Living Mulch Management Spatially Localizes Nutrient Cycling in Organic Corn Production

Peyton Ginakes,John M Baker,Thanwalee Sooksa-Nguan,Julie M Grossman

doi:10.3390/agriculture10060243

Peyton Ginakes, John M Baker + Show 2 more

Open Access

https://doi.org/10.3390/agriculture10060243

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Abstract

Kura clover (Trifolium ambiguum) is a perennial living mulch species that can be used in conjunction with zone tillage to reduce nitrogen pollution, maintain ground cover, and provide nitrogen to crops. In such systems, kura clover is maintained between crop rows by limiting tillage only to within-row areas. However, the effect of zone-tilled living mulches on soil quality and nutrient cycling in these distinct regions is relatively unexplored. We examined three pools of labile soil organic matter (SOM): microbial biomass, particulate organic matter (POM), and permanganate oxidizable carbon (POXC). Soil samples were collected from both within-row and between-row locations of a zone-tilled kura clover living mulch at three time points per year: before spring zone tillage, approximately ten days after spring zone tillage and corn (Zea mays) planting, and at corn harvest in 2015 and 2016. In 2016, POM and POXC decreased within rows relative to between-row regions after tillage, suggesting that zone till management stimulated decomposition of readily available SOM to effectively localize nutrient cycling in this region and slow mineralization between rows where living kura clover remained. This work shows that zone-tilled living mulches may be a promising avenue for enhancing the synchrony of nutrient mineralization specifically within crop rows, while maintaining year-round ground cover between rows.

Highlights

Maintaining living ground cover is a management practice known to reduce soil erosion and runoff, increase water infiltration, and build soil organic matter (SOM) [1,2]
Known as living mulches (LMs), provide year-round soil coverage, an especially imperative task in the Upper Midwestern region of the United States (US) where landscapes are often left bare in the winter and spring, and are subject to soil losses and degradation [9]
In 2016, permanganate oxidizable carbon (POXC) had a greater range, from 537 to 847 mg C kg−1 soil, and there was an interactive effect of soil location and sampling time (Table 1; p = 0.06)

Summary

Introduction

Maintaining living ground cover is a management practice known to reduce soil erosion and runoff, increase water infiltration, and build soil organic matter (SOM) [1,2]. Leguminous cover crop varieties in particular can provide significant nitrogen (N) contributions to subsequent crops [4,5,6,7,8]. Known as living mulches (LMs), provide year-round soil coverage, an especially imperative task in the Upper Midwestern region of the United States (US) where landscapes are often left bare in the winter and spring, and are subject to soil losses and degradation [9]. Perennial roots stabilize soil structure via the binding properties of root exudates [15,16], mycorrhizal associations [17,18], and the creation of macropores [19]

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