Elsevier

Field Crops Research

Volume 196, September 2016, Pages 145-159
Field Crops Research

Rye cover crop effects on maize: A system-level analysis

https://doi.org/10.1016/j.fcr.2016.06.016Get rights and content

Highlights

  • We synthesized measured and modeling data to examine rye effects on maize systems.

  • Soil water deficit caused by rye transpiration affected maize yield only in drought years.

  • 34% of the precipitation ended up in subsurface drainage at this site.

  • Rye produced 47 kg ha−1 of shoot biomass per each mm of water used.

  • APSIM simulated reduced NO3-N losses (26 ± 26%), but not drainage (4 ± 13%) or yield (2 ± 6%).

Abstract

Inclusion of a rye cover crop into maize-based systems can offer environmental benefits, but adoption of the practice in the US Midwest is still low. This is related to the possible risk of reduced maize yields following rye. We hypothesized that the magnitude of rye effects on maize yields and drainage water and nitrate (NO3)-N losses would be proportionally related to rye biomass. We tested this hypothesis by analyzing data from continuous maize treatments (with and without cover crop) in Iowa, US, that were fertilized following recommendations from late spring nitrate tests. Dataset included measurements (2009–2014) of soil water and temperature, drainage water and NO3-N losses, soil NO3, rye shoot and root biomass and C:N, and maize yields. We supplemented our analysis with a literature review and the use of a cropping systems model (APSIM) to calculate trade-offs in system performance characteristics. Experimentally, rye cover crop reduced drainage by 12% and NO3-N losses by 20% (or 31% per unit of N applied), and maize yields by 6%. We also found minimal effects on soil temperature, water deficits that reduced yields only during drought years (2012 and 2013), and lower NO3-N losses that were related to reduced NO3-N concentrations in drainage. Results also revealed a linear relationship between drainage and precipitation (r2 = 0.96), and rye transpiration and shoot biomass (r2 = 0.84). Model scenario analysis (4 termination dates × 30 years) indicated that rye cover crop decreases NO3-N losses (-25.5 ± 26%) but does not always reduce drainage water (-3.9 ± 13%) or grain yields (-1.84 ± 6%), which is consistent with experimental and literature results. However, analysis of the synthesized measured and simulated dataset do not support a strong relationship between these variables and rye biomass. These results are valuable for decision-making and add new fundamental knowledge on rye water and nitrogen use.

Introduction

Inclusion of winter cover crops in high-input rain-fed maize (Zea mays L.)-based cropping systems is a conservation practice for enhancing the environmental performance of these systems (Kaspar and Singer, 2011, Thorup-Kristensen et al., 2003). Cover crop shoots protect soil from erosion (Kaspar et al., 2001), and roots take up residual NO3-N from the soil during the fall-to-spring fallow period, reducing the movement of nutrients into surface and ground water (Dinnes et al., 2002, Kaspar et al., 2012, Kaspar et al., 2007, Salmerón et al., 2010). The use of cover crops also has the potential to provide long-term soil quality benefits such as improving carbon sequestration and soil physical properties (Basche et al., 2016a, Blanco-Canqui et al., 2015, Kaspar and Singer, 2011, Moore et al., 2014), and other ecosystem services such as weed and pest suppression and beneficial insect conservation (Schipanski et al., 2014). Water quality degradation, especially NO3 pollution of surface waters, is the most pressing environmental impact of these systems in the US Midwest. Cover crops have been promoted as one of the most viable options for reaching water quality goals set in the Midwest (e.g. Iowa Nutrient Reduction Strategy; Iowa Deptartment of Agriculture and Land Stewarship, 2013) because of their lower cost of adoption compared to built infrastructure such as denitrifying bioreactors and wetlands (Christianson et al., 2013, Dinnes et al., 2002).

