Controlled Drainage With Subirrigation Research Articles

Hydrological consequences of controlled drainage with subirrigation

Controlled drainage with subirrigation (CD-SI) could be a viable measure to cope with the imbalance in water demand and supply in groundwater dependent regions. CD-SI has the potential to i) retain, ii) recharge and iii) discharge groundwater, i.e. anticipate both dry and wet weather extremes. The aim of this paper is to specify the hydrological consequences of CD-SI at field scale. Four field CD-SI pilots with varying geohydrological conditions in Dutch sandy Pleistocene uplands were monitored (minimum 5 years) to study the effects on groundwater level, soil moisture content and soil water potential. Dynamic modelling using the SWAP-model, calibrated with PEST, was used to quantify all water balance components for the field pilots, needed for responsible implementation of CD-SI. Using SWAP-PEST, measured groundwater levels and soil moisture conditions were reproduced sufficiently accurate. Both the water supply rates and the water and crest levels in the control pit of CD-SI systems could be simulated dynamically, which is an important improvement to earlier modelling approaches. Model calculations were used to study the hydrological responses of CD-SI for meteorological dry to wet years and for each of the field sites. Simulations show that transpiration increases with 38 to 206 mm in dry years for sites with respectively low and higher hydraulic resistances in the subsoil. Simulations also show that the required water volume can be large (664 – 728 mm, respectively). CD-SI could thus improve hydrological conditions for crop growth, but the success depends on subtle differences in geohydrologic characteristics.

Potential of implementing irrigation in rainfed agriculture in Quebec: A review of climate change‐induced challenges and adaptation strategies

AbstractLeading to growing‐season water stress, eastern Canada's evolving climate has disrupted the region's rainfed farming systems. Accordingly, this review was conducted to assess the status of irrigation, climate‐induced challenges and opportunities and the impact of adaptation strategies on economic returns and the environment in Quebec's agricultural regions. While irrigation is limited mainly to high‐value crops, controlled drainage with sub‐irrigation (CDSI) has been implemented at a limited number of field sites. Given the greater rainfall variability and rising number of growing‐season heatwave events anticipated, previous studies have mainly focused on developing climate change adaptation practices. The present study identified two research gaps: (i) a lack of analyses of drought frequency and its effect on root zone soil moisture, crop ET, crop phenology and agricultural production at a regional scale under historical and future climates and (ii) a lack of regional‐scale studies addressing climate change adaptation options, including supplementary irrigation, and their potential effects on economic return and water resources under a changing climate. Additional studies must address these gaps for the development of climate change adaptation practices to secure food demand and water sustainability.

Soil nutrients and plant uptake parameters as related to greenhouse gas emissions.

Fertilizer and water management practices have short- and long-term effects on soil chemical and physical properties and, in turn, greenhouse gas (GHG) emissions. The goal of this 4-yr field study was to establish the relationships between soil properties, agronomic practices, and GHG (CO2 and N2 O) emissions under different fertilizer and water table management practices. There were two fertilizer treatments: inorganic fertilizer (IF) and a mix of solid cattle manure and inorganic fertilizer (SCM), combined with tile drainage(DR) and controlled drainage with subirrigation(CDS). The cropping system was a maize (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation. Nitrogen in biomass (BMN) and N in grain (GRN) were measured and used to calculate other plant N parameters. Nitrous oxide and CO2 fluxes were collected weekly, and their respective cumulative emissions were calculated. The results show that soil organic matter (OM), soil total carbon (C), and soil total nitrogen (N) were greater in SCM than IF by 23.7, 35.2, and 24.4%, respectively. Water table management did not significantly affect soil N and C. Increased CO2 emissions were witnessed under higher soil OM, soil total C, and total N. Plant N uptake parameters were negatively correlated with N2 O and CO2 emissions. Higher plant N uptake can reduce environmental pollution by limiting N2 O and CO2 emissions.

