Soil Functional Zone Management: A Vehicle for Enhancing Production and Soil Ecosystem Services in Row-Crop Agroecosystems

Abstract

There is increasing global demand for food, bioenergy feedstocks and a wide variety of bio-based products. In response, agriculture has advanced production, but is increasingly depleting soil regulating and supporting ecosystem services. New production systems have emerged, such as no-tillage, that can enhance soil services but may limit yields. Moving forward, agricultural systems must reduce trade-offs between production and soil services. Soil functional zone management (SFZM) is a novel strategy for developing sustainable production systems that attempts to integrate the benefits of conventional, intensive agriculture, and no-tillage. SFZM creates distinct functional zones within crop row and inter-row spaces. By incorporating decimeter-scale spatial and temporal heterogeneity, SFZM attempts to foster greater soil biodiversity and integrate complementary soil processes at the sub-field level. Such integration maximizes soil services by creating zones of ‘active turnover’, optimized for crop growth and yield (provisioning services); and adjacent zones of ‘soil building’, that promote soil structure development, carbon storage, and moisture regulation (regulating and supporting services). These zones allow SFZM to secure existing agricultural productivity while avoiding or minimizing trade-offs with soil ecosystem services. Moreover, the specific properties of SFZM may enable sustainable increases in provisioning services via temporal intensification (expanding the portion of the year during which harvestable crops are grown). We present a conceptual model of ‘virtuous cycles’, illustrating how increases in crop yields within SFZM systems could create self-reinforcing feedback processes with desirable effects, including mitigation of trade-offs between yield maximization and soil ecosystem services. Through the creation of functionally distinct but interacting zones, SFZM may provide a vehicle for optimizing the delivery of multiple goods and services in agricultural systems, allowing sustainable temporal intensification while protecting and enhancing soil functioning.

Cover Crop-Based, Organic Rotational No-Till Corn and Soybean Production Systems in the Mid-Atlantic United States

“…More research is also required to understand the allelopathic properties of cover crops and how they can be effectively managed to maximize weed suppression while minimizing negative impacts on cash crops. For example, zonal management of cover crop residues, where residues are moved from crop rows to inter-rows prior to cash crop planting, may help minimize negative allelopathic effects on the cash crop while enhancing weed suppressive effects in inter-rows [74]. However, this would have to be balanced with the need to ensure adequate mulch for weed suppression in crop rows.…”

Enhanced control of soil nitrogen cycling through soil functional zone management

“…Research is needed to investigate the capacity of SFZM to enhance crop nutrition and nutrient use efficiency across these different systems. Soil functional zone management may also offer benefits in addition to nutrient use efficiency, such as improvements to soil and water conservation as well as enhanced production potential (Williams et al, 2016). As such, SFZM provides an over‐arching management strategy for enhancing soil quality while maintaining or promoting increased yield output.…”

“…This movement coincides with the crop reaching its peak N demand phase. As the vast majority of crop roots are found in the top 5 to 6 inches of soil in the crop row, the movement of composted residues from the inter‐row to the row may enhance SOM mineralization and, hence, plant‐available N in the vicinity of crop roots (Williams et al 2016).…”

Managing soil functions for a sustainable bioeconomy—Assessment framework and state of the art

“…The same is true for the emerging practice of strip-tillage, which may also have potentially positive impacts on natural pest antagonists, microclimate and biological interactions (Williams et al, 2016).…”