scholarly journals Benefits and costs of a constructed wetland on a Wairarapa dairy farm

2015 ◽  
Vol 77 ◽  
pp. 173-176
Author(s):  
J.Praat J.Sukias T. Faulkner ◽  
A. Bichan

A demonstration wetland was constructed with community support in what was a "wet" 0.75 ha of a Wairarapa dairy farm. This has reduced the level of nitrate-nitrogen leaving the farm, and has also added biodiversity to the farm and the region. Comparison of nitrate-N levels of water flowing in and out of the wetland over three months show this water quality benefit may reduce farm N loss from 14 down to 13 kg N/ha/yr, which equates to an ongoing reduction of around 7% for a one-off investment of at least $55l000. However, other contaminants such as dissolved reactive phosphate may not necessarily be reduced, while counts of Escherichia coli increased in wetland outflow. This project required a range of skills unlikely to be available to an individual farmer without wider community support but now that the wetland is established it will demonstrate what is possible when more complex solutions are implemented for nutrient loss mitigation. Keywords: dairy farm, constructed wetland, denitrification, nitrate-N, water quality, biodiversity

2011 ◽  
Vol 21 (2) ◽  
pp. 176-180 ◽  
Author(s):  
P. Chris Wilson ◽  
Joseph P. Albano

Nitrate-nitrogen (N) losses in surface drainage and runoff water from ornamental plant production areas can be considerable. In N-limited watersheds, discharge of N from production areas can have negative impacts on nontarget aquatic systems. This study monitored nitrate-N concentrations in production area drainage water originating from a foliage plant production area. Concentrations in drainage water were monitored during the transition from 100% reliance on fertigation using urea and nitrate-based soluble formulations (SF) to a nitrate-based controlled-release formulation (CRF). During the SF use period, nitrate-N concentrations ranged from 0.5 to 322.0 mg·L−1 with a median concentration of 31.2 mg·L−1. Conversely, nitrate-N concentrations during the controlled-release fertilization program ranged from 0 to 147.9 mg·L−1 with a median concentration of 0.9 mg·L−1. This project demonstrates that nitrate-N concentrations in drainage water during the CRF program were reduced by 94% to 97% at the 10th through 95th percentiles relative to the SF fertilization program. Nitrate-N concentrations in drainage water from foliage plant production areas can be reduced by using CRF fertilizer formulations relative to SF formulations/fertigation. Similar results should be expected for other similar containerized crops. Managers located within N-limited watersheds facing N water quality regulations should consider the use of CRF fertilizer formulations as a potential tool (in addition to appropriate application rates and irrigation management) for reducing production impacts on water quality.


Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 308
Author(s):  
Kristen Almen ◽  
Xinhua Jia ◽  
Thomas DeSutter ◽  
Thomas Scherer ◽  
Minglian Lin

The potential impact of controlled drainage (CD), which limits drainage outflow, and subirrigation (SI), which provides supplemental water through drain tile, on surface water quality are not well known in the Red River Valley (RRV). In this study, water samples were collected and analyzed for chemical concentrations from a tile-drained field that also has controlled drainage and subirrigation modes in the RRV of southeastern North Dakota from 2012–2018. A decreasing trend in overall nutrient load loss was observed because of reduced drainage outflow, though some chemical concentrations were found to be above the recommended surface water quality standards in this region. For example, sulfate was recommended to be below 750 mg/L but was reported at a mean value of 1971 mg/L during spring free drainage. The chemical composition of the subirrigation water was shown to have an impact on drainage water and the soil, specifically on salinity-related parameters, and the impact varied between years. This variation largely depended on the amount of subirrigation applied, soil moisture, and soil properties. Overall, the results of this study show the benefits of controlled drainage on nutrient loss reduction from agricultural fields.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. W. McDowell ◽  
Z. P. Simpson ◽  
A. G. Ausseil ◽  
Z. Etheridge ◽  
R. Law

