Tailwater Recovery Systems Research Articles

Tailwater recovery systems can improve water quality: An area ripe for research in cranberry agriculture

Tailwater recovery systems can improve water quality: An area ripe for research in cranberry agriculture

Pesticide Potential in Tailwater Recovery Systems

Pesticide Potential in Tailwater Recovery Systems

Seasonal water quality trends in a tailwater recovery system in the Mississippi Delta

In the Mississippi Delta region, tailwater recovery (TWR) systems are an important best management practice to address both water quality and quantity issues. TWRs are surface water capture-and-irrigation reuse systems using a combination of a ditch to capture surface water, an on-farm storage (OFS) reservoir to store captured surface water, and pumps to move surface water from the ditch into the OFS reservoir and to irrigate nearby fields. To determine if TWR systems are an effective way to reduce water use and downstream nutrient loads, water quality and quantity data from a ditch and pond TWR system in Sunflower County, Mississippi, were measured for five years. Objectives of this study were to assess seasonal TWR system runoff and runoff water quality trends. All water quality parameters had clear seasonal variation, except for chlorophyll <i>a</i>. Dissolved oxygen (DO), solids, conductivity, total dissolved organic carbon (TDOC), total phosphorus (TP), and total Kjeldahl nitrogen (TKN) exhibited significant differences between OFS reservoir and ditch sites. Total solids were 2 to 4 times higher in the ditch than in the reservoir, depending on the season, indicating sediment lost from fields through runoff is not necessarily returned to the fields via irrigation from the reservoir. Nutrients were also generally higher in the ditch than in the reservoir. Phosphate (PO₄) was 1.4 times higher in the ditch in spring compared to the reservoir, while ammonium (NH₄) and nitrate (NO₃) were 2 to 4 times higher in the ditch during the summer. These results suggest the reservoir serves an important function to process nutrients and sediments through settling, biological uptake of nutrients, and biogeochemical transformations and emphasizes the importance of a closed TWR system.

Design of Tailwater Recovery Systems Accounting for Irrigation System Operation and Performance

Design of Tailwater Recovery Systems Accounting for Irrigation System Operation and Performance

Optimal Management of Irrigation Water from Aquifer and Surface sources

AbstractWe explore the economic merits of on-farm water storage with tailwater recovery systems to reduce aquifer depletion in a region with expanding irrigated acreage and substantial off-season precipitation. Gains are substantial on a broad scale and long planning horizon, including more than $4 billion in producer surplus, 5 million acre-feet of conserved groundwater, and land capitalization of $24 per acre. Sensitivity analyses provide insights with respect to the impact of discount rates, rainfed returns, return flows, and aquifer recharge rates. Results can inform stakeholders about the optimal allocation of funds directed at agricultural practice adoption and agricultural water investments.

Pesticide trends in a tailwater recovery system in the Mississippi Delta

AbstractTailwater recovery (TWR) systems are an important best management practice (BMP) used to address both water quality and quantity issues in the Mississippi Delta region. Tailwater recovery systems are surface water capture‐and‐irrigation reuse systems using a combination of ditches to capture surface water, an on‐farm storage (OFS) reservoir to store captured surface water, and pumps to move surface water from ditches to the reservoir and from the reservoir to irrigate nearby fields. It is anticipated that TWR systems improve water quality by allowing agricultural contaminants to settle out in ditches and reservoirs rather than being transported during irrigation to nearby fields and downstream aquatic systems. To determine if TWR systems are an effective way to reduce downstream pesticide transport, water samples from a ditch‐and‐reservoir TWR system in Sunflower County, MS, were routinely collected and analyzed for 5 yr. Objectives of this study were to assess seasonal pesticide and pesticide metabolite concentrations throughout the different components of the TWR system and identify any trends that may exist. Atrazine‐desethyl, atrazine‐desisopropyl, atrazine, clomazone, propanil, fipronil desulfinyl, metolachlor, fipronil, p,p'‐DDT, bifenthrin, beta‐cyfluthrin, and zeta‐cypermethrin were found in every season in both ditch and reservoir samples. Several pesticides that have not been used in the United States for decades were detected including DDT and its metabolites as well as dieldrin, heptachlor, lindane, and methyl parathion, demonstrating their environmental persistence. The reservoir featured more types and higher concentrations of pesticides, indicating a possible risk of cross‐crop injury from the recycling of the water from the reservoir for irrigation.

