Progress 12/22/06 to 12/21/11
Outputs
Progress Report Objectives (from AD-416): 1. Develop new tools and a knowledge base that will enable decision makers to more effectively manage and conserve water resources. 1.a Design and test sensors that will quantify the level of plant water stress in growing crops and can be used to make irrigation decisions. 1.b Determine the relationship between crop productivity and applied water as a function of environmental factors so that irrigation can be managed for optimal use of all available water. 2. Develop and evaluate techniques and methodologies that maintain efficient agricultural production under deficit irrigation and dryland production. 2.a Design and evaluate water management strategies that optimize water use and crop production with limited well capacity. 2.b Define and evaluate crop management systems to facilitate the transition from irrigated to dryland cropping, considering crop species and varieties, cultural practices, and that incorporate long range weather prediction. 3. Identify changes in soil microbial, chemical, and physical properties affecting soil water availability and develop management practices that impact soil properties to sustain and improve crop production where water supply is in transition from limited irrigation to rainfed production. 4. Develop Best Management Practices based on a growing region's climate variability. 4.a Develop optimal planting strategies that integrate seasonal climate forecast information into agricultural managment. 4.b Develop software tools that provide detailed knowledge of precipitation, temperature stress, and evapotranspiration and demand to producers and plant breeders. Approach (from AD-416): Develop and evaluate techniques and methodologies that utilize limited water resources efficiently to maintain economically viable deficit irrigated and dryland agricultural production systems. Develop new approaches, including acoustic detection of xylem cavitation and portable chamber technologies, to quantify the degree of crop drought stress and evaluate new and existing deficit irrigation strategies. Examine irrigation quantity and application rate effects on water use efficiency using the BIOTIC protocol for irrigation scheduling. Explore the efficiency of subsurface drip irrigation for storing water from low capacity wells in the soil during the fallow season. Determine the feasibility of enhancing water infiltration with adapted grasses and use water stored in playa lakes for forage production. Evaluate new crop species and cultural practices for facilitating the transition from irrigated to dryland cropping systems. Determine the effects of crop rotations and residue management systems on soil microbial, chemical, and physical properties including effects on soil water availability, infiltration, and rainfall capture efficiency. Assess the influence of row spacing and planting patterns on water use efficiency of different cropping systems. Use seasonal climate forecasts to develop optimal planting strategies and software tools to provide detailed predictions of precipitation, temperature stress, and evapotranspiration demand for producers and plant breeders. This multifaceted research program will provide the knowledge base for optimizing the use of scarce water resources especially in arid and semi-arid regions where ground water resources are being depleted. As water is lost from leaves it is pulled up from the soil through the roots and stems to replace that which was lost from the leaves. The water in stems is under considerable tension and has an upper tensile strength of very fine copper wire. When the tensile strength of the water columns is exceeded they break, resulting in a phenomena called xylem cavitations. We attempted to relate xylem cavitations to drought stress. We were able to demonstrate that drought leads to a characteristic pattern of xylem cavitation events that release ultrasonic acoustic emissions (AEs) that can be detected with current technology. Field experiments revealed that the primary obstacles to quantitation of AEs were wind noise and availability of rugged instrumentation. While irrigation scheduling using AEs as a basis for stress detection is possible, it is not currently agronomically feasible, at least in field settings. A portable, open, transparent chamber system for measuring canopy gas exchanges in the field was developed and successfully tested. This prototype chamber was then copied to develop a total of six chambers for field deployment. Finally, these chambers have been further modified to control internal atmospheric CO2 concentration. Because atmospheric CO2 is rising and because atmospheric CO2 directly impacts both plant photosynthesis and transpiration, methods for measuring whole canopy gas exchange responses under CO2 enrichment are needed for breeding programs aiming to develop crop cultivars resistant to stresses like drought in a future higher CO2 world. Playa wetlands, the predominate geomorphic feature of the Southern High Plains are marginal croplands that occupy about 5% of the regions land area. They are typically not agronomically exploited, and many have been targeted for the Conservation Reserve Program. We investigated whether these lands could be managed, or even exploited, for forage production. We identified one species that seemed capable of forage production in the ecotomes, eastern gamagrass. We also found that not all playas exhibit similar flooding patterns. Some that remain flooded for extended periods decimated gamagrass, while others flood for only 4-6 weeks at a time allowing the crop to thrive. Our research is now investigating the flooding frequency and duration of the hydroperiod and relating this to the types of species that live in the playas, with the ultimate goal of managing these systems as biomass and forage production systems. The results of the 2007-2011 climate forecasting research was generally consistent with previous work using statistical methods to predict seasonal climate over the central U.S. Although potential for winter forecasts and winter crop management based on ENSO state was found, similar forecast skill was not apparent for summer forecasts. Although the initial goal was to develop a Visual Basic agro-climate application for the entire U.S., the decision was made to narrow the application's focus to the Ogallala region. However, the Ogallala Agro-Climate Tool's data management algorithms may be adapted for use in a future web-based application that will focus on the entire continental U.S. Accomplishments 01 Ogallala Agro-Climate Tool PC application. Over the latter half of the 20th century and the first years of the 21st, pumping from irrigated agriculture has led to water level declines in the Ogallala Aquifer that have not been compensated for by natural recharge. The drawdown of this important water resource has led to questions about the long-term viability of the area's agricultural economy. The Ogallala Agro-Climate Tool, a Visual Basic application that can be run on Windows 2000, XP, an Vista operating systems, has been developed by ARS scientists in Lubbock Texas, to provide accurate information about the required irrigation levels for a range of crops, in addition to climate and crop evapotranspiration statistics for the Ogallala region. By providing estimates of the water requirements of the area's major crops, this easy to-use PC tool may help producers to identify wasteful irrigation practices and conserve the water resource of the aquifer.
