Calibration of Grassmaster II to estimate green and dry matter yield in Mediterranean pastures: effects of pasture moisture content

Accurate assessment of standing pasture biomass in livestock production systems is a major factor for improving feed planning. Several tools are available to achieve this, including the GrassMaster II capacitance meter. This tool relies on an electrical signal, which is modified by the surrounding pasture. There is limited knowledge on how this capacitance meter performs in Mediterranean pastures. Therefore, we evaluated the GrassMaster II under Mediterranean conditions to determine (i) the effect of pasture moisture content (PMC) on the meter’s ability to estimate pasture green matter (GM) and dry matter (DM) yields, and (ii) the spatial variability and temporal stability of corrected meter readings (CMR) and DM in a bio-diverse pasture. Field tests were carried out with typical pastures of the southern region of Portugal (grasses, legumes, mixture and volunteer annual species) and at different phenological stages (and different PMC). There were significant positive linear relations between CMR and GM (r2 = 0.60, P < 0.01) and CMR and DM (r2 = 0.35, P < 0.05) for all locations (n = 347). Weak relationships were found for PMC (%) v. slope and coefficient of determination for both GM and DM. A significant linear relation existed for CMR v. GM and DM for PMC >80% (r2= 0.57, P < 0.01, RMSE = 2856.7 kg ha–1, CVRMSE=17.1% to GM; and r2= 0.51, P < 0.01,RMSE = 353.7 kg ha–1, CVRMSE = 14.3% to DM). Therefore, under the conditions of this current study there exists an optimum PMC (%) for estimating both GM and DM with the GrassMaster II. Repeated-measurements taken at the same location on different dates and conditions in a bio-diverse pasture showed similar and stable patterns between CMR and DM (r2= 0.67, P < 0.01, RMSE = 136.1 kg ha–1, CVRMSE = 6.5%). The results indicate that the GrassMaster II in-situ technique could play a crucial role in assessing pasture mass to improve feed planning under Mediterranean conditions.

Evaluation of DUALEM, OptRx and Grassmaster II sensors for monitoring the spatial variability and the temporal stability of a Mediterranean pasture

Site-specific management (SSM) is a form of precision agriculture whereby decisions on resource application and agronomic practices are improved to better match soil and crop requirements as they vary in the field. SSM enables the identification of regions (homogeneous management zones) within the area delimited by field boundaries. These subfield regions constitute areas that have similar permanent characteristics. Traditional soil and pasture sampling and the necessary laboratory analysis are time-consuming, labour-intensive and cost prohibitive, not viable from a SSM perspective because it needs a large number of soil and pasture samples in order to achieve a good representation of soil properties, nutrient levels and pasture quality and productivity. The main objective of this work was to evaluate technologies which have potential for monitoring aspects related to spatial and temporal variability of soil nutrients and pasture green and dry matter yield (respectively, GM and DM, in kg/ha) and support to decision making for the farmer. Three types of sensors were evaluated in a 7ha pasture experimental field: an electromagnetic induction sensor (“DUALEM 1S”, which measures the soil apparent electrical conductivity, ECa), an active optical sensor ("OptRx®", which measures the NDVI, “Normalized Difference Vegetation Index”) and a capacitance probe ("GrassMaster II" which estimates plant mass). The results indicate the possibility of using a soil electrical conductivity probe as, probably, the best tool for monitoring not only some of the characteristics of the soil, but also those of the pasture, which could represent an important help in simplifying the process of sampling and support SSM decision making, in precision agriculture projects. On the other hand, the significant and very strong correlations obtained between capacitance and NDVI and between any of these parameters and the pasture productivity shows the potential of these tools for monitoring the evolution of spatial and temporal patterns of the vegetative growth of biodiverse pasture, for identifying different plant species and variability in pasture yield in Alentejo dry-land farming systems. These results are relevant for the selection of an adequate sensing system for a particular application and open new perspectives for other works that would allow the testing, calibration and validation of the sensors in a wider range of pasture production conditions, namely the extraordinary diversity of botanical species that are characteristic of the Mediterranean region at the different periods of the year.

