Progress 07/01/11 to 06/30/16
Outputs
Target Audience:Landscape managers, golf course superintendents, city foresters, water specialists, and park managers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Provided traning opportunities for 3 graduate students. How have the results been disseminated to communities of interest? Provided presentations to water specialists regarding how to best interpret reuse water quality for landscape irrigation; Provided seminar to regional green industry about proper species selection at the time of landscape planning and during the subsequent replacement of damaged plants when irrigation water quality is marginal. Provided reports to water department of cities regarding the impacts of water reuse on landscape ecosystems. a webinar was conducted to host water specialists across the country for discussions on graywater reuse in urban landscapes. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
There are different forms of reuse of residential wastewater for landscape irrigation, such as reuse of treated municipal sewage water (i.e. recycled water) and untreated household graywater. "Graywater" refers to water that has gone through one cycle of use in laundry, shower, or bath; it does not include water from toilets and dishwashers. "Recycled water" refers to any water after residential and sometimes industrial use undergoes significant treatment at a sewage treatment plant, to meet standards set by federal or state water laws and regulations. We have evaluated water quality of recycled water and graywater for landscape irrigation. Recycled water samples were collected from landscape sites where recycled water is used. Graywater samples were collected from graywater collection tanks. Water samples were tested for salinity level, bicarbonate content, pH, specific ion content (such as Na+, B, Cl-, and other ions), and nitrogen content. Results indicated that one of the concerns of recycled water irrigation is the presence of high levels of particular ions (sodium and chloride) that are toxic to some trees and shrubs. With sprinkler irrigation, sodium and chloride frequently accumulate by direct absorption through the leaves that are moistened. Sodium and chloride toxicity could occur on sensitive plants. The measured average Na and Cl concentrations were 105 and 100 mg/L, respectively, in recycled water samples. The average EC of recycled water sampled was 0.89 dS/m, indicating periodic leaching of salts is required to mitigate potential built up of soil salinity problems. The average soluble nitrogen of recycled water was 12.1 ppm. In comparison, graywater showed lower Na, Cl, and water electrical conductivity than recycled water, suggesting less salinity and ion toxicity impacts on landscape soils and plants. In contrast, the soluble nitrogen content appears slightly higher than recycled water. The nitrogen applied would stimulate plant growth and reduce N fertilization needs. In collaboration with three CSU faculty members (Drs. Sybil Sharvelle, Larry Roesner, and Mary Stromberger) and the Water Environment Research Foundation, we conducted a long-term graywater project. The project included two parts: existing household systems and new household systems. Four households were selected in AZ, CA, CO, and TX where graywater was applied for 5 to 33 years. New graywater irrigation systems were installed at three households (AZ, CA, and CO). At all households studied, plant health was monitored in addition to analysis of tissues to evaluate impacts to plant health. Soil samples were collected in areas irrigated with graywater and in a control area with similar vegetation irrigated with a source of freshwater. The research team found that most plants are healthy under long-term graywater irrigation. Among 22 plant species evaluated, the research team only observed three species (avocado, lemon tree, and Scotch pine) that were sensitive and showed reduced growth, or leaf burning, or reduced fruit production under graywater irrigation. Graywater irrigation was found to significantly increase sodium in households with graywater systems in place for more than five years (P<0.05), however not to levels of concern for plant health or soil quality. Graywater irrigation was also found to significantly increase surfactants in soil at households with graywater reuse systems in place for more than five years. In addition, soil collected from households with newly installed graywater systems had significantly higher surfactant concentration than control areas irrigated with graywater (P<0.05). Surfactant concentration did not continually increase with duration of graywater irrigation. Surfactant accumulation did not appear to result in phytoxicity to plants. The research team found no strong, consistent effect of graywater on numbers of E. coli or enterococci in soil. During the past 5+ years, PI and students have conducted studies to evaluate long-term recycled water irrigation on soil and plants. Results indicate a substantial impact of recycled water on soil properties, including increased soil sodium exchangeable percentage (ESP), increased soil Na, B, and P content with reduced K and Mg content. The accumulation of salts (especially Na) has potential to harm the growth of landscape plants. It has been found that soil pH was higher in sites irrigated with recycled water than in sites irrigated with surface water. The level of salt accumulation in soil depends on their concentration in irrigation water, amount of water applied annually, annual precipitation, the soil's physical and chemical properties, and drainage effectiveness. Sodium accumulated in soils with thick thatch layers, in compacted clayey sites and in areas where undisturbed hardened caliche layers restricted drainage. Therefore, careful management is required to prevent the accumulation of salts (especially sodium) in the soil. Proper species selection at the time of landscape planning and during the subsequent replacement of damaged plants is important to mitigate the potential negative effects of recycled water irrigation. To determine landscape plants performances, we visited the landscape sites that have been irrigated with recycled water for 10 years. During onsite visits, performance of landscape plants were recorded with a digital camera, and the extent of foliar damage, shoot dieback, presence of insects or disease, and crown density were rated and recorded. Concurrent with plant health evaluations, plant tissues were sampled. Leaves of different trees and shrubs were tested for chloride, sodium, boron, potassium, and other metal ions. These parameters were compared to the benchmark data to determine any positive or negative impacts and the degree of impacts. The overall plant health index ratings were different across deciduous tree and shrub species. In general, we observed that coffee tree and honey locus exhibited the best performance (i.e. the highest tolerance to recycled water irrigation). In contrast, rose bush and silver maple exhibited high degrees of branch die back and leave discoloration, suggesting that rose and silver maple had a lower level of tolerance to recycled water irrigation. Leave Na and Cl content increased for all species when compared to benchmark data, although the degree of increase is different among species and locations. Colorado spruce, Scotch pine, and ponderosa pine showed the highest average burning percentage among conifer species. Austrian pine exhibited similar response as ponderosa pine, but to a much lesser degree. Rocky Mountain juniper and pinyon pine had the highest tolerance of recycled water irrigation, exhibiting the lowest needle burning symptoms and the highest (best) health index among the conifer species evaluated in this study. Needle tissue analysis indicated that different levels of tissue ion accumulation among species irrigated with recycled water. The degree of needle burn was largely influenced by needle sodium concentration.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Skiles, D.J., S. Alshammary, and Y.L. Qian. 2014. Spatial and temporal salinity accumulation patterns on golf course fairway soils under effluent water irrigation. Australian Journal of Crop Science. 8:80-98.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Zhang, Y., Y.L. Qian, B. Mecham, and W. J. Parton. 2013. Development of best turfgrass management practices using the DAYCENT model. Agron. J. 105:1151-1159.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
6. Yao Zhang, Yaling Qian*, Dale J. Bremer, and Jason P. Kaye. 2013. Simulation of N2O emissions and estimation of global warming potential in turfgrass systems using the DAYCENT model. J. Environ. Qual. 42:11001108.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
7. Negahban-Azar, M., S.E. Sharvelle, Y.L. Qian, and A. Shogbon. 2013. Leachability of chemical constituents in soil-plant systems irrigated with synthetic graywater. Environ. Sci. Processes Impacts 15:760-772.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
J.Z. Wang, J.M. Fu, S. J. Wilhelm, and Y.L. Qian. 2013. Performance and physiological processes of Brilliant Kentucky bluegrass (Poa pratensis L.) in response to salinity and mowing management. Int. Turfgrass Res. J. 12:491-495.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Kory Nickell and Yaling Qian. 2013. Saltgrass germination responses to salinity with different seed treatments. Int. Turfgrass Res. J. 12: 187-192.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
David J. Skiles and Yaling Qian. 2013. Soil chemical property changes on golf course fairways under eight years of effluent water irrigation. Int. Turfgrass Res. J. 12:561-566.
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Qian, YL. 2012. Water Reuse for Turfgrass and Urban Landscape Plants: Case Studies and Keys for Long-term Sustainability. Colorado Water 29 (2): 2-5.
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Limei Wang, Yaling Qian, J. Brummer, J. Zheng, S. J. Wilhelm, and W. J. Parton. 2015. Simulated biomass, environmental impacts and best management practices for long-term switchgrass systems in a semi-arid region. Biomass and Bioenergy 75:254-266.
