Comparison of cover crop monocultures and mixtures for suppressing nitrogen leaching losses

Joshua Gaimaro, Dennis Timlin and Katherine Tully

Agricultural Water Management, 2022, vol. 261, issue C

Abstract: The 2025 goal of the Chesapeake Bay Program is to reduce agriculture’s nitrogen (N) loading by 20% from 2014 values. Cover cropping is an important best management practice for recycling and conserving N in cropping systems that might otherwise be lost to groundwater via leaching and runoff. The reduction of N leaching by winter cover crops depends largely on precipitation, timing of planting, and the selection of the appropriate crop species. We compared nitrate-nitrogen (NO3-–N) leaching losses among forage radish (Raphanus sativus L.), cereal rye (Secale cereal L.), a forage radish+cereal rye mixture, and no-cover control. Replicated field trials were conducted at the University of Maryland Central Maryland Research and Education Center over 2016–2018. We collected porewater from 60 cm below the ground surface using porous cup lysimeters following rainfall events and used NO3-–N concentrations paired with the HYDRUS 1-D soil moisture model to compare N leaching losses (in kg N ha−1) among cover crop treatments. We show that mean soil porewater NO3-–N concentrations were higher (by 5x) in the no-cover control compared to rye and radish+rye treatments (P < 0.0001). Overall, N leaching losses (kg N ha−1) were highest in the no-cover control plots (P < 0.0001), but the majority of N leaching losses in rye plots occurred during the fall while the majority of radish N leaching losses occurred during the winter and spring (after they winter-killed). The rye and radish+rye mixtures reduced N leaching losses by 80% in both years. Understanding how different cover crop species affect N leaching losses, can help us design cropping systems to minimize N losses to the Chesapeake Bay especially as climate change alters rainfall patterns across the region.

Keywords: Cover crops; Cereal rye; Forage radish; Nitrate-nitrogen; Leaching; HYDRUS (search for similar items in EconPapers)
Date: 2022
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0378377421006259
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:agiwat:v:261:y:2022:i:c:s0378377421006259

DOI: 10.1016/j.agwat.2021.107348

Access Statistics for this article

Agricultural Water Management is currently edited by B.E. Clothier, W. Dierickx, J. Oster and D. Wichelns

More articles in Agricultural Water Management from Elsevier
Bibliographic data for series maintained by Catherine Liu ().