Agriculture and Groundwater Quality - NORTH CAROLINA STATE UNIV

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
111	0210	2020	50%
111	0210	2050	30%
405	0210	2050	20%

Progress 10/01/12 to 09/30/17

Outputs
Target Audience: Nothing Reported Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The PI of this project transitioned entirely into a teaching role. This project was discontinued.

Publications

Type: Journal Articles Status: Published Year Published: 2017 Citation: Water Conservation Potential of Smart Irrigation Technologies in the Catawba-Wateree River Basin. Vick, R L; Grabow, L; Miller, G L; Huffman, R L. Journal of Irrigation and Drainage Engineering, 02/2017, Volume 143, Issue 2

Progress 10/01/15 to 09/30/16

Outputs
Target Audience: Nothing Reported Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The project PI's efforts have been redirected toward classroom teaching. This project is inactive.

Publications

Progress 10/01/14 to 09/30/15

Outputs
Target Audience: Nothing Reported Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The project PI's efforts have been redirected toward classroom teaching. This project is inactive.

Publications

Type: Journal Articles Status: Published Year Published: 2015 Citation: Nautiyal, M., Grabow, G. L., Huffman, R. L., Miller, G. L., & Bowman, D. Journal of Irrigation and Drainage Engineering Residential irrigation water use in the Central Piedmont of North Carolina. I: Measured use and water requirements. ASCE:141(4)
Type: Journal Articles Status: Published Year Published: 2015 Citation: Nautiyal, M., Grabow, G., Huffman, R., Miller, G., and Bowman, D. Journal of Irrigation and Drainage Engineering Residential Irrigation Water Use in the Central Piedmont of North Carolina. II: Evaluation of Smart Irrigation Technologies. ASCE:141(4)

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: Nothing Reported Changes/Problems:The PI has transitioned to instructional duties, essentially makingthis project inactive. What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? As has been indicated in earlier reports, the PI for this project is devoting all of his time to instructionalwork, mostly at the undergraduate level but including one-two graduate courses per year. He has no active research to report.

Publications

Progress 10/01/12 to 09/30/13

Outputs
Target Audience: The target audience is mainly undergraduate and graduate students. Some of the graduate students are working professionals who enroll in distance-education courses. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? One new course will be offered and another will be under development.

Impacts
What was accomplished under these goals? A new edition of Soil & Water Conservation Engineering was published.

Publications

Type: Books Status: Published Year Published: 2013 Citation: Huffman, R. L., Fangmeier, D. D., Elliot, W. J., and Workman, S. R. Soil and Water Conservation Engineering, 7th edition. 2013. ISBN:1-892769-86-7. ASABE, St. Joseph, MI. 523 pp.

Progress 10/01/11 to 09/30/12

Outputs
OUTPUTS: Field experiments comparing center-pivot and subsurface drip irrigation systems continued with the addition of another MS student on the project. PARTICIPANTS: Grabow, G. L., PI Huffman, R. L., PI Owens, W. A., M.S. student Kong, V., M.S. student TARGET AUDIENCES: Target audiences are agricultural producers ranging from small-scale specialty operations to large-scale commodity crops. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Nothing significant to report.

Publications

Ghali, I. E., Miller, G. L., Grabow, G. L., and Huffman, R. L. 2012. Using variability within digital images to improve Tall Fescue color characterization. Crop Science (52)2365-2374.

Progress 10/01/10 to 09/30/11

Outputs
OUTPUTS: The primary output for the reporting year was a new edition of Soil and Water Conservation Engineering, which was published by the American Society of Agricultural and Biological Engineers, St. Joseph, MI. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: The target audience for the textbook is upper-level undergraduate and graduate students in engineering curricula. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The new edition of Soil and Water Conservation Engineering provides updates and improvements to the discipline's leading textbook for upperclass undergraduate and graduate students.