- Type:
Websites
Status:
Published
Year Published:
2012
Citation:
Sybil Sharvelle, Roesner, Larry, Yaling Qian, Mary Atromberger, and Masoud Negahban Azar. 2012. Long-term effects of landscape irrigation using household graywater Experimental Study. A report for the Water Environment Research Foundation. Available online: http://www.aciscience.org/docs/Long-term%20Study%20on%20Landscape%20Irrigation%20Using%20Household%20Graywater.pdf
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Progress 10/01/14 to 09/30/15
Outputs
Target Audience:Landscape managers, Turfgrass managers, Water specialists; Urban planners Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Provide the research opportunity foraMS graduate student. How have the results been disseminated to communities of interest? Provided presentations to landscape managers, nursery & green industry professionals about the use of effluent water at conferences organized by Colorado Golf Course Industry, Turfgrass Associations, and the Rocky Mountain Regional Society of Arboriculture. Provided report to local water providers about the impacts of effluent water irrigation on landscape plants and soils Conducted an online presentation for people interested in water reuse. What do you plan to do during the next reporting period to accomplish the goals?To evaluate landscape plants under effluent water irrigation.
Impacts
What was accomplished under these goals?
To determine the impacts of effluent water irrigation on turfgrasses, soils, and landscape plants,we recently completed a long term (10+ years) field experiment. Ten years ago, prior to the start of using effluent water for irrigation, we collected soil and plant baseline information at different landscape facilities including 3 golf courses. The original plant and soil samples were archived for measurement comparison. In 2009 and 2015, 5 and 11 years after the start of effluent water irrigation for these sites, we re-sampled those sites. The long-term evaluations in real world conditions are very valuable. In addition, the deep soil sampling profile allows for a comprehensive examination. Our results indicated that soil salinity was increased in five out of ten landscape facilities. No clear trend of increasing soil salinity was observed at other five landscape sites. When data from all facilities were pooled, the average soil salinity (as gauged by soil electrical conductivity) was 0.84, 0.88, and 0.98 dS/m in 2004, 2009, and 2015, respectively. On average, soil pH was 0.25-0.3 units higher in 2015 and 2009 when compared to 2004. Along the 1 meter soil vertical profile, the degree of soil pH increase was greater at deeper than at shallow soil depths at 3 golf courses where soils were sampled to 1 m deep. The soil pH increase may be partially due to the bicarbonate concentration in effluent water. Also during effluent water storage in irrigation ponds, photosynthesis of algae removes carbonic acid from the water causing the pH to rise during daytime. A main implication of increasing soil pH is plant nutrient availability. We observediron and/or manganese deficiencies in some sensitive landscape plants. It is possible to amend soil and water with acidifying products to prevent significant soil pH increase undereffluent water irrigation, however, it is often necessary to re-apply these substances in order to sustain the effect. Soil sodicity [as gauged by exchangeable sodium percentage (ESP)] was higher in 2009 and 2015 when compared to 2004. However, there was a decrease in ESP from 7 out of ten sites in 2015 from the 2009 sampling data. All samples collected in 2004, 2009, and 2015 had an average ESP of 2.65%, 5.35%, and 4.43%. The reason for the reduction in soil ESP from 2009 to 2015 may partially be a result of the excessive rainfall occurred in 2015 and adjustment in management. Our results indicated that aerification and gypsum addition helped to displace sodium and reduce ESP at the surface depth, although soil ESP increased significantly at deeper soil depths. The greater degrees of increases in ESP and pH in deeper soil depths indicated it is difficult to manage soil sodium and pH at deeper soil depths, which would in turn impact deeper rooted plants such as trees Heavy metal concentration were measured for soil samples prior to and 11 years after effluent water irrigation. It is surprising that we did not find any increase in heavy metals in soil after 10+ years of irrigation with effluent water. In fact, soil Arsenic (As) and Cobalt (Co) contents decreased by 50% and 66% from 2004 to 2015, respectively. Soil Nickel (Ni), Chromium (Cr), Lead (Pb), Cadmium (Cd), and Copper (Cu) did not show significant change from 2004 to 2015. This is likely as a result of low heavy metal content in the recycled water; the average heavy metal concentrations in the effluent water sampled in 2015 were < 0.5, < 0.62, 0.33, 2.58, 0.29, and < 0.06 ug/L for As, Cr, Co, Ni, Pb, and Cd, respectively. Eleven years of effluent water irrigation has increased clipping sodium content by more than 4 times. Boron and chloride content increased, whereas tissue zinc content was reduced. Despite the significant mineral content changes, turfgrasses generally exhibited good quality. However, there was a linear relationship between turf quality and sodium content in the clippings. We observed salinity stress on sites with fine soil texture and poor drainage under effluent water irrigation.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Limei Wang, Yaling Qian, J. Brummer, J. Zheng, S. J. Wilhelm, and W. J. Parton. 2015. Simulated biomass, environmental impacts and best management practices for long-term switchgrass systems in a semi-arid region. Biomass and Bioenergy 75:254-266.
- Type:
Journal Articles
Status:
Under Review
Year Published:
2016
Citation:
Katrina Gillette, Yaling Qian, Ron Follett, Steve Delgraso. 2015. Nitrous oxide emissions from a golf course fairway and rough following application of different nitrogen fertilizers. J. Environ. Quality.
- Type:
Websites
Status:
Published
Year Published:
2015
Citation:
Qian, Y.L. 2015. Comparison of soil properties and mineral composition of turfgrass shoots prior to and after 10 years of irrigation with effluent water. USGA Turfgrass and Environmental Research Online, 14(2), 52-53. MarchApril 2015
- Type:
Websites
Status:
Published
Year Published:
2015
Citation:
Yaling Qian, Katrina Gillette, Yao Zhang, Tony Koski, and Ronald Follett . 2015. Carbon footprint and agronomy practices to reduce carbon footprint of golf courses. USGA Turfgrass and Environmental Research Online, 14(1): 1-2. JanuaryFebruary 2015
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2015
Citation:
Jason Young. 2015. Analysis of Root Growth in Two Turfgrass Species with Minirhizotron and the Soil Coring Method. MS Thesis. Colorado State University, Fort Collins.
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Progress 10/01/13 to 09/30/14
Outputs
Target Audience: Water and soil scientists; Plant scientists; Landscape managers; Water specialists; Golf course managers; Researchers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? 1. Participated training workshop to landscape managers, nursery and green industry professionals about graywater and recycled water; 2. Provided presentations for people interested in water reuse. How have the results been disseminated to communities of interest? Communicated potential benefits and drawbacks of using recycled water and graywater to landscape managers, nursery professionals, water managers, water treatment specialists, etc. Communicated how graywater and recycled water quality can best be evaluated. Privided updates tothe landscape managers, nursery & green industry professionals about the use of graywater and recycled water atannual Turfconference and the International Society of Arboriculture Annual Conference. What do you plan to do during the next reporting period to accomplish the goals? Continue the ongoing projects
Impacts
What was accomplished under these goals?