Impacts
(N/A)
Publications
- Goebel, T.S., Mckinnes, K., Lascano, R.J., Marchand, L., Davis, T. 2011. Modifying polymer flocculants for the removal of inorganic phophate from water. Tetrahedron Letters. 52(41): 5241-5244.
- Gitz, D.C., Xin, Z., Baker, J.T., Lascano, R.J., Burke, J.J. 2012. Effect of solar loading on greenhouse containers used in transpiration efficiency screening. Agronomy Journal. 104(2):388-392.
- Ziska, L.H., Bunce, J.A., Shimono, H., Gealy, D.R., Baker, J.T., Newton, P. C., Reynolds, M.P., Jagadish, K.S., Zhu, C., Howden, M., Wilson, L.T. 2012. Food security and climate change: On the potential to adapt global crop production by active selection to rising atmospheric carbon dioxide. Proceedings of the Royal Society of London B. Available: DOI: 10.1098/RSPB. 2012.1005.
- Codero, E.C., Kessomkiat, W., Abatzoglou, J., Mauget, S.A. 2011. The identification of distinct patterns in California temperature trends. Climatic Change. 108:357-382.
- Masiokas, M., Villalba, R., Prieto, M.R., Christie, D., Le Quesne, C., Betman, E., Luckman, B.H., Mauget, S.A. 2012. Andean snowpack since AD 1150 inferred from rainfall, tree-ring and documentary records. Journal of Geophysical Research Atmospheres. 117 D05112.
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Progress 10/01/10 to 09/30/11
Outputs
Progress Report Objectives (from AD-416) 1. Develop new tools and a knowledge base that will enable decision makers to more effectively manage and conserve water resources. 1.a Design and test sensors that will quantify the level of plant water stress in growing crops and can be used to make irrigation decisions. 1.b Determine the relationship between crop productivity and applied water as a function of environmental factors so that irrigation can be managed for optimal use of all available water. 2. Develop and evaluate techniques and methodologies that maintain efficient agricultural production under deficit irrigation and dryland production. 2.a Design and evaluate water management strategies that optimize water use and crop production with limited well capacity. 2.b Define and evaluate crop management systems to facilitate the transition from irrigated to dryland cropping, considering crop species and varieties, cultural practices, and that incorporate long range weather prediction. 3. Identify changes in soil microbial, chemical, and physical properties affecting soil water availability and develop management practices that impact soil properties to sustain and improve crop production where water supply is in transition from limited irrigation to rainfed production. 4. Develop Best Management Practices based on a growing region's climate variability. 4.a Develop optimal planting strategies that integrate seasonal climate forecast information into agricultural managment. 4.b Develop software tools that provide detailed knowledge of precipitation, temperature stress, and evapotranspiration and demand to producers and plant breeders. Approach (from AD-416) Develop and evaluate techniques and methodologies that utilize limited water resources efficiently to maintain economically viable deficit irrigated and dryland agricultural production systems. Develop new approaches, including acoustic detection of xylem cavitation and portable chamber technologies, to quantify the degree of crop drought stress and evaluate new and existing deficit irrigation strategies. Examine irrigation quantity and application rate effects on water use efficiency using the BIOTIC protocol for irrigation scheduling. Explore the efficiency of subsurface drip irrigation for storing water from low capacity wells in the soil during the fallow season. Determine the feasibility of enhancing water infiltration with adapted grasses and use water stored in playa lakes for forage production. Evaluate new crop species and cultural practices for facilitating the transition from irrigated to dryland cropping systems. Determine the effects of crop rotations and residue management systems on soil microbial, chemical, and physical properties including effects on soil water availability, infiltration, and rainfall capture efficiency. Assess the influence of row spacing and planting patterns on water use efficiency of different cropping systems. Use seasonal climate forecasts to develop optimal planting strategies and software tools to provide detailed predictions of precipitation, temperature stress, and evapotranspiration demand for producers and plant breeders. This multifaceted research program