Nitrous oxide emissions as affected by fertilizer and water table management under a corn-soybean rotation

Nitrous oxide (N2O) emissions from agricultural soils are influenced by several factors, including fertilizer and water management. A 4-year study (2012–15) was conducted to evaluate the impact of different types of fertilizer and water table management systems on N2O emissions under a corn-soybean rotation. The types of fertilizers assessed were inorganic fertilizer (IF) and a combination of inorganic fertilizer and solid cattle manure (SCM) (applied in 2012 and 2014, for corn only), while the water table management systems were regular tile drainage (DR), and controlled drainage with sub-irrigation (CDS). The IF and SCM were combined with DR and CDS in separate plots arranged as a two by two factorial design. The results show that, in 2012, 2013 and 2014, N2O fluxes were significantly (2012, 2013 p < 0.05; 2014 p < 0.1) affected by the fertilizer treatments. In 2012 and 2014, when fertilizer was applied to corn, the emissions were greater from IF than SCM; however, in 2013, under soybean cultivation, the emissions were greater from SCM than IF, indicating slow mineralization of SCM fertilizer compared to IF. In 2014, under corn and 2015 under soybean, the N2O fluxes were significantly higher (P < 0.05) from DR compared to CDS plots indicating a greater reduction of N2O to dinitrogen (N2) via denitrification. The results also showed that early in the growing season, high N2O fluxes were observed following planting due to fertilizer application, precipitation in excess of 100 mm per month in the early growing season, and spring tillage. The N emission factors of IF-DR, IF-CDS, SCM-DR, and SCM-CDS were 1.2, 0.9, 1.0, and 0.5, respectively. This study concludes that the combination of SCM and CDS is the most efficient at reducing N2O emissions while maintaining sustainable yields in a corn-soybean rotation.

Evaluating RZ-SHAW model for simulating surface runoff and subsurface tile drainage under regular and controlled drainage with subirrigation in southern Ontario

The response of both surface runoff and subsurface drainage as affected by water table management practices in tile-drained fields is poorly documented. Widely used to simulate management effects on crop production and water quality, the Root Zone Water Quality Model (RZWQM2) has recently been equipped with a subirrigation component. Coupled with Simultaneous Heat and Water (SHAW) model to improve its hydrological responses to cold climates, the hybrid RZ-SHAW has never been tested for simulating surface runoff and subsurface drainage under controlled drainage with subirrigation system. The objective of this study was to evaluate the model performance in predicting surface runoff, subsurface tile drainage, and crop yield under regular drainage (DR) and controlled drainage with subirrigation (CDS) for the first time. The RZ-SHAW model was calibrated and validated against tile drainage, surface runoff and crop yield data collected in a tile-drained field in Harrow, Ontario from June 2008 to December 2011 under DR and CDS treatments. Despite occasional underestimation in winter and overestimation in summer, the model was performing generally satisfactorily in simulating the accumulated subsurface drainage and runoff under both DR and CDS treatments with percent bias (PBIAS) within ±15 %, Nash-Sutcliffe model efficiency coefficient (NSE) >0.5 and the index of agreement (IoA) >0.75. Overall, the RZ-SHAW was capable of predicting the subsurface drainage and surface runoff under both DR and CDS treatment, and it provided reliable estimation for the impact of water table management practice on ET and crop yield, but its accuracy for simulating events of peak flow was not as precise for the CDS treatment than DR treatment.

Mitigating greenhouse gas emissions in subsurface-drained field using RZWQM2

Greenhouse gas (GHG) emissions from agricultural soils are affected by various environmental factors and agronomic practices. The impact of inorganic nitrogen (N) fertilization rates and timing, and water table management practices on N2O and CO2 emissions were investigated to propose mitigation and adaptation efforts based on simulated results founded on field data. Drawing on 2012–2015 data measured on a subsurface-drained corn (Zea mays L.) field in Southern Quebec, the Root Zone Water Quality Model 2 (RZWQM2) was calibrated and validated for the estimation of N2O and CO2 emissions under free drainage (FD) and controlled drainage with sub-irrigation (CD-SI). Long term simulation from 1971 to 2000 suggested that the optimal N fertilization should be in the range of 125 to 175 kg N ha−1 to obtain higher NUE (nitrogen use efficiency, 7–14%) and lower N2O emission (8–22%), compared to 200 kg N ha−1 for corn-soybean rotation (CS). While remaining crop yields, splitting N application would potentially decrease total N2O emissions by 11.0%. Due to higher soil moisture and lower soil O2 under CD-SI, CO2 emissions declined by 6% while N2O emissions increased by 21% compared to FD. The CS system reduced CO2 and N2O emissions by 18.8% and 20.7%, respectively, when compared with continuous corn production. This study concludes that RZWQM2 model is capable of predicting GHG emissions, and GHG emissions from agriculture can be mitigated using agronomic management.

