Tailwater Recovery System Research Articles

Sediment pesticide contamination and toxicity in an agricultural tailwater recovery system

ABSTRACT Tailwater recovery system (TWR) sediment quality in Mississippi, USA, was evaluated seasonally within the storage reservoir and drainage ditch system from 2016 to 2019 for pesticide contamination, effects and bioavailability to Hyalella azteca (Saussure). Sediment bioassays (28-day) measured H. azteca survival and growth and tissue residue risks from sediment pesticide exposure. Sediment pesticide contamination comprised six current-use herbicides, three current-use insecticides, three legacy insecticides and one metabolite (p,p’-DDE). Sediment clomazone, bifenthrin and ΣDDT concentrations were greatest in drainage ditch sites during summer and fall. H. azteca tissue pesticide residues comprised three current-use herbicides and insecticides, as well as two legacy insecticides. Tissue residue clomazone, Ζ-cypermethrin and ΣDDT concentrations were greatest in drainage ditch sites during fall and winter. H. azteca survival and growth varied seasonally and spatially with lowest survival during fall and winter and lowest survival in the storage reservoir relative to drainage ditch sites during winter. Growth decreased during winter and spring with lowest growth in drainage ditches relative to the storage reservoir during spring. Patterns of associated survival and growth with tissue pesticide residues indicate increased risk during fall in TWR and where system water flows mobilise sediment pesticides increasing the risk of ecological impairment.

Opinions on Irrigation Water Management Tools and Alternative Irrigation Sources by Farmers from the Delta Region of Mississippi

AbstractWater withdrawals for irrigation at an unsustainable rate resulted in a decline in the groundwater levels in the Mississippi River Valley Alluvial Aquifer (MRVAA) in the central southern USA. This drawdown of groundwater threatens agricultural production in the Mississippi Delta, an important agricultural region in the state of Mississippi, USA. Effective and efficient use of available resources is important to sustain and enhance agricultural productivity in this area. This study assessed the opinions of farmers on water conservation management practices and technologies that improve irrigation management and save water in the Mississippi Delta region based on data collected in an irrigation survey conducted in 2012. Most landowners believed that water conservation practices were effective in reducing irrigation water use without reducing maximum crop yields and have a positive return on investment. Land forming, tailwater recovery system, on‐farm storage, instream weirs to pond surface water, computerized hole selection for furrow irrigation, short irrigation runs, and irrigation scheduling were considered efficient water conservation technologies by landowners. Perceptions about use of different practices also depend upon the crops produced by the respondents. About 20 to 24% and 14.9 to 86% of survey respondents thought that on‐farm storage and center pivot, respectively, were inefficient water conservation practices for irrigating crops in the Mississippi Delta. The adoption of these practices may be increased if the landowners know the economic returns of implementing them.

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.

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.

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.

Factors influencing the willingness to pay for on-farm water infrastructure

The use of on-farm surface water infrastructure for irrigation is a recommendation by water resource managers to address groundwater overdraft. A contingent valuation question estimates Arkansas producers9 willingness to pay (WTP) to convert farmland into an on-farm reservoir and tail-water recovery system. The estimated mean WTP to convert land into water storage is −US$1,748 ac−1 (−US$4,319 ha−1), but this WTP varies substantially across farms by irrigation practice and perception of water scarcity. Producers who use conservation practices or live in water scarce regions have a mean WTP between US$5,279 to US$21,124 ac−1 (US$13,045 to US$52,198 ha−1) while producers who do not use conservation practices or live in water abundant regions have a mean WTP between −US$7,424 and −US$12,025 ac−1 (−US$18,345 to −US$29,714 ha−1). The significant variation in the WTP suggests that conservation programs would be more cost-effective by tailoring extension activities and government cost-shares to regional- and producer-specific characteristics.

Evaluation of the impacts of BMPs and tailwater recovery system on surface and groundwater using satellite imagery and SWAT reservoir function

For an agricultural watershed, best management practice (BMP) is a conservational way to prevent non-point source pollution and soil and water loss. Three BMPs, including tail water recovery pond, conservational tillage, and crop rotation, were evaluated in order to demonstrate the impacts of BMPs on water quality and quantity. Satellite imagery was used to estimate potential tailwater recovery ponds in this study. The Soil and Water Assessment Tool (SWAT) was applied to evaluate BMPs. Results showed that the use of conservational tillage reduced cumulative sediment, total nitrogen (TN), and total phosphorus (TP) yields. In the crop rotation scenario analysis, it was found that sediment and flow were not sensitive to crop rotation management. The corn-soybean rotation scenario had higher TN and lower TP yields than those of the continuous corn scenario. Continuous soybean scenario showed the lowest TN and low TP yields, which may because of the higher nitrogen fertilization demands, greater crop yield, and greater residue of corn than soybean crop. Based on the SWAT model simulation results, the tailwater ponds can reduce sediment yield and improve groundwater storage.

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.

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.