will provide the knowledge base for optimizing the use of scarce water resources especially in arid and semi-arid regions where ground water resources are being depleted. We used measurements of canopy temperature to schedule irrigations using two different irrigation scheduling methods: the Stress Time method and the Stress Degree Hour method. These two irrigation methods are being compared using several criteria, including cotton yield, total water use, water use efficiency, and seasonal irrigation application timing to determine which method is most suitable for cotton growers with limited access to irrigation water or who may wish to practice deficit irrigation. We are completing the ninth year of a long-term study that compares soil infiltration, erodibility, microbial biomass C, and enzyme activities of C cycling as affected by four dryland cropping systems. Soil microbial biomass C and enzyme activities showed significant differences due to system management history, while tillage produced no significant effects. These trends are important for soil and water conservation because increases in both organic matter quality and quantity can have beneficial effects on soil structure, C sequestration, and water availability for crop production. We have completed development of the Ogallala Agro-Climate Tool, a PC application that provides estimates of climate statistics, crop evapotranspiration and irrigation demand for a range of crop types over the United States' Ogallala aquifer region. The application can be downloaded from the ARS Ogallala Aquifer Project website at: http://www. ogallala.ars.usda.gov/OgAgCliTool_Install.php. Accomplishments 01 Ogallala Agro-Climate Tool PC application. Over the latter half of the 20th century and the first years of the 21st, pumping from irrigated agriculture has led to water level declines in the Ogallala aquifer that have not been compensated for by natural recharge. The drawdown of this important water resource has led to questions about the long-term viability of the area's agricultural economy. The Ogallala Agro-Climate Tool, a Visual Basic application that can be run on Windows 2000, XP, an Vista operating systems, has been developed by ARS scientists in Lubbock Texas, to provide accurate information about the required irrigation levels for a range of crops, in addition to climate and crop evapotranspiration statistics for the Ogallala region. By providing estimates of the water requirements of the area's major crops, this easy to-use PC tool may help producers to identify wasteful irrigation practices and conserve the water resource of the aquifer. 02 Temporary playa lakes may help recharge declining aquifers. ARS researchers at Lubbock, Texas, have measured water movement through temporary playa lakes or simply 'playas'. These depressions in the landscape of the Southern High Plains temporarily fill with water following rainfall events. Researchers have found that playas differ in the rate in which water is lost through the playas bottoms and infiltrat into the underlying ground water, including the Ogallala Aquifer. Howeve over the long-term, about half of the water in playas is lost to the atmosphere through evaporation, while the other half of the water infiltrates the soil and can ultimately recharge the aquifer. This information and datasets are now being used by the Texas Water Developme Board and the Llano Estacado Regional Water Planning Group to provide information for policy decisions aimed at best management of West Texas water resources.
Impacts
(N/A)
Publications
- Ephrath, J., Timlin, D.J., Reddy, V., Baker, J.T. 2011. Irrigation and elevated carbon dioxide effects on whole canopy photosynthesis and water use efficiency in cotton (Gossypium hirsutum L.). Plant Biosystems. 145:202-215.
- Pelletier, M.G., Viera, J., Schwartz, R.C., Lascano, R.J., Evett, S.R., Green, T.R., Wanjura, J.D., Holt, G.A. 2011. Fringe capacitance correction for a coaxial soil cell. Sensors. 11(1):757-770.
- Li, H., Lascano, R.J. 2011. Deficit irrigation for enhancing sustainable water use: Comparison of cotton nitrogen uptake and prediction of lint yield in a multivariate autoregressive state-space model. Soil Use and Management. 71(2):224-231.
- Mauget, S.A., Leiker, G.R. 2010. The Ogallala Agro-Climate Tool. Computers and Electronics in Agriculture. 74(1):155-162.
- Lascano, R.J., Van Bavel, C., Evett, S.R. 2010. A field test of recursive calculation of crop evapotranspiration. Transactions of the ASABE. 53(4) :1117-1126.
