FORAGE CROPS

Author: KADRI BEN BELGACEM LAFI.
Year: 2003.
University: LLEIDA [www.udl.es].
Place of defense: INGENIEROS AGRONOMOS.
Place of preparation: UNIVERSITAT DE LES ILLES BALEARS.

Summary: The studies presented in this thesis involving primarily a contribution to the understanding of the effect of water stress on the main components of biomass production in Medicago arborea (M.arborea) and Medicago citrina (M.citrina). It deals firstly studying the basic characteristics in terms of the initial growth, as a critical phase for the establishment of the crop. Then, in adult plants, we studied the pattern of water absorption in soil, photosynthesis and transpiration efficiency in the use of water in the leaves, the dynamics of its renewal and growth of the leaf mass. These studies include the evaluation of the effects of the architecture of the plant in the interception of light and the integration of the above factors in productive capacity. It also assesses the effect of water shortage developed gradually in the suelon in rainfed conditions (rainfall cancels 230 billion) in production-related parameters such as photosynthesis, transpiration, efficiency in the ujso water and leaf growth. By comparing the behavior of these species, it is worth noting the increased capacity M.arborea and M.strasseri regard d eM.citrina to establish conditions in moderate water shortage in the soil. M.citrina, however, accumulate greater proportion of root biomass, which would greatly help the economy of water and mineral elements in poor soils. The plants mature M.citrina because of the diferncias in its more open architecture, the largest branching stems and maintaining greater leaf biomass, solar radiation intercepts more and consequently maintains higher production of leaves. In addition, the ability of extracting water from deep areas and high efficiency in the use of water in the leaves makes them more persistent in water stress conditions. From the point of view agronomic, M.citrina once established field presents greater potential for biomass production that M.arborea, probably because its open architecture (leaf area index = 2.3) and longer leaves. In addition, the patterns of leaf senescence more restricted M.citrina and the ability to maintain leaf mass in drought conditions strong in the summer, give it greater capacity to grow after the first rains. This is particularly interesting in a sort forage in Mediterranean conditions.

Author: LILIANA PRIVITELLO MERCEDES JOSEFA.
Year: 2004.
University: CÓRDOBA [www.uco.es].
Place of defense: FACULTAD DE VETERINARIA.
Place of preparation: FACULTAD DE VETERINARIA.

Summary: Incorporating species parennes megatérmicas aid to the sustainability of the systems of rearing cattle in the region semiaárida temperate Argentina. For that reason has been introduced species Panicum coloratum L.cv. Green Klein (Kleingrass) from the family of Poaceae. Originating in East Africa, bearing and high resistance to drought with its introduction there were three objectives: A-Knowing their productive potential and nutritional quality with nitrogen fertilization. B-To evaluate the effect of a spring fertilization in the material deferred to the winter. C-Incorporating feedback on nutritional aspects and propose guidelines for the management of a system of farming in semi-arid environment. We conclude that Kleingrassa fertilized a good productive potential and a strong performance leaf. Fertilization does not change substantially the nutritional profile of the kind deferred. The quality that gives this species in summer takes its use in that time. Meets the needs of energy and protein metabolism for maintenance but not the total.

Author: VANESSA DE LOS REYES MENDOZA GRIMÓN.
Year: 2005.
University: LAS PALMAS DE GRAN CANARIA [www.ulpgc.es].
Place of defense: FACULTAD DE VETERINARIA.
Place of preparation: FACULTAD DE VETERINARIA.

Summary: In this thesis we study in a comprehensive manner the factors which determine the reuse of water. It conducted a field study in which they compare the results obtained when irrigated with treated water and water with conventional, using an irrigation system located buried. Cultivated species are Medicago sativa, a hybrid of Sorghum bicolor ssp bicolor and Sorghum bicolor sudanense spp. It keeps track of the main agronomic and economic parameters for two full production cycles: * Quality of water used (characterization químico-agronómica, microbiological and parasicológica). * Solutions and complete soil samples obtained periodically during the pilot phase, in addition to carrying out the extent of the parameters conventional characterization of the different forms of phosphorus in the soil. * System for irrigation and water management, controlling volumes used and conditions of system maintenance, as well as a study on optimizing the installation of the same. * Crops (introduction, production and duration of crops, as well as health and nutritional quality of the same). * An economic study of the data to draw conclusions on the management of water, soil, crop species and irrigation system that will optimize the reuse proposal.