Era uma vez...As sete casas da infortuna: relação actor - marioneta : Relatório de estágio

O presente relatório tem como objectivo analisar a realidade de uma Companhia de Marionetas em Portugal, Teatro e Marionetas de Mandrágora, incidindo sobre a relação entre o actor, marioneta e meio envolvente (site specific) no contexto de uma prática teatral concreta, a produção do espectáculo Era uma vez ...As Sete Casas da Infortuna, no Castelo de Santa Maria da Feira. Os resultados apurados acompanham os moldes em que se procurou passar de um actor convencional para a especialização de um micromundo teatral onde a aprendizagem foi, fulcral desde o processo de construção até, à manipulação em cena num universo de trabalho particularmente árduo e específico. A minha trajectória no seio da companhia começou pela familiarização e aprendizagem informal da prática das marionetas através da observação directa dos espectáculos e de diferentes projectos da companhia. A formação feita no local de estágio (atelier da Companhia) foi outra das modalidades de formação que acompanhou o meu trajecto ao longo do estágio através da minha colaboração em projectos como Teatro nas Instituições, sempre sob a égide da divisão de tarefas e de alguma autoaprendizagem com a devida supervisão e orientação de artistas especialistas, como o Director Criativo, enVide neFelibata. O laboratório de aprendizagem prosseguiu pela mão da marionetista Clara Ribeiro que orientou a minha formação no sentido de absorver princípios teórico-práticos como o Foco, o Movimento e o Olhar para uma melhor consciencialização do universo do teatro de marionetas e formas animadas. Ainda nessa aprendizagem, a figura de alguns artistas especialistas foi fulcral, nomeadamente a da cenógrafa Marta Fernandes da Silva, que revelou ser de extrema importância ao longo do estágio pois permitiu uma verdadeira intersecção entre as componentes teórica e prática. Dessa forma pude acompanhar todo o processo de criação do Era uma vez ...As Sete Casas da Infortuna, e colaborar na construção das marionetas que iria manipular como actor - marionetista. Relativamente à questão da componente da interpretação no estágio, esta foi assumida pela encenadora - marionetista, Filipa Alexandre que, com a sua orientação, permitiu um enfoque do grupo de trabalho num processo de criação colectiva. Assim, a nível pessoal, fui movido por uma necessidade premente de descodificar o papel do actor na sua relação com a marioneta e o meio envolvente (site specific). ABSTRACT: This study aims to examine the reality of a Puppet Company in Portugal, the Puppet Theater of Mandrágora, focusing on the relationship between actor, puppet and environment (site specific) in the context of an actual theatrical practice, Once upon a time ...Seven houses of infortune, in the Castle of Santa Maria da Feira. The results obtained follow the way in which one seeks to move from one "conventional" actor to the specialization of a micro theater where learning was central from the building process to manipulation on the scene in a universe of work particularly hard and specific. My initial course within the company began with the familiarization and informal learning of the practice of puppetry through direct observation of performances and various projects of the company. The training done at the company (workshop of the Company) was one of the training arrangements that accompanied my way along the training through assistance on projects such as Teatro nas Instituições, always under the auspices of the division of tasks and due self-teaching with appropriate supervision and guidance of expert artists, such as the Creative Director, enVide neFelibata. The learning laboratory continued by the hand of the puppeteer Clara Ribeiro who supervised my training in order to absorb theoretical and practical principles as the Focus, the Movement and the Look for better awareness of the world of puppetry and animated forms. Also at this level, the figure of some specialist artists were central, such as the scenographer Marta Fernandes da Silva, who proved to be extremely important during this training, allowing a true intersection between the theoretical and the practical components. I could experience the surroundings of the creation notebook of Era uma vez ...As Sete Casas da Infortuna, and collaborate in the preparation of puppets that would handle as an actor - puppeteer. As to the question of the interpretation component on training, this was in charge of stage director - puppeteer, and the Artistic Director, Filipa Alexandre, whose instructions allowed a focus of the working group in a process of collective creation. Accordingly, to a personal level, I was urged to decode the role of the actor in relation to the puppet and the environment (site specific).