Despite the evidence of the benefits of cover crops and the existence of incentives such as cost-share programs, adoption of the practice lags behind targets. Current records indicate that cover crops are used in only 1.55% of Iowa row-crop farmland (National Agricultural Statistics Service, 2016). In the Midwest, winter rye (Cereale secale L.) is a commonly used cover crop species (Singer, 2008) because it can withstand harsh winter conditions and has superior growth and N uptake compared to other species (Johnson et al., 1998, Kaspar and Bakker, 2015). Some studies have reported reductions in maize yield following a rye cover crop (Iqbal et al., 2015, Johnson et al., 1998, Kaspar and Bakker, 2015, Krueger et al., 2012, Krueger et al., 2011, Pantoja et al., 2015, Singer and Kohler, 2005, Singer et al., 2008), although rye and other grass winter cover crops do not consistently reduce maize yields in the Midwest (Basche et al., 2016a, Miguez and Bollero, 2005). Nonetheless, concerns regarding possible negative yield impacts of rye on maize have been found to be an impediment to the adoption of cover crops by producers (Arbuckle and Roesch-McNally, 2015). To promote the adoption of the practice, quantification of the actual risks and the trade-offs associated with cover crop use, along with the development of risk abatement strategies, are necessary (Arbuckle and Roesch-McNally, 2015; Carlson and Stockwell, 2013).

Miguez and Bollero (2005) identified that the effect of grass cover crops on maize yields throughout US studies was neutral, although significant variation existed across these studies. Similarly, rye cover crops generally reduce NO3-N loss but the magnitude of the leaching-reduction effect also varies widely across years, locations and management (Dabney et al., 2010, Dinnes et al., 2002, Kaspar and Singer, 2011, Thorup-Kristensen et al., 2003). This indicates that rye effects on the maize system depend on specific combinations of management choices and environmental conditions. Most studies have focused on quantifying rye effects on final maize yields and/or annual NO3-N losses, and many knowledge gaps still exist regarding the mechanisms by which rye affects these systems. Broadly speaking, rye effects on maize can be grouped into biotic and abiotic factors. Biotic factors include pests and disease pressure (Acharya et al., 2016, Bakker et al., 2016) and allelopathy (Dhima et al., 2006, Duiker and Curran, 2005, Raimbult et al., 1991, Tollenaar et al., 1993), and at present are not well understood (Blanco-Canqui et al., 2015). A larger body of evidence exists for abiotic factors, which allowed us to develop a generalized framework of the abiotic effects of rye on the maize system (Fig. 1). Literature findings have shown maize yield reductions following rye cover crop to be related to depletion of soil moisture (Krueger et al., 2011, Mirsky et al., 2015, Raimbult et al., 1991, Unger and Vigil, 1998) and/or plant available N (Crandall et al., 2005, Kessavalou and Walters, 1999, Krueger et al., 2011, Tollenaar et al., 1993), or to a mulching effect that reduces soil temperature and seedling growth (Munawar et al., 1990, Teasdale and Mohler, 1993). More specifically, rye abiotic effects on the maize system can arise from changes in the soil via: 1) the addition of organic C and N (shoot and root); 2) changes in soil surface cover that alter soil temperature and water dynamics; and 3) changes in the state variables such as inorganic N and soil water at the time of cover crop termination (Fig. 1). The magnitude of these changes affects the system differently, which may explain the wide variation in yield and NO3-N leaching responses to rye cover crops across different studies.

The amount of biomass produced by crops is strongly related to their water and N use (Gastal and Lemaire, 2002, Sinclair and de Wit, 1975, Sinclair and Rufty, 2012). For rye cover crops, this could mean that the greater the biomass, the higher the potential to alter water, N and temperature dynamics, resulting in increases in the potential for both yield penalty and reductions in NO3-N losses. Krueger et al. (2011) and Pantoja et al. (2015) found rye biomass production to have a direct relationship to maize yield penalty, while Malone et al. (2014) found in a modeling study that rye N uptake had a strong relationship with NO3-N losses. In this study, we hypothesized that the magnitude of rye cover crop abiotic effects on maize yields and environmental performance variables such as drainage water and NO3-N losses would be proportionally related to its biomass production. We tested this hypothesis and examined the underlying crop-soil dynamics that would support such a scenario by analyzing six years of data from a no-till continuous maize (with and without rye cover crop) experiment carried out in central Iowa, US. This dataset was collected over years that crops experienced drought, flood and historically average weather, and included measurements of many system variables shown in Fig. 1. We supplemented our analysis by using a calibrated cropping systems model for this site (Dietzel et al., 2016) to better understand growth-limiting factors and soil-crop dynamics with variability in both weather (30 years) and management (four simulated rye termination dates within a year). To our knowledge, current literature lacks a system-level analysis of the effect of rye on maize in which the most important system variables are analyzed simultaneously. Such analysis is necessary to further our understanding of the abiotic mechanisms by which rye impacts maize and the environmental performance of the system, and to provide baselines for quantifying trade-offs and risks associated with this practice.

