Water and nitrate loss through tiles under a clay loam soil in Ontario after 42 years of consistent fertilization and crop rotation

doi:10.1016/S0167-8809(01)00359-0

Agriculture, Ecosystems & Environment

Volume 93, Issues 1–3, December 2002, Pages 121-130

https://doi.org/10.1016/S0167-8809(01)00359-0 Get rights and content

Abstract

Concerns about increasing concentrations of agricultural nitrate in water resources have led to calls for new or revised agricultural land management practices. An essential step towards developing new practices is a good understanding of long-term, or “baseline”, nitrate leaching into tile drainage water, both with and without annual application of nitrogen fertilizer. Accordingly, an automated monitoring system was installed to measure nitrate levels in tile drainage water from experimental plots on a Brookston clay loam soil in southwestern Ontario that have had consistent agricultural management for 42 years. Crops included conventionally tilled continuous corn (CC, Zea mays L.), continuous bluegrass sod (Poa pratensis L.) and a corn–oat (Avena sativa L.)–alfalfa (Medicago sativa L.)–alfalfa rotation with all four crops of the rotation present each year. Fertilized and not-fertilized phases were included with each of the six crops to give a total of 12 treatments. Measurements included precipitation, tile discharge, corn yield and nitrate concentration and total nitrate loss in tile drainage water. The fertilized CC, fertilized rotation corn and second year fertilized alfalfa treatments produced 3-year flow weighted mean (FWM) nitrate concentrations in tile drainage water of 15.2, 18.0 and 16.2 mg N l⁻¹, respectively, all of which exceed the Canadian and European drinking water guideline values of 10 and 11.3 mg N l⁻¹, respectively. The 3-year cumulative nitrate losses were high at 82.0 kg N ha⁻¹ for fertilized CC, 99.9 kg N ha⁻¹ for fertilized rotation corn and 69.8 kg N ha⁻¹ for second year fertilized alfalfa. Given that the existing fertilizer recommendations are required to achieve economic corn yields, these results indicate that current corn production practices on Brookston clay loam can potentially cause nitrate pollution of the rural environment, as well as substantial economic loss to corn producers through inefficient crop use of applied nitrogen fertilizer. There is consequently a need for new agricultural practices that can increase the nitrogen use efficiency of corn production and minimize nitrate loss to the environment.

Introduction

Contamination of subsurface and ground water resources by agricultural nitrate may be increasing in southern Ontario (Rudolph and Goss, 1993), and this has led to calls for new or revised agricultural and land management practices (Tan et al., 1993, Drury et al., 1996). An essential step towards justifying these calls and developing new practices is a good understanding of the water and nitrogen dynamics of agricultural fields. Water dynamics determines the partitioning of water between surface runoff, storage in the root zone, tile discharge and deep percolation to the ground water. The proportions of water falling into each of these categories affect crop productivity directly by determining the amount of crop-available water in the root zone, and indirectly through the erosion of top soil. The dynamics of nitrogen are equally important because they are an essential nutrient determining crop yield and quality, as well as a potentially serious contaminant of surface and ground water resources. Nitrogen in the form of nitrate is extremely mobile and easily transported by percolating water out of the crop root zone and into tile drainage water and ground water.

Several studies have shown that tile drainage can be a major mechanism for water and nitrogen loss from the crop root zone (Bolton et al., 1970, Drury et al., 1993, Tan et al., 1998). It has also been found that the amount and temporal patterns of water and nitrogen discharge through tiles are affected in a complex manner by crop type, crop rotation, tillage, soil type, precipitation patterns, soil water content and time of year (Schwab and Fouss, 1967, Hoover and Schwab, 1969, Byrant et al., 1987). Because of this complexity, accurate characterization of water and nitrogen dynamics in tile drainage requires continuous year-round monitoring of flow volumes and nitrate concentrations over a multi-year period (Tan et al., 1993, Tan et al., 1998, Drury et al., 1996). Such studies are extremely rare however because of the extensive time and resources required, such as automated data collection equipment and backup electrical generators to ensure uninterrupted data collection during storm events.