Salinity Accumulation Patterns under Recycled Water Irrigation: The investigation on salinity accumulation patterns on 4 fairways of two golf courses irrigated with recycled water have been completed using two different types of sensors (5TE sensor vs. Turf Guard sensor). Spatial and temporal salt accumulation patterns were measured using a network of in-situ soil sensors located at two depths (15 and 30 cm vs. 8 and 19 cm). A positive correlation was observed between 5TE sensor-measured soil salinity and saturated paste extracted soil salinity (r = 0.77). In addition, a significant exponential relationship was observed between the values of soil salinity, measured by Turf Guard sensor, and those measured in saturated paste extraction (R² = 0.97). Moreover, a strong correlation between the average values of soil salinity and soil water content (r = 0.76), as well as the percentage of sand in the soil (r = - 0.63) were found. Overall, the highest salinity was pronounced for sites with fine soil texture and higher soil water content (an indication of poor drainage). The data of this study suggest that an adequate drainage network in predominantly clay soils irrigated with recycled water could better manage salinity accumulation associated with poor drainage. Long-term Monitering of Soil and Plants Work towards the understanding of long-term recycled wastewater and graywater irrigation on landscape plants and soil continues. Recycled water has marginal quality with relatively high levels of nutrients and salts. To determine the degree of plant health and soil property changes, we are in progress in comparing soil, landscape plants, and turfgrass samples collected at the initiation of and ten years after recycled water irrigation at several parks, green spaces, and golf courses. Ten years ago, prior to the start of using recycled water for irrigation, we collected soil and plant baseline information at those sites. The original plant and soil samples were archived for measurement comparison. In 2014, 10 years after the start of recycled water irrigation for these sites, we re-sampled those sites. The 10 year long-term evaluations in real world conditions are very valuable. In addition, the deep soil sampling profile allows for a comprehensive examination. At the same time, we are in process in determining turfgrass and landscape plants quality and mineral composition prior to and 10 years of irrigation with recycled water. Saltgrass Selection and development of salt tolerant turfgrasses and landscape plants is important for the long-term sustainability of water reuse and salinity management. Work towards the development of turf-type saltgrass continues. A master graduate student completed a research project in 2014 to address the growing demand for native, low-input turfgrass by breeding a turf-type variety of inland saltgrass (Distichlis spicata) that is well adapted to grow in arid and salty sites while maintaining acceptable quality. Two breeding cycles have been completed for improving the turf quality of inland saltgrass and the current elite lines were selected out of the second-generation nursery to initiate Cycle 3 selection. Objectives of this thesis research were to: (1) document, analyze, and report the second-generation nursery of 2,933 saltgrass plots grown at the Horticulture Research Center, (2) compare improvements of saltgrass through cycles of selections, and (3) maintain and evaluate Cycle 3 crossing blocks for survival, seed yield, and spread. Seed yield increased through cycles of selection and over half the flowering females in the second-generation elite population showed the ability to produce commercially acceptable levels of seed (448-673 kg/ha). The top 5 elite lines from the second-generation were recommended for potential vegetative variety releases. The variability observed in leaf shredding (relating to mowing quality) suggests that more work needs to be done before a uniform, seeded turf-type may be released.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Gillette, Katrina Lynn; Qian, Yaling; DelGrosso, Steve; Follett, Ronald . 2014. Methane emissions from a Colorado golf course: Effects of soil drainage. Presented at the ASA, CSSA and SSSA Annual Meetings [2014]. p. 87679.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Hanan Isweiri, Limei Wang, Sarah Wilhelm, Yaling Qian. 2014. Switchgrass Germination and Growth as Affected by Soil Salinity. Presented at the ASHS Annual Conference.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Zhang Yao and Yaling Qian. How Will Kentucky Bluegrass Turf Respond to Global Climate Change? Results from Ecosystem Modelling IHC 2014. South Brisbane, QLD 4001, AUSTRALIA
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Skiles, D.J., S. Alshammary, and Y.L. Qian. 2014. Spatial and temporal salinity accumulation patterns on golf course fairway soils under effluent water irrigation. Australian Journal of Crop Science. 8:80-98.
- Type:
Websites
Status:
Published
Year Published:
2014
Citation:
Qian, Yaling; Koski, Tony; Zhang, Yao; Follett, Ronald; Gillette, Katrina. 2014. Carbon footprint and agronomy practices to reduce carbon footprint of golf courses. USGA Turfgrass and Environmental Research Online. July/August. 13(4): p. 4-5.
- Type:
Journal Articles
Status:
Under Review
Year Published:
2015
Citation:
Limei Wang, Yaling Qian, Joe E. Brummer, Jiyong Zheng, Sarah Wilhelm, William J. Parton. 2014. imulated biomass, environmental impacts and best management practices for long-term switchgrass systems on marginal land in a semi-arid region. Biomass and Bioenergy (in review).
- Type:
Journal Articles
Status:
Under Review
Year Published:
2015
Citation:
Yao Zhang and Yaling Qian. 2014. How Will Kentucky Bluegrass Turf Respond to Global Climate Change? Results from Ecosystem Modelling. Acta Horticulturae (in review).
- Type:
Websites
Status:
Published
Year Published:
2014
Citation:
Yaling Qian. 2014. Soil analysis before and 10 years after effluent water irrigation. Golfdom. June. 70(6): p. 29
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2014
Citation:
Tess, Tess Katherine. 2014. Trait Evaluation of Second Generation Lines of Distichlis Spicata. M.S. Thesis. Colorado State University, Fort Collins.
- Type:
Theses/Dissertations
Status:
Submitted
Year Published:
2014
Citation:
Gillette, Katrina. 2014. Colorado Golf Carbon Project. Ph.D. Dissertation. Colorado State University, Fort Collins
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Yaling Qian, Katrina Gillette, Yao Zhang and Ronald F. Follett. 2014. C Sequestration and N2O Emissions in Urban Soils. Presented at the Symposium of Effects of Nutrient Cycling in Urban Grassland Soils on Soil and Water Quality. At ASA, CSSA and SSSA Annual Meetings [2014]. p. 85081.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Gillette, Katrina Lynn; Qian, Yaling; DelGrosso, Steve; Follett, Ronald. 2014. Soil drainage effects on N2O emissions from a Colorado golf course using controlled released fertilizers. Presented at the ASA, CSSA and SSSA Annual Meetings [2014]. p. 87654.
|
Progress 01/01/13 to 09/30/13
Outputs
Target Audience: Landscape Managers; Water Specialists; Golf Course Managers; Researchers. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? 1. Participatedtraining workshop for recycled water users through various water entities in Colorado. 2. Presentations to landscape managers. 3.Provided an online presentationfor people interested in water reuse. How have the results been disseminated to communities of interest? 1. Provided presentations to landscape managers, nursery & green industry professionals about the use of graywater and recycled water at conferences organized by ColoradoGolf Course Industry, Turfgrass Associations, and the Rocky Mountain Regional Society of Arboriculture. 2. Produced refereed journal articles. 3. Produced an online presentation for people interested in water reuse. What do you plan to do during the next reporting period to accomplish the goals? Conduct an experimenttitled " Comparison of soil properties and mineral composition of turfgrass shoots prior to andafter 10 years of irrigation withrecycled water".
Impacts
What was accomplished under these goals?
