A study of patchiness in mid-season dairy pastures : consequences and control : a thesis presented in partial fulfilment of the requirements for the degree of Master of Applied Science at Massey University

There is interest among some dairy farmers in increasing herbage intake of cows during spring by increasing pasture cover but without compromising pasture quality into the summer. "Late control" is a grazing management strategy developed in Massey University that meets those requirements (Matthews et al., 1996). In addition, it has been demonstrated in previous trials that Late control increases pasture production in the summer-autumn period by increasing ryegrass tillering vigour. Late control requires a period of lax grazing during spring to allow some reproductive growth development on ryegrass pastures, which is then controlled by hard grazing in late spring before anthesis. However, patchiness may develop in Late control during the lax grazing period when the herbage allowance is high. The objectives for the present experiment were to compare the pasture characteristics under Late control and conventional "Early control" spring management strategies in December-January, with particular reference to the consequences of vegetation heterogeneity to pasture production and utilisation over this period, and to discuss the implications to spring grazing management. The experiment involved detailed studies on three paddocks chosen from each of two farmlets of 22 paddocks used for a system trial comparing Early and Late control spring management on herds of 120 cows. Herbage mass distributions were estimated by taking 200 capacitance meter readings at random on each paddock. Relationships between herbage mass and utilisation and accumulation were estimated by using two 30 m permanent transects in each paddock. To determine botanical composition and tiller population variability within a sward, five tall patches and five short patches were sampled in each paddock. Paddocks in Late control before the control phase in December had more herbage mass than paddocks in Early control (3600 vs. 5000 kg DM/ha), but the variability of herbage mass was similar (1000 vs. 1000, standard deviation in kg DM/ha). The skewness of the herbage mass distribution was positive but greater in Early control than in Late control (0.57 vs. 0.32). Botanical composition was similar between treatments and within paddocks. Pasture morphology showed tiller size-density compensation in both treatments. Pasture characteristics in late control were not an impediment for efficient pasture removal in late control and more herbage was harvested than in Early control (1900 vs. 1000 kg DM/ha), although herbage allowance was greater in Early control. Short patches in both treatments were defoliated in less proportion than tall patches, but in Late control the proportion of short patches was less than in Early control. Therefore, low herbage mass and greater proportion of short patches in Early control had a negative effect on total herbage utilisation. Harvesting efficiency was controlled on Late control paddocks to avoid limitations to herbage intake, and the skewness of the distribution of herbage mass after grazing increased compared to Early control, as well as the proportion of tall poorly utilised patches. Topping of pastures after grazing was effective in removing poorly utilised material and in decreasing patchiness in January. In January, Late control paddocks had more herbage mass, but less patchiness than Early control paddocks (6300 vs. 4700 kg DM/ha). Sward characteristics were affected by treatment, and in general Late control increased ryegrass content and its leafiness during January compared to Early control. In January, herbage utilisation was greater in Late control than in Early control (3000 vs. 1700 kg DM/ha). It was concluded that because Late control had greater responses in tall patches, the objective should be to modify management to a longer rotation length before controlling reproductive growth in late spring, to allow a greater proportion of the sward to achieve high herbage mass. The combination of grazing and topping of pastures gave high herbage intakes and effective pasture control. More pasture was produced in Late control than in Early control and the rotation length can also be increased during the summer in Late control, which may benefit further ryegrass tillering

El Cid, un personaje transfronterizo

RESUMEN: En trabajos anteriores habíamos definido al Cid Campeador como un “habitante de frontera”, expresión que pretendía resaltar el carácter aventurero y arriesgado de Rodrigo Díaz, tanto en su actuación política como, sobre todo, militar. Del repaso de su vida, ciertamente, se saca la impresión de haber sido vivida constantemente al límite. Pues bien, sin perder de vista esta valoración de anteriores trabajos, ofrecemos en este artículo una nueva perspectiva de análisis para mejor entender el paso del Cid por la historia; por su historia concreta y limitada, y por los siglos en que su imagen se ha prolongado al amparo de la leyenda y del mito. Y acometemos este análisis utilizando una nueva palabra clave para definir a este personaje como un sujeto transfronterizo; es decir, como un individuo que sabe desenvolverse con soltura, incluso con fortuna, en etapas históricas, ambientes culturales, legalidades y formas de presencia radicalmente diferentes.ABSTRACT: In previous works, we have defined el Cid Campeador as an “inhabitant of the frontiers” of Christendom, a turn-of-phrase intended to highlight the adventurous and daring character of Rodrigo Díaz in his political life and, above all, in his military engagements. A review of his past certainly leaves a lasting impression that he lived his life to the hilt. Without losing touch with this viewpoint expressed in previous works, a new analytical perspective is advanced in this article to gain a deeper understanding of el Cid’s passage through history; through his own specific, time-bound history, and through those centuries in which his name lived on, taking refuge in both legend and myth. We begin this analysis referring to a new keyword that defines el Cid as a historical figure who crossed frontiers; in other words, as an individual who was able to conduct himself with almost fortuitous ease, in the face of radically different historical periods, cultural realms, codes of law, and demeanours.</p