Simulating hydrologic cycle and crop production in a subsurface drained and sub-irrigated field in Southern Quebec using RZWQM2

Agricultural system models are promising tools in evaluating the agro-environmental effects of water management practices. However, very few models have been tested using a comprehensive hydrologic data set. The present study’s objective was to evaluate the hydrologic component of RZWQM2 (Root Zone Water Quality Model) using a comprehensive hydrological dataset including subsurface tile drainage, subirrigation, soil water content, sap flow and crop growth data such as leaf area index, crop yield and crop growth stages. Drawing on 2008 and 2009 data from a farm site in Southern Quebec, the RZWQM2 model showed accurate simulation in soil water content, sap flow, growth stage, leaf area index, and crop yield. While mean values for growing season tile flow under both free drainage (FD) and controlled drainage with subirrigation (CD-SI) were reasonably accurate, winter tile flow was significantly overestimated, indicating RZWQM2’s reliability to be compromised by its imperfect winter drainage process. Accordingly, a Kalman filter technique was applied to enhance model reliability and reduce predictive uncertainties. A novel RZWQM2 model equipped with a Kalman filter algorithm adequately simulated, in both calibration and validation phases, the hydrology and corn growth which occurred under both FD and CD-SI systems at the selected field site. Simulation results suggest that RZWQM2 model can be used for water management under subsurface drained and irrigated field and the Kalman filter technique significantly improved the accuracy of RZWQM2 model in simulating winter drainage in cold areas.

Impact of Different Water Management Scenarios on Corn Water Use Efficiency

Abstract. This study investigated the water balance, crop yield, and water use efficiency (WUE) of a water table management system compared to a conventional drainage system at three nitrogen levels. A two-year field study was conducted using three blocks; each block was composed of two water management treatments: controlled drainage with subirrigation (CD-SI) and conventional or free drainage (FD). The water table depth was maintained at 60 cm below the soil surface in the CD-SI plots. Three nitrogen treatments (low, medium, and high) were applied in strips across all blocks. The seasonal water balance indicated surplus water conditions in the CD-SI plots, while the FD plots had deficit conditions. In 2008 and 2009, the corn grain WUE for the FD plots was 2.49 and 2.46 kg m -3 respectively. The corn grain WUE for the CD-SI plots was 2.43 and 2.26 kg m -3 in 2008 and 2009, respectively. The WUE of corn grain responded to the water treatments (p 0.05) on grain yields at the normal nitrogen level. Furthermore, the two water treatments had no effect on the aboveground dry biomass yields in both years.

Protecting Water Quality Using Controlled Drainage as an Agricultural BMP for Potato Production

Abstract. Subsurface drainage is used for removing excess water from agricultural lands to improve productivity, although it can cause water quality problems downstream. Agricultural drainage is identified as one of the contributing factors to Lake Winnipeg’s nutrient enrichment and subsequent water quality deterioration. It has been suggested that controlled drainage in the Lake Winnipeg watershed could be a potential best management practice (BMP). The objective of the study was to evaluate the flow and nutrient export through subsurface drainage by comparing free drainage with overhead irrigation (FDIR) and controlled drainage with subirrigation (CDSI) under potato crop. The experiment was carried out in southern Manitoba in a potato field with sandy loam soil using the same irrigation water source. Subsurface drainage was installed in 2009 at an average design depth of 0.9 m. Controlled drainage was accomplished by using drainage control structures at drainage outlets. Subirrigation was carried out by pumping water back through the subsurface drainage network. Drainage flow, nutrient export, and weather parameters were monitored during the growing seasons of 2010 and 2011. On average, controlled drainage reduced the flow volume by 91% in 2010 and 54% in 2011 compared to free drainage. The drainage volume from FDIR plots ranged from 13% to 53% of the rainfall received, while for CDSI plots it varied from 0% to 8%. In both years, average nitrate concentrations were lower in CDSI compared to FDIR plots. However, average phosphate concentrations were lower in 2010 and higher in 2011 under CDSI compared to FDIR. Compared to FDIR plots, average nitrate-N export from CDSI plots was reduced by 98% in 2010 and 67% in 2011. Average phosphate export was reduced by 94% in 2010; however, in 2011, it was 15% higher than FDIR. The majority of the export happened during the period dominated by heavy drainage outflow, which coincided with spring snowmelt. The nutrient export reduction by CDSI is attributed mainly to the drainage volume reduction by controlled drainage.

