow system. We found that ceasing biosolids application at six to nine times the recommended rate in a dryland-wheat fallow agroecosystem that the P and Zn plant-availability approaches the untreated control levels within three croppings. We are studying the long-lasting effects of a single water treatment residuals-biosolids co-application and the short-term impacts of a repeated application on soil phosphorus dynamics. Specifically, we will determine organic P mineralization rates, which organic or inorganic P pools dominate P equilibrium (WTR-sorbed, organic, water soluble, bioavailable, various P precipitates), and shifts between these pools over time under co-application conditions.

Impacts
Our studies show that long-term recycling of biosolids and water treatment residuals on dryland wheat, rangeland, and wildfire-burn areas is socially, environmentally, and economically sustainable. The wildfire-revegetation study results suggest that the application of biosolids can provide quick establishment of vegetative cover to prevent soil erosion and will affect plant biomass and canopy cover for three years after application. Scientifically, these results provide new information on recovery from biosolids overapplication and on the effects of WTR-biosolids application to shrub- or grassland on soil chemical characteristics.

Publications

Barbarick, K.A., and Ippolito, J.A. 2003. Termination of sewage biosolids application affects wheat yield and other agronomic characteristics. Agron. J. 95:1288-1294.
Barbarick, K.A., and Ippolito, J.A. 2003. Use of handheld moisture-measuring devices in Introductory Soil Science. Agronomy Abstracts. American Society of Agronomy. Madison, WI.
Barbarick, K. A., Doxtader, K. G., and Ippolito, J.A. 2003. Laboratory Manual for Introductory Soil Science. Eighth Edition. Pearson Publishing Co., Boston, MA.
Barbarick, K.A., Ippolito, J.A., and Peterson, G.A.. 2003. Biosolids application to no-till dryland crop rotations. Colorado Agricultural Experiment Station Technical Report. TR03-5.
Eghball, B., and Barbarick, K.A. 2002. Manure, Compost, and Biosolids. In Encyclopedia of Soil Science. R. Lal (ed.). Marcel Dekker, Inc. New York.
Green, C.H., Barbarick, K.A, Smith, R.E., Butters, G.L., Davis, J.G., Heil, D.M., Ippolito, J.A., and Loftis, J. 2003. Water treatment residual and vegetative filter strip effects on phosphorus runoff dynamics. Agronomy Abstracts. American Society of Agronomy. Madison, WI.
Ippolito, J.A., and Barbarick, K.A. 2003. A simple C/N assay for Introductory Soil Science classes. J. Nat. Res. Life Sci. Educ.32:69-72.
Ippolito, J.A., Barbarick, K.A, and Green, C.H. 2003. Can water treatment residuals adsorb selenium. Agronomy Abstracts. American Society of Agronomy. Madison, WI.
Ippolito, J., Barbarick, K.A, and Gourd, T.. 2003. Application of anaerobically digested biosolids to dryland winter wheat. Colorado Agricultural Experiment Station Technical Report. TR03-6.
Ippolito, J.A., Barbarick, K.A, Heil, D.M., Chandler, J.P., and Redente, E.F. 2003. Possible phosphorus retention mechanisms of a water treatment residual. J. Environ. Qual. 32:1857-1864.
AL-Sheikh, A. 2003. Potential use of variety and crop rotation as tools for agricultural sustainability. Ph.D. Thesis. Colorado State University.
Al-Sheikh, A., Delgado, J.A., Barbarick, K.A., Sparks, R., Dillon, M., Qian, Y., and Cardon, G.E. 2003. Mass balances and relationships between carbon, nitrogen, and phosphorus in high altitude coarse sandy soils. Agronomy Abstracts. American Society of Agronomy. Madison, WI.
Al-Wabel, M.A., Heil, D.M., Westfall, D.G., and Barbarick, K.A.. 2002. Solution chemistry influence on metal mobility in biosolids-amended soils. J. Environ. Qual. 31:1157-1165.
Barbarick, K.A., and Ippolito, J.A. 2003. Does the number of hours studied affect exam performances? J. Nat. Res. Life Sci. Educ. 32:32-35.

Progress 01/01/02 to 12/31/02

Outputs
Determining the time required for recovery of sites that receive excessive sewage biosolids can help manage private or public lands and estimate site-life. We compared dryland hard-red winter wheat (Triticum aestivum L., Vona or TAM 107) and soil responses, in a summer fallow rotation system from a 40 dry Mg biosolids /ha rate per cropping (six to nine times larger than the agronomic rate) that we discontinued after five applications, to the control (0 Mg /ha) responses for 3 croppings following discontinuation. We applied biosolids from the Littleton/Englewood, CO wastewater treatment plant to a Platner loam (Aridic Paleustoll) and a Weld loam (Aridic Argiustoll) soil at sites A and B, respectively. Using a split plot in time design for each site, we found that by the third cropping following cessation the discontinued biosolids treatment produced statistically the same wheat-grain yields, N and P uptake, surface ammoniumbicarbonate-diethylenetriaminepentaacetic acid (AB-DTPA) extractable P, Zn, and Cu, and the electrical conductivity of a saturated-soil-paste extract (EC), and soil nitrate-N in the 20-60-cm soil depth at site A, and surface AB-DTPA extractable P and Zn at both sites. We did not observe consistent trends for grain P, Zn, and Cu concentrations, N, Zn and Cu uptake (grain removal), EC, and surface soil nitrate-N, organic C and total N. Another concern regarding land application of biosolids is their impact on soil microbial activity. We determined that a single surface biosolids application at 40 Mg /ha to a shrubland site and 30 Mg /ha to a grassland site affected the percentage of root samples of western wheatgrass (Pascopyrum smithii (Rydb.) A. Love) and blue grama (Bouteloua gracilis (H.B.K.) Lag. ex steud) colonized by arbuscular mycorrhizal (AM) fungi 5 or 6 years later. We also ascertained the biosolids effects on microbial basal respiration rate (BRR), metabolically active microbial biomass C, and metabolic quotient for soils at the two sites. Western wheatgrass (shrubland site) showed a 33% significant increase and blue grama (grassland site) a 23% significant increase in the percentage of root samples colonized by AM fungi in soils receiving biosolids as compared to unamended soil. Biosolids application produced a significant increase in BRR and metabolic quotient on the shrubland site and created a significant increase (11 to 25%) in active microbial biomass at both sites. In a shrubland and a grassland ecosystem, we concluded that single biosolids addition increased mycorrhizal infections and did not adversely affect the biomass or activity of the microbial community.