A. Graywater for irrigation: There are major differences in constituents between recycled water vs. graywater. For example, compared to recycled water, sodium absorption ratio in graywater is lower, but surfactant content is much higher. While graywater reuse is rapidly growing, there remain unanswered questions with respect to impactson environmental quality and human health. What is the leachability of chemical constituents in soil-plant systems irrigated with graywater? Research was conducted in collaboration with Dr. Sybil Sharvelle and the Water Environment Research Foundation to determine the leachability of graywater constituents after applied to soil through a set of controlled greenhouse experiments. Four plant species including bermudagrass, tall fescue, 'Meyer' Lemon and 'Emerald Gaiety' Euonymus were included in the study. Three replicate columns for each species were set up and irrigated either with synthetic graywater or potable water for a 17-month duration. Leachate quality was assessed for dissolved organic carbon, nitrate, ammonium, total phosphorous, boron, sodium adsorption ratio, conductivity, surfactants, and total dissolved solids. The same constituents and also organic matter were measured in soil samples collected at the end of experiments. Findings: 1) Phosphorus did not leach through the 50 cm deep soil columns. 2) Salts, including boron, showed potential to leach through graywater irrigated soil. Therefore, detergents and personal care products high in salts and boron are not recommended for use when graywater is used for irrigation due to their potential to both accumulate in soil and leach through soil to reach groundwater. 3) Nitrogen present in graywater was beneficial to plant growth. A portion of the applied nitrogen was assimilated by plants, immobilized or removed through denitrification, but leaching of nitrogen was still observed as documented by statistically higher nitrogen in leachate collected from graywater-irrigated columns compared to potable water-irrigated columns (P < 0.05). Therefore, fertilizer application should be decreased in areas irrigated with graywater to ensure that N is not over applied in these areas. 4) Leaching of total inorganic nitrogen was lower for columns planted with grass species compared to other columns. When N leaching is a concern, grasses are recommended to be planted in graywater irrigated areas. 5) A low percentage of surfactants added to columns leached through (7% plus or minus 6% on average) and a mass balance on surfactant parent compounds showed that 92–96% of added surfactants were biodegraded. B. Recycled water for landscape irrigation: Recycled water used for landscape irrigation has the potential to change soil chemical properties over time. Changes in soil chemistry can be observed across a range of time scales and in a variety of soil conditions. We have conducted a study to determine long-term changes in soil chemistry in soils underrecycled water irrigation on golf course fairways. Soil testing was conducted forover 8years for a golf course in Colorado. Parameters of each soil sample tested included pH, extractable salt content (calcium, magnesium, potassium, sodium, iron, manganese, copper, zinc, phosphorus, and boron), base saturation percent of calcium, magnesium, potassium and sodium, soil organic matter (SOM), and cation exchange capacity (CEC). Regression analysis was used to evaluate the changes in individual soil parameters over time after the use of effluent water for irrigation. Soil pH, CEC, extractable aluminum, copper, manganese and iron along with both base saturation percentages and exchangeable percentages of calcium and magnesium did not change over time. The strongest indications of change are seen for extractable boron (R² = 0.56), Bray II extracted phosphate (R² = 0.56), and sodium base saturation percentage (R² = 0.44). The regression analysis indicated that B, P, and sodium increased linearly during the 8 year’s irrigation withrecycled water. Further studies are needed to determine if these parameters would continue to increase or would stabilize. Continued accumulation of sodium could eventually result in loss of soil structure. C. Saltgrass Due the increased salinity issue, salt tolerant turfgrasses are in demand. Inland saltgrass (Distichlis spicata L. Greene) has great potential as a revegetation species for sites characterized by high salinity. Saltgrass has low germination rates due to seed dormancy. Previously, we have shown in growth chamber studies that saltgrass seed germination is increased with the use of the germination enhancing chemicals, Proxy (C2H6ClO3P) and thiourea. Recently, we have conducted additional experiment to test germination and establishment of saltgrass under elevated soil salinity levels in field conditions as affected by Proxy and thiourea. As the average soil EC salinity increased from 3.5 to 7.6 dS m-1, saltgrass seed germination was not affected. Low germination and plot coverage were observed in high salinity treatment (soil salinity=12.4 dS m-1) than in low salinity plots (soil salinity=4.0 dS m-1). Our results indicate that Proxy at 5 mM a.i. enhanced saltgrass seed germination better than the other treatments at all salinity levels. The reseach findings from these projectsprovide guidelines to water managers and landscape managers as they implement water reuse in their communities.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Zhang, Y., Y.L. Qian*, B. Mecham, and W. J. Parton. 2013. Development of best turfgrass management practices using the DAYCENT model. Agron. J. 105:1151-1159.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Negahban-Azar, M., S.E. Sharvelle, Y.L. Qian, and A. Shogbon. 2013. Leachability of chemical constituents in soil-plant systems irrigated with synthetic graywater. Environ. Sci. Processes Impacts 15:760-772.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Kory Nickell and Yaling Qian. 2013. Saltgrass germination responses to salinity with different seed treatments. Int. Turfgrass Res. J. 12: 187-192.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
David J. Skiles and Yaling Qian*. 2013. Soil chemical property changes on golf course fairways under eight years of effluent water irrigation. Int. Turfgrass Res. J. 12:561-566.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
J.Z. Wang, J.M. Fu, S. J. Wilhelm, and Y.L. Qian*. 2013. Performance and physiological processes of Brilliant Kentucky bluegrass (Poa pratensis L.) in response to salinity and mowing management. Int. Turfgrass Res. J. 12:491-495.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Yao Zhang, Yaling Qian*, Dale J. Bremer, and Jason P. Kaye. 2013. Simulation of N2O emissions and estimation of global warming potential in turfgrass systems using the DAYCENT model. J. Environ. Qual. 42:11001108.
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: In collaboration with three CSU faculty members (Drs. Sybil Sharvelle, Larry Roesner, and Mary Stromberger) and the Water Environment Research Foundation, we completed a 5 year graywater project in 2012. One approach to water resource sustainability is household graywater reuse for residential landscape irrigation. Graywater refers to water that has gone through one cycle of use in laundry, shower, or bath. Graywater irrigation systems offer many benefits, however, there are potential risks associated with this approach, and those risks are largely unquantified. The objective of this research project was to elucidate information on the fate and occurrence of graywater constituents and their potential impacts on soil quality, groundwater quality, and plant and human health as a result of its application for residential landscape irrigation. This project began in May 2008 and included two parts: existing household systems and new household systems. Field studies were conducted on both households with existing systems and households with newly installed systems. Four households were selected in AZ, CA, CO, and TX where graywater was applied for 5 to 33 years. In addition, new graywater irrigation systems were installed at three households (AZ, CA, and CO). Baseline samples were collected at the households with newly installed systems prior to initiation of graywater irrigation. Households with newly installed systems were monitored for two to four years. At all households studied, plant health was monitored in addition to analysis of tissues to evaluate impacts to plant health. Soil samples were collected in areas irrigated with graywater and in a control area with similar vegetation irrigated with a source of freshwater. The research team found that most plants are healthy under long-term graywater irrigation. Among 22 plant species evaluated, the research team only observed three species (avocado, lemon tree, and Scotch pine) that were sensitive and showed reduced growth, or leaf burning, or reduced fruit production under graywater irrigation. Graywater irrigation was found to significantly increase sodium in households with graywater systems in place for more than five years (P<0.05), however not to levels of concern for plant health or soil quality. Graywater irrigation was also found to significantly increase surfactants in soil at households with graywater reuse systems in place for more than five years. In addition, soil collected from households with newly installed graywater systems had significantly higher surfactant concentration than control areas irrigated with graywater (P<0.05). Surfactant concentration did not continually increase with duration of graywater irrigation. Surfactant accumulation did not appear to result in phytoxicity to plants. The antimicrobials triclosan and triclocarban were detected in graywater irrigated areas, but not freshwater irrigated areas. These constituents were only detected in surface soil samples and are not easily transported through soil. The research team found no strong, consistent effect of graywater on numbers of E. coli or enterococci in soil. PARTICIPANTS: Dr. Sybil Sharvelle. Colorado State University - Department of Civil and Environmental Engineering Dr. Larry Roesner Colorado State University - Department of Civil and Environmental Engineering Dr. Mary Stromberger - Colorado State University - Soil and Crop Sciences Dr. Masoud Negahban Azar Colorado State University - Department of Civil and Environmental Engineering Partner organization: Water Environmental Research Foundation TARGET AUDIENCES: Landscape Managers Home owners Water specialists PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
This project provided science based data on effects of graywater irrigation on soil quality and plant health which can be applied to make informed decisions on graywater reuse. This project is one of the first to address leaching of graywater chemical constituents through soil and potential for groundwater contamination. It provides scientifically sound conclusions. At the completion of the project, a webinar was conducted to host water specialists across the country for discussions on graywater reuse in urban landscapes. The research information has reached many citizens across the country via newspapers and public presses. While Colorado has not yet legalized the practice of graywater reuse for residential landscape, the project helps to provide scientific data so that the policy maker can make informed decision in the future.
Publications
- Qian, Y.L. 2012. Water Reuse for Turfgrass and Urban Landscape Plants: Case Studies and Keys for Long-term Sustainability. Colorado Water 29 (2):2-5.
- Sybil Sharvelle, Roesner, Larry, Yaling Qian, Mary Atromberger, and Masoud Negahban Azar. 2012. Long-term effects of landscape irrigation using household graywater-Experimental Study. A report for the Water Environment Research Foundation. Available online: http://www.aciscience.org/docs/Long-term%20Study%20on%20Landscape%20I rrigation%20Using%20Household%20Graywater.pdf
- Graus M., S.D. Allyson, R. Fall, B. Yuan, Y.L. Qian, P. Westra, J. Gouw, C. Warneke. 2013. Biosphere-atmosphere exchange of volatile organic compounds over C4 biofuel crops. Atmospheric Environment. 66:161-168.
- Koduah Owusu Ansah. 2012. Warm season turfgrasses as potential candidates to phytoremediate arsenic pollutants at Obuasi goldmine in Ghana. M.S. Thesis. Colorado State University, Fort Collins.
- Zhang, Yao. 2012. Simulated carbon and nitrogen dynamics in turfgrass systems using the daycent model. M.S. Thesis. Colorado State University, Fort Collins.
- Gillette, Katrina L.; Qian, Yaling; Follett, Ronald; Koski, Anthony; Del Grosso, Stephen. 2012. Trace gas fluxes from Colorado golf courses. ASA, CSSA and SSSA Annual Meetings [2012]. p. 71088.