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Progress 10/01/09 to 09/30/10
Outputs
Progress Report Objectives (from AD-416) 1. Develop new tools and a knowledge base that will enable decision makers to more effectively manage and conserve water resources. 1.a Design and test sensors that will quantify the level of plant water stress in growing crops and can be used to make irrigation decisions. 1.b Determine the relationship between crop productivity and applied water as a function of environmental factors so that irrigation can be managed for optimal use of all available water. 2. Develop and evaluate techniques and methodologies that maintain efficient agricultural production under deficit irrigation and dryland production. 2.a Design and evaluate water management strategies that optimize water use and crop production with limited well capacity. 2.b Define and evaluate crop management systems to facilitate the transition from irrigated to dryland cropping, considering crop species and varieties, cultural practices, and that incorporate long range weather prediction. 3. Identify changes in soil microbial, chemical, and physical properties affecting soil water availability and develop management practices that impact soil properties to sustain and improve crop production where water supply is in transition from limited irrigation to rainfed production. 4. Develop Best Management Practices based on a growing region's climate variability. 4.a Develop optimal planting strategies that integrate seasonal climate forecast information into agricultural managment. 4.b Develop software tools that provide detailed knowledge of precipitation, temperature stress, and evapotranspiration and demand to producers and plant breeders. Approach (from AD-416) Develop and evaluate techniques and methodologies that utilize limited water resources efficiently to maintain economically viable deficit irrigated and dryland agricultural production systems. Develop new approaches, including acoustic detection of xylem cavitation and portable chamber technologies, to quantify the degree of crop drought stress and evaluate new and existing deficit irrigation strategies. Examine irrigation quantity and application rate effects on water use efficiency using the BIOTIC protocol for irrigation scheduling. Explore the efficiency of subsurface drip irrigation for storing water from low capacity wells in the soil during the fallow season. Determine the feasibility of enhancing water infiltration with adapted grasses and use water stored in playa lakes for forage production. Evaluate new crop species and cultural practices for facilitating the transition from irrigated to dryland cropping systems. Determine the effects of crop rotations and residue management systems on soil microbial, chemical, and physical properties including effects on soil water availability, infiltration, and rainfall capture efficiency. Assess the influence of row spacing and planting patterns on water use efficiency of different cropping systems. Use seasonal climate forecasts to develop optimal planting strategies and software tools to provide detailed predictions of precipitation, temperature stress, and evapotranspiration demand for producers and plant breeders. This multifaceted research program will provide the knowledge base for optimizing the use of scarce water resources especially in arid and semi-arid regions where ground water resources are being depleted. Though current off-the-shelf technology precludes development of affordable technology that can discriminate the waveform differences between AEs arising from cavitation events and from other sources, component costs continue to fall. We are currently relating Acoustic Emissions to plant water status of plants in the field using a more expensive system. Attempts to locate and evaluate inexpensive components continue. We used measurements of canopy temperature to schedule irrigations using two different irrigation scheduling methods: the Stress Time method and the Stress Degree Day method. These two irrigation methods are being compared against cotton yields and water use efficiency criteria to determine which method is better for cotton growers with limited access to irrigation water. We have conducted yearly soil samplings from the research plots in order to evaluate selected soil chemical, microbial and biochemical properties that may provide indications of more favorable conditions for plant growth (i.e., increases in soil water) in soil under alternative management compared to continuous cotton. Soil samplings and field measurements for water infiltration and availability will be done this fall 2010. We can now predict winter rainfall over the central U.S. based on the previous spring's Pacific sea-surface temperatures (SST). Advanced statistical methods were used to look for ways to predict summer rainfall based on previous winter SST, but similar predictive relationships were not found. Lacking such relationships, future work will develop summer crop management tools that rely only on detailed climatological data. In subobjective 2.a.2, the field experiment is running one year behind schedule due to weather-related delay in 2008. This year, treatments are being administered to the cotton crop, but very high rainfall this year may limit growth and yield differences due to irrigation levels. Due to 15 months without a research technician and subsequent hire of a fresh natural resources graduate, subobjective 3.2 and 3.3 are behind schedule. Although the crop is growing well, problems with the data acquisition are still being addressed. The new research technician is climbing a steep learning curve of electronics and instrumentation, and this is his last challenge to get the field and lab experiments running reliably. The system used depends on MS-DOS to run a computer that controls a Tektronix 1502 cable tester. It is uncertain how long we will be able to maintain this installation due to the increasing complexity of available computers and the scarcity of the Tektronix cable testers. Accomplishments 01 An open chamber system for measuring canopy gas exchanges in cotton. Cr plants absorb carbon dioxide (CO2) from the atmosphere during photosynthesis and lose water (H2O) back to the atmosphere during transpiration. Measurements of CO2 and H2O fluxes of crop plants are essential to understanding the impacts of crop species and varietal selections, as well as environmental variables and cultural practices, o crop productivity. Scientists at the Wind Erosion and Water Conservation Laboratory at Big Spring and Lubbock, Texas, have developed and tested a open or flow-through chamber system that can be left in the field for extended periods and that continuously measures whole canopy gas exchang across wide ranges of canopy leaf areas and soil water contents. Six identical chamber systems have been built. This system allows simultaneo measurement of photosynthesis, water use and water use efficiencies in cultivar trials for plant breeders and for agronomists testing new agricultural practices. This information is useful for growers, policy makers and researchers in identifying effective agricultural practices aimed at increasing water use efficiency and on-farm profitability.