Impacts
These results provide economic benefit to cities since land application provides a relatively inexpensive means of biosolids recycling. Our studies show that long-term recycling of biosolids on dryland wheat and native vegetation is socially, environmentally, and economically sustainable since recovery from overapplication appears to occur within a few cropping cycles and land application does not appear to have deleterious effects on soil microorganisms. Scientifically, these results provide new information on recovery from biosolids overapplication and on the long-term effects of single biosolids application to shrub- or grassland on soil microorganisms.

Publications

Barbarick, K.A., and J.A. Ippolito. 2002. Does the number of hours studied affect exam performance? Agron. Abstracts. American Society of Agronomy. Madison, WI.
Green, C.H., K.A. Barbarick, G. Butters, D.M. Heil. 2002. The impact of vegetative filter strips and water treatment residuals on phosphorus runoff. Agron. Abstracts. American Society of Agronomy. Madison, WI.
Ippolito, J.A., K.A. Barbarick, and E.F. Redente. 2002. Combinations of water treatment residuals and biosolids affect on two range grasses. Comm. Soil Sci. Plant Anal. 33:831-844.
Ippolito, J., K.A. Barbarick, and T. Gourd. 2002. Application of anaerobically digested biosolids to dryland winter wheat. Colorado Agricultural Experiment Station Technical Report. TR02-5.
Ippolito, J.A., and K.A. Barbarick. 2002. A simple C/N assay for Introductory Soil Science. American Society of Agronomy. Madison, WI.
Ippolito, J.A., and K.A. Barbarick. 2002. Phosphorus extraction methods from water treatment residual-amended soil. American Society of Agronomy. Madison, WI.

Progress 01/01/01 to 12/31/01

Outputs
Water-treatment residuals (WTR) can adsorb large quantities of P; thus, they can possibly be used to mitigate P input into fresh-water systems from over application of sewage biosolids or from runoff from large feedlots. One unanswered question is how stable is the adsorption of P onto WTR? We treated WTR with inorganic P to its adsorption capacity of approximately 10 g P/kg WTR. We followed with desorption of the treated WTR by shaking in 0.01 M calcium chloride for 1d, 2d, 4d, 7d, 14d, 28d, 84 d, and 211d. These batch studies suggested solid octacalcium phosphate formation as the P adsorbing mechanism. X-ray diffraction and electron microprobe analysis using wavelength dispersive spectroscopy results indicated that surface P chemisorption as an amorphous surface mineral phase might occur. We continued our study to determine how the long-term, continuous application of Littleton/Englewood biosolids affects the agronomic rate. We are using biosolids rates of 0, 2.24, 4.48, 6.72, 8.96, and 11.2 Mg/ha and N fertilizer rates of 0, 22.4, 44.8, 67.2, 89.6, and 112 kg/ha applied over seven years to Weld loam (Aridic Paleustoll) soils growing dryland wheat (Triticum aestivum L. Vona or TAM107). Another interesting challenge is to incorporate biosolids application into no-till crop rotations. We usually incorporate biosolids in land-application programs. In the summer of 1999 we established crop rotations consisting of wheat-fallow, wheat-corn-fallow, and wheat-wheat-corn-sunflowers-fallow on land owned by the cities of Littleton and Englewood near Byers, CO. We will compare biosolids versus N fertilizer at "agronomic rates" within each rotation A large problem following wildfires is the rapid reestablishment of vegetative cover to reduce soil erosion. In 1997, we established a research site in the Buffalo-Creek wildfire burn area in Jefferson County, CO where we applied and incorporated Denver Metro composted biosolids at rates of 0, 5, 10, 20, 40, and 80 Mg/ha followed by seeding with a US Forest Service approved mixture. Five growing seasons following biosolids addition we again found a significant linear effect of biosolids on biomass production and plant canopy cover; however, production levels were smaller due to another unusually dry growing season.

Impacts
These results provide economic benefit to cities since land application provides the less expensive means of biosolids recycling. Our studies show that long-term recycling of biosolids on dryland wheat and wildfire-burn areas is socially, environmentally, and economically sustainable. The wildfire-revegetation study results suggest that the application of biosolids can provide quick establishment of vegetative cover to prevent soil erosion and will affect plant biomass and canopy cover for four growing seasons after application.