- Zhang, Yao; Qian, Yaling; Mecham, Brent; Parton, William. 2012. Development of best turfgrass management practices using Daycent model. ASA, CSSA and SSSA Annual Meetings [2012]. p. 72858.
- Zhang, Yao; Qian, Yaling; Bremer, Dale; Kaye, Jason. 2012. Simulation of N2O emissions from two cool season turfgrass lawns using the DAYCENT model. ASA, CSSA and SSSA Annual Meetings [2012]. p. 72912.
- Christensen, Dana; Koski, Anthony; Qian, Yaling; Kopec, David; Pessarakli, Mohammad. 2012. Heritability estimates and accession evaluation in Distichlis spicata. ASA, CSSA and SSSA Annual Meetings [2012]. p. 75219.
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: In 2011, work continued in monitoring recycled water quality. We found that recycled water pH increases during open irrigation pond storage. This is related to the fact that the storage of recycled water in onsite, open irrigation ponds led to increased algae populations because of the presence of phosphorous and nitrogen in recycled water. Algae use dissolved carbonates as their source of carbon, resulting in the release of OH-. As expected, we have found that the soil pH of recycled water irrigated sites increased to above 7.5 over a five year period, despite the fact that the average pH of recycled water leaving the wastewater treatment plant is about 7.1. In 2011, work continued in determining long-term changes in soil chemical property on recycled water irrigated landscape sites. We collected soil information from 10 landscape sites (parks and golf courses) at 2 time-points: 1) immediately after the site started to use recycled water for landscape irrigation, and 2) 5 years after the initiation of recycled water irrigation. We found that soil salinity did not increase significantly at most of the sample sites over the five-year period. However, the average soil exchangeable sodium percentage (ESP) increased from 2.65% to 5.35% over the five-year period. These results suggested sodicity is of greater concern than salinity at most of the testing sites, since soil ESP is the parameter that exhibited the most significant changes after the start of recycled water for irrigation. Increased soil ESP may reduce soil aggregates stability and reduce overall soil health. Soil and /or water amendment with calcium based products may help to displace Na and reduce ESP. To evaluate management practices for reducing soil ESP under recycled water irrigation, eight golf course fairways were subjected to different management treatments. Four fairways were subjected to gypsum application following aerification (aerify 1-2 times a year and apply gypsum at 50 lb/1000 sq ft/year). The other 4 fairways were control with no gypsum addition. For control sites, soil ESP at 0-40 cm depth tripled over a five year period. For gypsum treated fairways, the increase in ESP over the 5 year period at 0-40 cm depths was not statistically significant. Our project demonstrated that gypsum application following aerification is effective in reducing soil ESP under recycled water irrigation, especially at the shallow soil depths (0-40 cm). In 2011, we compared the impacts of "recycled water" irrigation vs. "graywater" irrigation. Graywater refers to water that has gone through one cycle of use in laundry, shower, or bath; it does not include water from toilets and dishwashers. Compared to recycled water, sodium absorption ratio in graywater is lower. We did not find dramatic soil ESP increase with graywater irrigation at levels that we found with recycled water irrigation. We also found less accumulation of sodium in graywater irrigated-plants than recycled water irrigated-plants. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Recycled water, the product of treated wastewater, inherently contains some level of nutrients, salts, and other constituents that can affect water quality. However, water reuse contributes significantly to regional water conservation and water use efficiency, and offers economic and environmental benefits. Urban green spaces are the leading users of recycled water. In Colorado, many thousands of hectares of green spaces are using recycled water for irrigation. This project has helped in filling out information gaps in recycled water reuse and addresses impacts of using recycled water on soils and plants. First, this project has generated information to help landscape planners and managers determine what should be monitored and what proactive steps should be taken to minimize any negative effects during planning and managing landscapes receiving recycled water. Secondly, the project has selected plant species that can better tolerate recycled water irrigation. Thirdly, we are in the process of developing management strategies that can not only aid in establishment of turfgrass on recycled water irrigated turf sites but also in re-vegetation of salt-affected soils and ecosystems. Currently, the research findings of this project are used by Colorado water entities to develop best management practices for landscapes with recycled water irrigation. This work has positive impacts on urban water conservation through recycled water irrigation both locally and nationally.
Publications
- Qian, Yaling and Ronald Follett. 2011. Carbon dynamics and sequestration in urban turfgrass ecosystems. In Lal, R. and B. Augustin (eds). Carbon Sequestration in Urban Ecosystems. Springer Publications. ISBN 978-94-007-2365-8
- Suplick-Ploense, M.R., S.F. Alshammary and Y.L. Qian, 2011. Spectral Reflectance Response of Three Turfgrasses to Leaf Dehydration. Asian Journal of Plant Sciences, 10: 67-73.
- Gillette, K. L., Follett, Ronald, Qian, Yaling, Koski, Anthony, Del Grosso, Stephen. 2011. The Carbon Footprint of Colorado Golf Courses Estimated by Clubhouse Energy Use, Trace Gas Emissions and Modeling Carbon Sequestration. In the 20011 ASA-CSSA-SSSA Int. Annual Meetings Abstract.
- Graus, M, A. Eller, R. Fall, B. Yuan, Y.L. Qian, P. Westra, Joost de Gouw, C. Warneke. 2011. Comparison of VOC emissions from conventional and alternative biofuel crops. Abstract in the 242nd ACS National Meeting & Exposition, Denver, CO.
- Qian, Yaling, Mohamed Shahba, and Sarah Wilhelm. 2011. Effect of Seed Treatments, Seeding Date, and Seeding Rate on Saltgrass Seed Germination and Establishment. USGA Turfgrass and Environmental Research Online. 10(1): p. [1-7].
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: Recycled water has emerged as a reliable and consistently available source of water for golf course irrigation. The main constituents of recycled water include total dissolved salts, nutrient elements, and organic compounds. Recycled water has relatively high levels of sodium concentration relative to calcium and magnesium. Golf course managers are often concerned about salinity and sodicity issues associated with recycled water irrigation. We studied temporal and spatial salinity accumulation patterns on recycled water irrigated golf courses using on-site soil salinity and soil water content sensors located at 15 and 30 cm below soil surface. In-ground measurements indicated that salinity can vary widely across a seemingly homogenous golf course fairway in a manner reflective of the underlying soil physical characteristics. Strong correlation was observed between average soil salinity and mean soil water content (r =0.76), soil salinity and the percentage of sand in the soil texture composition (r = -0.63). At several sites, high salinity is not a result of water reuse, but a historical geological contribution. Drainage appears to be vital in maintaining low soil salinity levels under recycled water irrigation in clay soils. Slow to infiltrate, percolate and difficult to leach; predominately clay soils irrigated with recycled water can accumulate soil salinity over time. Our data suggested that a robust drainage network in predominantly clay soils irrigated with recycled water could better manage salinity accumulation associated with poor drainage. To determine long-term changes in soil chemical property on recycled water irrigated fairways, we collected soil baseline information in 2004 from 3 golf courses that had just started to use recycled water for landscape irrigation. In 2009-2010, 5 years after the initiation of recycled water irrigation, soil samples were collected 30 cm from the original sampling spots and analyzed for soil characteristics. Samples were taken at 0-20, 20-40, 40-60, 60-80, and 80-100 cm depths. Results from this study suggest that soil salinity (as gauged by soil electrical conductivity) and soil organic matter content did not increase at most of the sample sites over the five-year period. The average soil exchangeable sodium percentage (ESP) increased from 2.65% to 5.35%. Samples collected from all sites showed a significant increase in soil pH (~0.3 units). Our results suggested that sodicity is the primary concern on these landscape soils when recycled water is used for irrigation. The nature of recycled wastewater warrants special management steps to be taken to minimize the possible drawbacks associated with its constituents. To evaluate management practices for reducing sodium under recycled water irrigation on golf course fairways, eight golf course fairways were subjected to different management treatments. Four fairways were subjected to gypsum application following aerification. The other 4 fairways were control with no gypsum addition. The study is in progress. PARTICIPANTS: Skiles, DJ. MS graduate student. Nichell, KJ. MS graduate student. TARGET AUDIENCES: Water conservation specialists, Landscape managers, Turfgrass managers. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The contribution of water reuse to water conservation varies by location. In arid and semi-arid US, water reuse has increased dramatically. Golf courses are by far the leading urban landscape users of recycled wastewater, because intensively managed turf can use nutrients in the wastewater efficiently and it is easier to implement recycled wastewater irrigation systems on golf courses than other urban areas. In Colorado, more than 50 golf courses have been retrofitted to use recycled water for irrigation. This scope of reuse can increase the regional water use efficiency and offers economic and environmental benefits. This study will further fill out information gaps and address impacts of using recycled water on soils and plants. Our research outcomes about temporal and spatial salinity accumulation patterns will contribute to development of proper management practices. Our data suggested that a robust drainage system in predominantly clay soils irrigated with recycled water could better manage salinity accumulation associated with poor drainage. Our work on urban water conservation through irrigation with municipal recycled water is accepted and adopted to develop best management practices statewide. Currently, the research findings of this project are used by Colorado water entities to develop best management practices for landscapes with recycled water irrigation.