In 1959, a tile drainage—crop rotation—fertilization study was established near Woodslee in southwestern Ontario. The experimental site has received consistent soil and crop management for 42 years and includes fertilized and not-fertilized treatments (Bolton et al., 1970, Drury and Tan, 1995, Drury et al., 1998). The site thus provides a valuable opportunity for characterizing the long-term and “baseline” effects of cropping and fertilization on water and nitrogen movement into subsurface tile drains. Accordingly, the site was instrumented in the fall of 1997 for detailed, year-round monitoring of water and nitrogen movement via subsurface tile discharge. Crop yield and precipitation were also monitored. The objective of this study was to determine the long-term effects of fertilization and crop rotation on the flow characteristics, nitrate concentrations and total nitrate loss for tile drainage water from an established and stable cropping system.

Section snippets

Experimental site and agronomic practices

The field site is located at the Honorable Eugene F. Whelan Experimental Farm, Agriculture and Agri-Food Canada, Woodslee, Ontario (42°13′N, 82°44′W) on Brookston clay loam (Orthic Humic Gleysol), which is an important agricultural soil in the region. The soil has an average root zone texture of 28% sand, 35% silt, 37% clay, an average organic carbon content in the Ap horizon of 2.0–2.5% and a surface slope of 0.05–0.10% (Stone et al., 1987, Drury and Tan, 1995). The field site consists of 12

Precipitation and tile drainage volume

The 1998 and 1999 growing seasons (May–October) were dry, with total growing season precipitation being, respectively, 32 (153.4 mm) and 38% (177.9 mm) below the 42-year average (Table 1). The 2000 growing season, on the other hand, was very wet, with total growing season precipitation above the 42-year average by 40% (189.4 mm).

The cumulative tile drainage volumes were much greater in 1998 than in 1999 and 2000 (Table 2). The high 1998 tile flows, despite low growing season rainfall (Table 1),

Conclusions

Consistent long-term (42 years) cropping and fertilization on a nearly flat clay loam soil had substantial impacts on FWM nitrate concentrations and cumulative nitrate losses in tile drainage water during a 3-year study period (1998–2000). Rotation corn CC, and second year alfalfa treatments that were fertilized almost always produced annual FWM nitrate concentrations in tile water that exceeded the Canadian and European drinking water guideline values of 10 and 11.3 mg N l⁻¹, respectively. In

Acknowledgements

We thank Mr. V. Bernyk, Dr. T. Oloya, Mr. M. Soultani and Mr. D. Pohlman for their expert technical assistance.

References (19)

C.S. Tan et al.
Effect of controlled drainage and tillage on soil structure and tile drainage nitrate loss at the field scale
Water Sci. Technol.
(1998)
J.L. Baker et al.
Nitrate-nitrogen in tile drainage as affected by fertilization
J. Environ. Qual.
(1981)
D.A.J. Barry et al.
Estimation of nitrate concentrations in groundwater using a whole farm nitrogen budget
J. Environ. Qual.
(1993)
E.F. Bolton et al.
Nutrient losses through tile drains under three cropping systems and two fertilizer levels on a Brookston clay soil
Can. J. Soil Sci.
(1970)
G.J. Byrant et al.
Tile drain discharge under different crops
Can. Agric. Eng.
(1987)
C.F. Drury et al.
Long-term (35 years) effects of fertilization, rotation and weather on corn yields
Can. J. Plant Sci.
(1995)
C.F. Drury et al.
Influence of tillage on nitrate loss in surface and tile drainage
Soil Sci. Soc. Am. J.
(1993)
C.F. Drury et al.
Influence of controlled drainage–subirrigation on surface and tile drainage nitrate loss
J. Environ. Qual.
(1996)
C.F. Drury et al.
Long-term effects of fertilization and rotation on denitrification and soil carbon
Soil Sci. Soc. Am. J.
(1998)

There are more references available in the full text version of this article.