Water quality characteristics of tailwater recovery systems associated with agriculture production in the mid-southern US

In the Lower Mississippi River Basin, tailwater recovery (TWR) systems are water conservation practices implemented to mitigate downstream nutrient losses and alleviate groundwater depletion as supplemental irrigation sources. This study was conducted to characterize water quality within TWR systems and assess the influence of precipitation and fertilizer application events, as well as reservoir levee protection, on water quality. Three TWR systems were selected, and water samples were collected during the growing seasons of 2014–2016. Nitrate (NO3) and dissolved inorganic orthophosphate (DIP) were observed to be significantly lower (p < 0.001) in reservoirs when compared with TWR influent and effluent; hence, reservoirs demonstrate a vital role in reducing downstream nutrient contribution. Mean NO3 in the reservoirs, TWR influent, and TWR effluent was 0.05 ± 0.01 mg L-1, 0.10 ± 0.01 mg L-1, and 0.14 ± 0.02 mg L-1, respectively. Mean DIP concentrations in the reservoirs, TWR influent, and TWR effluent was 0.39 ± 0.03 mg L-1, 0.96 ± 0.04 mg L-1, and 1.03 ± 0.08 mg L-1, respectively. Mean NO3 concentration was also significantly lower (p = 0.001) in the reservoir with levees protected with vegetation (0.02 ± 0.01 mg L-1) compared to (0.06 ± 0.01 mg L-1) reservoirs with levees protected with concrete rubble. Total suspended solids (TSS) of the influent and reservoir were significantly different, with the reservoir TSS reduced on average by 43% compared to the influent. Water quality was influenced by reservoir levee protection materials, especially NO3 and dissolved oxygen concentrations which were lower with vegetated protection.

Outflow hydrology of tailwater recovery systems with comparisons to a control catchment*

AbstractConservation practices termed tailwater recovery (TWR) systems are being installed throughout the Lower Mississippi River basin to mitigate damage from agricultural production. Many of the costs and benefits of these systems have yet to be documented; therefore, the objective of this study is to assess whether TWR systems have the potential to impact on the hydrology of downstream systems. In this study, we compare hydrologic parameters of two TWR systems—one with an on‐farm storage reservoir (TWR‐OFS) and one without (TWR‐D)—and a control ditch (CTRL). Systems were monitored at one outflow location each using flow meters. Estimated percentage differences between TWR‐D and CTRL sites were determined, in which the CTRL site was found to have greater values reflected in the parameters, including length of event median 94% and mean 60%; time to peak median 80% and mean 70%; time to base median 88% and mean 60%; peak flow median 86% and mean 67% and discharge median 134% and mean 101%. The TWR‐D and TWR‐OFS sites differed in peak flow, with TWR‐OFS being 40% greater. Evidence from this investigation shows that TWR systems have the potential to influence downstream hydrology by retaining water.

Residual herbicide concentrations in on‐farm water storage–tailwater recovery systems: Preliminary assessment

AbstractOn‐farm water storage–tailwater recovery systems reduce groundwater usage and intercept agrochemical loads, but pesticide residue dynamics in these systems are not well understood. This study monitored concentrations of seven herbicides in seven northeast Arkansas tailwater recovery systems (April 2017–March 2018). Clomazone, glyphosate, metolachlor, and quinclorac were frequently detected, with minimal detections of 2,4‐D, dicamba, and propanil. Concentrations peaked during the growing season (1 Apr.–15 Sept.), reflecting an interaction of application and precipitation. Clomazone, glyphosate, and quinclorac concentrations were greater in ditches (&lt;0.80–67, &lt;0.50–6.2, and &lt;0.40–62 μg L−1, respectively) than in the associated reservoir (&lt;0.80–6.0, &lt;0.50–4.1, and &lt;0.40–6.0 μg L−1, respectively), but metolachlor concentrations were not different between structure types (maximum 22–32 μg L−1). Off‐season concentrations were mostly below detection, except for quinclorac. Cycling recovered tailwater through the system and irrigating from reservoirs may minimize risk of cross‐crop contaminations with residual herbicides. Managed groundwater recharge should use reservoir water during winter to protect groundwater quality.