Publications

Huffman, R.L., Fangmeier, D.F., Elliot, W.J., Workman, S.R., and Schwab, G.O. 2011. Soil and Water Conservation Engineering, 6th ed. American Society of Agricultural and Biological Engineers, St. Joseph, MI. 523pp. Grabow, G. L., Huffman, R. L., and Evans, R. O. (2011). SDI dripline spacing effect on corn and soybean yield in a piedmont clay soil. Journal of Irrigation and Drainage Engineering, 137(1), 27-36.

Progress 10/01/09 to 09/30/10

Outputs
OUTPUTS: Results of residential irrigation controller studies have been shared with representatives of Cary and Raleigh. These results are also incorporated into a study in progress on the Catawba River system in western NC. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Municipalities will recommend the use of smart irrigation controllers to reduce the use of treated water for landscape irrigation. The smart technologies can reduce water use while maintaining acceptable turf quality.

Publications

Grabow, G.L., Huffman, R.L., and Evans, R.O. 2006. SDI Dripline Spacing Effect on Corn and Soybean Yield in a Piedmont Clay Soil. ASCE, Journal of Irrigation and Drainage Engineering 137(1):27-36.

Progress 10/01/08 to 09/30/09

Outputs
OUTPUTS: Two studies dealing with evaluation of smart irrigation controllers progressed during this period. Data were collected and analyzed for 24 suburban residential irrigation systems. Water use and turf quality were compared for the summer of 2009. In general, the smart controllers reduced water usage while maintaining acceptable turf quality. The second study was in its first year, where meters and dataloggers were installed on residential irrigation systems on three lakes in the Catawba River system in western North Carolina. Baseline water use data were collected during the 2009 irrigation season. Smart controllers will be installed for 2010 to evaluate their effectiveness in reducing water use for landscape irrigation. PARTICIPANTS: The other investigators on these projects are Drs. Garry L. Grabow and Grady L. Miller. Graduate students are Mayank Nautiyal and Robert Vick. Support was provided by the Town of Cary, NC, and Duke Power. We have worked with representatives of Cary and Raleigh water resources departments. TARGET AUDIENCES: The eventual audiences are landowners in urban and suburban areas that use municipal water for landscape irrigation. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Neither of the studies mentioned above were completed in the reporting period. However, preliminary results were shared with the sponsors and will be reported when the analyses are completed.

Publications

No publications reported this period

Progress 10/01/07 to 09/30/08

Outputs
OUTPUTS: A second year of data was collected for the turf irrigation controller comparison study. Rainfall in 2008 was more typical than the previous year, which had a severe drought. Representatives from several municipalities visited the project and were briefed on the implications of smart irrigation system control. Two related studies are proposed. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Agencies/corporations in NC have requested projects to evaluate the impacts of smart irrigation controllers on turf in the areas under their jurisdiction. As the benefits become clearer, it is likely that smart controllers will soon be strongly recommended (if not required) for landscape irrigation systems.

Publications

No publications reported this period

Progress 10/01/06 to 09/30/07

Outputs
The first year's results of a comparison study of various controller technologies for turfgrass irrigation were presented at a technical conference. The summer of 2007 had extreme drought conditions in North Carolina, imposing a severe test on the irrigation systems. Systems were compared for most efficient use of water while maintaining acceptable turf health.

Impacts
As competition for water intensifies, maximizing utility of limited resources becomes more important. This ongoing study shows which commercially available irrigation control technologies provide the best water use efficiency within the technical capabilities of homeowners and others responsible for turfgrass maintenance.

Publications

Huffman, R. L., Vepraskas, M. J., and Pati, S. 2007. Assessment of Groundwater Flows at Juniper Bay and Their Impacts on the Surrounding Area. NCDOT Project 2002-19, FHWA/NC/2006-19. February 2007.

