Browsing Texas AgriLife Research by Title
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Ward, Ruby; Chen, Chi Chung; McCarl, Bruce A.; Keplinger, Keith O. (Texas Water Resources Institute, February 1998)[more][less]
Abstract: The EAA implemented a pilot irrigation suspension program in 1997 on 9,669 acres mainly in Medina and Uvalde counties with the objective of increasing springflow at Comal Springs, and providing relief to municipalities in meeting Critical Period (drought) Management Rules. The Aquifer region, however, experienced a wet Spring in 1997, so that even irrigators not enrolled in the program applied little or no irrigation water. If conditions were dry in Spring 1997, aquifer simulation results indicate that suspending irrigation on enrolled acreage would have reduced pumping by 23,206 acre-feet and would have augmented Comal springflow by 6,498 acre-feet during the program year and by 17.7 cfs in August. The level of the eastern portion of the Aquifer would have been expect to rise by about 3.8 feet, and the cost per acre-foot of suspended irrigation would have been about $99. Payments to irrigators totaled $2,350,000. The ISP Program did cause farmer adjustments. Participants in the ISP program planted less corn, cotton, vegetables, and peanuts in favor of more sorghum and wheat. Irrigators who converted to dryland purchased somewhat less fertilizer, seed, and labor, but secondary effects on the local economy appeared to be small. The price paid per suspended acre was much higher than regional lease rates and average cropping profit margins in many instances. Factors which may have accounted for the high bids include: 1) lack of experience with an ISP, 2) its late start up, 3) the belief that bids might affect future water prices or offers, 4) tendencies to bid high enough to cover costs under a worst case scenario of a total loss of dryland crops, 5) collusion and need to bid high enough to compensate all under current land lease arrangements. Bids in future ISP solicitations might be lower, or might not. Given the substantial difference between local irrigated land rental rates and ISP bids, it seems unlikely that the EAA could attract sufficient acreage by capping bids at rental rates. There may be, however, some latitude for the EAA to set a maximum per acre rate somewhere between local rental rates and the ISP bids. This, combined with announcing the program and executing contracts in October or November, has the possibility of substantially reducing program cost. The EAA may also want to consider offering an option contract which when implemented would suspend irrigation in April or May. Waiting until April or May would provide the EAA more information on current year weather allowing better information on whether irrigation suspension is really necessary since: 1) more time would have elapsed allowing administrators to know Aquifer elevation at a later date, and 2) information of weather, irrigation use to date and projected irrigation for the remainder of the cropping year is increased this point. The cost of a single implementation of such a program may be substantially higher than a January 1 contract, since irrigators may sustain greater loss. Expected program cost, however, could be lower, since this option would be exercised less frequently, offsetting over higher cost of implementation. Good alternatives to an ISP are limited. We evaluated the potential of 1) implementing more efficient irrigation technology and 2) buying land and leasing it back during wet or average years. The ISP is a more cost effective source of critical water than is the use of subsidized irrigation efficiency largely because the ISP can put in place only when water is needed. Also, while not considered here, evidence in areas such as the High Plains suggests that irrigator pumping is not reduced by the amount an increase in irrigation efficiency would imply. This is because irrigators may choose to irrigate more water intensive crops and/or irrigate more acreage when efficiency is increased. The high bids experienced in the 1997 program compared to price of land in the Aquifer region suggests that a buy-leaseback arrangement could substantially reduce the cost to the EAA of suspending irrigation. This, of course, would require an alternate set of administrative costs by the EAA and may be less expensive than the ISP. Also the picture may be altered by the adjudication of water rights in the Aquifer which will likely be finished within three to five years. After water rights adjudication, however, buying and leasing back water rights may be a very appropriate and cost effective strategy for the EAA. In sum, we conclude that the 1997 pilot ISP was a reasonable response to the drought condition experienced in 1996. Fine-tuning the selection criteria, bid arrangement, allowing greater lead time, and/or implementing an ISP or option contract later in the year, holds the potential for reducing the cost of program implementation. A land-based ISP is an interim arrangement that can be implemented in the absence of a fully functioning permit system. After water rights are adjudicated in the region, ISP and option contracts will take on more conventional forms involving buy, lease, and option contracts for water rights. It is expected that water-based versus land-based arrangements would likely facilitate the transfer of water at lower rates. URI: http://hdl.handle.net/1969.1/6152 Files in this item: 1