The use of efficiency frontiers to evaluate the optimal land cover and irrigation practices for economic returns and ecosystem services

Efficiency frontiers are a useful tool for governmental agencies that balance the protection of ecosystem services with the economic returns from an agricultural landscape because the tool illustrates that a compromise of objectives generates greater value to society than optimizing a sole objective. Policy makers facing the problem of groundwater overdraft on an agricultural landscape want to know if regulations or irrigation technology adoption will enhance both economic and ecosystem service benefits. Conjunctive water management with on-farm reservoirs and tail water recovery system is frequently suggested to alleviate groundwater and surface water quality problems in the Lower Mississippi River Basin of the United States, and this study evaluates the consequence of the adoption of this technology for the balance of ecosystem service and economic objectives. A compromise of objectives that maximizes the value to society provides 76% more value to society without reservoirs and 66% more value to society with reservoirs than the sole objective of economic returns. The reservoirs help an agricultural landscape maximizing economic returns to align more closely with a landscape maximizing the value to society, although there are still significant gains possible from finding a landscape that directly compromises on the objectives.

Water-quality analysis of an intensively used on-farm storage reservoir in the northeast Arkansas delta.

The use of farm reservoirs for supplemental irrigation is gaining popularity in the Mississippi Alluvial Plain (MAP). Due to depletions of several aquifers, many counties within the MAP have been designated as critical-use groundwater areas. To help alleviate stress on these aquifers, many farmers are implementing storage reservoirs for economic and conservation benefits. When used in tandem with a tailwater recovery system, reservoirs have the potential to trap and transform potential contaminants (e.g., nutrients and pesticides) rather than releasing them through drainage into receiving systems such as lakes, rivers, and streams. Roberts Reservoir is an intensively used, 49-ha on-farm storage reservoir located in Poinsett County, Arkansas. Water-quality analyses and toxicity assessments of the reservoir and surrounding ditches indicated a stable water-quality environment with no observed toxicity present in collected samples. Results of this study suggest that water released into a local receiving stream poses no contaminant risk and could be maintained for irrigation purposes, thereby decreasing the need for additional groundwater depletion.

Optimization Size of Tailwater Recovery System in Wetland Paddy Field

In this study, a tailwater recovery system in paddy field was simulated in order to supply reuse water to industries. Field experiment and historical data were obtained for a two-tank model parameter estimation and verification. The simulation results showed that the optimization tailwater recovery system corresponding to the area of 6,036 ha in the first crop season and 1,994 ha in the second crop season in the paddy field. The volumes of the tailwater and reuse water are 18.74 × 106 and 15.52 × 106 t, respectively which can supplement 86,000 ton per day to satisfy the water requirement of industrial park with farm pond. However, an increase in the height of field’s bunds, active capacity of pond, and scale of purification unit will aid in the development of tailwater recovery system around paddy fields.

Use of Vegetation to Mitigate Nutrient Discharges in Container Nursery Runoff

Sedimentation in an abandoned irrigation pond (lower pond) at a container nursery facility in Cumberland County, New Jersey, has created a shallow wetland area. This wetland receives nutrient-rich overflow from an on-site tailwater recovery system. Three years of surface water quality monitoring data revealed that this discharge was negatively impacting receiving waters. In the fall of 2004 and summer of 2005, 4,000 native wetland plants were used to modify existing conditions at the wetland. Almost one year of water quality monitoring data was collected to determine the effectiveness of these plants in removing nutrients from the system and mitigating the impact of the system discharge on water quality. Monitoring results show that the addition of vegetation to the lower pond reduced total phosphorus (TP) loads to Harrow Run, a tributary to the Cohansey River. In addition, concentrations of nitrogen in the form of nitrite and nitrate (NO2 + NO3-N) in Harrow Run were found to have very little correlation to those discharged from the tailwater recovery system.

IRRIGATION AND NITRATE MOVEMENT EVALUATI ON IN CONVENTIONAL AND ALTERNATE?FURROW IRRIGATED COTTON

One of the important criteria in determining best management practices for irrigated agriculture is understandingthe interaction between irrigation system performance and the movement of water and solutes through the soil. The objectiveof this fouryear study was to evaluate the irrigation efficiency (IE) and the potential movement of applied nitrogen for acommercial cotton field in Arizona. In the first two cotton seasons, the grower used a conventional furrow irrigation practiceconsisting of 1.0m row spacing and irrigation in every furrow. To reduce the amount of surface water runoff (RO) observedduring the first two seasons, the grower changed to alternatefurrow irrigation and narrowed the row spacing to 0.8 m in thethird and fourth seasons. Measurements of irrigation inflow and outflow and estimates of daily crop evapotranspiration wereused to calculate the amount of RO, deep percolation (DP), and soil water storage during each irrigation event, which in turnwere used to estimate the IE attained in each cotton season. Potassium bromide (KBr) was applied to 15 sample sites at thestart of the growing season in each year to monitor the movement of bromide (Br ). Prior to the application of KBr and afterharvest for each year, soil samples were taken from the sample plots to a depth of 2.7 m and analyzed for bromide and nitrate.Runoff of applied irrigation water decreased from an average of 21% under the conventional practice to 13% after changingto alternate furrows. However, since the average fraction of irrigation water lost to DP was increased from 18% to 22% underthe alternatefurrow practice, the overall gains in IE (3% to 4%) were small. Furthermore, bromide and nitrate leachingbelow the cotton root zone appeared to be somewhat increased with the alternatefurrow practice. Implementing a tailwaterrecovery system and improving irrigation scheduling would potentially increase IE and reduce the overirrigation and nitrateleaching observed for the commercial cotton production system.