Ecosystem service delivery by cover crop mixtures and monocultures is context dependent

Abstract

While cover crops and mixtures are increasingly used to provide ecosystem services in agroecosystems, some fundamental questions remain about how cover crop performance and composition vary in different conditions, limiting optimal cover crop use. We conducted a field experiment at a research farm in New York, including a subset of treatments in three working farm fields. We selected two common cover crops, hairy vetch (Vicia villosa Roth), a legume, and common wheat (Triticum aestivum L.), a grass, with multiple cultivars of each. We looked at the effect of cover crop composition spanning intraspecific and grass-legume mixtures on five ecosystem services: cover crop productivity, weed suppression, total biomass nitrogen, soil N retention, and long-term N supply via legume fixed N. We did not find intraspecific diversity to have an effect on any ecosystem services we measured, nor was that response context dependent. We did observe significant ecosystem service improvements in the grass-legume mixture, though this was context dependent and the performance of the mixture varied relative to the monocultures at different farm sites. Regardless of this interaction however, the grass-legume mixture was as good as or better than either monoculture for all services and sites, except soil N accrual at one site. Consequently, increasing complexity in cover crops through grass-legume mixtures is a low risk practice that may have the potential to deliver ecosystem service outcomes greater than those of monocultures across a range of growing conditions. 1 INTRODUCTION Cover crops are increasingly used by a wide range of farmers to support various ecosystem services from erosion control to pest regulation, with nutrient management and soil health as high priorities (

Three years of cover crops management increased soil organic matter and labile carbon pools in a subtropical vegetable agroecosystem

“…Legume cover crops, on the other hand, can be more effective at providing additional N through biological N fixation, which will improve soil fertility and cash crop productivity. Therefore, to maximize the multiple benefits of cover crops use, mixtures of legume/grass species have also been recommended (Finney et al., 2017; Reiss & Drinkwater, 2020). Mixtures of legume and grass cover crop species can enhance biomass accumulation relative to monocultures, as legumes provide additional N needed by grasses (Blesh et al., 2019; Brennan & Smith, 2005; Jian et al., 2020).…”

Leguminous service crops in cereal production at high latitudes : provision of ecosystem services and disservices from a novel intercropping system

“…Besides production of food, agroecosystems can supply ecosystem services such as nutrient cycling, carbon sequestration, pollination and biological control (Swinton et al 2007;Zhang et al 2007;Bommarco et al 2013). These services could help reduce the impact of agriculture on the environment and the climate, as well as sustaining agricultural production in the long-term (Bommarco et al 2013;Lal 2019;Reiss & Drinkwater 2020). Neglecting the importance of supporting and regulating functions in agroecosystems may lead to negative impacts on both the agroecosystem itself and surrounding ecosystems, e.g.…”

Combining crop diversification practices can benefit cereal production in temperate climates

“…Perennial legumes may deposit N that can be recovered by grasses in cover crop mixtures (Schipanski and Drinkwater 2012). Reiss and Drinkwater (2020) reported no difference in the amount or the proportion of legume N derived from N 2 fixation in a cover crop mixture compared to the same legumes as sole cover crop. Frankow-Lindberg et al (2009) showed that mixtures of forage crops have a higher ability to suppress weeds but also pointed out red clover as a weaker competitor.…”