Cited by (53)

The role of agricultural drainage, storm-events, and natural filtration on the biogeochemical cycling capacity of aquatic and sediment environments in Lake Erie's drainage basin
2023, Science of the Total Environment
Lake Erie is the most at risk of the Great Lakes for degraded water quality due to non-point source pollution caused by agricultural activities in the lake's watershed. The extent and temporal patterns of nutrient loading from these agricultural activities is influenced by the timing of agronomic events, precipitation events, and water flow through areas of natural filtration within the watershed. Downstream impacts of these nutrient loading events may be moderated by the co-loading of functionally relevant biogeochemical cycling microbial communities from agricultural soils. This study quantified loading patterns of these communities from tile drain sources, assessed whether functional communities from agricultural sources influenced downstream microbial functionality, and investigated how distance from agricultural sources, storm events, and areas of natural filtration altered nutrient cycling and nutrient fluxes in aquatic and sediment environments. Water and sediment samples were collected in the Wigle Creek watershed in Ontario, from tile drains through to Lake Erie, from May to November 2021, and microbial nitrogen (N) and phosphorous (P) cycling capacity (quantitative PCR), and nutrient levels were evaluated. Results showed that N and P functional groups were co-loaded with nutrients, with increased loading occurring during storm events and during agricultural activities including fertilization and harvest. Overall functional capacity in the aquatic environment decreased with distance from the agricultural sources and as water transited through natural filtration areas. In contrast, the sediment environment was more resilient to both agricultural disturbances and abiotic factors. This study expands our understanding of when and where different stages of N and P cycling occurs in agriculturally impacted watersheds, and identifies both seasons and regions to target with nutrient mitigation strategies.
Nutrient retention of newly restored wetlands receiving agricultural runoff in a temperate region of North America
2023, Ecological Engineering
Globally, eutrophication is deemed to be the greatest threat to freshwater resources and is particularly problematic for large shallow lakes where the prevalence of cyanobacterial blooms has increased in recent decades. Restored wetlands have been identified as natural infrastructure that can reduce nutrient loads from agricultural landscapes, thereby reducing eutrophication in downstream freshwater systems. While restored wetlands are generally accepted as efficient nutrient transformers and processors, there are relatively few studies that examine nutrient retention based on detailed hydrological budgets across seasons. We determined the nutrient retention capacity for phosphorus and nitrogen species of newly restored wetlands (<8 years old) receiving nonpoint source agricultural runoff over two water years. These restored wetlands are located in an intensive agricultural region that contributes to the central and western basin of Lake Erie. Two-year mean TP and TN wetland retention capacities were 11.7 ± 5.9 and 261.2 ± 112.3 kg ha⁻¹ yr⁻¹, respectively. Two-year mean TP and TN wetland retention efficiencies were 46 ± 13 and 47 ± 8%, respectively. The mean SRP retention capacity and reduction efficiency over the two-year monitoring period were 4.8 ± 1.7 kg ha⁻¹ yr⁻¹ and 60 ± 11%, respectively. Investigating data over two water years revealed that nutrient retention was noticeably different across seasons for both TP and TN, with the highest retention occurring in summer for TP (5.7 ± 2.7 kg P ha⁻¹) and in the spring for TN (99.9 ± 50.0 kg N ha⁻¹). Our findings demonstrate that restored wetlands in agriculturally intensive temperate regions designed primarily for wildlife habitat can effectively reduce nonpoint source nutrients under a range of hydrological conditions. However, further research is needed to investigate the long-term effectiveness of restored wetlands as natural infrastructure for nutrient reduction, and to evaluate the potential environmental trade-offs and economic benefits of their implementation.
Straw returning on sloping farmland reduces the soil and water loss via surface flow but increases the nitrogen loss via interflow
2022, Agriculture, Ecosystems and Environment