Impacts
(N/A)
Publications
- Mauget, S.A., Zhang, X.J., Ko, J. 2009. The tactical value of ENSO forecast information to dual-purpose winter wheat production in the US Southern High Plains. Journal of Applied Meteorology and Climatology. 48(10):2100-2117.
- Mauget, S.A., De Pauw, E. 2010. The ICARDA Agro-Climate Tool. Meteorological Applications. 17(1):105-116.
- Sullivan, J., Pope, L., Sutherland, B., Bennet, P., Blum, J., Stapletont, A., Gitz, D.C. 2009. Assessment of DNA damage as a tool to measure UV-B tolerance in soybean lines differing in foliar flavonoid composition. In: Gao, W., Smoltz, D., Slusser, J., editors. UV Radiation in Global Change: Measurements, Modeling and Effects on Ecosystems. Spring-Verlag New York: Isinghua University Press. p. 437-457.
- Baker, J.T., McMichael, B.L., Burke, J.J., Ephrath, J., Gitz, D.C., Lascano, R.J. 2009. Sand abrasion injury and biomass partitioning in cotton seedlings. Agronomy Journal. 101(6):1297-1303.
- Bell, C.W., Acosta Martinez, V., McIntyre, N.E., Cox, S., Tissue, D.T., Zak, J.C. 2009. Linking microbial community structure and function to seasonal differences in soil moisture and temperature in a Chihuahuan Desert Grassland. Microbial Ecology. 58(4):827-842.
- Baker, D.N., Baker, J.T. 2009. Cotton source/sink relationships. In: McD. Stewart, J, Oosterhui, D.M., Heitholt, J.J., Mauney, J.R., editors. Physiology of Cotton. Netherlands: Springer. p. 80-96.
- Acosta Martinez, V., Dowd, S.E., Bell, C., Lascano, R.J., Booker, J.D., Zobeck, T.M., Upchurch, D.R. 2010. Microbial community composition as affected by dryland cropping systems and tillage in a semiarid sandy soil. Diversity. 2(6):910-931.
- Masiokas, M., Villalba, R., Luckman, B., Mauget, S.A. 2010. Intra-to multidecadel variations of snowpack and streamflow records in the Andes of Chile and Argentina between 30 degrees and 37 degrees S. Journal of Hydrometeorology. 11:822-831.
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Progress 10/01/08 to 09/30/09
Outputs
Progress Report Objectives (from AD-416) 1. Develop new tools and a knowledge base that will enable decision makers to more effectively manage and conserve water resources. 1.a Design and test sensors that will quantify the level of plant water stress in growing crops and can be used to make irrigation decisions. 1.b Determine the relationship between crop productivity and applied water as a function of environmental factors so that irrigation can be managed for optimal use of all available water. 2. Develop and evaluate techniques and methodologies that maintain efficient agricultural production under deficit irrigation and dryland production. 2.a Design and evaluate water management strategies that optimize water use and crop production with limited well capacity. 2.b Define and evaluate crop management systems to facilitate the transition from irrigated to dryland cropping, considering crop species and varieties, cultural practices, and that incorporate long range weather prediction. 3. Identify changes in soil microbial, chemical, and physical properties affecting soil water availability and develop management practices that impact soil properties to sustain and improve crop production where water supply is in transition from limited irrigation to rainfed production. 4. Develop Best Management Practices based on a growing region's climate variability. 4.a Develop optimal planting strategies that integrate seasonal climate forecast information into agricultural managment. 4.b Develop software tools that provide detailed knowledge of precipitation, temperature stress, and evapotranspiration and demand to producers and plant breeders. Approach (from AD-416) Develop and evaluate techniques and methodologies that utilize limited water resources efficiently to maintain economically viable deficit irrigated and dryland agricultural production systems. Develop new approaches, including acoustic detection of xylem cavitation and portable chamber technologies, to quantify the degree of crop drought stress and evaluate new and existing deficit irrigation strategies. Examine irrigation quantity and application rate effects on water use efficiency using the BIOTIC protocol for irrigation scheduling. Explore the efficiency of subsurface drip irrigation for storing water from low capacity wells in the soil during the fallow season. Determine the feasibility of enhancing water infiltration with adapted grasses and use water stored in playa lakes for forage production. Evaluate new crop species and cultural practices for facilitating the transition from irrigated to dryland cropping systems. Determine