tr178.pdf (244.9Kb) -
Cox, Maeona; Mason, Louise; Reasonover, Frances; Tribble, Marie (Texas Agricultural Experiment Station, 1958)[more][less]
Description: 28 pg URI: http://handle.tamu.edu/1969.1/86564 Files in this item: 29
Bull0907.pdf (36.17Mb)(more files) -
Jackson, A. D. (Texas Agricultural Experiment Station, 1926)[more][less]
Description: 12 pg URI: http://handle.tamu.edu/1969.1/4005 Files in this item: 13
b0338 0012.tif (6.824Mb)(more files) -
Stewart, B. R.; Kunze, O. R.; Hobgood, Price. (Texas Agricultural Experiment Station, 1958)[more][less]
Description: 8 pg URI: http://handle.tamu.edu/1969.1/86537 Files in this item: 9
Bull0890.pdf (19.20Mb)(more files) -
Boyles, Rheba Merle; Hard, Graham; Roberson, Nena; Eaton, Fannie Brown (Texas Agricultural Experiment Station, 1958)[more][less]
Description: 20 pg URI: http://handle.tamu.edu/1969.1/86557 Files in this item: 21
Bull0911.pdf (67.15Mb)(more files) -
Fraps, G. S. (George Stronach) (Texas Agricultural Experiment Station, 1909)[more][less]
Description: 72 pg URI: http://handle.tamu.edu/1969.1/3455 Files in this item: 73
b0126 0072.tif (6.687Mb)(more files) -
Fraps, G. S. (George Stronach) (Texas Agricultural Experiment Station, 1912)[more][less]
Description: 39 pg URI: http://handle.tamu.edu/1969.1/3490 Files in this item: 40
b0145 0039.tif (6.701Mb)(more files) -
Cory, V. L. (Vivian L.) (Texas Agricultural Experiment Station, 1927)[more][less]
Description: 47 pg URI: http://handle.tamu.edu/1969.1/86268 Files in this item: 48
b0367 0046.tif (6.892Mb)(more files) -
Donnelly, K.C.; Schrab, G.E.; Brown, K.W. (Texas Water Resources Institute, October 1991)[more][less]
Abstract: Municipal solid waste (MSW) landfills have been found to contain many of the same hazardous constituents as found in hazardous waste landfills. Because of the large number of MSW landfills, these sites pose a serious environmental threat to groundwater quality. This study was conducted to assess the environmental hazards that materials leaching from four MSW landfills pose to groundwater supplies. Four leachate and one upgradient groundwater samples were collected from landfills selected to be representative of landfills of differing ages and types of wastes. Each sample was tested through three genetic toxicity bioassays (The Aspergillus diploid assay, the Bacillus DNA repair assay and the Salmonella/microsome assay) to measure the ability of each sample to induce mutations in bacteria, bind to microbial DNA, or cause chromosome damage in diploid fungi. Genetically toxic chemicals may cause cancer, genetic disease, sterility, abortions, heart disease or a variety of other chronic effects. These chronic effects can be subtle and may not appear for decades after exposure. In addition to the three genetic toxicity assays, each sample was tested in the Microtox test to measure acute toxicity. This assay is a measure of the ability of the sample to cause cell death. Organisms exposed to elevated levels of acute toxins may express the toxic effects through organ disfunction or the complete death of the organism. Each sample was chemically analyzed using GC/MS techniques and the chemical concentrations were used to calculate a chemical based risk assessment which is an estimate of the potential carcinogenic health effects associated with the mixture of chemicals in the sample. All four leachate samples exhibited acute toxicity in the Microtox test. Leachate from landfills representative of both an old unlined landfill which received residential waste and a new operating landfill receiving residential waste contained concentrations of some priority pollutants in excess of promulgated standards for drinking water. Chemical based risk assessments for these same two leachates showed them to have mean and 98th percentile cancer risks of 1 in a thousand (10-3) which is greater than both leachate from a Superfund landfill and leachate from the Love Canal landfill. The results of the acute and genetic toxicity bioassays, combined with the chemical analyses and associated cancer risk assessment clearly showed that leachate from municipal solid waste landfills is just as toxic as that which leaches from landfills where residential and hazardous wastes were codisposed. URI: http://hdl.handle.net/1969.1/6182 Files in this item: 1
tr153 done.pdf (2.157Mb) -
Yarnell, S. H. (Sidney Howe) (Texas Agricultural Experiment Station, 1942)[more][less]
Description: 33 pg URI: http://handle.tamu.edu/1969.1/86202 Files in this item: 34
Bull0615.pdf (35.29Mb)(more files) -
Moore, D. S.; Lacewell, R. D.; Laughlin, D. H. (Texas Water Resources Institute, December 1980)[more][less]
