Nutrient losses from an irrigated watershed in southern Idaho

Water, sediment and nutrients flowing into and out of the 82,000 ha Twin Falls,ID irrigation tract were measured from 2005 to 2008. Approximately 80% of the water flowing into the watershed was irrigation water diverted from the Snake River. About 40% of the watershed inflow returned to the Snake River. Much of this return flow was water from subsurface drain tiles and tunnels that drain shallow groundwater. Converting from furrow to sprinkler irrigation, improved irrigation management, and constructed sediment ponds have reduced sediment loss from 460 kg/ha in 1971 to <100 kg/ha in 2005. In 2007 and 2008, more sediment and phosphorus entered the watershed than returned to the Snake River. Diverting irrigation water into the watershed removed 6300 Mg of sediment, 21 Mg of dissolved P, and 32 Mg of total P from the Snake River on average each year. However, the watershed contributed almost 900 Mg of nitrate-N annually to the Snake River. Conservation practices have effectively reduced sediment and phosphorus losses from the watershed, emphasis now must shift to reducing nitrate loss from the watershed

Phosphorus losses from an irrigated watershed in the Northwestern U.S.: Case study of the Upper Snake Rock Watershed

Watersheds utilizing surface water for irrigation often return a portion of the water to a water body. This irrigation return flow often includes sediment and nutrients that reduce the quality of the receiving water body. Research in the 82,000 ha Upper Snake Rock (USR) watershed from 2005 to 2008 showed that, on average, water diverted from the Snake River annually supplied 547 kg/ha of total suspended sediment (TSS), 1.1 kg/ha of total phosphorus (TP) and 0.50 kg/ha of dissolved phosphorus (DP) to the irrigation tract. Irrigation return flow from the USR watershed contributed 414 kg/ha of TSS, 0.71 kg/ha of TP and 0.32 kg/ha of DP back to the Snake River. Significantly more TP flowed into the watershed than returned to the Snake River while there was no significant difference between inflow and return flow loads for TSS and DP. Average TSS and TP concentrations in return flow were 71 and 0.12 mg/L, respectively, which exceeded the TMDL limits of 52 mg/L TSS and 0.075 mg/L TP set for this section of the Snake River. Monitoring inflow and outflow for five water quality ponds constructed to reduce sediment and phosphorus losses from the watershed showed that TSS concentrations were reduced 36 to 75%, but DP concentrations were reduced only 7 to 16%. This research showed that continued implementation of conservation practices should result in irrigation return flow from the USR watershed meeting the TMDL limits for the Snake River

Moving toward sustainable irrigation in a southern Idaho irrigation project

Private and public irrigation development projects were a fundamental part of bringing irrigation arid regions of the western U.S. The Twin Falls Canal Company in southern Idaho provides a case study of private and public irrigation development because the project was developed by private investors under the Carey Act and receives a portion of its irrigation water from Bureau of Reclamation reservoirs. The project survived initial financial struggles and waterlogged soil to focus on sustaining the production by reducing chronic furrow irrigation erosion and nutrient losses in irrigation return flow. Average sediment loss from the project was 460 kg/ha in 1970. A cooperative effort by the canal company, state and federal agencies, and farmers improved water quality by installing sediment ponds on fields, applying polyacrylamide with furrow irrigation, converting from furrow to sprinkler irrigation, and constructing water quality ponds on irrigation return flow streams. From 2006-2018, the project retained on average 165 kg/ha of sediment and 0.4 kg/ha of total phosphorus annually, which removed 13,000 Mg of sediment and 33 Mg of total phosphorus from the Snake River each year. Nitrate-N from subsurface drainage, however, was lost at 10 kg/ha each year, which is equivalent to 380 Mg of urea fertilizer from the entire project. While sediment and phosphorus concentrations in irrigation return flow have decreased, they were still greater than the irrigation water concentrations, indicating that more can be done to reduce the project’s influence on water quality in the Snake River

Soil water measurements relevant to agronomic and environmental functions of chemically treated soil

Modern agricultural, turf, and landscape management routinely apply and depend upon chemical applications to optimize system function for specific outcomes. The effectiveness of these applied chemicals to achieve desired outcomes usually depends upon their interaction with and transport by water. To fully and accurately assess the role of water as a chemical delivery and activation system requires a good understanding of how the applied chemicals, soil, and water interact, the scale at which a phenomenon is important, the nature of soil variability, and which of the three dominant soil water properties ?content, movement, or potential energy? is most suited to assessing water’s role. The science of this assessment process is extensive and its literature is voluminous. For the uninitiated, however, it is worth being aware at least of the basics of soil water assessment and where some of the pitfalls lie. This presentation describes soil as a three-phase system ?solids, liquid, and gases? and highlights some of the key measurements and measurement considerations necessary to appropriately characterize treatment efficacy for specific, and especially, non-intuitive effects. The presentation cannot be comprehensive or substitute for requisite university-level courses in soil physics and soil chemistry, but can, perhaps, alert applicators to situations and considerations that demand more than mere cursory assessment for proper evaluation and interpretation

The Psychological Science Accelerator’s COVID-19 rapid-response dataset

In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data

Phosphorus losses from an irrigated watershed in the Northwestern U.S.: Case study of the Upper Snake Rock Watershed

Watersheds utilizing surface water for irrigation often return a portion of the water to a water body. This irrigation return flow often includes sediment and nutrients that reduce the quality of the receiving water body. Research in the 82,000 ha Upper Snake Rock (USR) watershed from 2005 to 2008 showed that, on average, water diverted from the Snake River annually supplied 547 kg/ha of total suspended sediment (TSS), 1.1 kg/ha of total phosphorus (TP) and 0.50 kg/ha of dissolved phosphorus (DP) to the irrigation tract. Irrigation return flow from the USR watershed contributed 414 kg/ha of TSS, 0.71 kg/ha of TP and 0.32 kg/ha of DP back to the Snake River. Significantly more TP flowed into the watershed than returned to the Snake River while there was no significant difference between inflow and return flow loads for TSS and DP. Average TSS and TP concentrations in return flow were 71 and 0.12 mg/L, respectively, which exceeded the TMDL limits of 52 mg/L TSS and 0.075 mg/L TP set for this section of the Snake River. Monitoring inflow and outflow for five water quality ponds constructed to reduce sediment and phosphorus losses from the watershed showed that TSS concentrations were reduced 36 to 75%, but DP concentrations were reduced only 7 to 16%. This research showed that continued implementation of conservation practices should result in irrigation return flow from the USR watershed meeting the TMDL limits for the Snake River

The applied model of imagery use: Examination of moderation and mediation effects

The applied model of mental imagery use proposed an interaction effect between imagery type and imagery ability. This study had two aims: (a) the examination of imagery ability as a moderating variable between imagery type and dispositional flow, and (b) the testing of alternative mediation models. The sample consisted of 367 athletes from Scotland and Australia, who completed the Sport Imagery Questionnaire, Sport Imagery Ability Questionnaire, and Dispositional Flow Scale-2. Hierarchical regression analysis showed direct effects of imagery use and imagery ability on flow, but no significant interaction. Mediation analysis revealed a significant indirect path, indicating a partially mediated relationship (P = 0.002) between imagery use, imagery ability, and flow. Partial mediation was confirmed when the effect of cognitive imagery use and cognitive imagery ability was tested, and a full mediation model was found between motivational imagery use, motivational imagery ability, and flow. The results are discussed in conjunction with potential future research directions on advancing theory and applications. © 2015 John Wiley &amp; Sons A/S. Published by John Wiley &amp; Sons Ltd