1. Emmalee Allen 1 with Ramesh Sivanpillai 2 1. Department of Plant Sciences/Agroecology program and 2 Department of Botany University of Wyoming

2. 2007: total agricultural value of production in Wyoming: $1021.4 million 1 Top commodities 1 : livestock hay Sugar beets Grain (wheat and barley) wool Alfalfa is most important crop in WY 2 2009: Alfalfa in Wyoming $190 Million 2 1. "WYOMING." Welcome to the State of Wyoming. State of Wyoming, 2012. 2. Garcia Y Garcia, A. "Towards the Recommendation of Scientifically-based Irrigation Scheduling Strategies in Wyoming: A Case Study for Forage Alfalfa Crop Production "

3. Semi-arid climate 1 2050 m (6,700 feet) elevation 1 Temp range of -48.3 to +35 degrees Celsius(-55-95 degrees Fahrenheit) 3 60 frost free days 3 Killing frost possible year round 4 101.6 cm (40 in.) precipitation in the Wind River Mountain Range 17.78-20.32 cm (7-8 in.) in the irrigated areas. Soils is well drained sandy soils. 4 3. "This Is Eden Valley." Eden Valley History Project. Western Wyoming Community College,. 4. Klajic, Leisl A. "The Eden Project." Bureau of Reclamation, 2000. Web. 2013

4. 1886 first irrigation permits distributed. Permits allowed for diversion of water from the Big Sandy River 4 1905 First Irrigation and Land Company project started 4 1960Big Sandy Dam and Reservoir completed 4 1980 Colorado River Basin Salinity control study released 5 Reported that in 1960-1977 The Big Sandy River contributed 149,200 tons of salt to the Colorado River 5 1988-1989: Center pivots were installed 1990 Report: 25 locations nationwide for voluntary conversion to center pivot 6 70 percent federal cost share 25 year operations and maintenance 6 11 pivots in Eden Valley by 1990 6 Experienced 100% crop yield incerase 6 50-70% decrease in water use 6 5. U.S.D.A, 1980. 6. Wyoming Hydrogram (Oct. 1990)

5. 140 acres in southwest Eden Valley 7 owned since 1961 7 200 head of sheep for 20 years 7 Brome and Timothy grass alfalfa mix 7 oats and beardless barley, peas 7 produce two harvests 7 Mid July Late August/early September 1989 transition from flood to center pivot Irrigation (CPI) 7 First under government program to transition to center pivot 7 Better production, even distribution 7 Continuously run pivot never run out of water 7 As of 2012 8 : 369,000 tons of salt saved 15,230 acres-feet of water 7. Interview by William Webster. 20 Apr. 2013. 8. 2012 M & E Progress Update Report

6. Figure 1. Big Sandy Unit (Wyoming State Water Program 9 )

7. Effect of center pivot irrigation instillation on alfalfa yield was investigated. Remotely sensed images prior to CPI installation as well as images post installation were analyzed to assess the difference.

8. Six Landsat images prior to first harvest (Late June 18 through 27) Pre CPI: 1984,85, and 87 Post CPI: 1991-93 1990 and 1986 images were not usable Collected by USGS Downloaded and pre-processed by Ramesh Sivanpillai ERDAS IMAGINE 2011 Images from 2007, 2009, 2010, and 2011 analyzed for mapping current conditions

9. Classified each image Rule based classification Each image was converted to Normalized Difference Vegetation Index (NDVI) (B4 NIR – B3 RED )/(B4 NIR + B3 RED ) Sampled ~10 pixels for these classes: No growth Low vigor Low-medium vigor Medium vigor High vigor NDVI image was classified to generate crop vigor map/year Acreages were calculated for each class/year

10. 1984 19851987 No growth Low vigor Low-medium vigor Medium vigor High vigor

11. 198419851987 Minimum NDVI-0.2-0.10.07 Maximum NDVI0.7110.750.79 No growth23.8 acres9.8 acres22.02 acres Low vigor25.6 acres6.2 acres25.15 acres Low Medium Vigor 59.0 acres92.8 acres43.15 acres Medium Vigor48.5 acres55.6 acres64.94 acres High vigor17.3 acres 9.8 acres 18.90 acres Table 1. Minimum and Maximum NDVI values as well as acreage amount within each category for years 1984,85, and 87

12. 1991 1992 1993 No growth Low vigor Low-medium vigor Medium vigor High vigor

13. 199119921993 Minimum NDVI0.15-0.050.03 Maximum NDVI0.810.760.82 No growth8.90 acres26.91 acres23.13 acres Low vigor19.80 acres12.50 acres21.13 acres Low Medium Vigor23.35 acres46.50 acres63.83 acres Medium Vigor45.15 acres56.30 acres40.03 acres High vigor76.95 acres32.03 acres 26.02 acres Table 2. Minimum and Maximum NDVI values as well as acreage amount within each category for years 1991.92. and 93.

16. Vigor on average are higher after the installation of CPI Were higher in 1991-1993 and 2007-2011 Slight decrease in 2007-2011from 1991-1993 Landsat images are useful to distinguish growth patterns in small fields Extensive archive is helpful to analyze past growth (since 1984 for Landsat 5) Rule-based classification is an objective technique to classify crop vigor Ground truth data is required to validate classified images

17. 1. "WYOMING." Welcome to the State of Wyoming. State of Wyoming, 2012. Web. 24 Apr. 2013.. 2. Garcia Y Garcia, A. "Towards the Recommendation of Scientifically-based Irrigation Scheduling Strategies in Wyoming: A Case Study for Forage Alfalfa Crop Production - UNIVERSITY OF WYOMING." USDA Research, Education, and Economics Information System. University of Wyoming, n.d. Web. Apr. 2013. 3. "This Is Eden Valley." Eden Valley History Project. Western Wyoming Community College, 2005. Web. Apr. 2013.. 4. Klajic, Leisl A. "The Eden Project." Bureau of Reclamation, 2000. Web. 2013. 5. Big Sandy River, Colorado River Basin Salinity Control Study. Publication. Casper, Wyoming: U.S.D.A, 1980. U.S. Department of Agriculture Soil Conservation Service. Web 6. "Wyoming Helps Reduce Salt in the Colorado River." Wyoming Hydrogram 2 (Oct. 1990): 3-4. Wyoming Water Research Center. Web. 2013. 7. Interview by William Webster. N.p., n.d. Web. 20 Apr. 2013. 8. 2012 Monitoring and Evaluation Progress Update Report Big Sandy Salinity Control Area. Rep. Bureau of Reclamation, Department of Interior, 2012. Web. 2013. 9. Tyrrell, Pat. "Green River Basin Water Plan Technical Memoranda." Wyoming State Water Plan. N.p., n.d. Web. 2013.

18. WyomingView Internship opportunity AmericaView for funding WyomingView USGS for Landsat images Ramesh Sivanpillai, Botany WyGISC Bill and Dean Webster, Landowners for providing ground truth data