Publications
- Wilhelm, S., S. Alshammary, and Y.L. Qian. 2010. Establishment, growth, and irrigation requirements of Kentucky bluegrass and tall fescue as influenced by two water sources. Research Journal of Environmental Sciences 4:443-451.
- Nickell, K.J. 2010. Saltgrass revegetation of saline soil. M.S. Thesis. Colorado State University, Fort Collins.
- Skiles, D. J. 2010. Changes in golf course fairway soils under effluent water irrigation. M.S. Thesis. Colorado State University, Fort Collins.
- Qian,Y.L., S. Wilhelm, K.Nickell, A. Holmquist, and S. Lohman. 2010. Soil analysis before and 5 years after recycled water irrigation. Proceedings of the Twenty-fifth Annual WateReuse Symposium in Washington DC.
- Qian,Y.L., R. F. Follett, and J. M. Kimble. 2010. Soil organic carbon input from urban turfgrasses. Soil Sci. Soc. of Amer. J. 74:366-371.
- Qian, Y.L., M. Shahba, and S.Wilhelm. 2011. Effect of Seed Treatments, Seeding Date, and Seeding Rate on Saltgrass Seed Germination and Establishment. USGA Turfgrass and Environmental Research Online. 10(1): p. [1-7].
- Qian, YL and DJ Skiles. 2010. Salinity management in turfgrass systems irrigated with effluent water. In 2010 Turfgrass and Environmental Research Summary. p. 4. USGA Turfgrass and Environmental Research Online. 9(23):4
- Sharvelle, S., L. Roesner, Y.L. Qian, and M. Atromberger. 2010. Long term study on landscape irrigation using household graywater: Eperimental study. A report for the Water Environment Research Foundation. Available online.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: There are two forms of reuse of residential wastewater for landscape irrigation: treated municipal sewage water (i.e. recycled water) and untreated household graywater. Graywater refers to water that has gone through one cycle of use in laundry, shower, or bath; it does not include water from toilets and dishwashers. In collaboration with three CSU faculty members and the Water Environment Research Foundation, a field experiment is on-going to evaluate the effects of long-term application of graywater on landscape plant health and soil quality. Data has been collected on plant health and soil quality from four homes that have had graywater irrigation systems in place for 5 to 31 years. Homes included in the study are located in AZ, CA, CO, and TX. For each site, sample areas were selected where graywater was applied for irrigation and control areas were also sampled with similar vegetation that had been irrigated with fresh water. Plant growth was determined and plant health was evaluated. For evergreen conifers, we also collected data on the number of years of needle retention and year-to-year growth increments. Among 23 landscape plants studied, St. Augustinegrass, bermudagrass, four-wing saltbush, juniper, euonymus, rose of Sharon, and chrysanthemum responded very well to graywater irrigation and were ranked as resistant to graywater irrigation. The following plants exhibited moderate resistance to graywater irrigation: California valeriana and plum tree. The following plants were moderately sensitive to graywater irrigation: mugo pine and bearded iris. Landscape plants that are sensitive to graywater irrigation included: Scotch pine, Hass avocado, and lemon tree. We did not find consistent trends regarding the influence of irrigation water source and individual leaf mineral content. The nature of the plant sensitivity is likely complex. Nevertheless one concern about the long-term use of graywater for landscape irrigation is the potential for salinity problems. The relationship between landscape plant's salinity tolerance and their graywater response was assessed by comparing individuals plants' salinity tolerance reported in the literature with the observations in this study. We found that although discrepancy existed, the correlation between gray water tolerance and salinity tolerance was significant. The regression coefficient value of 0.36 suggested that approximately 36 percent of the variance of landscape plants' response to graywater is associated with their response to salinity, in this case, salinity tolerance. Sodium absorption ratio (SAR) of recycled water irrigated soil has been found to be relatively high in our previous studies. As a comparison, this research indicates that graywater has less impact on soil SAR compared to recycled water irrigation. It is possible that sodium does not accumulate as much in soils irrigated with graywater compared to recycled wastewater due to the water chemistry, i.e. lower sodium and higher surfactants in graywater than recycled wastewater. Surfactants may change soil surface tension resulting in infiltration modification. PARTICIPANTS: The described study is part of a big project titled "Long-term Study on Landscape Irrigation Using Household Graywater" funded by the Water Environment Research Foundation. Investigators of the project include: Dr. Roesner - serves as the Principal Investigator. Dr. Sybil Sharvelle is studying the fate of surfactants and also is responsible for measurement of surfactants and antimicrobials in graywater and soil. Dr. Yaling Qian is a horticulturist and is responsible for overseeing the horticultural aspects of the project. Dr. Mary Stromberger is a soil scientist and is responsible for soil chemistry as well as soil microbiology and pathogen studies. TARGET AUDIENCES: Landscape managers, city planners, water quality specialist, lawn care professionals, environmental scientists. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
In a typical household, graywater is nearly 40% of the total wastewater generated. Graywater for residential landscape irrigation offers economic and environmental benefits. When used for irrigation of a typical residential landscape, it could supply about 30% of the demand, and with increasing emphasis on xeriscape in the semi-arid West, it has the potential to supply more of the irrigation demand in some areas. As communities throughout the United States are becoming interested in innovated approaches to water resource sustainability, household graywater reuse for irrigation is gaining in popularity. Some states, including California, Arizona, and New Mexico, and several other countries have legalized the practice. However the use of such systems has not become widespread due to concerns about human safety and landscape soil and plants health issues. This study will further fill in information gaps and address concerns regarding household graywater irrigation impacts. Our research outcomes concerning the different responses of landscape plants to graywater irrigation will contribute to proper landscape plant selections and successful management. Further, our work on urban water conservation through irrigation with municipal recycled water is accepted and adopted locally, statewide and even nationally.
Publications
- Skiles, David J and Yaling Qian. 2009. Spatial and temporal variability of soil salinity in effluent water irrigated fairways. In the 2009 ASA-CSSA-SSSA Int. Annual Meetings Abstract. Pittsburgh, PA.
- Jingbo Chen, Jun Yan, Yaling Qian, Yanqin Jiang, Tingting Zhang, Hailin Guo, Aigui Guo, Jianxiu Liu. 2009. Growth responses and ion regulation of four warm season turfgrasses to long-term salinity stress. Scientia Horticulturae 122:620-625.
- Johnson, G.A., Y.L. Qian, and J.G. Davis. 2009. Topdressing Kentucky bluegrass with compost increases soil water content and improves turf quality during drought. Compost Science and Utilization 17:95-102.
- Kory Nickell and Yaling Qian. 2009. Saltgrass ecotype evaluation for revegetation of saline sites. In the 2009 ASA-CSSA-SSSA Int. Annual Meetings Abstract. Pittsburgh, PA.
- Qian, Yaling. 2009. Irrigation with recycled wastewater. Sports Turf. November 2009:36-37.