the effects of crop rotations and residue management systems on soil microbial, chemical, and physical properties including effects on soil water availability, infiltration, and rainfall capture efficiency. Assess the influence of row spacing and planting patterns on water use efficiency of different cropping systems. Use seasonal climate forecasts to develop optimal planting strategies and software tools to provide detailed predictions of precipitation, temperature stress, and evapotranspiration demand for producers and plant breeders. This multifaceted research program will provide the knowledge base for optimizing the use of scarce water resources especially in arid and semi-arid regions where ground water resources are being depleted. Significant Activities that Support Special Target Populations The value of El Nino�Southern Oscillation (ENSO) forecast information to combined winter wheat and cattle grazing production systems over the U.S. Southern High Plains was estimated via computer simulation. These simulations had two goals: 1) estimate the profit and risk effects of a simple forecast method based on equatorial Pacific sea-surface temperatures (SST) in the months before planting, i.e., May-July, and, 2) identify management practices that maximize the value of seasonal forecast information in dual-purpose wheat management. Profit outcomes were derived from the simulations based on four production scenarios that assumed wheat prices varying about either historical ($3.22 bu-1) or elevated ($7.00 bu-1) means, and returns on live weight gain consistent with the grain producer leasing pasturage ($0.75 kg-1) or owning cattle ($2.42 kg-1). Under each production scenario the most profitable management strategy for specified forecast conditions was identified among 125 management practices defined by planting date, nitrogen application, and cattle stocking rate. The simple forecast system's value was compared with that of an ideal forecast method that exactly predicted whether regional November-March precipitation would fall in the driest, middle, or wettest 33rd percentile of historical values. Forecast value was calculated as the difference between profits resulting from the most profitable management practices for specific forecast conditions, and those derived from a most profitable baseline practice that assumed no forecast information. In the $3.22 bu-1 simulations the best practices for specific forecast conditions varied under different cattle ownership conditions. However, the simple forecast system's value distributions were comparable to that of the perfect forecast system, which suggests that more accurate regional precipitation forecasts may not lead to increases in forecast value. In the $7.00 bu-1 simulations, even perfect categorical forecasts produced minor profit effects. The best management practices for most forecast conditions planted on a date best for grain production, applied the maximum nitrogen level, and avoided cattle stocking rates that might decrease grain yields. Because these practices were identical to the baseline practices best when no forecast information is available, forecast value as defined here was $0.0 ha-1 under all but dry forecast conditions. The profit effect of dry forecasts from both the perfect and ENSO methods were negligible. This lack of a profit effect under $7.00 bu- 1 wheat price conditions is attributed here to increased profit margins rather than an increased commodity value. When production costs increase and profit margins narrow under $7.00 bu-1 conditions, forecast value effects reappear. However, under both elevated and historical wheat price conditions the best no-forecast baseline practices are also shown to have value relative to a sub-optimal management practice. This suggests that when forecast information is not available; which is the case in most growing regions, producers might profit from following management practices that are best for growing region's climatology.
Impacts
(N/A)
Publications
- Baker, J.T., Van Pelt, R.S., Gitz, D.C., Payton, P.R., Lascano, R.J., McMichael, B.L. 2009. Canopy gas exchange measurements of cotton in an open system. Agronomy Journal. 101(1):52-59.
- Gitz, D.C., Baker, J.T. 2009. Methods for creating stomatal impressions directly onto archivable slides. Agronomy Journal. 101(1):232-236.
- Allen, V., Brown, C.P., Segarra, E., Green, C.J., Wheeler, T.A., Acosta Martinez, V., Zobeck, T.M. 2008. In search of sustainable agricultural systems for the Llano Estacado of the U.S. Southern High Plains. Agriculture, Ecosystems, & Environment. 124:3-12.
