CIMO - Resumos em Proceedings Não Indexados à WoS/Scopus
Permanent URI for this collection
Browse
Browsing CIMO - Resumos em Proceedings Não Indexados à WoS/Scopus by Field of Science and Technology (FOS) "Ciências Naturais::Ciências da Terra e do Ambiente"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- Improving soil health through nature-based solutions: the effects of olive-pomace-based compostsPublication . Royer, Ana Caroline; Lado, Marcos; Fonseca, Felícia; Hernandez Hernandez, Zulimar; Figueiredo, Tomás d'AquinoLoss of soil organic matter (SOM) is a major issue in Mediterranean regions, especially in NE Portugal, where about 70% of soils are classified as Leptosols. On the other hand, olive groves dominate the region's farmland, and the olive oil industry generates large quantities of by-products. Two-phase olive pomace (OP) has a high organic load and is phytotoxic due to its high phenolic content. Composting OP with other agri-residues offers a nature-based solution that addresses untreated OP disposal challenges while recycling nutrients and supporting the circular economy. This study evaluates the effects of olive pomace-based composts (OPC) on soil physical and chemical properties. OPC was produced by composting OP with sheep manure and almond shells. In a pot trial, 3 OPCs produced with different %OP (OPC44, OPC31 and OPC25) and a commercial organic corrective (HMC) were incorporated in the 0-5cm layer of an eutric Leptosol (2.1% OM) at three doses (10, 20, 40 t.ha-1) + control. Pots were seeded with Italian ryegrass (Lolium multiflorum) and watered to keep soil moisture above 70% field capacity. After 138 days trial, soil properties were analysed for SOM and its physical fractionation, total C and N, extractable K, P Olsen, pH, effective cation exchange capacity (CEC), bulk density, porosity, field capacity, and aggregate stability. Multivariate analysis showed that compost dose had a stronger influence on soil properties than compost type. Linear regression revealed that SOM, total C, extractable K, pH and effective CEC increased proportionally with dose. The highest dose led to SOM and total C increases of 13.3 and 8.4 g·kg⁻¹, respectively. Compared to HMC, OPCs were better K sources. Organic amendment decreased bulk density (by 8-15%) and increased soil porosity, field capacity, and improved aggregate stability by ~20% (particularly with OPC31 and OPC44). OPC application also enhanced both physical and chemical protection of SOM. C content was highest in macroaggregates, stored as unprotected and coarse particulate OM. Higher doses — especially of OPC31 and OPC44 — promoted larger C accumulation in strongly physically and chemically protected pools, as compared to control and HMC. OPCs application increased mineral-associated OM, likely due to their colloidal nature, supporting long-term SOM stabilization. This study highlights the potential of OPC to improve SOM content, fertility, and soil structure in degraded Mediterranean soils. Composting OP provides a sustainable approach to valorise agri-waste, enhance soil functions, and support climate-smart agriculture.
- Performance of ESA-CCI-SM Satellite product for estimating soil water deficit: a case study in NE PortugalPublication . Figueiredo, Tomás d'Aquino; Royer, Ana Caroline; Hernandez Hernandez, ZulimarThe Mediterranean climate is characterised by hot and dry summers and water deficit in soils. Monitoring soil water deficit is of crucial importance in Mediterranean cropland, allowing a more cost-effective soil and water management. Satellite-borne data sources provide high temporal resolution information but usually lack the spatial resolution to adequately account for soil variability, namely on the physical-chemical properties that affect soil water storage capacity. As a case study located in Bragança, NE Portugal, the present work aimed at exploring the use of ESA-CCI-SM satellite product to estimate water deficit for a wide range of soil water storage capacities. A satellite-borne soil moisture data series (ESA-CCI-SM product) was clipped for Bragança area (25 x 25 km pixel). Temperature and precipitation (P) records of a weather station located in Bragança were used to compute monthly reference evapotranspiration (ET0, Thornthwaite) and the soil water balance (SWB, Thornthwaite-Mather) along the same period (2003-2016, 168 months). SWB were computed for soil water storages (Smax) representing the Smax range of regional soils (25, 50, 75, 100, 150 mm). Following earlier work by the authors, monthly soil water deficit series (SWD), obtained for the 5 Smax, were analysed and compared with the SM monthly averages series, using basic statistical methods. Average annual P and ET0 in the study period were 750 and 711 mm, respectively. In all years, SWD occurred from June to September, with peaks in July and August (ca. 110 mm each), but it was also recorded in February and in November (1 out of 14 years). Annual SWD decreased linearly with Smax increase (R²=0.994), from 400 mm (Smax 25 mm) to 290 mm (Smax 150 mm). The number of SWD months also decreased in the same range of Smax, from 77 to 74 out of 168. Linear regression models relating SWD to SM monthly data for each Smax were derived and applied to estimate SWD in dry months. Model performance declined with Smax increase, from Smax 25 mm (R2=0.928) to Smax 150 mm (R2=0.873), while SEE remained similar along the Smax range (23 mm). Model parameters are well correlated (R2>0.95) with Smax, allowing the integration in a single model the two variables (SM and Smax). Dry months (SWD>0) were discriminated from non-dry (SWD=0) by SM, respectively lower or higher than 0.21 m3 m-3, with 91% (Smax 25 mm) to 94% (Smax 150 mm) matching frequency. Median SM in the whole Smax range was 0.14 and 0.25 m3 m-3, for dry and non-dry months, respectively. Performance reached encourages the application of the regression models derived for estimating SWD from SM, still with a considerable uncertainty due to the high SEE obtained. As the range of Smax tested was quite large, the regression models can be applied to deliver remote-based estimates of SWD accounting for the variability of soil water storage capacities found in NE Portugal.