Section snippets

Soil

The dataset used in this study was derived from observations collected from 2009 to 2014 in the Comparison of Biofuel Systems (COBS) experiment. This experiment was conducted in a 9-ha field that is part of the Iowa State University Agronomy and Agricultural Engineering Research Farm, in Boone County, Iowa (41.92°N, 93.75°W). The soil is a Webster silty clay loam (fine-loamy, mixed, superactive, mesic Typic Endoaquoll) and Nicollet loam (fine-loamy, mixed, superactive, mesic Aquic Hapludoll),

Rye shoot and root biomass and C:N

Over the 6-yr period, rye shoot biomass at termination day varied from 120 to 2499 kg ha−1 (Table 4). The low rye biomass production in 2009 and 2013 coincided with relatively cool spring weather conditions in those years (Fig. 2). In 2014, poor growth was related to winterkill, caused by extremely harsh conditions during that winter. On the other hand, the unusually warm temperatures in February and March of 2012 allowed rye to produce the highest biomass over the 6-year period even when it was

Discussion

In this study, we approached rye cover crop abiotic effects on maize yields and environmental performance from a systems perspective (Fig. 1). Initially, we hypothesized that the magnitude of rye effects on maize yields and environmental performance variables such as cumulative drainage water and NO3-N losses would be proportionally related to rye biomass production, an easily measurable trait. Experimental, literature and modeling results did not support the hypothesized relationship for yield

Conclusions

Coupling experimental and literature findings with modeling, we provided a system-level analysis of rye cover crop effects on maize and extrapolated results beyond the study period to obtain a more complete picture of the abiotic effects of the inclusion of a rye cover crop in rain-fed maize-based systems. Modeling scenario analysis showed that in the long term, rye improves environmental performance (26% reduction in NO3-N losses) without consistently reducing maize yields. However,

Acknowledgements

This project was supported by the Iowa Nutrient Research Center (project: ‘Quantifying temporal and spatial variability in NO3-N leaching across Iowa’), the United States Department of Agriculture’s National Institute of Food and Agriculture (competitive grant No. 2012-67011-1966) and the Agriculture and Food Research Initiative (Hatch project No. 1004346). We thank Robert Ewing, Dave Sundberg, Carl Pedersen and other personnel from the COBS project for contributing to the data collection. We

References (90)

  • R.W. Malone et al.

    Evaluating and predicting agricultural management effects under tile drainage using modified APSIM

    Geoderma

    (2007)
  • M. Salmerón et al.

    Effect of winter cover crop species and planting methods on maize yield and N availability under irrigated Mediterranean conditions

    F. Crop. Res.

    (2011)
  • M.E. Schipanski et al.

    A framework for evaluating ecosystem services provided by cover crops in agroecosystems

    Agric. Syst.

    (2014)
  • T.R. Sinclair et al.

    Nitrogen and water resources commonly limit crop yield increases, not necessarily plant genetics

    Glob. Food Sec.

    (2012)
  • P.J. Thorburn et al.

    Modelling decomposition of sugar cane surface residues with APSIM-residue

    F. Crop. Res.

    (2001)
  • P.J. Thorburn et al.

    Modelling nitrogen dynamics in sugarcane systems: recent advances and applications

    F. Crop. Res.

    (2005)
  • L.J. Abendroth et al.

    Corn growth and development (PMR 1009)

    (2011)
  • J. Acharya et al.

    Effect of cereal rye winter cover crop (Secale cereal) termination on corn seedling diseases. (Abstr.)