Nitrate, Phosphorus, and Salt Export through Subsurface Drainage from Corn Fields in the Canadian Prairies

<abstract> <bold><sc>Abstract.</sc></bold> High fertilizer inputs and uncontrolled subsurface drainage can result in the export of nutrients from farmland, leading to negative environmental impacts. Controlled drainage can be an effective best management practice to minimize the export of nutrients. However, information about controlled drainage in the Canadian Prairies is scarce. The objective of this study was to compare free drainage with overhead irrigation (FDIR) to controlled drainage with sub-irrigation (CDSI) in terms of nitrogen, phosphorus, and salt exports from corn fields in the Canadian Prairies. The irrigation water had low concentrations of nitrate (≤0.2 mg L^-1) and orthophosphate (<0.1 mg L^-1) and low electrical conductivity (0.55 dS m^-1), which were assumed to have low influence on the export of nutrients and salts. In 2010, the exports of NO₃-N (138 kg ha^-1), PO₄-P (0.6 kg ha^-1), and salts (2.34 Mg ha^-1) from the FDIR treatment during the growing season were significantly larger (p < 0.05) than exports from the CDSI treatment, which were 0.07 kg ha^-1, 0.08 kg ha^-1, and 0.41 Mg ha^-1, respectively. This comparison did not include the drainage outflow arising from spring snowmelt due to delays in the installation of monitoring equipment. In 2011, which included the drainage outflow due to spring snowmelt events, the exports of NO₃-N (36 kg ha^-1), PO₄-P (0.27 kg ha^-1), and salts (1.1 Mg ha^-1) from FDIR were significantly larger (p < 0.05) than the exports from CDSI, which were 10 kg ha^-1, 0.08 kg ha^-1, and 0.39 Mg ha^-1, respectively. Therefore, controlled drainage with subirrigation (CDSI) showed significant reductions in export of NO₃-N (71%), PO₄-P (69%), and salts (64%) compared to free drainage with overhead irrigation (FDIR). This study shows the advantage of controlled drainage over free drainage in reducing the export of nutrients and salts.

Effect of Water Table Management and Irrigation on Potato Yield

In Canada, the Province of Manitoba is the second largest potato producer after Prince Edward Island. Potato is a moisture-sensitive crop, and excess or inadequate soil water content can adversely affect the yield and quality. Potato in Manitoba experiences periods of excess as well as insufficient water content within the soil profile during the growing season. The objective of this study was to compare the effect of four different water management treatments on potato yield in a fine sandy loam soil in southern Manitoba: controlled drainage with subirrigation (CDSI), free drainage with overhead irrigation (FDIR), no drainage with overhead irrigation (NDIR), and no drainage with no irrigation (NDNI). In November 2009, tile drains were installed at a depth of 0.9 m. CDSI was done through drainage control structures with a target water table depth of 0.6 m. Overhead irrigation was done using a traveling gun. Groundwater level, drainage discharge, and potato yield data were collected during the 2010 and 2011 growing seasons. In 2010, potato yield was not found to be significantly different between the treatments due to the large variability between the replicates. However, in 2011, potato yield from the FDIR treatment was significantly higher compared to NDNI and CDSI (p <0.05). The NDNI treatment yield was significantly lower (p < 0.05) than the other three treatments. When compared with NDNI, the other treatments showed a yield increase of 15% to 32%. Maintaining adequate soil moisture by overhead irrigation was most effective for increasing potato yield when rainfall is inadequate.