Publications

Barbarick, K.A., and Ippolito, J.A. 2001. Wheat grain and soil changes following termination of sewage biosolids application. Colorado Agricultural Experiment Station Technical Bulletin. TB01-1.
Ippolito, J.A., and Barbarick, K.A. 2001. Environmental management of biosolids and water treatment residuals. WEF/AWWA/CWEA Joint Residuals and Biosolids Management Conference Proceedings Biosolids 2001: "Building Public Support" proceedings. Feb. 21-25. San Diego, CA.
Ippolito, J.A. 2001. Phosphorus Adsorption/Desorption of Water Treatment Residuals and Biosolids Co-application Effects. Ph.D. Dissertation, Colorado State University.
Ippolito, J.A., and Barbarick, K.A. 2001. Water treatment residual phosphorus adsorption mechanisms. Agron. Abstracts. American Society of Agronomy. Madison, WI.
Ippolito, J., Barbarick, K.A., and Gourd, T. 2001. Application of anaerobically digested biosolids to dryland winter wheat. Colorado Agricultural Experiment Station Technical Report. TR01-5.
Meyer, V.F., Redente, E.F., Barbarick, K.A., and Brobst, R. 2001. Biosolids application affect runoff water quality following forest fire. J. Environ. Qual. 30:1528-1532.

Progress 01/01/00 to 12/31/00

Outputs
Water-treatment residuals (WTR) can adsorb large quantities of P; thus, they can possibly be used to mitigate P input into fresh-water systems from over application of sewage biosolids or large feedlots. One unanswered question is how stable is the adsorption of P onto WTR. We treated WTR with inorganic P to its adsorption capacity of approximately 10 g P kg/ha 1 WTR. We followed desorption while shaking in 0.01 M CaCl2 for 1d, 2d, 4d, 1 wk, 2 wk, 4 wk, and 3 mo. We found that solution Al and Ca concentrations increased and solution P content decreased as time of shaking increased. Our WTR desorption studies show that adsorbed P is held tightly and may transform to even more stable forms over 3 mo. We continued our study to determine how the long-term, continuous application of Littleton/Englewood biosolids affects the agronomic rate. We are using biosolids rates of 0, 2.24, 4.48, 6.72, 8.96, and 11.2 Mg/ ha and N fertilizer rates of 0, 22.4, 44.8, 67.2, 89.6, and 112 kg/ha applied over seven years to Weld loam (Aridic Paleustoll) soils growing dryland wheat (Triticum aestivum L. Vona or TAM107). Another interesting challenge is to incorporate biosolids application into no-till crop rotations. We usually incorporate biosolids in land-application programs. In summer 1999, we established crop rotations consisting of wheat-fallow, wheat-corn-fallow, and wheat-wheat-corn-sunflower-fallow on land owned by cities of Littleton and Englewood near Byers, CO. We will compare biosolids versus N fertilizer at "agronomic rates" within each rotation. Wheat, corn, and sunflower yields for 2000 were small since we established our plots in a field following a wheat crop that had been lost to hail damage. A large problem following wildfires is the rapid reestablishment of vegetative cover to reduce soil erosion. In 1997, we established a research site in the Buffalo-Creek wildfire burn area in Jefferson County, CO where we applied and incorporated Denver Metro composted biosolids at rates of 0, 5, 10, 20, 40, and 80 Mg/ha followed by seeding with an US Forest Service approved mixture. Following four growing seasons of biosolids addition, we again found a significant linear effect of biosolids on biomass production and plant canopy cover; however, production levels were smaller due to the unusually dry growing season.

Impacts
These results provide economic benefit to cities since land application provides the less expensive means of biosolids recycling. Our studies show that long-term recycling of biosolids on dryland wheat and wildfire-burn areas is socially, environmentally, and economically sustainable. The wildfire-revegetation study results suggest that the application of biosolids can provide quick establishment of vegetative cover to prevent soil erosion and will affect plant biomass and canopy cover for four growing seasons after application.

Publications

Barbarick, K. A. 2000. Lecture Notes for Introductory Soil Science. Seventh Edition. Pearson Publishing Co., Boston, MA.
Barbarick, K.A., and Ippolito, J.A. 2000. Nitrogen fertilizer equivalency of sewage biosolids applied to dryland winter wheat. J. Environ. Qual. 29: 1345-1351.
Ippolito, J.A., and Barbarick, K.A. 2000. Modified nitric acid plant tissue digest method. Comm. Soil Sci. Plant Anal. 31:2473-2482.
Ippolito, J., Barbarick, K.A., and Jepson, R. 2000. Application of anaerobically digested biosolids to dryland winter wheat. Colorado Agricultural Experiment Station Technical Report. TR00-5.
Ippolito, J.A., and Barbarick, K.A. 2000. Phosphorus desorption from a water treatment residual. Agron. Abstracts. American Society of Agronomy. Madison, WI, p. 43.
Pierce, B.L. 2000. Microbial Responses to Biosolids Treatment of Rangelands. Ph.D. Thesis. Colorado State University. Fort Collins, CO.

