Two-Stage Weir Control of Subsurface Drainage for Water Table Management

Water table management systems can be designed to alleviate soil water excesses and deficits, as well as reduce nitrate leaching losses in tile discharge. With this in mind, a standard tile drainage (DR) system was compared over 8 years (1991 to 1999) to a controlled tile drainage/subirrigation (CDS) system on a low-slope (0.05 to 0.1%) Brookston clay loam soil (Typic Argiaquoll) in southwestern Ontario, Canada. In the CDS system, tile discharge was controlled to prevent excessive drainage, and water was pumped back up the tile lines (subirrigation) to replenish the crop root zone during water deficit periods. In the first phase of the study (1991 to 1994), continuous corn (Zea mays, L.) was grown with annual nitrogen (N) fertilizer inputs as per local soil test recommendations. In the second phase (1995 to 1999), a soybean (Glycine max L., Merr.)-corn rotation was used with N fertilizer added only during the two corn years. In Phase 1 when continuous corn was grown, CDS reduced total tile discharge by 26% and total nitrate loss in tile discharge by 55%, compared to DR. In addition, the 4-year flow weighted mean (FWM) nitrate concentration in tile discharge exceeded the Canadian drinking water guideline (10 mg N l–1) under DR (11.4 mg N l–1), but not under CDS (7.0 mg N l–1). In Phase 2 during the soybean-corn rotation, CDS reduced total tile discharge by 38% and total nitrate loss in tile discharge by 66%, relative to DR. The 4-year FWM nitrate concentration during Phase 2 in tile discharge was below the drinking water guideline for both DR (7.3 mg N l–1) and CDS (4.0 mg N l–1). During both phases of the experiment, the CDS treatment caused only minor increases in nitrate loss in surface runoff relative to DR. Hence CDS decreased FWM nitrate concentrations, total drainage water loss, and total nitrate loss in tile discharge relative to DR. In addition, soybean-corn rotation reduced FWM nitrate concentrations and total nitrate loss in tile discharge relative to continuous corn. CDS and crop rotations with reduced N fertilizer inputs can thus improve the quality of tile discharge water substantially.

Download Full-text

Design Guidelines for Water Table Management Systems on Coastal Plain Soils

Applied Engineering in Agriculture ◽

10.13031/2013.26558 ◽

1989 ◽

Vol 5 (4) ◽

pp. 539-548 ◽

Cited By ~ 9

Author(s):

R. O. Evans ◽

R. W. Skaggs

Keyword(s):

Water Table ◽

Coastal Plain ◽

Design Guidelines ◽

Management Systems ◽

Water Table Management

Download Full-text

Performance Evaluation of Subsurface Drainage System with Reference to Water Table Response in Aduthurai, Tamil Nadu, India

Current Journal of Applied Science and Technology ◽

10.9734/cjast/2017/36558 ◽

2017 ◽

Vol 24 (1) ◽

pp. 1-8

Author(s):

M Punitha ◽

R Rajendran

Keyword(s):

Performance Evaluation ◽

Water Table ◽

Tamil Nadu ◽

Drainage System ◽

Subsurface Drainage

Download Full-text

Effects of Controlled Drainage on Water Table Recession Rate

Transactions of the ASABE ◽

10.13031/trans.11922 ◽

2017 ◽

Vol 60 (3) ◽

pp. 813-821 ◽

Cited By ~ 5

Author(s):

Samaneh Saadat ◽

Laura Bowling ◽

Jane Frankenberger ◽

Kyle Brooks

Keyword(s):

Water Table ◽

Subsurface Drainage ◽

Drainage Water ◽

Optimal Operation ◽

Rainfall Event ◽

Controlled Drainage ◽

Recession Rate ◽

Watershed Approach ◽

Recession Rates ◽

Paired Watershed

Abstract. Controlled drainage is a best management practice that decreases nitrate loads from subsurface drainage, but questions remain about optimal operation strategies. One unanswered question is whether the outlet should be lowered prior to or directly after a rainfall event to reduce the amount of time that the water table is at a level that would be detrimental to either trafficability or crop yield. The objective of this study was to determine how much controlled drainage lengthens the time needed for the water table to fall after a rainfall event, to inform possible improvement in the management of controlled drainage systems. This objective was addressed using water table recession rates from two pairs of controlled and free-draining fields located at the Davis Purdue Agricultural Center in Indiana over a period of nine years (2006-2014). At each pair, comparison of mean recession rates from the two fields indicated that controlled drainage reduced recession rate. The significance of the relationship between paired observations and the effect of controlled drainage was determined by a paired watershed approach using analysis of variance (ANOVA) and covariance (ANCOVA). Raising the outlet of the subsurface drainage system decreased the mean rate of water table recession by 29% to 62%, increasing the time needed for the water table level to fall from the surface to 30 and 60 cm depths by approximately 12 to 26 h and 24 to 53 h, respectively. Based on these results, it can be concluded that lowering the outlet before storm events would reduce the amount of time that the water table is at a detrimental level for either crop growth or trafficability. However, the trade-off between costs and benefits of active management depends on the sensitivity of the crop and probability of a severe storm. Keywords: Drainage water management, Managed drainage, Paired watershed approach, Tile drainage, Water table drawdown.

Download Full-text