Soybean response to dicamba exposure in furrow irrigation

AbstractSensitive crop exposure to residual dicamba in irrigation is a potential hazard in regions with overlapping use of transgenic dicamba‐resistant crops and on‐farm water storage–tailwater recovery (OFWS‐TWR) systems. This field study examined non–dicamba‐resistant soybean [Glycine max (L.) Merr.] for response to a dicamba dose gradient (7.6–630 g ae ha−1) in a furrow irrigation system. In a second study, growth stage and application timing effects were explored, with dicamba applied at 160 g ae ha−1 in entirety to V3 or R1 soybean or split across exposure events. Plant injury 14 and 28 d after treatment (DAT) increased with dose, with significant injury at 160–630 g ae ha−1. Plant injury 28 DAT was higher after split exposure compared with single exposure. Height and yield reduction occurred at 160–630 g ae ha−1 and in plants treated at reproductive growth stages. Regression models associated yield loss of 10, 20, and 30%, with effective doses of 19, 43, and 110 g ae ha−1, respectively, and plant injury 14 DAT of ∼10, ∼25, and ∼40%, respectively. Dicamba doses in irrigation that elicited equivalent response to foliar exposure were up to an order of magnitude higher, suggesting soybean plants are less sensitive to root uptake of dicamba. Alternately, dissipation in the environment may reduce total uptake. Off‐target dicamba exposure in irrigation will likely result in yield loss if tailwater dicamba concentrations exceeding ∼0.20 mg L−1 in 30.8 ha‐mm irrigation. This high residual concentration would likely only occur in OFWS‐TWR systems under “worst‐case scenario” conditions.

Soybean response to dicamba in irrigation water under controlled environmental conditions

AbstractWhile much research has focused on crop damage following foliar exposure to auxin herbicides, reports documenting the risk posed by exposure via root uptake of irrigation water are lacking. Herbicide residues circulated in tailwater recovery systems may pose threats of cross-crop impacts to nonresistant cultivars with known sensitivity to auxins. An auxin-susceptible soybean [Glycine max(L.) Merr.] cultivar was grown in a controlled growth chamber environment and exposed to dicamba dissolved in irrigation water applied to the soil surface, simulating furrow irrigation. Five herbicide treatment concentrations, ranging from 0.05 to 5.0 mg L−1and encompassing estimated field doses of 3.1 to 310g ha−1, were applied to the soil of potted soybean plants at V3/V4 or R1 growth stages. Plant injury (0% to 100%), dry mass, height, number of pods, and number of pod-bearing nodes were measured. Kruskal-Wallis and logistic regression analyses were performed to determine treatment differences and examine dose effects. Yield losses were projected using (1) 14 d after treatment plant injury assessments based on injury–yield relationships described for foliar exposures and (2) pod counts. Dicamba concentration was the main significant factor affecting all growth response metrics, and growth stage was a significant explanatory variable only for the height response metric. A nonlinear response to dicamba dose was observed, with the threshold response dose required to affect 50% of plants being three times greater for 40% crop injury compared with 20% injury. Yield projections derived from plant response to root uptake compared with foliar exposure indicate that soybean may express both magnitude of injury and specific symptomology differently when exposure occurs via root uptake. Drift exposure–based models may be incompatible to predict soybean yield loss when injury results from irrigation. Data are needed to develop correlations for predicting yield losses based on field-scale exposure to dicamba in irrigation water, as well as assessment of real-world concentrations of herbicide residues in tailwater recovery systems.

Economic costs of using tailwater recovery systems for maintaining water quality and irrigation

Best management practices (BMPs) are conservation efforts implemented to address environmental challenges associated with agricultural production. One such BMP, a tailwater recovery (TWR) system, has a dual purpose aimed at mitigating solids and nutrient losses from agricultural landscapes and creating an additional surface water source for irrigation. This study analyzes the costs of using five TWR systems to reduce solids, nutrients, and retain water. All systems were located in the Lower Mississippi Alluvial Valley and were used to irrigate crops including rice (Oryza sativa), corn (Zea mays), and soybeans (Glycine max). Costs to reduce solids and nutrients were calculated using annual payments and revenue losses due to lost tillable area from implementation of TWR systems. Similarly, cost to save and irrigate a mega-liter (ML) of water was determined as the annual payment for TWR systems, revenue losses and measured pumping cost. The range of mean total cost to reduce solids using TWR systems was $0 to $0.77 per kg; P was $0.61 to $3315.72 per kg; and N was $0.13 to $396.44 per kg. The range of mean total cost to retain water using TWR systems was $189.73 to $628.23 per ML, compared to a range of mean cost of groundwater of $13.99 to $36.17 per ML. Compared to other BMPs, TWR systems are one of the least expensive ways to reduce solid losses but remain an expensive way to reduce nutrient losses. The costs of using TWR systems to provide an additional irrigation water source range from less expensive than common conservation practices used to improve water use efficiency to more expensive and comparable to practices such as desalination. Therefore, TWR systems may be a prohibitively more expensive BMP to retain nutrients and water on some agricultural landscapes than other solutions.