Progress 01/01/99 to 12/31/99

Outputs
Co-application of water-treatment residuals (WTR) and sewage biosolids provides municipalities with recycling options. The WTR can adsorb large quantities of P; thus, potentially reducing the overapplication of P associated with the biosolids. Too much WTR in the mixture; however, can adsorb all of the biosolids-borne P. With co-application of WTR and biosolids, we found inconsistent effects on two range grasses grown in the greenhouse. Also, WTR:biosolids of 8:1 adsorbed all of the biosolids available P. One of the greatest challenges regarding land-application of sewage biosolids for beneficial use is determining the agronomic rate. Generally, we base this rate on the N released for plant use. Using Littleton/Englewood biosolids rates of 0, 2.24, 4.48, 6.72, 8.96, and 11.2 Mg ha(-1) and N fertilizer rates of 0, 22.4, 44.8, 67.2, 89.6, and 112 kg ha-1 applied over six years to Weld loam (Aridic Paleustoll) soils growing dryland wheat (Triticum aestivum L. Vona or TAM107), we found that for application of 1 dry Mg of L/E biosolids before each planting delivered an equivalent of about 8.2 kg N fertilizer with each application. In an associated greenhouse study, we learned that a single application of an agronomic rate of biosolids provided N carryover for only one additional cropping. We adopted a new HNO(3)-digestion procedure that allows a convenient time for digestion of easily-solubilized to recalcitrant plant material. The new procedure will greatly speed our completion of plant-tissue analyses. A large problem following wildfires is the rapid reestablishment of vegetative cover to reduce soil erosion. In 1997, we established a research site in the Buffalo-Creek wildfire burn area in Jefferson County, CO where we applied and incorporated Denver Metro composted biosolids at rates of 0, 5, 10, 20, 40, and 80 Mg ha-1 followed by seeding with an US Forest Service approved mixture. We found a significant linear effect of biosolids on biomass production and plant canopy cover.

Impacts
These results provide economic benefit to cities since land application provides the less expensive means of biosolids recycling. Knowing the N equivalency of biosolids compared with N fertilizer will allow cities to apply the biosolids at an agronomic rate. Our studies show that long-term recycling of biosolids on dryland wheat and wildfire-burn areas is socially, environmentally, and economically sustainable.

Publications

BARBARICK, K. A., K. G. DOXTADER, AND J.A. IPPOLITO. 1999. Laboratory Manual for Introductory Soil Science. Seventh Edition. Burgess Publishing Co., Minneapolis, MN.
BAUDER, T.A., K.A. BARBARICK, J.F. SHANAHAN, P. AYERS, AND P. CHAPMAN. 1999. Drilling-fluid (mud) effects on sorghum-sudangrass growth and Fe availability. J. Environ. Qual. 28:744-749.
IPPOLITO, J.A., AND K.A. BARBARICK. 1999. A modified nitric acid plant tissue digest. Agron. Abstracts. American Society of Agronomy. Madison, WI, p. 30.
IPPOLITO, J.A., K.A. BARBARICK, AND E.F. REDENTE. 1999. Co-application effects of water treatment residuals and biosolids on two range grasses. J. Environ. Qual. 28:1644-1650.
IPPOLITO, J., K.A. BARBARICK, AND R. JEPSON. 1999. Application of anaerobically digested biosolids to dryland winter wheat. Colorado Agricultural Experiment Station Technical Report. TR99-8.

Progress 01/01/98 to 12/31/98

Outputs
We consider trace-elements added in sewage biosolids (sewage sludge) to accumulate in the soil surface without significant transport below the plow layer. We used 11 years of field-study information from biosolids addition to dryland hard red winter wheat (Triticum aestivum L. 'Vona' or 'TAM107') to determine the distribution of NH(4)HCO(3)- diethylenetriaminepentaacetic acid (AB-DTPA) extractable Cd, Cr, Cu, Mo, Ni, Pb, and Zn in in soil depths to 150 cm. We applied five or six applications of biosolids from the cities of Littleton and Englewood, CO to Weld loam (Aridic Paleustoll) or Platner loam (Aridic Paleustoll) at four locations. We focused on the 0 (control), the 56- or 67-kg/ha N fertilizer rates, and the 6.7 and 26.8 Mg/ha biosolids rates that we added every crop year. We observed significant (p<0.10) accumulations of the trace elements in the plow layer of the biosolids-amended soils. Only Zn showed consistent increases in extractable levels below the plow layer at all four sites. The biosolids Zn concentration (average of about 1300 Mg/kg) was larger than any other trace element resulting in larger loading of this element. We also investigated the effect of surface-applied biosolids on the canopy cover, aboveground production, and nutrient status of native species in a sagebrush community in western Colorado. Biosolids were applied once in 1991 at nine rates consisting of 0, 5, 10, 15, 20, 25, 30, 35, and 40 Mg/ha to plots measuring 3320 m2. Biosolids application increased the biomass of perennial grasses up to 300% at 25 Mg/ha treatment rates in 1993. Biosolids amendment also affected the quality of grass forage through a change in the Cu:Mo ratios. Prior to the application of biosolids, western wheatgrass (Agropyron smithii Rydb.), bluebunch wheatgrass (Agropyron spicatum (Pursch) Scribn. & Smith), and Indian ricegrass (Oryzopsis hymenoides (R. & S.) Ricker)had Cu:Mo ratios below 1.2:1, which is known to cause Mo-induced Cu deficiencies in cattle (Bovis abortus), sheep (Ovis aries), and some wild ruminants. Biosolids treatment raised the Cu:Mo ratio above 2:1 for western wheatgrass and bluebunch wheatgrass one year following application at low rates and two years following amendment at intermediate application rates. The Cu:Mo ratio of Indian ricegrass also was increased above 2:1 two years following surface application at intermediate biosolids application rates. These results provide economic benefit to cities since land application provides the less expensive means of biosolids recycling. The AB-DTPA soil extraction procedure allows monitoring of plant nutrients and trace metals in a single extractant. Our studies show that long-term recycling of biosolids on dryland wheat and rangeland is socially, environmentally, and economically sustainable. The scientific impact of our research indicates that the AB-DTPA extractant is a better tool than the more commonly used 4M HNO(3) extraction for monitoring soil accumulation of trace elements. The rangeland study results suggest that the application of biosolids can improve forage availability and nutritional value of some native grasses for livestock and wildlife consumption.