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Progress 10/01/07 to 09/30/08
Outputs
Progress Report Objectives (from AD-416) 1. Develop new tools and a knowledge base that will enable decision makers to more effectively manage and conserve water resources. 1.a Design and test sensors that will quantify the level of plant water stress in growing crops and can be used to make irrigation decisions. 1.b Determine the relationship between crop productivity and applied water as a function of environmental factors so that irrigation can be managed for optimal use of all available water. 2. Develop and evaluate techniques and methodologies that maintain efficient agricultural production under deficit irrigation and dryland production. 2.a Design and evaluate water management strategies that optimize water use and crop production with limited well capacity. 2.b Define and evaluate crop management systems to facilitate the transition from irrigated to dryland cropping, considering crop species and varieties, cultural practices, and that incorporate long range weather prediction. 3. Identify changes in soil microbial, chemical, and physical properties affecting soil water availability and develop management practices that impact soil properties to sustain and improve crop production where water supply is in transition from limited irrigation to rainfed production. 4. Develop Best Management Practices based on a growing region's climate variability. 4.a Develop optimal planting strategies that integrate seasonal climate forecast information into agricultural managment. 4.b Develop software tools that provide detailed knowledge of precipitation, temperature stress, and evapotranspiration and demand to producers and plant breeders. Approach (from AD-416) Develop and evaluate techniques and methodologies that utilize limited water resources efficiently to maintain economically viable deficit irrigated and dryland agricultural production systems. Develop new approaches, including acoustic detection of xylem cavitation and portable chamber technologies, to quantify the degree of crop drought stress and evaluate new and existing deficit irrigation strategies. Examine irrigation quantity and application rate effects on water use efficiency using the BIOTIC protocol for irrigation scheduling. Explore the efficiency of subsurface drip irrigation for storing water from low capacity wells in the soil during the fallow season. Determine the feasibility of enhancing water infiltration with adapted grasses and use water stored in playa lakes for forage production. Evaluate new crop species and cultural practices for facilitating the transition from irrigated to dryland cropping systems. Determine the effects of crop rotations and residue management systems on soil microbial, chemical, and physical properties including effects on soil water availability, infiltration, and rainfall capture efficiency. Assess the influence of row spacing and planting patterns on water use efficiency of different cropping systems. Use seasonal climate forecasts to develop optimal planting strategies and software tools to provide detailed predictions of precipitation, temperature stress, and evapotranspiration demand for producers and plant breeders. This multifaceted research program will provide the knowledge base for optimizing the use of scarce water resources especially in arid and semi-arid regions where ground water resources are being depleted. Significant Activities that Support Special Target Populations As plants undergo increasing levels of drought stress, water inside xylem elements in the plant's stem collapse or cavitate and emit sound energy that can be detected in order to quantify the amount of drought stress a plant is experiencing. Spectral distribution of acoustic energy from xylem cavitation events was investigated in greenhouse grown cotton. A playa (or pan) is a dry or ephemeral lake bed that fills with run-off water following rainfall events and are a common feature of the landscape in the semi-arid Southern High Plains of the United States. Research plots of the forage crop Gamagrass has been established in several playas. Selected playas have been instrumented with sensors to monitor water depth throughout the year. It was found that the frequency and duration of the hydroperiod varies from playa to playa. Hence, some playas are better suited to forage production using monocultures of Eastern Gamagrass than others. Crop photosynthesis, dark respiration and transpiration are all major crop physiological processes that respond to environmental variables, including drought stress. A portable, open transparent chamber system for measuring canopy gas exchanges was developed and tested. With minor chamber effect, the chamber accurately estimates E for many field applications such as comparison of canopy gas exchanges and water use efficiencies among irrigation treatments. The value of El Nino�Southern Oscillation (ENSO) forecast information to combined winter wheat and cattle grazing production systems over the U.S. Southern High Plains was estimated via computer simulation. Profit outcomes were derived from the simulations based on four production scenarios that assumed wheat prices varying about either historical ($3. 22 bu-1) or elevated ($7.00 bu-1) means, and returns on live weight gain consistent with the grain producer leasing pasturage ($0.75 kg-1) or owning cattle ($2.42 kg-1). This suggests that when forecast information is not available � which is the case in most growing regions during most years - producers might profit from following management practices that are best for the growing region's climatology. (NP211, Component 4a)
Impacts
(N/A)
Publications
- Mauget, S.A., Ko, J. 2008. A two-tier statistical forecast method for agricultural and resource management simulations. Journal of Applied Meteorology and Climatology. 47(6):1573-1589.
- Sullivan, D., Gitz, D.C., Liu-Gitz, L., Gao, W., Slusser, J. 2007. Coupling short-term changes in ambient UV-B levels with induction of UV- screening compounds. Photochemistry and Photobiology. 83(4):863-870.