Economic analyses of implemented tailwater recovery systems in the Lower Mississippi Alluvial Valley

Tailwater recovery (TWR) systems are being implemented on agricultural landscapes to reduce nutrient loss and save water on the landscape for irrigation. These systems are a large financial investment for both the United States Department of Agriculture Natural Resources Conservation Service (USDA NRCS) and private producers with total costs ranging from $400,000 to 900,000. Although economic analyses of TWR systems have been modeled, analyses of implemented TWR systems have yet to be completed. Economic studies are necessary to guide adaptive management of conservation funding for appropriation in methods with the greatest return. Therefore, an analysis was conducted on the costs and benefits of TWR systems by first comparing net present value (NPV) and benefit-to-cost ratios (BCR) of operation scenarios with and without TWR systems, as well as, with and without sediment reduction benefits. Second, the impact of the level of USDA NRCS financial assistance on NPV was evaluated. Three discount rates of 3, 7, and 10% were used on both rented and owned land schemes. Five TWR system scenarios were used in the investigation including dryland, irrigated, irrigation improvements, TWR systems, and TWR systems with external benefits of sediment loss mitigation. NPV and BCRs were positive and greater than one for TWR systems if producers owned the land but remained negative or less than one if land was rented. Beyond improvements to irrigation infrastructure, farms with a TWR system installed lost NPV of $51 to $328 per ha. Therefore, TWR systems are not considered to be economically viable when land is not owned.

Water quality improvements from implementation of tailwater recovery systems

Impacts of nutrient loading from agricultural landscapes have gained widespread attention and led to the implementation of conservation practices aimed at mitigating nutrient loss to downstream systems. A relatively new conservation practice, tailwater recovery (TWR) systems, has been considered as a potential mitigation strategy. The objective of this study was to compare concentrations and loads between effluent of TWR systems (TE) and effluent of similar catchments without TWR systems (CE), under the same agronomic management. Tailwater recovery systems, CE, and paired differences between TE and CE were compared over seasons. Nutrient concentrations and hydrologic discharge were monitored at five TWR system outflow and control catchment outflow locations on a flow event basis. Results revealed that of all experimental analytes, including total suspended solids, total phosphorus, total Kjeldahl nitrogen, nitrate–nitrite, and ammonium, only total phosphorus concentrations were greater (F1,97 = 8.58, p < 0.005) at CE locations than TE locations. The difference between loads of TE and CE showed reduced loads per hectare leaving TWR systems. This included loads of total phosphorus, total nitrogen, organic nitrogen, total inorganic nitrogen, and nitrate–nitrite. Analyses revealed no differences across seasons for TE and paired differences between TE and CE. However, CE concentrations and loads were seasonally different, where ammonium was greater in the summer than in the winter and spring, but not different than fall. Additionally, only loads of total nitrogen were different across seasons, where winter was greater than spring, but not different than summer and fall. This study provides evidence that TWR systems are a positive contribution to reducing nutrient loads compared to control locations.

Development of Water Budget for Tailwater Recovery Systems in the Lower Mississippi Alluvial Valley

AbstractUnsustainable groundwater use for agricultural irrigation has led to declining aquifer levels across the United States, necessitating implementation of water conservation practices. One con...

Reduction of solids and nutrient loss from agricultural land by tailwater recovery systems

Best management practices are being implemented throughout the Lower Mississippi River Alluvial Valley with the aim of alleviating pressures placed on downstream aquatic systems by sediment and nutrient losses from agricultural land; however, research evaluating the performance of tailwater recovery (TWR) systems, an increasingly important practice, is limited. This study evaluated the ability of TWR systems to retain sediment and nutrients draining from agricultural landscapes. Composite flow-based samples were collected during flow events (precipitation or irrigation) over a two-year period in six TWR systems. Performance was evaluated by comparing concentrations and loads in water entering TWR systems (i.e., runoff or influent) from agricultural fields to water overflow exiting TWR systems (effluent). Tailwater recovery systems did not reduce concentrations of solids and nutrients, but did reduce loads of solids, phosphorus (P), and nitrogen (N) by 43%, 32%, and 44%, respectively. Annual mean load reductions were 1,142 kg solids, 0.7 kg of P, and 3.8 kg of N. Performance of TWR systems was influenced by effluent volume, system fullness, time since the previous event, and capacity of the TWR system. Mechanistically, TWR systems retain runoff on the agricultural landscape, thereby reducing the amount of sediment and nutrients entering downstream waterbodies. System performance can be improved through manipulation of influential parameters.