La sombra del Cid y de otros mitos medievales en el pensamiento franquista

El pensamiento franquista, huérfano de argumentos para legitimar y enraizar la figura del caudillo Francisco Franco en la historia de España, busca su fuente nutricia, entre otros referentes ideales, en algunas leyendas y mitos de ascendencia medieval hispana: el de la Reconquista y Cruzada, o lucha sin cuartel contra el infiel musulmán; el de Fernán González, presunto símbolo de la defensa de la unidad de Castilla y, por extensión, de toda España; o el del Cid, ilusorio arquetipo del defensor de la patria, legendario vasallo siempre fiel y leal a su rey y a su reino, utópico cancerbero de la moralidad pública y garante imaginario de la continuidad en el ejercicio del poder.Francoist thought, bereft of arguments to legitimize and embed the figure of the Caudillo Francisco Franco in the history of Spain, sought its inspirational sources, among other ideal references, in various legends and myths of Spanish medieval stock: the Reconquista and the Crusades, or the allout war against the Muslim infidel; that of Fernán González, supposedly the symbolic defender of Castilian unity and, by extension, of the rest of Spain; or that of El Cid, illusory archetype of the defender of the Fatherland, legendary vassal of constant faith and loyalty to his king and to his kingdom, utopian guardian of public morality, and imaginary guarantor of continuity in the exercise of power.peerReviewe

Castilla, 1065: un reino prematuro

Por inercia, los historiadores hispanos sitúan la elevación del condado de Castilla a la categoría de reino en los años 1035 o inmediatamente siguientes. El dato, sin embargo, puede ponerse bajo sospecha si repasamos detenidamente la realidad sociopolítica del momento en el conjunto del reino de León. En este trabajo, a modo de aproximación y sugerencia, defendemos el retraso del momento hasta la fecha de toma de posesión del reino castellano –indudablemente ya reconocido como tal– por parte de Sancho II en 1065, aunque su consolidación no se hará efectiva sino unas décadas más tarde.From habit, Spanish historians consider the elevation of Castile from an earldom to a kingdom by 1035 or the immediate following years. This fact can be questioned following a deep analysis of the sociopolitical reality of that time throughout the kingdom of Leon. In this study it will be defended, as an approximation and a suggestion, a retardation of this event till the moment in which Sancho II took over the Castilian kingdom –at that moment un - doubtedly acknowledged as a kingdom– which occurred in 1065, although the consolidation of the kingdom will not be effective till some decades later

All-pass-filter-based active damping for VSCs with LCL filters connected to weak grids

LCL filters are commonly used to connect Voltage Sourced Converters (VSCs) to the grid. This type of filter is cheaper than a single inductor for the same current THD, but it generates resonance problems if no active or passive damping method is applied. Active damping methods are becoming popular in the literature because they improve efficiency, but they are sometimes difficult to implement and additional measurements are required. This paper proposes an active damping method for VSCs connected to weak grids that is based on making zero the open-loop phase at the resonance frequency. It will be shown that this strategy provides adequate damping of oscillations and that it can be achieved in two different ways: at the design stage (if the design constraints make it possible) or with an all-pass filter in series with the current controller. Two methods to design the all-pass filter are proposed. Also, the proposed active damping technique is compared with three alternatives already proposed in the literature. All the control algorithms are verified by simulation and in a 15 kW prototype of a three-phase VSC connected to a configurable weak grid via a LCL filter