Potential benefits of tanniferous forages in integrative crop-livestock agroecosystems

Abstract

Integrating livestock into cropping systems may enhance ecosystem services while still providing efficient food production. Including tanniferous forages in crop-livestock systems could further enhance ecosystem services. Interest in phytochemicals, such as tannins, has increased over the past several decades, and research continues to reveal the potential benefits of tannins in agricultural systems. However, research evaluating the influence of tanniferous forages in integrative crop-livestock systems is limited. We discuss how tannins influence soil microbial dynamics and nutrient cycling, the function of tannins in forages, and the role tannins have in improving the health of foraging animals. We speculate on potential advantages for human health from consumption of animal-based foods from animals that consumed tanniferous forages or supplemental plant materials. Expanding our knowledge and integration of phytochemicals in muti-faceted agroecosystem research and utilizing their influence in agriculture system dynamics may be an effective tool to enhance agroecological sustainability.

Tannins and Climate Change: Are Tannins Able To Stabilize Carbon in the Soil?

“…Especially high tannin concentrations can be found in plants living in conditions of low soil fertility and low pH; for example, in pine roots, the concentration of tannins may reach 20% dry weight . The tannin concentration in agricultural plants is mostly lower . However, in some agricultural plants, like legumes, the tannin concentration may reach 10% dry weight .…”

“…6 The tannin concentration in agricultural plants is mostly lower. 7 However, in some agricultural plants, like legumes, the tannin concentration may reach 10% dry weight. 8 Tannins are polyphenolics divided into two distant groups, hydrolyzable tannins (HT) and condensed tannins (CT) (Figure 1).…”

Soil greenhouse gas flux and nitrogen mineralization following manure application from tannin‐fed dairy cows

“…Livestock systems, especially dairy systems, are a significant source of GHG and NH 3 emissions, with large fractions coming from manure handling and land application (Aguirre‐Villegas & Larson, 2017). Amending dairy cow feed with plant‐extracted tannins (Duval et al., 2016; Powell et al., 2009) and better integrating crop–livestock systems through recycling of on‐farm products are potential solutions to limit on‐farm GHG and NH 3 emission (Clemensen et al., 2022; Wiesner et al., 2020). There is evidence that tannin‐amended feed can reduce gas fluxes at the animal and barn scales, including enteric CH 4 emissions (Honan et al., 2021; Kataria, 2015; Tan et al., 2011), NH 3 (Lazzari, 2022; Powell et al., 2011), and total GHG emissions (Duval et al., 2016; Norris, Tedeschi, Muir, et al., 2020, Norris, Tedeschi, Foster, et al., 2020).…”