Climate change, and specifically global temperature increase, is expected to alter plant phenology. Temperate deciduous fruit trees have cultivar-specific chill and heat requirements to break dormancy and bloom. In this study, we aimed to estimate chill and heat requirements (in chill portions, CP, and growing degree hours, GDH, respectively) of 25 almond (30–36 years) and 12 apple (14–26 years) cultivars grown under a Mediterranean climate. The set included early and late blooming genotypes. Long-term phenological and temperature records were analyzed by means of partial least squares (PLS) regression. The main difference between early and late genotypes was chill requirement, ranging from 8.40 CP of early genotypes to 55.41 CP of extra-late genotypes. However, as chill requirements are quite easily attained by all almond cultivars in this study, year-to-year variations in actual blooming dates for each genotype are governed by variability of mean forcing temperatures. In contrast, different chill and heat combinations resulted in similar mean blooming dates for the studied apple cultivars. Mean temperature in both chilling and forcing phases determined their blooming time in the location studied. Overlaps and gaps between both phases were obtained. Despite some limitations, the PLS analysis has proven to be a useful tool to define both chilling and forcing phases. Nevertheless, since the delineation of these phases determine the total amount of CP and GDH, further efforts are needed to investigate the transition of these phases.
15 September 2022 in Agronomy for Sustainable Development
Carbon sequestration and storage in biomass is one of the most important measures to mitigate climate change. Mediterranean woody crops can sequestrate carbon in the biomass of their permanent structures for decades; however, very few studies have focused on an assessment of biomass and carbon sequestration in these types of crops. This study is the first to estimate above- and belowground biomass carbon stock in Mediterranean woody crops through a bottom-up approach in the NE Iberian Peninsula in 2013. Moreover, this is the first time that an assessment of the annual changes in carbon stock in the study area over a six-year period is presented. For this purpose, eight crop- and site-specific equations relating biomass or biometric variables to crop age were calculated. Most of the data were our own measurements, but unpublished data supplied from other authors as well as data from literature were also considered. Census of Agriculture data was used to scale results from individual data up to the municipality level at the regional scale. Results show that in woody cropland in NE Spain the total biomass carbon stock in 2013 was 5.48 Tg C, with an average value of 16.44 ± 0.18 Mg C ha−1. Between 2013 and 2019, although there was a 2.8% mean annual decrease in the area covered by woody crops, the carbon stock in the biomass of these crops increased annually by 3.8% due to the growth of the remaining woody cropland. This new estimation of carbon stocks may contribute to better understand carbon balances and serve as a baseline to global inventories. It may also serve to assess and manage carbon storage as an ecosystem service provided by Mediterranean woody cropland for mitigating climate change and, in combination with adaptive strategies, for supporting a productive and resilient agro-food system.
Climate change is expected to heavily impact agriculture in the Mediterranean region due to higher temperatures and droughts. Within the agricultural systems, vineyards are one of the most affected by climate. Here we provide a diagnosis of the main impacts of climate change in three protected designations of origin (PDOs) in Catalonia (NE Spain) in the 21st century. This is fundamental for assessing the future suitability of grapevine cultivation in the study area. For this purpose, we estimated the annual net water needs of the vineyard and a set of agroclimatic parameters of crop phenology and ripening. Climate change impacts were estimated at 1 km pixel resolution using temperature and precipitation projections based on the IPCC AR5 RCPs 4.5 and 8.5 climate change scenarios. Water needs would be 2 to 3 times greater than current water needs and a general advance and shortening of the ‘Budburst to Harvest’ period were estimated. The flowering date would advance from 3 to 6 weeks and the harvest from 1 to 2.5 months, resulting in a duration of the ‘Budburst to Harvest’ period from 10 to 80 days shorter. Changes in temperature during ripening were also estimated. Minimum temperature and daily thermal amplitude during ripening could increase from 1.4 to 2.9 °C and from 0.4 to 2.8 °C, respectively, by the end of the century. Additionally, the number of tropical nights (nights with T min > 20 °C) at ripening would increase from 2 to 23.7 days during the second half of the 21st century. Dynamics would be similar in the three PDOs studied although the magnitude of impact would differ, leading, in some cases, to significant limitations for grapevine cultivation and wine production if no adaptation strategies are applied in the near future. Increases in water needs were slightly greater in Empordà PDO, while the potential impact on crop phenology and grapevine quality was greater in the Pla de Bages PDO. These results, despite the limitations from simplified methods, incomplete data and unaddressed uncertainties, could serve as a basis for the design of specific adaptation strategies to improve and maintain vineyards in the PDOs studied and could be extrapolated to similar PDOs and regions.
The impact of long-term organic (ECO) versus conventional (CON) agricultural management on subsurface soil microbiota diversity and soil physicochemical properties remains unclear in Mediterranean vineyards. This study evaluated long-term ECO and CON effects in the Alt Penedès terroir (Spain), focusing on subsurface soil microbial diversity and soil characteristics. ECO increased the fungal-to-bacterial ratio and ammonium-oxidizing bacteria but reduced total subsurface soil bacterial populations and soil organic carbon. While ECO did not enhance annual yield production in the vineyard, fungal abundance, and ammonium-oxidizing archaea, it slightly increased the overall alpha diversity (Shannon and Inverse Simpson indexes) and significantly altered taxa composition in subsurface soil with a more robust and modular community. Crop management, soil texture, training system, and rootstock, but not vine variety, significantly influenced beta diversity in subsurface soil. The Mantel test revealed subsurface soil texture, Ca2+/Mg2+ ratio, and salinity as the main key soil drivers shifting the microbial community (beta diversity), while C/N and topsoil organic matter significantly correlated with bacterial abundance; NH4+ correlated with fungal abundance; and N-Kjeldahl, pH, and Mg2+/K+ correlated with alpha diversity. Integrating soil microbiota and physicochemical monitoring allowed us to confirm the positive effect of long-term agroecological practices on subsurface soil health and to identify the critical factors shaping their microbial communities in Mediterranean vineyards.
Climate change is expected to negatively impact agricultural production, leading to phenological and metabolic changes, increased water demands, diminished yields, and changed organoleptic characteristics, restricting the positive geographic productivity potential. As an adaptive strategy, agriculture in mountainous regions has gained prominence despite the fact that it entails new challenges. Indeed, mountain-specific conditions and limitations need to be considered, compared to the traditional productive regions. Consequently, there is a lack of information about the most suitable locations because the new conditions and limitations need to be accounted for. This study provides a crop suitability assessment approach to be used in mountainous regions where data about crop yield or development is scarce or nonexistent. Specifically, we evaluated the suitability of vineyards and apple orchards in the southern Pyrenees and Pre-Pyrenees. Using Geographical Information System (GIS) techniques, integrated with fuzzy logic and the Analytic Hierarchy Process (AHP), we combined traditional climatic, soil, and topographic indicators with factors relevant to mountainous regions. Our results indicated that the most suitable areas were primarily in lower basins and sunny hillsides, with smaller water needs. Vineyards would benefit from a very low risk of late spring frosts and elevated solar radiation, whereas apple orchards from a reduced risk of hailstorms, a very low risk of late spring frosts, and mild slopes. The fuzzy membership functions combined with the AHP facilitated the integration of indicators, effectively identifying areas with high potential for crop development. This approach contributes to landscape management and planning by offering a modifiable tool for assessing crop suitability in mountainous regions.