Browsing by Author "Lado, Marcos"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- Carbon storage patterns and landscape sustainability in northeast portugal: a digital mapping approachPublication . Patrício, Matheus Bueno; Lado, Marcos; Figueiredo, Tomás de; Azevedo, João; Bueno, Paulo; Fonseca, FelíciaThis study investigated the impact of regional land abandonment in northeast Portugal. It specifically focused on carbon sequestration opportunities in the Upper Sabor RiverWatershed, situated in the northeast of Portugal, amidst agricultural land abandonment. The study involved mapping the distribution of soil organic carbon (SOC) across four soil layers (0–5 cm, 5–10 cm, 10–20 cm, and 20–30 cm) at 120 sampling points. The quantification of SOC storage (measured in Mg C ha−1) allowed for an analysis of its relationship with various landscape characteristics, including elevation, land use and land cover (LULC), normalized difference vegetation index (NDVI), modified soil-adjusted vegetation index (MSAVI), topographic wetness index (TWI), and erosion risk (ER). Six statistical tests were employed, including multivariate approaches like Cubist and Random Forest, within different scenarios to assess carbon distribution within the watershed’s soils. These modeling results were then utilized to propose strategies aimed at enhancing soil carbon storage. Notably, a significant discrepancy was observed in the carbon content between areas at higher elevations (>1000 m) and those at lower elevations (<800 m). Additionally, the study found that the amount of carbon stored in agricultural soils was often significantly lower than in other land use categories, including forests, mountain herbaceous vegetation, pasture, and shrub communities. Analyzing bi- and multivariate scenarios, it was determined that the scenario with the greatest number of independent variables (set 6) yielded the lowest RMSE (root mean squared error), serving as a key indicator for evaluating predicted values against observed values. However, it is important to note that the independent variables used in set 4 (elevation, LULC, and NDVI) had reasonably similar values. Ultimately, the spatialization of the model from scenario 6 provided actionable insights for soil carbon conservation and enhancement across three distinct elevation levels.
- Nutrients concentration and uptake by ryegrass after soil amendment with olive-pomace-based compostsPublication . Royer, Ana Caroline; Lado, Marcos; Fonseca, Felícia; Hernandez Hernandez, Zulimar; Figueiredo, Tomás deOlive groves are predominant in the agriculture of Northeast Portugal. Two-phase olive pomace was composted with sheep manure and almond shell to obtain olive pomace-based composts (OPC). This plant efficacy trial evaluates the effects of composts, application dose and irrigation regime on foliar concentration and nutrient efficiency use by ryegrass. Three OPCs containing different proportions (%) of olive pomace at the initial mixture (OPC 44, OPC 31 and OPC 25) and a commercial organic corrective (HMC) were amended to an Eutric Leptosol at three application doses (10, 20 and 40 t.ha-1 + control). Experiment was conducted in pots with two irrigation regimes (50-70% and 70-100% of soil field capacity, respectively, corresponding to the two ryegrass growth periods prior to cutting). Plant N levels were assessed through elemental analysis, and P, K, Ca, Mg, Na, Mn, Fe, Zn and Cu levels in the crop dry matter were obtained through Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The ratio of concentration and dry matter determined nutrient exportations. Overall, the soil amendment significantly increased the foliar macronutrient levels compared to control ryegrass. Both nutrient concentration and exportation on leaves significantly increased with higher water input into the pots, strengthening the relationship between soil water content and nutrient bioavailability. Results were more evident for macronutrients than for micronutrients. Dose factor had a major influence on the nutrient concentration, although it didn’t always increase proportionally. Nutrient absorption was more influenced by compost type, with HMC and OPC25 inducing the greatest macronutrient exports. Compost with a higher proportion of olive pomace seems to have a slower release of nutrients to the plant. Recycling olive pomace through composting and its use as soil amendment may contribute to crop nutrition and soil health, towards sustainable agriculture in the region.
- Short-term effects of olive-pomace-based conditioners on soil aggregation stabilityPublication . Royer, Ana Caroline; Figueiredo, Tomás de; Fonseca, Felícia; Lado, Marcos; Hernandez Hernandez, ZulimarMediterranean agriculture asks for sustainable strategies to prevent actual soil organic matter decline rates. Composting agri-food by-products for application in farmland, besides contributing to a circular economy at regional or local scales, may improve soil resistance to physical degradation. Aggregate stability (AS) is a crucial property for building up such resistance. Olive pomace is an abundant by-product of the olive oil industry that may be valorized through composting. This study aimed to assess the influence on AS of olive-pomace-based composts (OPC) applied to a sandy loam Leptosol and a clay loam Fluvisol. To assess the effects of compost characteristics on AS, three OPCs resulting from different olive pomace proportions in the composting raw material (44, 31, and 25% by volume) were applied to aggregate samples in three doses (10, 20, and 40 t.ha−1, plus control) with fine and coarse grain sizes. Controlled laboratory conditions subjected samples to daily wetting-drying cycles during a 30-day experiment. AS was measured by wet sieving. OPC application significantly increased AS in the Leptosol amended with fine (+15% vs. control) and coarse (+19%) grain-size compost. In well-aggregated Fluvisol, amendment induced a significant increase in AS only in the compost coarse grain size (+12%). The application dose significantly affected AS, with 10 t.ha−1 being the best-performing dose. OPC applications in weakly aggregated soils are seemingly an encouraging soil management practice for improving soil resistance to physical degradation and reducing soil organic matter decline rates in Mediterranean farmland.