The eutrophication caused by nitrogen loss from sloping farmland is a serious concern, especially in the context of increasing frequency of extreme rainfall events. The relative importance that the surface runoff and interflow processes govern the nitrogen loss under extreme rainfall events, however, is ambiguous. Moreover, this ambiguity could be further enhanced by conservation practices on sloping farmland, such as straw returning and contour tillage. To better understand these ambiguities, five simulated rainfall experiments at the intensity of 100 mm h⁻¹ under four treatments including downslope tillage (DT), cross-slope tillage (CT), cross-slope tillage with whole straw returning (CT + WR), cross-slope tillage with crushed straw returning (CT + CR), were conducted in 2 years' maize season on a typical purple sloping farmland in the hilly area of Sichuan, China. Results showed: 1) Compared with DT, straw returning and cross-slope tillage significantly reduced surface runoff and nitrogen load of surface runoff. However the concomitant potential increase of the interflow runoff would result in the increase of nitrogen loss via interflow, offsetting the benefits of conservation practices; 2) The nitrogen loss through interflow is 6.38 ± 0.21 kg ha⁻¹, accounting for 77.9 % of the total nitrogen loss and suggesting that interflow is the dominant process; 3) Dissolved organic nitrogen is one of the main nitrogen loss forms, accounted for 41.06 % (24.31–57.69 %) of the total nitrogen loss in surface runoff and 32.02 % (12.28–47.81 %) for interflow, should not been ignored; 4) The results of the three prediction models showed that the nitrogen loss caused by interflow drainage under extreme rainfall should not be ignored. These findings enhance our understanding of nitrogen exports induced by extreme rainfall events and provide references for nitrogen loss predictions and control in sloping farmland.
Cover crop mixtures: A powerful strategy to reduce post-harvest surplus of soil nitrate and leaching
2022, Agriculture, Ecosystems and Environment
Citation Excerpt :
Thus, NO3- leaching studies in annual cropping systems such as corn, wheat, and soybeans under contrasting soil textures in response to mixtures of cover crops are needed. In cold and humid climates, substantial NO3- leaching occurs during the non-growing season (NGS), contributing to a significant amount of total NO3- contamination in groundwater (Drury et al., 2016; Savard et al., 2007; Gupta et al., 2004; Tan et al., 2002). These losses are due to the presence of NO3- in the soil after the main crop harvest and a surplus of water, which causes significant drainage events and movement of the NO3- below the root zone (Drury et al., 2016; Fallow et al., 2003; Tan et al., 2002).
Cover cropping is a practice with potential to reduce post-harvest surplus of soil nitrate (NO₃^-), a mobile form of nitrogen naturally susceptible to losses. Increased soil NO₃^- leaching occurs when high soil NO₃^- coincides with high drainage events – a common occurrence during the non-growing season in cold and humid climates. The potential of cover crops to reduce NO₃^- leaching can be affected by the performance of the cover crop and by edaphic-climatic conditions (e.g., freeze-thaw cycles, soil type) and is subjected to interannual variation. Here, we evaluate soil type and crop rotation effects on soil parameters (i.e., NO₃^- concentration, temperature, water content) and on NO₃^- leaching under freeze-thaw conditions, using a high-frequency weighing lysimeter system. The soil type consisted of silt loam (SIL) and loamy sand (LS) soils and the crop rotation consisted of a rotation with a mixture of leguminous/non-leguminous cover crops (+CC) and no cover crop (-CC). This research was conducted during periods of 2017/2018 and 2018/2019 subjected to significant drainage. Our results indicated that cover crops did not affect drainage but affected soil temperature, with warmer soils observed over the winter when cover crops were used (+CC) than without cover-crops (-CC). Moreover, the cereal-crucifer-legume mixture after spring wheat reduced soil NO₃^- content by 80% compared to -CC during 2017/2018. For 2018/2019, due to poor establishment of the cereal-legume mixture under-seeded to corn, no reduction in soil NO₃^- content was observed. The reduction in soil NO₃^- in +CC plots for 2017/2018 translated to a significant reduction (by 67%) in NO₃^- leaching averaged across soil types. Soil drainage, NO₃^- content and NO₃^- leaching were not affected by soil type, an effect in part influenced by the boundary controls of the lysimeter system which mimicked soil conditions of a non-LS adjacent/reference field. To expand our results, we estimated the potential drainage of a hypothetical excessively drained LS (ED-LS) – a soil naturally subjected to high hydraulic conductivity and low water holding capacity. Overall, our results indicated that cover cropping can reduce NO₃^- leaching independent of soil type but the effect can be pronounced for ED-LS.
Residual nitrogen for succeeding crops in legume-based cropping system
2022, Advances in Legumes for Sustainable Intensification