- Shahba, M.A., Y.L. Qian, and S.J. Wallner. 2009. Influence of Proxy on saltgrass seed germination in saline soils. Int. Turfgrass Research Journal 11:849-857.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Reuse of domestic wastewater for turf and landscape irrigation is one way to maximize existing urban water resources. To better understand the long-term effects of recycled water irrigation on urban landscape plants including turfgrass, two experiments are on-going. First experiment is to determine whether the use of recycled water over time has an effect on the nitrate and phosphorus content of the soil. We took soil samples from golf courses that have been irrigating with recycled water for various periods of time. Soil cores were sampled to a depth of one meter and then subdivided into 20-cm increments. Regression analysis was conducted to evaluate the relationship between the length of time of recycled water usage and soil nitrate or phosphorus content. Results indicate that though there is no significant correlation between the number of years of irrigating with recycled water and the amount of nitrate in the soil, there is a strong correlation between the number of years of recycled water irrigation and the amount of phosphorus at the surface 0-20 cm of the soil. The second experiment is to evaluate and compare landscape plants performance on landscape sites that have used recycled water irrigation to those with non-saline surface water irrigation. Results to-date indicated that many turfgrass and landscape plants are tolerant of recycled water. Some species of trees and shrubs, however, are susceptible to certain attributes of recycled water, especially after several years of exposure. We have found that, in Colorado, Rocky Mountain juniper and pinion pine were more resistant to recycled wastewater irrigation than Austrian pine that was in turn more resistant than scotch pine, ponderosa pine and Colorado blue spruce. Salt accumulation is of concern for sites irrigated with recycled water for long-term. Many turfgrasses are more sensitive to salinity during germination than established turf stands. Turf managers often reported difficulty in establishing turfgrass under high salinity conditions. In 2008, we have studied the effects of germination regulating chemicals in enhancing seed germination under salinity conditions and alleviating salinity stress in saltgrass. Our investigation showed that 5.0 mM ethephon, 10 mM fusicoccin, 0.5mM kinetin, 30 mM thiourea and Proxy at 5.0 mM a.i. increased seed germination percentage and speed of saltgrass under saline conditions. Proxy was the most effective growth regulator in ameliorating salinity effect on saltgrass seed germination at 15 dS m-1, followed by thiourea, fusicoccin, ethephon and kinetin. Soaking saltgrass seeds in Proxy solution for 48 hours increased seed germination percentage and speed under both non-saline and saline conditions. PARTICIPANTS: Sarah J Wilhelm. Department of Horticulture & Landscape Architecture, Colorado State University. Mohamed A. Shahba. Department of Horticulture & Landscape Architecture, Colorado State University. S. F. Alshammary. Fulbright scholar. TARGET AUDIENCES: Landscaper planners, Urban landscape managers, Water specialists, Turfgrass managers, Environmental scientists. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Understanding the responses of turfgrass and urban landscape plants and soils to recycled wastewater irrigation is critical to the long-term success of water reuse. Our experiments results advocate that proper management of recycled water irrigation and periodic monitoring of soil and groundwater parameters are necessary to ensure successful, safe, long term recycled wastewater irrigation. Our experiment on relative tolerance of landscape plants to recycled water has aided in proper plant species selection at the time of landscape planning and during the subsequent replacement of damaged plants. This is important to mitigate the potential negative effects of recycled wastewater irrigation. Our research outcomes about germination-regulating chemicals in enhancing seed germination under salinity conditions have led us to conduct further study in development of practical and effective seed treatment procedures for establishing saltgrass under saline conditions.
Publications
- Alshammary, S. and Y.L. Qian. 2008. Long term effects of effluent water irrigation on soil nitrate and phosphorus profiles under turfgrass. International Journal of Soil Science 3:101-108.
- Alshammary, S. and Y.L. Qian. 2008. Response of four warm-season grasses to saline irrigation water under arid climate. American Journal of Plant Physiology 3:121-130.
- Harivandi, M.A., K.B. Marcum, and Y.L. Qian. 2008. Recycled, gray, and saline water irrigation for turfgrass. In M. Kenna and J.B. Beard (eds.). Water Quantity and Quality Issues for Turfgrasses in Urban Landscapes. Special Pub No. 27. Council for Agricultural Science and Technology. Ames, IA.
- Qian, Y.L. 2008. Water Reuse for Urban Landscape Irrigation. Rumbles (Magazine for the Rocky Mountain Section of AWWA and the Rocky Mountain Water Environmental Association) August 2008.
- Qian Y.L. 2008. Using Effluent Water for Golf Course Irrigation: Water Quality Interpretation. The Reporter 43 (4): 3-5.
- Qian, Y.L. 2008. Recycled wastewater instigates different responses in turfgrass trees and soils. Turfgrass Trends. June 1-3
- Shahba, M. A., Y. L. Qian, and K. D. Lair. 2008. Improving seed germination of saltgrass under saline conditions. Crop Sci. 48:756-762.
- Shahba, M. A. and Y. L. Qian. 2008. Effect of seeding date, seeding rate, and seed treatments on saltgrass seed germination and establishment. Crop Sci.48:2453-2458.
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Progress 01/01/07 to 12/31/07
Outputs
Reuse of treated wastewater for turf and landscape irrigation is one way to maximize the existing urban water resources. Golf courses are the leading urban landscape users of recycled wastewater. To better understand the long-term effects of recycled wastewater irrigation on turfgrass systems, we have compared soil chemical properties on golf course fairways that have used recycled wastewater irrigation to those with non-saline surface water irrigation (surface water was stream and ditch water from melting snow of the Rocky Mountains). Seven to 33 years irrigation of turfgrass on a fine textured soil with recycled wastewater (ECiw range = 0.47 to 1.32 dS/m) resulted in an increase of soil salinity by 3.0 dS/m, that was 187% higher than sites irrigated with surface water (ECiw range = 0.15 to 0.30 dS/m). Sites irrigated with recycled wastewater for more than 7 years had higher ESP and SAR than the surface water irrigated soil, although the ESP and SAR values on fairways
are not high enough to be classified as a sodic soil. Many turfgrass and landscape plants are tolerant of recycled water. Some species of trees and shrubs, however, are susceptible to certain attributes of recycled water, especially after several years of exposure. We used existing landscapes that were under long-term recycled wastewater irrigation to determine the relative tolerance of different species of conifers to recycled wastewater. We tested more than 100 conifer trees, consisting of six confer species, on 4 large landscape facilities. It was found that Rocky Mountain juniper and pinion pine were more resistant to recycled wastewater irrigation than Austrian pine that was in turn more resistant than scotch pine, ponderosa pine and Colorado blue spruce. Rocky Mountain juniper and pinion pine grew well under RWW irrigation for 7-20 years and accumulate lower levels of toxic ions (such as Na, Cl, and B) than other conifers. In contrast, the more sensitive species, scotch pine,
ponderosa pine and Colorado spruce accumulated almost 200% higher Na in the needles than juniper and pinion pine. The degree of needle burn was largely influenced by needle sodium concentration, i.e. the higher the sodium, the greater the needle burn. In 2007, we investigated the salinity tolerance of 14 saltgrass [Distichlis spicata var. stricta (Greene.)] selections. We found that salinity level that caused 25% clipping reduction ranged from 21.2 dS/m to 29.9 dS/m. The data on 25% clipping reduction salinity of saltgrass generated in this study rank saltgrass as one of the most salt-tolerant species that can be used as turf.
Impacts
In Colorado, the use of recycled wastewater has risen significantly in recent years; there are about 50 golf courses in Colorado are using recycled wastewater for irrigation. Understanding the responses of turfgrass and urban landscape plants and soils to recycled wastewater irrigation is critical to the long-term success of water reuse. Proper species selection at the time of landscape planning and during the subsequent replacement of damaged plants is important to mitigate the potential negative effects of recycled wastewater irrigation. Our recycled water irrigation project has already provided valuable information to city planners, water specialists, and landscape managers with information regarding what proactive steps should be taken to minimize negative effects during the planning and managing of landscapes receiving recycled wastewater. Our research reports published last year were recommended to their members by the Water Reuse Committee of Rocky Mountain
Section of American Water Works Association.
Publications
- Rukavina, H. H.G. Hughes, and Y.L. Qian. 2007. Freezing tolerance of saltgrass ecotypes. HortScience 42:157-160.
- Shahba, M and Y.L. Qian. 2007. Effects of seeding date, seeding rate, and seed treatments on saltgrass seed germination and establishment. Agron. Abstr. New Orleans, LA
- Christensen, D, A. J. Koski, D. Holm, Y. L. Qian, J. Detling, and S. J. Wallner. 2007. Response to selection for turf traits in Distichlis spicata. Agron. Abstr. New Orleans, LA
- Qian, Y.L., J.M. Fu, S.J. Wilhelm, D. Christensen, and A.J. Koski. 2007. Relative salinity tolerance of turf type saltgrass selections. HortScience 42:205-209.