AbstractUnderstanding the lag time between land management and impacts on riverine nitrate–nitrogen (N) loads is critical to understand when action to mitigate nitrate–N leaching losses from the soil profile may start improving water quality. These lags occur due to leaching of nitrate–N through the subsurface (soil and groundwater). Actions to mitigate nitrate–N losses have been mandated in New Zealand policy to start showing improvements in water quality within five years. We estimated annual rates of nitrate–N leaching and annual nitrate–N loads for 77 river catchments from 1990 to 2018. Lag times between these losses and riverine loads were determined for 34 catchments but could not be determined in other catchments because they exhibited little change in nitrate–N leaching losses or loads. Lag times varied from 1 to 12 years according to factors like catchment size (Strahler stream order and altitude) and slope. For eight catchments where additional isotope and modelling data were available, the mean transit time for surface water at baseflow to pass through the catchment was on average 2.1 years less than, and never greater than, the mean lag time for nitrate–N, inferring our lag time estimates were robust. The median lag time for nitrate–N across the 34 catchments was 4.5 years, meaning that nearly half of these catchments wouldn’t exhibit decreases in nitrate–N because of practice change within the five years outlined in policy.


Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1086
Author(s):  
Mario Licata ◽  
Roberto Ruggeri ◽  
Nicolò Iacuzzi ◽  
Giuseppe Virga ◽  
Davide Farruggia ◽  
...  

Dairy wastewater (DWW) contains large amounts of mineral and organic compounds, which can accumulate in soil and water causing serious environmental pollution. A constructed wetland (CW) is a sustainable technology for the treatment of DWW in small-medium sized farms. This paper reports a two-year study on the performance of a pilot-scale horizontal subsurface flow system for DWW treatment in Sicily (Italy). The CW system covered a total surface area of 100 m2 and treated approximately 6 m3 per day of wastewater produced by a small dairy farm, subsequent to biological treatment. Removal efficiency (RE) of the system was calculated. The biomass production of two emergent macrophytes was determined and the effect of plant growth on organic pollutant RE was recorded. All DWW parameters showed significant differences between inlet and outlet. For BOD5 and COD, RE values were 76.00% and 62.00%, respectively. RE for total nitrogen (50.70%) was lower than that of organic compounds. RE levels of microbiological parameters were found to be higher than 80.00%. Giant reed produced greater biomass than umbrella sedge. A seasonal variation in RE of organic pollutants was recorded due to plant growth rate Our findings highlight the efficient use of a CW system for DWW treatment in dairy-cattle farms.


2013 ◽  
Vol 68 (7) ◽  
pp. 1672-1678 ◽  
Author(s):  
M. Bozic ◽  
G. Nikolic ◽  
Z. Rudic ◽  
V. Raicevic ◽  
B. Lalevic

This paper deals with the consequences of cultural eutrophication and unconventional solutions for shallow lake restoration. Cultural eutrophication is the primary problem that affects especially shallow lakes, due to their physical characteristics (e.g. shallow depth, lack of stratification). Palic Lake, a very shallow Pannonian lake, received treated municipal wastewaters coming from the lagoons of a wastewater treatment plant. The sewage discharge mainly increased the nutrient load to the lake in the last decades. The lake sustainability is affected by inappropriate quality of water that flows into the lake, and abundance of deposited sediment. The technology that can provide both improvement of water quality and resolution of the sediment problem is a constructed wetland, which is designed to utilise the natural processes involving wetland vegetation, soil and their associated microbial assemblages to assist in additional water treatment. The technical solution is based on three key aspects: quality and quantity of deposited sediment, enriched by nutrients; effluent quality; desired lake water quality. A designed constructed wetland can accomplish the desired water quality and gradually remediate deposited sediment.