Progress 10/01/05 to 09/30/06

Outputs
A multi-year study of the role of groundwater flows in the water balance of a wetland restoration project in the North Carolina coastal plain was completed. Based on field observations and modeling work for this particular site, groundwater inflows were found to contribute around 20% of the total yearly influx. It was recommended that a perimeter ditch around the site be maintained to intercept some of the shallow influx, as well as to prevent hydraulic trespass on neighboring property due to the higher water table within the restoration area itself. These findings are site-specific and cannot be extended to wetland restoration projects in general. A new project examining alternative control methods for turfgrass irrigation was started. Plots were prepared and the irrigation systems installed. Data collection will begin in 2007.

Impacts
The study of groundwater's importance in a wetland restoration project was part of a larger study that is documenting the processes and problems with wetland conversions. These findings will help agencies involved in wetlands mitigation achieve higher success rates on conversion projects, thereby saving the public money.

Publications

Grabow, G. L., R. L. Huffman, R. O. Evans, D. L. Jordan, R. C. Nuti. 2006. Water distribution from a subsurface drip irriation system and dripline spacing effect ocotton yield and water use efficiency in a coastal plain soil. Trans. ASABE 49(6).
Vepraskas, M. J. , Huffman, R. L. , Kreiser, G. S. 2006. Hydrologic models for altered landscapes. Geoderma, 131(3-4), 287-298.

Progress 10/01/04 to 09/30/05

Outputs
Studies of the subsurface flows entering and leaving a wetland conversion project are nearing completion. Models have been developed and calibrated and are being used to assess the impacts of conversion on flows and adjacent properties. Management schemes for a perimeter drain are being examined. Studies of subsurface drip irrigation with commodity crops have been scaled back.

Impacts
The understanding gained through the wetland conversion studies will help reduce the cost of wetland mitigation by improving both the selection of candidate sites and the methods used for modifying hydrology in the attempt to achieve wetland conditions. Management schemes to prevent hydrologic trepass will help avoid problems with adjacent landowners.

Publications

Fangmeier, D.F., Elliot, W.J., Workman, S.R., Huffman, R.L., and Schwab, G.O. 2006. Soil and Water Conservation Engineering, 5th ed. Thomson Delmar Learning. 502pp.

Progress 10/01/03 to 09/30/04

Outputs
Coring and instrumentation of the groundwater project on wetland restoration was completed. Hydraulic heads are being monitored in twenty nests of piezometers in four transects spanning the perimeter ditch around the project site. These data are used to determine the influence of the perimeter ditch on the subsurface flows entering/leaving the site. Model development using these data is underway. Subsurface drip irrigation of cotton was run comparing full and 2/3 applications. The results are not yet available, but little difference in yield is expected due to ample rainfall this year.

Impacts
Environmental regulations require that wetlands destroyed by road (and some other) projects be mitigated by creation of wetlands elsewhere. The current success rate of wetland conversion projects is unacceptably low. The understanding gained through the wetland conversion studies will help reduce the cost of wetland mitigation by improving both the selection of candidate sites and the methods used for modifying hydrology in the attempt to achieve wetland conditions. Subsurface drip irrigation holds promise as an alternative to conventional sprinkler irrigation for many crops. It has already shown favorable results in yield comparisons, but work is still needed to determine optimum line spacings for different soils and crops so that the most economical systems can be designed. Adoption of subsurface drip irrigation will reduce labor and management requirements and will likely allow more efficient use of water with most crops.

Publications

Huffman, R. L. 2004. Seepage evaluation of older swine lagoons in North Carolina. Transactions of the ASAE, Vol. 47(5):1507-1512.

Progress 10/01/02 to 09/30/03

Outputs
A water balance analysis of the Juniper Bay wetland restoration project suggests that there is a significant net influx of groundwater into the project site. While the predicted amount seemed very high (approx. equal to one third of the rainfall), a sensitivity analysis indicated that even if the evapotranspiration calculations were off by 50 percent, a significant influx would still be required to close the water balance. A likely source of error that is yet to be evaluated was the probable overestimation of surface outflows due to clogging of the weir structure by beavers and floating trash. Exploratory coring and piezometer installation was completed on the Juniper Bay groundwater study. Instrumentation was assembled, tested, and installation is progressing. Groundwater potential data collection has begun. As the groundwater potential database builds, it will allow assessment of the subsurface flows suggested by the water balance work described above. Subsurface drip irrigation studies completed another year in both coastal plain (cotton/peanut) and piedmont (corn/wheat/soybean) settings. Yield data has not been analyzed yet, but the high rainfalls in 2003 make it unlikely that the irrigation treatments will show significant differences.