Impacts
(N/A)

Publications

BARBARICK, K.A.,IPPOLITO, J.A., AND WESTFALL, D.G. 1998. Extractable elements in the soil profile after years of biosolids application. J. Environ. Qual. 27:801-805.
BARBARICK, K., J. IPPOLITO, AND D. WESTFALL. 1998. Distribution of extractable trace elements in the soil profile after several years of biosolids application. In Great Plains Soil Fertility Conference Proceedings. Volume 7. Denver, CO.
BARBARICK, K.A., AND IPPOLITO, J.A. 1998. Mineralization rates for repeated biosolids application. Agron. Abstracts. American Society of Agronomy. Madison, WI, p. 343.
BARBARICK, K.A. 1998. Exam frequency comparison in Introductory Soil Science. J. Nat. Resour. Life Sci. Educ. 27:55-58.
IPPOLITO, J., BARBARICK, K.A., AND JEPSON, R. 1998. Application of anaerobically digested biosolids to dryland winter wheat. Colorado Agricultural Experiment Station Technical Report. TR98-4.
PIERCE, B.L., REDENTE, E.F., BARBARICK, K.A., BROBST, R.B., AND HEGEMAN, P. N. 1998. Plant biomass and elemental changes in shrubland forages following biosolids application. J. Environ. Qual. 27:789-794.

Progress 01/01/97 to 12/31/97

Outputs
The United States Environmental Protection Agency encourages land application of sewage biosolids (sewage sludge) for beneficial use, but they have established strict guidelines regarding this practice. Consequently, we have investigated the effects of biosolids on dryland wheat production and associated environmental concerns. These studies have continued for 16 years. We utilize study sites on two farms in eastern Adams County, Colorado to determine the effects of Littleton/Englewood biosolids on yields, protein, and elemental content of dryland hard red winter wheat (Triticum aestivum L. cv. TAM107) and on soil chemical properties as compared to NH(4)NO(3) fertilizer. Biosolids application ranged from 0 to 27 Mg/ha and N fertilizer ranged from 0 to 134 kg per hectare. The soils at our four dryland wheat sites were Aridic Paleustolls (Weld and Platner loam). One focus of our research was to study biosolids effects on ammonium bicarbonate diethylenetriaminepentaacetic acid (AB-DTPA) and 4M HNO(3) extractable levels of soil Cd, Cu, Mo, Ni, P, Pb, and Zn, and the relationship between the soil extractable concentrations and grain concentrations. We tested linear, quadratic, and either exponential-rise (plateau) or exponential-decay models for AB-DTPA- and 4 M HNO(3)- extractable concentrations compared with the cumulative quantity of biosolids-borne element added and with elemental grain concentrations. Models for AB-DTPA-extractable Cu, P, Pb, and Zn and 4 M HNO(3) extractable Cu and P versus the cumulative quantity added produced R squared values less than 0.45. For grain concentrations, only the models for AB-DTPA versus grain Zn produced an R squared less than 0.49. For monitoring soil levels of Cd, Cu, Mo, Ni, P, Pb, and Zn in Paleustolls (common soils in the western Great Plains dryland wheat areas) that continuously receive biosolids, we recommend AB DTPA over 4 M HNO(3) soil extractions. The AB DTPA extractions also provide soil fertility information (NO(3)-N and plant available P, K, and micronutrients). These results provide economic benefit to cities since land application provides the less expensive means of biosolids recycling. The AB DTPA soil extraction procedure allows monitoring of plant nutrients and trace metals in a single extractant. Our studies show the efficacy of the beneficial use of biosolids and serve as a demonstration that long-term recycling of biosolids on dryland wheat is socially, environmentally and economically sustainable. The scientific impact of our research indicates that the AB-DTPA extractant is a better tool than the more commonly used 4M HNO(3) extraction for monitoring soil and wheat grain accumulation of trace elements.

Impacts
(N/A)

Publications

BARBARICK, K. A. 1996. Using organic materials as nitrogen fertilizers. Service-In-Action. No. 546, Colorado State University Cooperative Extension Service (Revision).
BARBARICK, K.A. 1997. Winter wheat response to biosolids (sewage sludge) additions. In J. Johnson (ed.) Making Better Decisions - 1996 Winter Wheat Variety Performance Trial Results. Colorado Agricultural Experiment Station Technical Report. TR97-7.
BARBARICK, K.A., IPPOLITO, J.A. AND WESTFALL, D.G. 1997. NH4HCO3-DTPA extractable trace elements to 150-cm depth in biosolids amended soils. Agron. Abstracts. American Society of Agronomy. Madison, WI, P. 31.
BARBARICK, K.A., IPPOLITO, J.A. AND WESTFALL, D.G. 1997. Sewage biosolids cumulative effects on extractable-soil and grain elemental concentrations. J. Environ. Qual. 26:1696-1702.
IPPOLITO, J., BARBARICK, K.A., AND JEPSON R. 1997. Application of anaerobically digested biosolids to dryland winter wheat. Colorado Agricultural Experiment Station Technical Report. TR97-6.

