Soil Carbon Storage in Willamette Valley Grass Seed Systems: A review

Authors: GONZALEZ MATEU, MARTINA - Oregon State University; MOORE, AMBER - Oregon State University; Trippe, Kristin; ANDERSON, NICOLE - Oregon State University; VERHOEVEN, ELIZABETH - Oregon State University

Submitted to: bioRxiv
Publication Type: Pre-print Publication
Publication Acceptance Date: 11/29/2022
Publication Date: 11/29/2022
Citation: Gonzalez Mateu, M., Moore, A., Trippe, K.M., Anderson, N., Verhoeven, E. 2022. Soil Carbon Storage in Willamette Valley Grass Seed Systems: A review. bioRxiv. https://doi.org/10.1002/essoar.10512940.1.
DOI: https://doi.org/10.1002/essoar.10512940.1

Interpretive Summary: Agricultural systems have potential to store carbon (C) when soil C management practices are in place. Some of these practices may include the production of perennial crops, inclusion of grass species in a crop rotation, reduced tillage, and leaving post-harvest crop residues in the field. Increases in soil C could be beneficial to enhance soil fertility, soil biodiversity, and soil structure, and could also provide opportunities for participation in future C markets. There is great interest to determine the C storage of Oregon grass seed systems and the role of management practices on C cycling for potential involvement in cap-and-trade, soil C, or soil health incentive programs. A better understanding of these factors should help inform future offset projects and help establish the potential for the grass seed industry to participate in incentive programs that may reward management decisions that lead to reduced greenhouse gas emissions or greater C storage. This review presents the current state of knowledge on C storage in both perennial and annual grass seed cropping systems and identifies knowledge gaps as a resource for C storage estimates. Soil C discussions are focused on two main themes: 1) overall estimates of soil C storage and the factors that influence this parameter in the topsoil of grass seed production fields, and 2) comparison of how soil C storage in grass seed cropping systems compare to intensively managed and uncultivated/minimally managed cropping systems.

Technical Abstract: Agricultural systems have potential to store carbon (C) when soil C management practices are in place. Some of these practices may include the production of perennial crops, inclusion of grass species in a crop rotation, reduced tillage, and leaving post-harvest crop residues in the field. Increases in soil C could be beneficial to enhance soil fertility, soil biodiversity, and soil structure, and could also provide opportunities for participation in future C markets. There is great interest to determine the C storage of Oregon grass seed systems and the role of management practices on C cycling for potential involvement in cap-and-trade, soil C, or soil health incentive programs. A better understanding of these factors should help inform future offset projects and help establish the potential for the grass seed industry to participate in incentive programs that may reward management decisions that lead to reduced greenhouse gas emissions or greater C storage. This review presents the current state of knowledge on C storage in both perennial and annual grass seed cropping systems and identifies knowledge gaps as a resource for C storage estimates. Soil C discussions are focused on two main themes: 1) overall estimates of soil C storage and the factors that influence this parameter in the topsoil of grass seed production fields, and 2) comparison of how soil C storage in grass seed cropping systems compare to intensively managed and uncultivated/minimally managed cropping systems.