No abstract

There is little open-source software for trickle irrigation design and none of it is designed to simulate operating conditions on a specific hydraulic network already assembled in the field. Farmers employing trickle irrigation frequently need to change irrigation block operations over the years (parcel combinations), because of plant renovations in certain areas of the irrigated field or the adoption of precision irrigation. This work free software developed using Visual Basic® language that is able to simulate different block combinations of parcels, taking into consideration the pump parameters of flowrate, pressure, power requirements and efficiency and the main hydraulic network parameters of water speed, pressure and head loss. The software we developed was applied to a trickle irrigation system for citrus growing. The equations used to calculate head loss were Hazen-Williams and Darcy-Weisbach, and users could choose between these two equations depending on their application. The software worked efficiently for making the hydraulic calculations, providing simulations that graphically assisted users in choosing which combination of operation parcels (block combinations) and pump parameters (rotation speed and impeller diameter) for optimal operation of the irrigation system. The program ensured that the pressure along the irrigation network was compatible with the nominal operating pressure of the pipeline and safety valves.

Caracterização da produção de biomassa de capim-elefante (Pennisetum purpureum, Schum.), cv. Cameroon, em função da adubação nitrogenada e irrigação em região semiárida Guilherme Busi de Carvalho Tese apresentada para obtenção do título de Doutor em Ciências. Área de concentração: Irrigação e Drenagem Piracicaba 2014 Guilherme Busi de Carvalho Engenheiro Agrônomo Caracterização da produção de biomassa de capim-elefante (Pennisetum purpureum, Schum.), cv. Cameroon, em função da adubação nitrogenada e irrigação em região semiárida versão revisada de acordo com a resolução CoPGr 6018 de 2011

The world largest citrus plantations are located in Sao Paulo State, Brazil. Some of them are irrigated by drip systems, especially when it is expected a rising in prices from orange market or, for the local reality of production, when the plants are in the initial stages of development. By projecting the irrigation for the later stages, the systems are generally designed to support two laterals per row of trees, aiming to greaten the wet bulb diameter and hence the water necessity of these trees. However, it has been checked in the practice of the farms that, from the same doubled line design, there is an implementation of one single line in the initial stages, given that the water requirements are smaller and it is possible to reduce costs. This work reveals that, before adopting this idea, it is essential to simulate the possible occurrences, especially under situations of laterals lying on some degrees of declivity. Simulations were done for conventional and compensating emitters. The pressure variation is affected in both of cases under accentuated declivities (i.e., 5% or 7,5%) and there are possibilities of ruptures for laterals with compensating emitters under these conditions.