Progress 01/01/96 to 12/30/96

Outputs
We continued study sites on two farms in eastern Adams County, Colorado to determine the effects of Littleton/Englewood biosolids (sewage sludge) on yields, protein, and elemental content of dryland hard red winter wheat (Triticum aestivum L. cv. TAM107) as compared to NH4NO3 fertilizer. Biosolids application ranged from 0 to 27 Mg ha-1 and N fertilizer ranged from 0 to 134 kg ha-1. We use one site to more accurately determine the N value of the biosolids; and, we found that 1.0 dry Mg biosolids ha-1 was equivalent to about 13 kg N. One study involving land application of biosolids to rangeland continued. Near Wolcott, Colorado biosolids have produced some microbial biomass and production differences even five years after biosolids addition. Further study of the long-term effects of a single application of biosolids on the microbial population will continue in 1997. Our study investigating the effects of drillers' mud (bentonite, etc. used for oil drilling) on dryland winter wheat showed that the mud did not affect grain production or quality. Compaction was the only noticeable effect that drillers' mud application had on the dryland-wheat system the first year. Greenhouse studies showed that the mud did not provide a soil-water availability benefit, but it did provide a labile source of Fe in an Fe-deficient soil. We speculate that the available Fe originates from pyrite encountered during drilling or from shavings from the drill bit itself.

Impacts
(N/A)

Publications

BARBARICK, K.A., IPPOLITO, J.A. AND WESTFALL, D.G. 1996. Distribution and mineralization of biosolids N applied to dryland wheat. J. Environ. Qual. 25:796-801.
BARBARICK, K. A., AND DOXTADER, K.G. 1996. Laboratory Manual for Introductory Soil Science. Sixth Edition. Burgess Publishing Co., Minneapolis, MN.
BAUDER, T.A., BARBARICK, K. A., AND SHANAHAN, J.F. 1996. Influence of drilling-mud on the growth of sorghum-sudangrass. Agron. Abs. American Society of Agronomy. Madison, WI, p. 26.
EBERL, D.D., BARBARICK, K. A., AND LAI, T.M. 1995. Influence of NH4-exchanged clinoptilolite on nutrient concentrations in sorghum-sudangrass. In Natural Zeolites 93 Occurrence, Properties, Use. Brockport, NY. p. 491-504.
IPPOLITO, J., BARBARICK, K. A., AND JEPSON R. 1996. Application of anaerobically digested biosolids to dryland winter wheat. Colorado Agricultural Experiment Station Technical Report. TR96-6.

Progress 01/01/95 to 12/30/95

Outputs
We established four study sites on two farms in eastern Adams County, Colorado in 1983 to determine the effects of Littleton/Englewood biosolids (sewage sludge) on yields, protein, and elemental content of dryland hard red winter wheat (Triticum aestivum L. cv. TAM107) as compared to N fertilizer. Biosolids application ranged from 0 to 27 Mg ha-1 and N fertilizer ranged from 0 to 134 kg/ha. The first 11 years of study showed that biosolids significantly increased protein, P, Cu, Ni, and Zn concentrations compared with the control and N fertilizer. Continued application of 27 Mg biosolids/ha lead to significant accumulation of NO3-N and increased the potential for leaching below the root zone. The grain concentrations of P, Cu, and Zn have approached a "plateau" despite continued application. Two studies involving land application of biosolids to rangeland near Wolcott and Fort Collins, Colorado showed that sewage biosolids have produced some biomass production benefits without posing environmental threats. Our study investigating the effects of drillers' mud on dryland winter wheat showed that the mud did not affect grain production or quality but did provide a labile source of Fe in a greenhouse study.

Impacts
(N/A)

Publications

Progress 01/01/94 to 12/30/94

Outputs
We established four study sites on two farms in eastern Adams County, Colorado in 1983 to determine the effects of Littleton/Englewood biosolids (sewage sludge) on yields, protein, and elemental content of dryland hard red winter wheat (Triticum aestivum L. cv. TAM107) as compared to NH4NO3 fertilizer. Biosolids application ranged from 0 to 27 Mg ha-1 and N fertilizer ranged from 0 to 134 kg ha-1. Above average precipitation and excellent snow cover resulted in yields that were 2.6 to 3.0 times the county average at the east site and above-average protein content for all biosolids treatments at both locations. With the loss of one of the long-term locations, we established a new site where we used rates of 0 to 112 kg N fertilizer ha-1 and 0 to 11 Mg biosolids ha-1. Two studies involving land application of biosolids to rangeland continued. Near Wolcott, Colorado sewage biosolids from Upper Eagle Valley Sanitation District created shifts in range-species distribution and biomass production. We initiated a study investigating the effects of drillers' mud (bentonite, etc. used for oil drilling) on dryland winter wheat. We are studying three methods of application to determine if we can reduce compaction during application. In addition to crop yield and quality and soil chemical properties, we are determining compaction effects using penetrometer readings.

Impacts
(N/A)

Publications

Progress 01/01/93 to 12/30/93

Outputs
We established four study sites on two farms in eastern Adams County, Colorado in 1983 to determine the effects of Littleton/Englewood biosolids (sewage sludge) on yields, protein, and elemental content of dryland hard red winter wheat (Triticum aestivum L. cv. TAM107) as compared to NH4NO3 fertilizer. Biosolids application ranged from 0 to 27 Mg/ha and N fertilizer ranged from 0 to 134 kg/ha. Above average precipitation and excellent snow cover resulted in above-average yields and protein content for all treatments. With the loss of one of the long-term locations, we established a new site where we used rates of 0 to 112 kg N fertilizer/ha and 0 to 11 Mg biosolids/ha. Two studies involving land application of biosolids to rangeland continued. Near Wolcott, Colorado sewage biosolids from Upper Eagle Valley Sanitation District created shifts in range-species distribution and biomass production. North of Fort Collins, Colorado, biosolids applied to slopes of 8 or 15% created changes in runoff-water quality when rainfall simulation at a rate of about 10 cm/hr was conducted. None of the water-quality parameters exceeded USEPA standards for drinking water quality. The water-quality data indicated that almost 4 Mg biosolids/ha on 15% slopes should prevent significant NO3-N accumulations in the runoff. Application of 5 Mg biosolids/ha created maximum biomass production for both biosolids and composted biosolids.