Assessment of irrigation reservoir levee impairment in Arkansas, United States

The use of surface water resources for irrigation in the state of Arkansas increased over the years following 2000 due to groundwater depletion. In order to reduce dependence on groundwater, irrigation reservoirs and tailwater recovery systems are used to capture and store water for irrigation. Irrigation reservoir levees are typically constructed from local soils that are often low in cohesion, and the use of rock armoring and geotextiles is limited due to high costs, resulting in levees that are susceptible to erosion. Wind-driven waves erode the exposed inner slopes of the levees, resulting in the need for frequent repairs, an added expense for agricultural producers. Evaluation of the status of irrigation storage reservoirs and identification of design factors that contribute to erosion are needed to address the problem. A survey was conducted in 2013 to 2015 to assess the current state of levee erosion and attempt to identify associated factors. It was found that 79% of the 584 homogeneous levee segments contained within 148 surveyed reservoirs had block failures and near-vertical slopes. Despite regional winds with preferential southerly and northerly directions, levees of all orientations were damaged by waves. For the surveyed irrigation reservoir levees, soil type, vegetation, inner slope, and berm presence were found to be poor predictors of the state of impairment. The most important variable associated with levee failure was maximum effective fetch length, such that longer fetches were more likely to have block failures and greater loss of top width.

Assessment of Levee Treatments for an Irrigation Reservoir in Arkansas

Abstract. On-farm irrigation reservoirs, together with tailwater recovery systems, are commonly used to store water in the Mississippi River Valley alluvial floodplain to supplement limited groundwater resources. The inner slopes of the earthen embankments that enclose these reservoirs are subjected to continuous erosion due to wind-generated waves. Various methods have been used to protect the embankments, but none of them have been shown to be both sustainable and cost-effective. In an effort to assess levee protection strategies, a range of treatment techniques, including levee configurations and surface treatments, were applied on the embankments of the University of Arkansas Pine Bluff (UAPB) Lonoke Demonstration Reservoir in 2007. The treatment techniques included 17 different slope configurations along the east and west embankments and five chemical and mechanical treatments along the north and south embankments. Embankment erosion was measured by comparing new surveys conducted in 2015 and 2017 with as-built information provided by the USDA Natural Resources Conservation Service (NRCS). The change in levee profile between the surveys and the as-built profiles was used to quantify the effectiveness of the treatment methods for protection against wave action. An artificial neural network (ANN) prediction model was developed to establish relationships between erosion parameters (eroded area and maximum retreat) and four independent variables (existence of berm, face slope, maximum effective fetch, and probability of wind speed). Data from 27 sections were used for training, and data from seven sections were used for testing. Almost all of the slope treatments were significantly eroded over the eight to ten years that elapsed between construction and the surveys. Although having a berm did not significantly reduce the total eroded volume, in most cases it delayed the bank retreat. For any two identical slope configurations, the one with the longest fetch typically had at least slightly higher erosion and retreat. In general, milder slopes performed better than steeper slopes. The survey results showed that geo-synthetic fabric, fly ash, and soil cement were more effective at reducing wave erosion than the other treatment methods. Keywords: Embankment erosion, Irrigation reservoir, Levee erosion, Wave erosion.

Assessing Irrigation Aquifer Depletion: Introduction

Assessing Irrigation Aquifer Depletion: Introduction

Potential for recycling of suspended solids and nutrients by irrigation of tailwater from tailwater recovery systems

Abstract Within the Lower Mississippi Alluvial Valley, conservation practices are being utilized to mitigate nutrient loading to streams from agricultural landscapes. This study was conducted to determine the potential to use solids, phosphorus (P) and nitrogen (N) captured by tailwater recovery (TWR) systems for reuse onto production fields through irrigation applications. Seven TWR systems were assessed for seasonal changes in nutrient concentrations and application loads. Samples were collected every three weeks from 2013 to 2015 for seasonal analyses and weekly during the 2014 and 2015 growing seasons for nutrient load analyses. Water samples collected in spring contained greater concentrations of solids than samples collected in winter and summer. In addition, spring samples contained greater concentrations of nitrate–nitrite than samples collected in all other seasons, and spring samples also contained higher ammonium than summer and fall samples. Mean nutrient loads per hectare recycled onto the landscape for an irrigation season were 325.10 kg ha−1 solids, 0.86 kg ha−1 P, and 7.26 kg ha−1 N, with the N being 77% organic. TWR systems can be used to recycle solids, P and N onto agricultural landscapes through irrigation events; however, nutrient loads will not be sufficient to alter agronomic fertilizer recommendations.