Impacts
Environmental regulations require that wetlands destroyed by road (and some other) projects be mitigated by creation of wetlands elsewhere. The current success rate of wetland conversion projects is unacceptably low. The understanding gained through the wetland conversion studies will help reduce the cost of wetland mitigation by improving both the selection of candidate sites and the methods used for modifying hydrology in the attempt to achieve wetland conditions. Subsurface drip irrigation holds promise as an alternative to conventional sprinkler irrigation for many crops. It has already shown favorable results in yield comparisons, but work is still needed to determine optimum line spacings for different soils and crops so that the most economical systems can be designed. Adoption of subsurface drip irrigation will reduce labor and management requirements and will likely allow more efficient use of water with most crops.

Publications

Huffman, R. L. 2003. Land shaping for drainage. In: Encyclopedia of Water Science, B. A. Stewart and T. A. Howell, eds. Dekker. ISBN: 0-8247-4241-9.

Progress 10/01/01 to 09/30/02

Outputs
Studies of subsurface drip irrigation with peanuts and cotton in a coastal plain setting indicate yield response approximately equal to yields with sprinkler irrigation and significantly better than yields on unirrigated plots. Similar studies with corn in clay soils in the piedmont show crop response to alternate row dripline spacing is as good as with every-row spacing. Results from one year of monitoring nitrate movement under subsurface drip and sprinkler in the coastal plain are inconclusive. A three-year investigation of groundwater hydrology at a wetlands restoration project was begun. Initial coring and instrumentation are underway.

Impacts
Subsurface drip irrigation has high water-use efficiency and allows precise timing and placement of water and fertilizers. It provides an alternative practice where water supplies are limited and environmental impacts must be kept to a minimum. The knowledge gained from the wetland hydrology work will help planners assess the likelihood of successful conversion of a site to a wetland while avoiding hydrologic trepass onto neighboring properties.

Publications

No publications reported this period

Progress 10/01/00 to 09/30/01

Outputs
Data from a subsurface drip irrigation (SDI) plot in piedmont clays showed no difference between irrigated and unirrigated wheat. Poor germination rates and use of an indeterminate variety contributed to overall poor yields. Data from a plot in coastal plain sands showed significantly better yields of cotton with SDI compared to sprinkler-irrigated and unirrigated yields (seed: 3347, 2885, and 2715 lb/ac; lint: 1422, 1213, and 1093 lb/ac). Sprinkler and unirrigated yields were not significantly different. A comparison of peanut yields showed significantly better yields from SDI versus sprinkler-irrigated (3455 and 3049 lb/ac). Fungicide treatments were also tested on the peanuts, which showed significant yield differences, but there was no interaction between irrigation and fungicide treatments. A large-plot SDI experiment was installed in the piedmont which will allow simultaneous evaluation of all crops in a rotation. 2002 will be the first crop year for that work.

Impacts
Subsurface drip irrigation (SDI) permits more efficient use of water and reduces the likelihood of migration of agricultural chemicals. Although initial costs are higher than for sprinkler irrigation, savings in operating costs and environmental benefits may outweigh them. The yield improvements shown in these experiments may help convince producers to adopt SDI.

Publications

Parsons, J.E., D.L. Thomas, and R.L. Huffman, eds. 2001. Agricultural non-point source water quality models: Their use and application. Southern Cooperative Series Bulletin 398. ISBN 1-58161-398-9. www3.bae.ncsu.edu/Regional-Bulletins/.