http://hdl.handle.net/10174/1129 Tue, 08 Sep 2026 14:27:55 GMT 2026-09-08T14:27:55Z http://hdl.handle.net/10174/42557 Title: Limestone and stocking rate: effects on sheep growth and sward dynamics in a Mediterranean Montado Authors: Carreira, Emanuel; Serrano, João; Silva, Flávio; Geraldo, Ana; Cruz, Margarida; Mata, Ester; Silva, Rafael; Infante, Paulo; Charneca, Rui; Pereira, Alfredo Editors: Trindade, Henrique; Almeida, José; Carneiro, João; Fangueiro, David; Castro, M; Abreu, Manuel; Maças, Benvindo; Madruga, João; Moreira, O; Silva, J; Freitas, M; Cruz, C Abstract: his study evaluated the effects of two grazing systems—continuous (CS) versus deferred stocking (DS)—and dolomitic limestone application on pasture structure, forage quality, and sheep performance in a Mediterranean silvopastoral system (Montado). A 6-month trial (December 2023–June 2024) was conducted in four 1-ha plots: UC (CS, unlimed), UD (DS, unlimed), TC (CS, limed), and TD (DS, limed). DS produced markedly higher pasture utilisation (animal-days) than CS (3,111 vs 1,281) and liming increased mean sward height (TC 241.2 mm; others 132.8–205.6 mm). Crude protein (CP) declined and neutral detergent fibre (NDF) increased across time but were similar across treatments; CP tended to be slightly higher with limestone (TC, TD). The average daily gain was greater in CS, but the total cumulative liveweight gain per treatment was superior in DS (UD = 433.9 kg; TD = 472.2 kg vs UC = 223.9 kg; TC = 277.9 kg), indicating a more efficient pasture herbage conversion at higher instantaneous stocking pressure. Integrating DS with dolomitic limestone appears to enhance system-level productivity without compromising animal performance, offering a pragmatic pathway for sustainable intensification in dryland pastures Sun, 07 Jun 2026 23:00:00 GMT http://hdl.handle.net/10174/42557 2026-06-07T23:00:00Z http://hdl.handle.net/10174/39899 Title: Evaluation of the ground speed Effect on the Performance of the Row-Side Continuous Canopy Shaking Harvester Prototype in a High-Density Olive Grove Authors: Dias, A.B.; Pinheiro, A.; Falcão, J.M.; Peça, J.O. Editors: Pérez Ruiz, Manuel; Egea Cegarra, Gregorio; Pérez Urrestarazu, Luis; Diaz de la Torre, Isabel; Rodríguez Lizana, Antonio; Franco Salas, Antonio; González Ortega, Manuel Jesús; Pineda Martos, Rocío; Prior Fernández, Alejandro Abstract: In 2009 authors begin the development of the Row-Side Continuous Canopy Shaking Harvester (RSCCSH) prototype. The prototype comprises two symmetrical harvesters trailed by a farm tractor. Each harvester has a vibratory rotor with flexible rods, a catching platform with conveyors belts and a temporary storage bag. The detachment efficiency of canopy shakers are influenced by shaking frequency, ground speed and olive canopy characteristics. Between 2015 and 2017 a trial to evaluate the ground speed effect in the performance of the RSCCSH was carried out. The trial was established in an irrigated olive orchard of Picual variety planted with the array 7m x 3.5m. In a randomly design with three replications, the following treatments were evaluated: V400 - ground speed of 0.4 kmh-1; V600 - ground speed of 0.6 kmh-1; V800 - ground speed of 0.8 kmh-1; V1000 – ground speed of 1.00 kmh-1; V750 - ground speed of 0.75 kmh-1; V910 - ground speed of 0.91 kmh-1. Olive detachment efficiency tends to decrease with an increase in ground speed. No significant differences were found between treatments in olive losses to the ground. The best option in terms of harvesting rate (kgh-1) will correspond to the interval between 600 and 800 mh-1. Thu, 31 Aug 2023 23:00:00 GMT http://hdl.handle.net/10174/39899 2023-08-31T23:00:00Z http://hdl.handle.net/10174/39847 Title: Avaliação do desempenho de espalhadores de estrume na aplicação localizada de composto em olival Authors: Dias, António Bento; Dias, Ivo Lourenço; Falcão, José; Cruz, Vasco Editors: Gonçalves, J.M.; Ruiz Canales, A.; Guilherme, M.; Conceição, L.A.; Jarém Ceballos, C. Abstract: Sendo a compostagem de bagaço de azeitona com folhas de oliveira e estrume de ovinos ou bovinos uma técnica exequível ao nível da exploração agrícola, apenas será possível fechar o ciclo da economia circular com a sua aplicação no solo do olival. Tal requer que se disponha de tecnologia que garanta a colocação do composto à taxa pretendida no local desejado. Avaliou-se a utilização de dois semi-reboques distribuidores de estrume na aplicação localizada de composto na faixa de solo coincidente com a linha de plantação de um olival em sebe. Em três linhas aleatoriamente selecionadas para cada um dos equipamentos, registou-se o tempo gasto na distribuição de cada carga, o número de árvores por carga e registou-se por amostragem a massa de composto distribuída ao solo. Os resultados obtidos revelaram que qualquer dos equipamentos permite a localização de idênticas doses de composto com velocidades de avanço que não diferiram significativamente entre si. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/10174/39847 2025-01-01T00:00:00Z http://hdl.handle.net/10174/35891 Title: Performance of machine learning algorithms for forest species classification using WorldView-3 data in the Southern Alentejo region, Portugal Authors: Coelho, Ana Margarida; Sousa, Adélia; Gonçalves, Ana Cristina Abstract: Recent advances in remote sensing technologies and the increased availability of high spatial resolution satellite data allow the acquisition of detailed spatial information. These data have been used for monitoring the Earth's surface, namely monitoring land use land cover, quantifying biomass and carbon, and evaluating the protection and conservation of forest areas. O WorldView-3 is a high spatial resolution satellite (0.50m) with 8 multispectral bands (visible and infrared) which allows obtaining detailed data from the Earth's surface. This study aims to map the forest occupation by specie with two WoldView-3 images, and to evaluate the performance of machine learning classifiers (maximum likelihood, support vector machine and random forest) in two regions of Alentejo, south of Portugal. The main forest species are Quercus suber in one region and Quercus rotundifolia in another. The procedures performed were multiresolution image segmentation and object-oriented classification based on 4 bands (blue, green, red and near infrared). As auxiliary data, vegetation indices (NDVI and SAVI) and principal components were calculated. In the object-oriented classification process, the three classifiers were tested. The support vector machine classifier was the one that presented the best accuracy (kappa and overall accuracy), for both images, allowing to obtain good results in the identification of forest species. In the image dominated by Quercus suber, the values of kappa and overall accuracy were 90% and 95%, and for the image where Quercus rotundifolia predominated, 90% and 96% respectively. The methodology applied to the high spatial resolution satellite data showed very good results in the identification and mapping of main forest species. Higher precision values stand out for the image where the Quercus rotundifolia predominates, where there is less spectral variation, namely fewer land use classes, thus reducing errors between classes that may be spectrally similar. Thu, 31 Aug 2023 23:00:00 GMT http://hdl.handle.net/10174/35891 2023-08-31T23:00:00Z