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Progress 10/01/06 to 09/30/07
Outputs
Progress Report Objectives (from AD-416) 1. Develop new tools and a knowledge base that will enable decision makers to more effectively manage and conserve water resources. 1.a Design and test sensors that will quantify the level of plant water stress in growing crops and can be used to make irrigation decisions. 1.b Determine the relationship between crop productivity and applied water as a function of environmental factors so that irrigation can be managed for optimal use of all available water. 2. Develop and evaluate techniques and methodologies that maintain efficient agricultural production under deficit irrigation and dryland production. 2.a Design and evaluate water management strategies that optimize water use and crop production with limited well capacity. 2.b Define and evaluate crop management systems to facilitate the transition from irrigated to dryland cropping, considering crop species and varieties, cultural practices, and that incorporate long range weather prediction. 3. Identify changes in soil microbial, chemical, and physical properties affecting soil water availability and develop management practices that impact soil properties to sustain and improve crop production where water supply is in transition from limited irrigation to rainfed production. 4. Develop Best Management Practices based on a growing region's climate variability. 4.a Develop optimal planting strategies that integrate seasonal climate forecast information into agricultural managment. 4.b Develop software tools that provide detailed knowledge of precipitation, temperature stress, and evapotranspiration and demand to producers and plant breeders. Approach (from AD-416) Develop and evaluate techniques and methodologies that utilize limited water resources efficiently to maintain economically viable deficit irrigated and dryland agricultural production systems. Develop new approaches, including acoustic detection of xylem cavitation and portable chamber technologies, to quantify the degree of crop drought stress and evaluate new and existing deficit irrigation strategies. Examine irrigation quantity and application rate effects on water use efficiency using the BIOTIC protocol for irrigation scheduling. Explore the efficiency of subsurface drip irrigation for storing water from low capacity wells in the soil during the fallow season. Determine the feasibility of enhancing water infiltration with adapted grasses and use water stored in playa lakes for forage production. Evaluate new crop species and cultural practices for facilitating the transition from irrigated to dryland cropping systems. Determine the effects of crop rotations and residue management systems on soil microbial, chemical, and physical properties including effects on soil water availability, infiltration, and rainfall capture efficiency. Assess the influence of row spacing and planting patterns on water use efficiency of different cropping systems. Use seasonal climate forecasts to develop optimal planting strategies and software tools to provide detailed predictions of precipitation, temperature stress, and evapotranspiration demand for producers and plant breeders. This multifaceted research program will provide the knowledge base for optimizing the use of scarce water resources especially in arid and semi-arid regions where ground water resources are being depleted. Accomplishments An Open System for Measuring Canopy Gas Exchanges: There is an urgent research need for the ability to monitor crop water loss to the atmosphere and crop carbon dioxide uptake from the atmosphere under a wide range of experiments from the field to the greenhouse. We have completed construction of three chambers we call CETA (Canopy Evapo- Transpiration and Assimilation) chambers and are currently testing these chambers for their ability to monitor crop water loss. Using these chambers, we compared plant water loss to the air against water loss of these same plants using a weighing scale. We found good agreement between the CETA chambers and the weighing scales. (NP201 Problem area 2) Managing Soil Properties through Dryland Cropping Systems Intensities: The transition from irrigated to dryland production is occurring in the Southern High Plains region due to the low recharge to the Ogallala Aquifer, which supplies the water for our agricultural activities. Increasing organic matter content of the soil can improve the water storage-reservoir for dryland crop production in both cotton and sorghum. The High Biomass Crop Dryland Study was successfully established on USDA- ARS land near Lubbock, Texas, in 2003 and it is currently in its fifth growing season. Current data is showing 1.7 times higher soil microbial biomass and 2 fold increases in enzyme activities and soil nutrient cycling under crop rotations with a winter cover crop such as cotton-rye- sorghum and haygrazer-rye compared to continuous cotton or cotton-sorghum rotations. In addition, soil organic matter content is higher under a rotation of hay (alfalfa-sorghum-rye) compared to the other rotations studied. Significant differences in water infiltration rates through the soil were found among cropping systems under no-tillage compared to conventional tillage. However, lint yield of cotton have been similar in continuous cropping compared to the cotton in rotations, and this was dependent on the amount of rainfall. Continuation of this long-term study is vitally important for the long-term evaluation and confirmation of these trends, and their implications in water management and crop productivity in dryland farming. (NP 201-Problem area 2.5 Cropping and Tillage strategies to best use limited water supplies) Improved Statistical Forecast Methods for Agricultural Management Simulations: Simple statistical methods to predict winter rainfall based on preceding El Ni�o indicators can be used to predict future climate for farmers. In order to improve these forecast systems currently in use, three mathematical methods were applied to the problem of forecasting U.S. winter precipitation. Over the Southern High Plains a "two-tier" method was found to provide the best predictive ability. This result may provide greater forecast value for winter wheat management. In the shorter term, we suggest that these management simulations based on this improved forecast method could be used in computer simulation games designed to introduce winter wheat producers to the use of these climate forecasts for agricultural production decisions. (NP 211 Component: Develop new tools and a knowledge base that will enable decision makers to more effectively manage and conserve water resources. Problem Areas: Problem Area 2, Irrigation Water Management and Security, and Problem Area 5, Watershed Management, Water Availability, and Ecosystem Restoration) Technology Transfer Number of Newspaper Articles,Presentations for NonScience Audiences: 4
Impacts
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Publications
- Baker, J.T., Gitz, D.C., Payton, P.R., Wanjura, D.F., Upchurch, D.R. 2007. Leaf gas exchange to quantify drought in cotton irrigated based on canopy temperature measurements. Agronomy Journal. 99(3):637-644.
- Timlin, D.J., Fleisher, D.H., Kim, S., Reddy, V., Baker, J.T. 2007. Evapotranspiration measurement in controlled environment chambers: a comparison between time domain reflectometry and accumulation of condensate from cooling coils. Agronomy Journal. 99:166-173.
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