Impacts
(N/A)

Publications

Progress 01/01/92 to 12/30/92

Outputs
Four study sites on two farms in eastern Adams County, Colorado were establishedin 1982 to determine the effects of Littleton/Englewood sludge on yields, protein, and elemental content of dryland hard red winter wheat (Triticum aestivum L. cv. TAM107) as compared to NH4NO3 fertilizer. Sludge application ranged from 0 to 40 Mg ha-1 and N fertilizer ranged from 0 to 112 kg ha-1. Late spring rain helped to produce above-average yields and protein content for all treatments. Estimates of the fate of N (four applications) showed that 7 and 28 Mg sludge ha-1 have resulted in greater losses of N than 56 kg N fertilizer ha-1. Volatilization is considered as the major cause of this N loss. For 7 different sewage sludges, an r of .95 was found for regression analysis of N mineralization as affected by C/N and quantity of low molecular weight primary amines in sludge. These results should help predict N mineralization rates for sludges. Two studies involving land application of sludges to rangeland continued. Near Wolcott, Colorado sewage sludge from Upper Eagle Valley sanitation district created shifts in range species distribution and biomass production. North of Fort Collins, Colorado sludge applied to slopes of 8 or 15% created changes in runoff-water quality when rainfall simulation at a rate of about 10 cm hr-1 was conducted. The water-quality data will help the city determine application rates on slopes >8%.

Impacts
(N/A)

Publications

Progress 01/01/91 to 12/30/91

Outputs
Four study sites on two farms in eastern Adams County, Colorado were establishedin 1983 to determine the effects of Littleton/Englewood sludge on yields, protein, and elemental content of dryland hard red winter wheat (Triticum aestivum L. cv. TAM107) as compared to NH4NO3 fertilizer. Sludge application ranged from 0 to 40 Mg ha-1 and N fertilizer ranged from 0 to 134 kg ha-1. Lack of adequate soil moisture in 1990-91 again resulted in very small yields for both treatments. Sludge application generally has not significantly increased wheat grain concentrations of Cd, Ni, or Pb. Some NO3-N has accumulated in the soil due to the relatively large N content in the initial liquid-sludge application. The Littleton/Englewood sludge is an acceptable low-grade fertilizer. For 7 different sewage sludges, a protein characterization study showed that the quality of protein degradation products in all sludges were similar; however, the quantity of each varied. These results should help identify the labile sources of C and N in sewage sludges. Two studies involving land application of municipal sludges to rangeland were initiated. Near Wolcott, Colorado nine rates of sewage sludge from Upper Eagle Valley sanitation district were applied. North of Fort Collins, Colorado sewage sludge, composted sewage sludge, and a combination of sewage and water-treatment sludge were added to overgrazed rangeland.

Impacts
(N/A)

Publications

Progress 01/01/90 to 12/30/90

Outputs
Four study sites on two farms in eastern Adams County, Colorado were establishedin 1982 to determine the effects of Littleton/Englewood sludge on yields, protein and elemental content of dryland hard red winter wheat (Triticum aestivum L. cv. Vona) as compared to NH4NO3 fertilizer. Sludge application ranged from 0 to 40 Mg ha-1 and N fertilizer ranged from 0 to 112 kg ha-1. Hot, dry conditions in 1989-90 resulted in minimal grain yields for both treatments and prompted us to switch from Vona to the TAM107 cultivar. Sludge application generally has not significantly increased wheat grain concentrations of Cd, Ni, or Pb. Some NO3-N has accumulated in the soil due to the relatively large N content in the initial liquid-sludge application. The Littleton/Englewood sludge is an acceptable low-grade fertilizer. For 7 different sewage sludges, a protein characterization and C and N mineralization study elucidated some aspects of N release. Low molecular weight primary-amine fractions and C/N of the sludges accounted for the majority of the variability in N mineralization in a sludge-amended Bresser sandy loam soil (Aridic Argiustoll). A study of mountain meadows in the Leadville, Colorado area has shown the extent of metal contamination resulting from mining activity. Sequential extraction procedures identified the form of the metals in the soil. A replicated-plot study showed that some pasture forges suffered from Zn-induced Fe deficiencies.

Impacts
(N/A)

Publications

Progress 01/01/89 to 12/30/89

Outputs
Four study sites on two farms in eastern Adams County, Colorado were establishedin 1982 to determine the effects of Littleton/Englewood sludge on yields, protein and elemental content of dryland hard red winter wheat (Triticum aestivum L. cv. Vona) as compared to NH(4)NO(3) fertilizer. Sludge application ranged from 0 to 40 Mg ha and N fertilizer ranged from 0 to 112 kg ha . In 1988-89, both N fertilizer and sewage sludge produced significant yield and protein increases while the sludge resulted in superior yield and protein levels compared to N fertilizer. Over seven years of study, sludge application generally has not significantly increased wheat grain concentrations of Cd, Ni, or Pb. The Littleton/Englewood is an acceptable low-analysis fertilizer. A protein extraction procedure is being investigated as a simple technique to determine the N mineralizationof various sewage sludges. Recommendations on a procedure will be available in the near future. Study of mountain meadows in the Leadville, Colorado area have shown the extentof metal contamination related to mining activity. Metal distribution in soils and various plant species have been delineated to help alleviate livestock health problems. Sequential extraction procedures will indentify the form of the form of the metals that exist in the soil.

