Carbon sequestration by grass, crucifer and legume groundcovers in olive orchards

Abstract

Establishment of groundcovers (GC) is an efficient practice to reduce soil and nutrient losses in olive orchards, so they can act as a sink of atmospheric carbon and improve soil fertility. The aim of this study was to assess the carbon sequestration potential of several species used as groundcovers in two olive orchards. The experiment was conducted during three growing seasons in two olive orchards in Andalusia (Spain). In an experimental field, a grass (Brachypodium distachyon) and two crucifers (Eruca vesicaria and Sinapis alba) were used; in the other experimental field, three legumes were sown: common vetch (Vicia sativa), bitter vetch (Vicia ervilia) and hairy vetch (Vicia villosa).In both fields the species were sown and compared with the spontaneous vegetation of the area. The carbon release from groundcovers was studied and soil organic carbon (SOC) analysed during the decomposition period to assess the atmospheric carbon fixation. The increments of SOC in the first 20 cm of soil reached higher values with crucifers and grass than legumes. Sinapis alba obtained the best result with 2.56 Mg SOC ha À1 yr À1 . Establishment of groundcovers are an efficient tool for atmospheric carbon sequestration and to protect the soil from erosion.

Cropping with Vicia villosa and native grass improves soil’s bacterial structure and ecological network in a jujube orchard

“…The total N in the soil and alkali-resolving N fixation of Vicia villosa was 970 and 56.8 mg kg −1 respectively ( Wang et al, 2023b ; Chen et al, 2016 ). Its nutrient preservation qualities and low degree of lignification in the stem were found in previous studies ( Yang et al, 2022 ; De Torres et al, 2018 ). Although some information about the soil microbial composition in orchards cropped with Vicia villosa was preliminary reported in previous studies ( Wang et al, 2022c ; Jiang et al, 2019 ), the understanding of the co-occurrence network of the microbial community remains limited.…”

Impacts of Fertilization on Environmental Quality across a Gradient of Olive Grove Management Systems in Alentejo (Portugal)

“…In each of these square plots, the percentages of bare soil and herbaceous and woody plant cover were visually estimated and considered as indicators of soil protection. The average richness of the total plant cover, with cover vegetation that contributes to the control and mitigation of soil erosive processes such as grasses, crucifers, and legumes (which also contribute to nitrogen fixation in soil) [61,62], was also independently estimated. The herbaceous diversity (including all herbaceous plants) was calculated for each plot using Shannon's index [63] (Equation ( 2)):…”

“…Erosion estimation (A, t ha −1 year −1 ) for each type of olive grove sampled, specifying planting densities and management systems, where R: rainfall erosivity (J ha −1 ); K: soil erodibility (Mg J −1 ); LS: length and degree of slopes (dimensionless and in %); C: soil cover (dimensionless); and P: conservation practices (dimensionless). mitigation of soil erosive processes such as grasses, crucifers, and legumes (which also contribute to nitrogen fixation in soil) [61,62], was also independently estimated. The herbaceous diversity (including all herbaceous plants) was calculated for each plot using Shannon's index [63] (Equation ( 2)):…”

“…Finally, it is worth mentioning that plant cover crops sown in olive groves tend to be dominated by grasses and crucifers because their biomass helps to minimize the effects of soil erosion as they have a root system that promotes the production of soil aggregates, thus preventing the soil compaction caused by tillage practices [62,86]. In addition, legumes that help to fix nitrogen and increase soil fertility in crops [87] are equally common.…”

Viticulture and the European Union's Common Agricultural Policy (CAP): Historical overview, current situation and future perspective

“…Given their high potential, it has also been one of the agricultural practices foreseen within the eco‐schemes to benefit climate regulation and the environment in the new CAP. In fact, there are numerous studies on the benefits of implementing cover crops of grasses, crucifers and legumes, as they improve soil properties, increase atmospheric carbon sequestration and provide nutrients to crops (Ping et al, 2018; Repullo‐Ruibérriz de Torres et al, 2018). To avoid water or nutrient competition with vines, cover crops must be controlled (Delpuech & Metay, 2018).…”