A number of challenges will face the world in the years to come, including food security, climate change risks, and increasing demand for energy. Therefore, agriculture and food systems are increasingly focused on producing sustainably. By delivering multiple services in line with sustainability principles, legume crops could play a significant role in this context. In addition, legumes are also potentially competitive crops, which are useful for increasing crop diversity and reducing the use of external inputs in modern cropping systems due to their environmental and socioeconomic benefits. In a cropping system involving legumes most important aspect is N balance which summarizes the complex N inflow and outflow of the system. Legumes hold potential to variegate cropping systems, restore inter-related biodiversity, and assist break-crops. The key part of the residual N is obtained from rhizodeposition and recoverable debris which become part of the active soil organic matter pool that derives the N pool in soil for the long term. The ability of legumes to fix atmospheric nitrogen as well as produce biomass and sequester carbon (C) is a crucial factor in reducing greenhouse gases emissions. Therefore, legumes have been envisioned as a solution for decreasing nitrous oxide (N₂O) emissions. The foremost goal of writing this review article is to have an enhanced interpretation of nitrogen dynamics, its residual effect, increase its use efficiency under diverse agroclimatic conditions, its influence on C stabilization, climate change, and enhance soil health by stimulating microbial activity and biomass. In fact, legumes are expected to play an increasingly critical role over the coming decades.
Cover crops differentially influenced nitrogen and phosphorus loss in tile drainage and surface runoff from agricultural fields in Ohio, USA
2021, Journal of Environmental Management
Nitrogen (N) and phosphorus (P) loss from crop production agriculture is transported to adjacent and downstream water bodies, resulting in negative environmental impacts including harmful and nuisance algal blooms. Cover crops are a conservation management practice that replaces bare soil with vegetation outside of the cash crop growing season, purportedly reducing N and P loss by increasing water and nutrient demand in agroecosystems. In this study, we compared nitrate (NO₃⁻-N), total N (TN), dissolved reactive P (DRP), and total P (TP) loads in subsurface (tile) drainage and surface runoff from fields with cover crop management (CC) and fields without cover crop management (NoCC) using continuous monitoring data from 40 agricultural fields located throughout northcentral Ohio, United States (US). We found that average monthly tile NO₃⁻-N and TN loads from CC fields were ~50% less than NoCC fields, while average monthly tile discharge, DRP, and TP loads did not differ between CC and NoCC fields. Cover crops also did not significantly influence average monthly surface metrics. Cover crops reduced monthly totals of tile NO₃⁻-N and TN loads by ~1.0–2.6 kg N ha⁻¹ from January to June (winter and spring), coinciding with critical periods of nutrient loss from agroecosystems in the midwestern US, but increased monthly totals of tile DRP (by 0.4–12.1 g DRP ha⁻¹) and TP (by 1.2–31.6 g TP ha⁻¹) loads during some months. We found similar patterns at the annual time scale whereby CC fields had lesser cumulative annual totals of tile NO₃⁻-N and TN but greater cumulative annual totals of tile DRP and TP. These results show that the influence of cover crops on N loads, but not P, were consistent across temporal scales of examination, demonstrating that cover crops effectively increased N demand and mitigated N losses from agricultural fields. The variable influence of cover crops on P loads underscores the need for greater understanding of the factors and mechanisms that control P loss in systems that include cover crop management. Furthermore, these findings stress the importance of identifying and selecting conservation management practices tailored to the natural resource concern.

View all citing articles on Scopus

View full text

Water and nitrate loss through tiles under a clay loam soil in Ontario after 42 years of consistent fertilization and crop rotation

Abstract

Introduction

Section snippets

Experimental site and agronomic practices

Precipitation and tile drainage volume

Conclusions

Acknowledgements

Water Sci. Technol.

Nitrate-nitrogen in tile drainage as affected by fertilization

J. Environ. Qual.

Estimation of nitrate concentrations in groundwater using a whole farm nitrogen budget

J. Environ. Qual.

Nutrient losses through tile drains under three cropping systems and two fertilizer levels on a Brookston clay soil

Can. J. Soil Sci.

Tile drain discharge under different crops

Can. Agric. Eng.

Long-term (35 years) effects of fertilization, rotation and weather on corn yields

Can. J. Plant Sci.

Influence of tillage on nitrate loss in surface and tile drainage

Soil Sci. Soc. Am. J.

Influence of controlled drainage–subirrigation on surface and tile drainage nitrate loss

J. Environ. Qual.

Long-term effects of fertilization and rotation on denitrification and soil carbon

Soil Sci. Soc. Am. J.