Abstract: Salinity of the waters from the Red River and its major tributaries has virtually eliminated its use for irrigation of agricultural crops in Texas and Oklahoma. A chloride control project has been proposed whereby the source salt waters will be captured and diverted to storage facilities. The purpose of this study was to estimate the net direct benefits to agricultural producers attributable to the proposed salinity control project. Further, estimates of project costs, municipal and industrial benefits and benefits from improving the water in Lake Kemp were obtained to complete a benefit-cost analysis. The procedure used to estimate agricultural benefits was to use a FORTRAN program to develop initial tableaus of a recursive linear programming model representing agricultural production in the study area. Alternative scenarios involving profit maximizing behavior on the part of producers, current cropping patterns, and with and without SAR crop yield effects were developed to provide a range of benefit estimates. The basis for benefit evaluation was to use parameters prescribed by the U.S. Water Resources Council's Principles and Standards and recent proposed changes along with those developed in this study to estimate the increase in net returns to producers in the study area between a with project and a without project condition for a 100 year period of analysis. Benefits were discounted to their present value with discount rates of 7 1/8 percent and 3 1/4 percent for comparative purposes. Benefits estimated herein were used in conjunction with external estimates of project costs and other benefits to evaluate the economic feasibility of the salinity control project. In all scenarios considered, cotton emerged as the major irrigated X crop. Scenarios involving profit maximizing behavior on the part of producers resulted in benefit estimates of over $65 million and $117 million without and with SAR crop yield effects, respectively, at the 7 1/8 percent discount rate. Under a constrained profit maximization scenario where SAR crop yield effects were included and in which producers were assumed to keep current cropping patterns in 1990, adjust to 50 percent of the optimal land use in 2000, and were fully adjusted to optimal land use by 2010, resulted in agricultural benefit estimates of over $87 million at the 7 1/8 percent discount rate. In a scenario where producers were assumed to maintain current cropping patterns throughout the 100 year period of analysis, benefits were estimated to be $28.8 million and $35.8 million without and with SAR crop yield effects, respectively, at the 7 1/8 percent discount rate. Benefit-cost analysis performed in this study indicated that the proposed project was economically feasible under assumptions of all scenarios considered except where current cropping patterns were followed for the entire analysis period. B/C ratios of 1.068 and 1.291 resulted for the profit maximization scenarios without and with SAR crop yield effects, respectively. Where benefits from the constrained scenario were included in the benefit-cost analysis, a B/C ratio of 1.162 resulted. Finally, with current cropping patterns maintained through 2090, B/C ratio estimates Of .907 and .938 resulted without and with SAR crop yield effects included, respectively. URI: http://hdl.handle.net/1969.1/6270 Files in this item: 1
tr112.pdf (5.298Mb) -
Rivers, G. W.; Atkins, I. M. (Texas Agricultural Experiment Station, 1954)[more][less]
Description: 7 pg URI: http://handle.tamu.edu/1969.1/86454 Files in this item: 8
Bull0778.pdf (21.65Mb)(more files) -
Ball, O. M. (Oscar Melville) (Texas Agricultural Experiment Station, 1908)[more][less]
Description: 16 pg URI: http://handle.tamu.edu/1969.1/3424 Files in this item: 17
b0109 0004.tif (6.702Mb)(more files) -
Metzer, Robert B.; Lindsay, Kenneth E.; Pratt, J. Neal; Novosad, Albert C. (Texas Agricultural Experiment Station, 1972)[more][less]
Description: 16 pg. URI: http://handle.tamu.edu/1969.1/86596 Files in this item: 17
Bull0873.pdf (20.26Mb)(more files) -
Trew, E. M. (Texas Agricultural Experiment Station, 1957)[more][less]
Description: 12 pg URI: http://handle.tamu.edu/1969.1/86430 Files in this item: 13
Bull0873.pdf (30.78Mb)(more files) -
Staten, Raymond D. (Texas Agricultural Experiment Station, 1957)[more][less]
Description: 24 pg URI: http://handle.tamu.edu/1969.1/86407 Files in this item: 25
Bull0855.pdf (86.66Mb)(more files) -
Bayles, John J. (John Jasper) (Texas Agricultural Experiment Station, 1932)[more][less]
Description: 28 pg URI: http://handle.tamu.edu/1969.1/4010 Files in this item: 29
b0472 0015.tif (15.63Mb)(more files) -
Curtis, Geo. W. (Texas Agricultural Experiment Station, 1892)[more][less]
Description: 8 pg URI: http://handle.tamu.edu/1969.1/2865 Files in this item: 9
b0022 0210.tif (13.85Mb)(more files) -
Ball, O. M. (Oscar Melville) (Texas Agricultural Experiment Station, 1905)[more][less]
Description: 16 pg URI: http://handle.tamu.edu/1969.1/2918 Files in this item: 17
b0081 0001.tif (15.24Mb)(more files) -
Fraps, G. S. (George Stronach) (Texas Agricultural Experiment Station, 1910)[more][less]
Description: 29 pg URI: http://handle.tamu.edu/1969.1/3467 Files in this item: 30
b0130 0029.tif (6.780Mb)(more files)
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