Organic carbon pools and storage in the soil of olive groves of different age

Abstract

Summary Compared with annual crop cultivation, tree groves might represent a relevant land‐use system to improve C sequestration, but few data are available to support this hypothesis. To evaluate the potential of olive tree (Olea europaea L., 1753) cultivation to store soil organic C (SOC), we assessed (i) the distribution of organic C in active (water‐extractable and particulate organic C, WEOC and POC, respectively), intermediate (organic matter associated with stable sand‐size aggregates and silt‐ and clay‐size aggregates, SSAs and SCAs, respectively) and passive (organic matter resistant to oxidation, rSOM) pools, (ii) the phenol content of the C pools, (iii) the humic‐C distribution of the intermediate C pool and (iv) the stocks of SOC pools in two olive groves of different age (7 years (OG7) and 30 years (OG30)) compared with a nearby site with cereal crops (arable soil, AS). In OG30 the organic C stock of the olive grove was no different from that of the AS, but the distribution of SOC pools changed with the age of the olive groves. The WEOC and POC increased in the Ap horizon of OGs, probably because of the herbaceous cover and distribution of chipped prunings on the soil. There were fewer SSAs in OG7 than AS, possibly because of pedoturbations from deep tillage before the olive trees were established, but they increased in OG30. The increase in SSAs and SCAs in the Bw and BC horizons of OG30 was associated with humic‐C and unextractable‐C and a smaller phenol content than AS. This suggested that the olive tree roots had a positive role through rhizodeposition and root turnover, which favoured the stabilization of organic matter into aggregates at depth. In contrast to the active and intermediate C pools, the passive C pool did not vary following the change in land use from arable to olive grove. Highlights Effects of land‐use change from arable to olive grove on soil organic C pools and stocks. Soil organic C stock increased from 7‐ to 30‐year‐old olive orchard. Olive tree cultivation affected active and intermediate C pools, but not the passive C pool. After 30 years, the olive grove stored an amount of SOC similar to that of the arable system.

Is new olive farming sustainable? A spatial comparison of productive and environmental performances between traditional and new olive orchards with the model OliveCan

“…Long-term capacity of olive groves to store carbon in the soil was also confirmed by Nieto et al (2010) and Massaccesi et al (2018). While some estimations of carbon storage assume a linear relationship between carbon inputs and carbon stocks, results in our study lead to rejection of this hypothesis.…”

“…They help preserve natural resources by protecting the soil and sequestering carbon. In fact, agricultural management of olive trees has the potential to increase the accumulation of soil organic matter (Nieto et al, 2010;Massaccesi et al, 2018). The potential of olive tree plantations for storing stable organic carbon acting as CO2 sinks has been confirmed under some soil conservation practices (Sofo et al, 2005;Proietti et al, 2014;Lopez-Bellido et al, 2016;Proietti et al, 2016;Brunori et al, 2017;Proietti et al, 2017).…”

Effect of land-use types on edaphic properties and plant species diversity in Mediterranean agroecosystem

“… Allen et al (2006) point out that 60% of interrelationships among plants and environmental variables in olive groves, could be explained through the interpretation of soil properties, slope gradient and slope aspect, and that the existing variation of plant species composition is the result of different management practices. However, sustainable practices in olive groves and no use of herbicides improve soil fertility ( Vignozzi et al, 2019 , Massaccesi et al, 2018 , Bilalis et al, 2011 ). The use of fungicides on the other hand, generates secondary pollutants to the soil, which contribute to the increase of the concentration of heavy metals and therefore they should not be ignored ( Ballabio et al, 2018 ).…”

Recent Achievements and New Research Opportunities for Optimizing Macronutrient Availability, Acquisition, and Distribution for Perennial Fruit Crops

“…The need to improve or, at least, maintain current soil organic matter has long been considered a tenet of sustainable orchard production, but has also recently received attention in conventional orchard management [23]. In olive, carbon budgeting has been used to measure soil carbon pools and storage [24]. Their practices are important to account for carbon sequestration occurring in orchards or for measure changes in soil organic carbon in response to changes in practices.…”