Speaker
Description
Introduction
Olive orchards represent a major component of agricultural systems in the Mediterranean basin. In recent decades, modern high-yielding intensive cropping systems are expanding fast, often replacing low-yielding traditional orchards. These changes in olive farming may result in higher environmental impacts as new orchards are highly mechanized and require a higher use of inputs (water, fertilizer, energy, pesticides), but quantitative reports in this regard are scarce in the literature. This work provides a comparative assessment of the productive and environmental performances of real orchards with contrasting characteristics and management schemes using the decision support system ‘SATDOS’.
Materials and Methods
SATDOS integrates a well-established process-based simulation model of olive orchards (OliveCan, López-Bernal et al., 2018), an improved model for calculating nutrient balances and fertilizer requirements (FertiliCalc, Villalobos et al., 2020) and a new tool (CCO2E) for accounting for CO2 emissions resulting from cultural practices. The water footprint is also computed using a corrected procedure that considers the evapotranspiration of natural vegetation as the baseline for nil footprint (Fereres et al., 2017). With these elements, the system aims to provide simultaneous information on different sustainability indicators related to the water, carbon and nutrient balances of the orchard.
Six olive orchards located in the province of Córdoba, Spain, were selected for the study. We aimed to include representative examples of contrasting olive cropping systems. The sample included the following orchards:
- ‘SHD-I-C’: irrigated hedgerow orchard (1852 trees/ha) under conventional management
- ‘SHD-R-O’: rainfed hedgerow orchard (1143 trees/ha) under organic management
- ‘HD-I-O’: medium-density irrigated orchard (521 trees/ha) under organic management
- ‘HD-I-C’: medium-density irrigated orchard (204 trees/ha) under conventional management
- ‘T-R-C’: traditional rainfed orchard (83 trees/ha) under conventional management
- ‘T-R-O’: traditional rainfed orchard (83 trees/ha) under organic management
Data required to run SATDOS was collected from different sources, including interviews with farm managers for delineating the operations and materials used in 2023. Weather data were gathered automatically from public Spanish databases.
Results
Actual yields of the farms ranged from 1500 (SHD-I-C) to 225 kg oil/ha (T-R-O), with the highest values in the irrigated plantations and the low yield of T-R-O. Productivity was positively correlated with net ecosystem productivity (NEP) (r2=0.69). CO2 emissions ranged from 1500 (SHD-I-C) to 320 kg CO2/ha (T-R-O), being higher with higher level of mechanisation and input use. The extreme values of water footprint were estimated for the traditional farms, with the rest exhibiting values between 0.70 and 1.20 m3/kg oil. Regarding fertilisation plans, N was supplied in excess as compared to the requirements estimated by SATDOS in all cases (the excess ranged from 24 to 143 kg N/ha).
Discussion
Substantial differences in the productive and environmental performances of the studied farms were found. Our results suggest that CO2 emissions increase as the farm intensifies and irrigation is applied, just as NEP and oil yield increase, revealing a trade-off between some negative environmental impacts and farm productivity.
This work shows the potential of SATDOS as a decision support system for evaluating the cost/benefit of specific management schemes from the economic and environmental perspectives. This may be helpful for preventing unnecessary environmental impacts associated to specific strategies. As an example, an excess of N supply was found for all the orchards, which may contribute to diffuse pollution and indirectly lead to increased CO2 emissions.
Funding
This work has been developed under the framework of the project TED2021-132217A-I00, funded by MCIN/AEI/10.13039/501100011033 and the European Union “NextGenerationUE”/Recovery and Resilience Facility.
References
- Fereres, E., Villalobos, F.J., Minguez, M.I., van Halsema, G., Perry, C.J. (2017). Commentary: On the water footprint as an indicator of water use in food production. Irrig Sci. 35, 83–85. https://doi.org/10.1007/s00271-017-0535-y
- López-Bernal, Á., Morales, A., García-Tejera, O., Testi L., Orgaz, F., De Melo-Abreu, J.P., Villalobos, F.J. (2018) OliveCan: A Process-Based Model of Development, Growth and Yield of Olive Orchards. Front. Plant Sci. 9, 632 https://doi.org/10.3389/fpls.2018.00632
- Villalobos, F.J., Delgado, A., López-Bernal, Á., Quemada, M. (2020) FertiliCalc: A Decision Support System for Fertilizer Management. Int. J. Plant Prod. 14, 299–308. https://doi.org/10.1007/s42106-019-00085-1
| Keywords | Carbon exchange; Decision support system; Olea europaea L.; Sustainability; Water Footprint |
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