Authors: Mafalda Pacheco Ferreira1,2,3, Mário Duarte1, Rosa Santos Coelho1,2,3, Samuel Guerreiro1,2,4, Ângela Prazeres1, Maria Godinho1,2,3
1ESAS – Santarém Polytechnic University
2UI_IPSantarém, Unidade de Investigação do Instituto Politécnico de Santarém
3Life Quality Research Centre
4LEAF – Linking Environment and Food
Abstract
It is widely believed that the inclusion of cover crops in traditional crop rotation practices can significantly influence soil organic carbon storage, playing a crucial role in climate change mitigation and adaptation strategies. The present study, aimed to assess the potential of cover crops for soil organic carbon storage in monoculture systems in the Ribatejo region of Portugal.Carbon content in aboveground biomass, belowground biomass, and soil was quantified in two monoculture fields in Ribatejo, Portugal (Carregueira and Chamusca) during 2021/22 and 2022/23 agricultural years. Carbon quantification was conducted following the GSOC MRV protocol (FAO, 2020) and IPCC (2008) guidelines. Experimental modalities in each site were: (CG) Control group maintaining traditional monoculture practices with natural vegetation as a reference and (GL) Introduction of site-specific grass-legume intercropping. In Carregueira, the carbon stored in aboveground biomass was approximately five times higher in grasslegume intercropping (2.26 t ha-1) compared to natural vegetation (0.4 t ha-1). Belowground biomass carbon remained consistent at 1.9 t ha-1. The introduction of grass-legume intercropping increased soil carbon storage. In Carregueira, it reached 28.6 t ha-1 with grass-legume intercropping and 20.6 t/ha with natural vegetation intercropping. In Chamusca, the values were 15.8 t/ha and 12.6 t/ha, respectively. Soil stored the highest carbon content, accounting for 78% to 93% of the total. Root/above ground biomass ratio was similar for the grass-legume cover crop (0.50) in both sites, but different between sites for the natural vegetation (2.68 in Carregueira and 1.11 in Chamusca). Total carbon content ranged from 22.1 t/ha to 31.8 t/ha.This study advances our understanding of cover crop integration and underscores the key contribution of grass-legume cover crops in improving soil carbon storage and promoting sustainable soil management for climate change mitigation. Furthermore, the research persists in a follow up project.
Keywords: carbon sequestration, climate change, horticultural monoculture, soil management, soil quality.
Read the full article in March 2024 Newsletter