1994 ◽  
Vol 74 (1) ◽  
pp. 59-66 ◽  
Author(s):  
B. T. Bowman ◽  
G. J. Wall ◽  
D. J. King

The risk of surface-water contamination by herbicides is greatest following application to cropland when the active ingredients are at the maximum concentration and the soil is the most vulnerable to erosion following cultivation. This study determined the magnitude of surface runoff losses of herbicide and nutrients at, and subsequent to, application. The first of three weekly 10-min, 2.6-cm rainfalls were simulated on triplicated 1-m plots (a set) on which corn had been planted and the herbicide (metolachlor/atrazine, 1.5:1.0) and fertilizer (28% N at 123 kg ha−1) had just been applied. Identical simulations were applied to two other adjacent plot sets (protected from rainfall) 1 and 2 wk following herbicide application. Runoff (natural, simulated) was monitored for soil, nutrient and herbicide losses. Concentrations of total phosphorus in surface runoff water and nitrate N in field-filtered samples were not significantly influenced by the time of the rainfall simulation but exceeded provincial water-quality objectives. Atrazine and metolachlor runoff losses were greatest from simulated rainfall (about 5% loss) immediately following application. Subsequent simulated rainfall usually resulted in < 1% herbicide runoff losses. Herbicide concentrations in all plot runoff samples exceeded provincial drinking-water quality objectives. Since herbicide surface transport is primarily in the solution phase (not via association with soil particles), water-management conservation technologies are the key to retaining these chemicals on cropland. Key words: Herbicide, runoff, rainfall simulation, partitioning, water quality


2001 ◽  
Vol 1 ◽  
pp. 10-16 ◽  
Author(s):  
James L. Baker

The primary mode of nitrogen (N) loss from tile-drained row-cropped land is generally nitrate-nitrogen (NO3-N) leaching. Although cropping, tillage, and N management practices can be altered to reduce the amount of leaching, there are limits as to how much can be done. Data are given to illustrate the potential reductions for individual practices such as rate, method, and timing of N applications. However, most effects are multiplicative and not additive; thus it is probably not realistic to hope to get overall reductions greater than 25 to 30% with in-field practices alone. If this level of reduction is insufficient to meet water quality goals, additional off-site landscape modifications may be necessary.


Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3418
Author(s):  
Bing Li ◽  
Rui Jia ◽  
Yiran Hou ◽  
Chengfeng Zhang ◽  
Jian Zhu ◽  
...  

In aquaculture, constructed wetland (CW) has recently attracted attention for use in effluent purification due to its low running costs, high efficiency and convenient operation,. However, less data are available regarding the long-term efficiency of farm-scale CW for cleaning effluents from inland freshwater fish farms. This study investigated the effectiveness of CW for the removal of nutrients, organic matter, phytoplankton, heavy metals and microbial contaminants in effluents from a blunt snout bream (Megalobrama amblycephala) farm during 2013–2018. In the study, we built a farm-scale vertical subsurface flow CW which connected with a fish pond, and its performance was evaluated during the later stage of fish farming. The results show that CW improved the water quality of the fish culture substantially. This system was effective in the removal of nutrients, with a removal rate of 21.43–47.19% for total phosphorus (TP), 17.66–53.54% for total nitrogen (TN), 32.85–53.36% for NH4+-N, 33.01–53.28% NH3-N, 30.32–56.01% for NO3−-N and 42.75–63.85% for NO2−-N. Meanwhile, the chlorophyll a (Chla) concentration was significantly reduced when the farming water flowed through the CW, with a 49.69–62.01% reduction during 2013–2018. However, the CW system only had a modest effect on the chemical oxygen demand (COD) in the aquaculture effluents. Furthermore, concentrations of copper (Cu) and lead (Pb) were reduced by 39.85% and 55.91%, respectively. A microbial contaminants test showed that the counts of total coliform (TC) and fecal coliform (FC) were reduced by 55.93% and 48.35%, respectively. In addition, the fish in the CW-connected pond showed better growth performance than those in the control pond. These results indicate that CW can effectively reduce the loads of nutrients, phytoplankton, metals, and microbial contaminants in effluents, and improve the water quality of fish ponds. Therefore, the application of CW in intensive fish culture systems may provide an advantageous alternative for achieving environmental sustainability.


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