Conservation Systems: Effects of Manure Application on Drainage Water Quality

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.

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Impact of Controlled Drainage and Subirrigation on Water Quality in the Red River Valley

Water ◽

10.3390/w13030308 ◽

2021 ◽

Vol 13 (3) ◽

pp. 308

Author(s):

Kristen Almen ◽

Xinhua Jia ◽

Thomas DeSutter ◽

Thomas Scherer ◽

Minglian Lin

Keyword(s):

Water Quality ◽

Surface Water ◽

Surface Water Quality ◽

Drainage Water ◽

River Valley ◽

Red River ◽

Nutrient Loss ◽

Controlled Drainage ◽

Red River Valley ◽

The Impact

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.

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