Kura Clover Living Mulch Reduces Fertilizer N Requirements and Increases Profitability of Maize

Jonathan R Alexander,John M Baker,Rodney T Venterea,Jeffrey A Coulter

doi:10.3390/agronomy9080432

Jonathan R Alexander, John M Baker + Show 2 more

Open Access

https://doi.org/10.3390/agronomy9080432

Copy DOI

Abstract

Kura clover living mulch (KCLM) systems have been previously investigated for their incorporation into upper Midwestern row crop rotations to provide ecosystem services through continuous living cover. Reductions in soil erosion and nitrate loss to surface and groundwater have been reported, but factors affecting agronomic performance and nutrient management are not well defined. To achieve realized environmental benefits, research must develop agronomic management techniques, determine economic opportunities, and provide management recommendations for row crop production in KCLM systems. Two experiments were conducted in 2017 and 2018 to determine the response to N fertilizer application for maize production in KCLM. The first-year maize experiment followed forage management, and the second-year maize experiment followed maize after forage management. Eight fertilizer N treatments ranging from 0–250 kg N ha−1 were applied to each experiment and grain and stover yields were compared to conventionally managed maize hybrid trials that were conducted nearby. First-year maize did not need fertilizer N to maximize yield and profitability in either growing season, and second-year maize required a fertilizer N rate near local University guidelines for maize following soybean. The net economic return from maize grain and stover in the KCLM averaged over first and second-year maize experiments and 2017 and 2018 growing seasons were $138 ha−1 greater than the conventional comparison.

Highlights

Kura clover (Trifolium ambiguum M. bieb), a rhizatomous perennial legume forage, is well suited for incorporation into upper Midwestern row-cropping systems as a perennial cover crop or living mulch [1]
Results from this study demonstrate that kura clover living mulch may be integrated into current
This study suggests that the N contribution from the living mulch is supplied in-season following row establishment and suppression management, and that mineralized N is sourced from labile and biomass N pools accumulated during forage management

Summary

Introduction

Kura clover (Trifolium ambiguum M. bieb), a rhizatomous perennial legume forage, is well suited for incorporation into upper Midwestern row-cropping systems as a perennial cover crop or living mulch [1]. Living cover and active root uptake during the fall and spring months reduce soil erosion and nitrate leaching from maize production by up to three-quarters in the KCLM system compared to conventional management [5,6]. While harvest of maize residue in conventional production systems can increase soil erosion and negatively affects soil carbon, structure, and fertility [9,10], soil physical and chemical properties were unaffected by 5–7 years of continuous maize stover removal under KCLM management in the upper Midwest [11].

Objectives

Methods

Results

Discussion

Conclusion