- Qian Y.L. and M.A. Harivandi. 2007. Salinity issues associated with recycled wastewater irrigation of turfgrass landscapes. In Handbook of Turfgrass Management and Physiology (M. Pessarakli ed.). CRC Press. ISBN: 978-0-8493-7069-4
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Progress 01/01/06 to 12/31/06
Outputs
As communities throughout US are becoming interested in innovative approaches to water resource sustainability, recycled wastewater (RWW) reuse and household graywater reuse for turf and landscape irrigation is gaining in popularity. In collaboration with three CSU faculty members and Water Environment Research Foundation, a project was completed in 2006. This project comprised an extensive literature review and synthesis of information to define current knowledge and information gaps regarding household graywater irrigation impacts on residential landscaping. The literature review examined overall graywater issues, especially 1) quantity, quality, treatment methods, and legality, and 2) potential effects of graywater on residential landscape plants and soil chemical and microbial functions. Knowledge gaps were found in five areas, particularly as it relates to human health, landscape plants and the environment. At the same time, work towards the understanding of
long-term recycled wastewater irrigation on landscape plants and soil continues. Water samples were collected to assess variability of chemical properties of recycled wastewater in the Front Range of Colorado. Results indicated that there were variations in water quality between wastewater treatment facilities. The chemical constituents of recycled wastewater were dominated by sulfate, bicarbonate, chloride, and sodium. The average sodium and chloride concentrations of 50 water samples collected from all the sites were 99 mg/L and 95 mg/L, respectively. Adjusted sodium absorption ratio (SAR) of RWW samples ranged from 1.6 to 8.3. We have collected and analyzed soil, turfgrass clippings, and different landscape plant samples from 14 landscape facilities (7 were irrigated with recycled wastewater while the other 7 were irrigated with surface water). Our results indicated potential problems associated with recycled wastewater irrigation exist. Salts (especially the relatively high Na+
and high EC) in the treated wastewater were associated with needle burn symptoms observed in several conifer species subjected to RWW irrigation. Likely, problems associated with saline soils may increase in the future as more recycled wastewater is applied to turf sites. Selection and development of salt tolerant turfgrasses and landscape plants is important for the long-term sustainability of water reuse. Work towards the development of turf-type saltgrass continues. In 2006, we investigated different seed treatments in enhancing germination and establishment of inland saltgrass. We found that cold moist stratification and dry scarification significantly improved germination and enhanced establishment of seeded saltgrass.
Impacts
The graywater literature review and synthesis describes the status of knowledge that currently exists about graywater and its reuse at the household level. The knowledge gaps identified will help the water foundation to identify the research needs and priorities. Our recycled water irrigation project helps to determine what proactive steps should be taken to minimize any negative effects during planning and managing landscapes receiving recycled wastewater. Understanding the responses of urban landscape plants and soils to recycled wastewater irrigation and identifying proper management practices are critical to the long-term success of water reuse.
Publications
- Johnson, G. A., Qian, Y. L., and Davis, J. G. 2006. Effects of compost topdressing on turf quality and growth of Kentucky bluegrass. Online. Applied Turfgrass Science doi:10.1094/ATS-2006-0113-01-RS.
- Roesner, Larry, Yaling Qian, Melanie Criswell, Mary Atromberger, Stephen Klein. 2006. Long-term effects of landscape irrigation using household graywater - literature review and synthesis. A report for the Water Environment Research Foundation. Available online: http://www.cleaning101.com/files/SDA_WERF_Graywater_2006.pdf
- Qian, Y.L. Urban landscape irrigation with recycled wastewater. 2006. Colorado Water Resource Research Institute. Research Report No. 204.
- Qian YL, J.A. Cosenza, S.J. Wilhelm, and D. Christensen. 2006. Techniques for enhancing saltgrass seed germination and establishment. Crop Sci. 46:2613-2616.
- Johnson, G.A., J.G. Davis, Y.L. Qian. 2006. Topdressing turf with composted manure improves soil quality and protects water quality. Soil Sci. Soc. of Amer. J. 70:2114-2121.
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Progress 01/01/05 to 12/31/05
Outputs
The increasing water shortage in the arid and semi-arid western US requires use of recycled wastewater when possible. Recycled wastewater has become a common water source for irrigating golf courses and urban landscapes, creating the need to study the effects of recycled wastewater irrigation on landscape plants and soils. We have collected and analyzed irrigation water, soil, turfgrass clippings, and ponderosa pine needle samples from 14 landscape facilities (7 were irrigated with recycled wastewater while the other 7 were irrigated with surface water). Soils (sampled to 11.4 cm) from sites where recycled wastewater was used for at least 4 years exhibited 0.3 units of higher pH and 200%, 40%, and 30% higher concentrations of extractable Na, B, and P, respectively. Compared to sites irrigated with surface water, sites irrigated with recycled wastewater exhibited 187% higher EC and 481% higher sodium adsorption ratio (SAR) of saturated paste extract. We found that some
conifer trees suffer different degrees of decline after prolonged use of recycled wastewater, depending on species, soil texture, and the effectiveness of drainage system. The decline in Ponderosa pine is more associated with sodium accumulation than chloride accumulation. Pine needles collected from reuse sites exhibited 11 times higher Na content, 1.3 times higher chloride content, and 50% higher B content than samples collected from the control sites. Tissue Ca level and K/Na ratio were negatively associated with needle burn symptoms, suggesting that calcium amendment and K addition may help mitigate the needle burn syndrome in ponderosa pine caused by high Na+ in the tissue. Findings of this project have prompted us to further to evaluate different management options in mitigating problems associated with water reuse in urban landscapes. In evaluating different mowing regimes on creeping bentgrass salinity tolerance, we have found that as mowing height decreased, creeping
bentgrass exhibited reduced salinity tolerance. Declining salt tolerance under lower mowing heights is associated with carbohydrate depletion that reduces the plant's ability to produce osmo-protectants (such as reducing sugars), to exclude Na from shoots, and to selectively uptake and transport K. This work showed that a moderate increase in mowing height could help to improve the quality of creeping bentgrass growing under saline conditions.
Impacts
This information is useful to landscape planners and managers to determine what should be monitored and what proactive steps should be taken to minimize any negative effects during planning and managing landscapes receiving recycled wastewater. Understanding the responses of urban landscape plants and soils to recycled wastewater irrigation and identifying proper management practices are critical to the long-term success of the water reuse practice. We have found that modification of common management practices (increasing mowing height, for example) can also be used to reduce the negative impacts of salinity on turf quality by enhancing the plant's ability to respond to elevated soil salinity.
Publications
- Qian, Y.L., Fu, J.M., Klett, J., and Newman, S.E. 2005. Effects of long-term recycled wastewater irrigation on visual quality and ion content of ponderosa pine. J. Environ. Hort. 23:185-189.
- Qian, Y.L. and Mecham, B. 2005. Long term effects of recycled wastewater irrigation on soil chemical properties on golf course fairways. Agron. J. 97:717-721.
- Fu, J.M., Koski, A.J., and Qian, Y.L. 2005. Responses of creeping bentgrass to salinity and mowing management: growth and turf quality. HortScience 40:463-467.
- Qian, Y.L. and Fu, J.M. 2005. Response of creeping bentgrass to salinity and mowing management: carbohydrate availability and ion accumulation. HortScience 40:2170-2174.
- Criswell, M.C., Roesner, L.A., Qian, Y.L., Stromberger, M.E., and Klein, S.M. 2005. Experimental design of a long-term study on landscape irrigation using household graywater. In 2005 World Water Congress -ASCE Conference Proceedings. Anchorage, Alaska.
- Suplick-Plonese and Qian, Y.L. 2005. Evapotranspiration, rooting characteristics, and dehydration avoidance: comparisons between hybrid bluegrass and Kentucky bluegrass. Int. Turf. Res. J. 10:891-898.
- Johnson, G.A. 2005. Effects of topdressing established Kentucky bluegrass with composted manure. M.S. Thesis. Colorado State University. Dept. of Horticulture and Landscape Architecture. Fort Collins, CO.
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