    Phytopathology

    (2016)
  • J.G. Arbuckle et al.

    Cover crop adoption in Iowa: The role of perceived practice characteristics

    J. Soil Water Conserv.

    (2015)
  • S.V. Archontoulis et al.

    Nonlinear regression models and applications in agricultural research

    Agron. J

    (2013)
  • S.V. Archontoulis et al.

    Evaluating APSIM maize, soil water, soil nitrogen, manure, and soil temperature modules in the Midwestern United States

    Agron. J.

    (2014)
  • S.V. Archontoulis et al.

    A model for mechanistic and system assessments of biochar effects on soils and crops and trade-offs

    GCB Bioenergy

    (2015)
  • M. Bakker et al.

    Winter rye cover crops as a host for corn seedling pathogens. (Abstr.)6

    Phytopathology

    (2016)
  • D.M. Bates et al.

    Nonlinear Regression Analysis and Its Applications

    (2007)
  • A.M. Blackmer et al.

    Nitrogen fertilizer recommendations for corn in Iowa (PM1714)

    (1997)
  • H. Blanco-Canqui et al.

    Cover crops and ecosystem services: Insights from studies in temperate soils

    Agron. J.

    (2015)
  • E.B. Brennan et al.

    Winter cover crop seeding rate and variety effects during eight years of organic vegetables: III. Cover crop residue quality and nitrogen mineralization

    Agron. J.

    (2013)
  • J.L. Bruin et al.

    Use of a rye cover crop following corn in rotation with soybean in the upper Midwest

    Agron. J.

    (2005)
  • S. Carlson et al.

    Research priorities for advancing adoption of cover crops in agriculture-intensive regions

    J. Agric. Food Syst. Community Dev.

    (2013)
  • S.M. Crandall et al.

    Cropping system and nitrogen dynamics under a cereal winter cover crop preceding corn

    Plant Soil

    (2005)
  • S.M. Dabney et al.

    Using cover crops and cropping systems for nitrogen management

  • A.L. Daigh et al.

    Subsurface drainage flow and soil water dynamics of reconstructed prairies and corn rotations for biofuel production

    Vadose Zo. J.

    (2014)
  • A.L.M. Daigh et al.

    Subsurface drainage nitrate and total reactive phosphorus losses in bioenergy-based prairies and corn systems

    J. Environ. Qual.

    (2015)
  • De Rosario Martínez, H., 2015. {phia}: Post-hoc interaction...
  • K.V. Dhima et al.

    Allelopathic potential of winter cereals and their cover crop mulch effect on grass weed suppression and corn development

    Crop Sci.

    (2006)
  • R. Dietzel et al.

    Above- and belowground growth, biomass, and nitrogen use in maize and reconstructed prairie cropping systems

    Crop Sci.

    (2015)
  • R. Dietzel et al.

    How efficiently do corn- and soybean-based cropping systems use water? A systems modeling analysis

    Glob. Chang. Biol.

    (2016)
  • D.L. Dinnes et al.

    Nitrogen management strategies to reduce nitrate leaching in tile-drained Midwestern soils

    Agron. J.

    (2002)
  • S.W. Duiker et al.

    Rye cover crop management for corn production in the Northern mid-Atlantic region

    Agron. J.

    (2005)
  • G.W. Feyereisen et al.

    Plant growth component of a simple rye growth model

    Trans. ASABE

    (2006)
  • F. Gastal et al.

    N uptake and distribution in crops: an agronomical and ecophysiological perspective

    J. Exp. Bot.

    (2002)
  • R.H. Gelderman et al.

    Nitrate-Nitrogen

  • T. Griffin et al.

    Cover crops for sweet corn production in a short-season environment

    Agron. J.

    (2000)
  • G.L. Hammer et al.

    Can changes in canopy and/or root system architecture explain historical maize yield trends in the U.S. corn belt?

    Crop Sci.

    (2009)
  • Iowa Deptartment of Agriculture et al.

    Iowa Nutrient Reduction Strategy

    (2013)
  • Cited by (0)

    View full text