Impacts
(N/A)

Publications

Progress 01/01/88 to 12/30/88

Outputs
Four study sites on two farms in eastern Adams County, Colorado were establishedin 1982 to determine the effects of Littleton/Englewood sludge on yields, protein and elemental content of dryland hard red winter wheat (Triticum aestivum L. cv. Vona) as compared to NH(subscript 4)NO(subscript 3) fertilizer. Sludge application rates ranged from 0 to 40 Mg ha(superscript -1) and N fertilizer rates ranged from 0 to 120 kg ha(superscript -1). Six years of study have indicated that the application of sludge generally has produced equivalent yields, increased levels of protein, P and Zn in grain, and greater potential income as compared to the N fertilizer. Over five years of the study, sludge application, generally, has not significantly increased wheat grain concentrations of Cd, Ni and Pb. The Littleton/Englewood sludge is an acceptable low-analysis fertilizer. Application of fresh-water treatment sludges to an iron deficient and an acidic soil growing sorghum-sudangrass (Sorghum bicolour L. (Moench) cv. NB 280S) showed that sludges high in Fe could serve as Fe fertilizer when applied at rates of 5 to 25 g kg(superscript -1). A basic pH sludge acted as a liming agent in the acidic soil. Only Cd levels in the plants produced on the acidic soil that received greater than 15 g kg(superscript -1) of low pH, alum sludge posed a health or environmental concern (>2 mg Cd kg(superscript -1)). The 25 g kg(superscript -1) sludge rates significantly reduced P availability.

Impacts
(N/A)

Publications

Progress 01/01/87 to 12/30/87

Outputs
Municipalities such as Littleton and Englewood, Colorado are expressing interestin a program involving beneficial reuse of their serage sludge. Consequently, four study sites on two farms in eastern Adams, County, Colorado were established in 1982 to determine the effects of Littleton/Englewood sludge on yields, protein and elemental content of dryland hard red winter wheat (Triticul aestivum L. cv. Vona) as compared to commercial NH(4)NO(3) fertilizer. Sludge application rates ranged from 0 to 40 Mg Ha and N fertilizer rates ranged from 0 to 120 kg ha. Five years of study have indicated that the application of sludge generally has produced equivalent or greater yields, increased levels of protein, P and Zn in grain, and greater potential income as compared to the N fertilizer. The greater potential income arises from higher price for the wheat due to the higher protein content. Over four years of the study sludge application when compared to the NH(4)NO(3) treatments, generally have not significantly increased wheat grain concentrations of Cd, N and Pb. The NH(4)HCO(3)-DTPA soil extracts have indicated that sludge application has produced some accumulation of trace metals; however, the wheat generally has not absorbed significantly greater amounts of Cd, Ni, or Pb.

Impacts
(N/A)

Publications

Progress 01/01/86 to 12/30/86

Outputs
The fifth year of a project involving application of municipal, anaerobically digested sewage sludge to dryland wheat was initiated. The only significant differences found between sludge and N fertilizer treatments in the fourth year was that sludge produced grain with significantly higher Zn and P. Economic analyses of the first four years of data illustrated that the higher protein content produced by the sludge gave significantly higher gross returns than the N fertilizer. Evaluation of NH(4)HCO(3)-DTPA (AB-DTBA) as a routine soil test for sludge-amended soils continued. Results from land application of sludge to field plots indicated that the AB-DTPA levels correlated significantly with the Zn and Pb content of the wheat grain (r>0.8). The Cd, Cu and Ni content in AB-DTPA did not correlate with the grain concentrations since sludge application did not produce significant changes in the grain levels of these metals. The field data supplement a greenhouse evaluation that showed that AB-DTPA Cd, Cu, Ni, Pb and Zn levels correlated significantly (r>0.9) with concentrations of these elements in Swiss chard (Beta vulgaris, L. Cv. Fordhook Giant). A study was initiated to develop a simple, routine method of detemining N mineralization rates in sludge. Greenhouse, field and laboratory studies are being used to evaluate various simple digestions procedures.

Impacts
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Publications

Progress 01/01/85 to 12/30/85

Outputs
The fourth year of a project involving application of municipal, anaerobically digested sewage sludge to dryland winter wheat was initiated. In the third year, an excellent correlation between yields obtained with commercial nitrogen (N) fertilizer and sludge was found. The sludge provided the equivalent of 17 kg N/ha for each Mg sludge/ha applied. A greenhouse study also showed that immediate incorporation of liquid sludge provided for significantly greater N uptake by seven forage cuttings of wheat compared to a delayed incorporation. A greenhouse study to evaluate NH(4)HCO(3)-DTPA as an extractant of sludge-amended soils was completed. Two sludges (from Fort Collins, Colorado and Chicago, Illinois) were applied to two soils growing swiss chard (Beta vulgaris L., cv. Fordbook Giant). Results show that the concentrations of Cd, Cu, Ni and Zn in the soil extractant correlated very well (r>0.08) with plant concentrations of these metals. The NH(4)HCO(3)-DTPA solution will be recommended for routine testing of sludge-amended soils.

Impacts
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Publications