Corn Yield Response to Drainage and Subirrigation in the Canadian Prairies

Subsurface drains are commonly used in humid regions to deal with high water tables. However, corn (Zea mays L.) could benefit from subsurface drainage even under semi-arid conditions where high-intensity rainfall causes the water table to rise within the root zone for short periods. In southern Manitoba, seasonally high water tables with high salinity have led to salinization of the root zone, making subsurface drainage an attractive option to increase yields. The objective of this research was to evaluate agronomic performance of corn under water table management using subirrigation and tile drainage. Four treatments were tested in this experiment: (1) controlled drainage with subirrigation (CDSI), (2)no drainage with overhead irrigation (NDIR), (3) free drainage with overhead irrigation (FDIR), and (4) no drainage with no irrigation (NDNI) as control. The impacts of these treatments on crop performance, measured by yield, kernel quality, plant biomass, and plant height, were evaluated over two growing seasons. In the first year, which was 57% wetter than the 30-year average, yields were 8.48 (NDNI), 10.36 (NDIR), 10.10 (FDIR), and 9.22(CDSI) Mg ha-1 with only the mean yield difference for the NDIR and the CDSI treatments being statistically significant (p = 0.014). In the second year, which was 16% drier than normal, yields were 9.25 (NDNI), 10.47 (NDIR), 11.28 (FDIR), and 9.49 (CDSI) Mg ha-1 with no statistically significant differences in yield.

Surface runoff and sub-surface drainage phosphorus losses under regular free drainage and controlled drainage with sub-irrigation systems in southern Ontario

Tan, C. S. and Zhang, T. Q. 2011. Surface runoff and sub-surface drainage phosphorus losses under regular free drainage and controlled drainage with sub-irrigation systems in Southern Ontario. Can. J. Soil Sci. 91: 349–359. Soil phosphorus (P) loss and its partition in various pathways may differ depending on water management practices. A study was conducted using large field plots equipped with automatic flow volume measurement and sampling systems over a 5-yr period to determine the effectiveness of regular free drainage (RFD) and controlled drainage with sub-irrigation (CDS) for mitigating soil P losses of various forms [dissolved reactive P (DRP), dissolved un-reactive P (DURP), and particulate P (PP)] and to identify the relative roles of surface runoff and sub-surface tile drainage in soil P loss. For RFD, flow weighted-means (FWM) of DRP, DURP, PP and the total P (TP) concentrations over the 5-yr period were averaged at 0.057, 0.057, 0.627, and 0.741mg P L−1 in surface runoff water and at 0.034, 0.053, 0.393, and 0.480 mg P L−1 in tile drainage water, respectively. CDS increased FWM of DRP, DURP and the TP concentrations in surface runoff water and DRP concentration in tile drainage, but decreased the FWM of DURP, PP and the TP concentrations in tile drainage water. The CDS produced similar annual total dissolved P (TDP) loss, the sum of DRP and DURP, but reduced losses of PP by 15% and of TP by 12%, relative to RFD. The PP loss accounted for over 80% of TP loss for both CDS and RFD. Of the total soil P loss, from 3 to 5% was accounted for in surface runoff water, while from 95 to 97% was accounted for in tile drainage water, for RFD. For CDS, from 29 to 35% of the total soil P loss was in surface runoff water, while 65 to 71% was in tile drainage water. Subsurface tile drainage played a predominant role in soil P loss. CDS can be considered a beneficial management practice to reduce soil P loss under the similar climate and relatively flat field conditions in Southern Ontario.

EFFECT OF CONTROLLED DRAINAGE AND SUBIRRIGATION ON SUBSURFACE TILE DRAINAGE NITRATE LOSS AND CROP YIELD AT THE FARM SCALE

An on-farm evaluation of controlled drainage and subirrigation systems can raise farmer awareness and acceptance of these innovative technologies. A four hectare field experiment was established on sandy-loam soil near Harrow in Essex County, Ontario. The field was modified to allow the implementation of two water table-management treatments, controlled drainage with subirrigation (CDS) and free outlet tile drainage (DR). Volume of tile drainage, nitrate concentration and loss in the tile drainage water and crop yields were measured. The objectives of the study were to provide on-farm demonstrations of controlled drainage and subirrigation systems, and to determine their effect on crop yields and environmental benefits.The CDS system reduced flow weighted mean nitrate concentration in tile drainage water by 38% and total nitrate loss by 37% compared to the DR system from May 1995 to April 1997. The CDS system increased marketable tomato yields by 11% in 1995. The average marketable tomato yields were 58.4 t ha−1 for DR system and 64.9 t h−1 for CDS system. The CDS system also increased corn yields by 64% in 1996. The average corn yields were 6.7 t ha−1 for DR system and 11.0 t ha−1 for CDS system. Thus, the CDS system effectively reduced total nitrate loss and improved yields of both processing tomatoes and grain corn on a sandy loam soil.