Sistema de irrigação por capilaridade na produção de porta-enxertos de mudas citricas na fase de sementeira / Irrigation system by capillary action in the citrus rootstocks production in seedings stage

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

The water and nutrition management in the production of citrus rootstocks in the seedling phase performed by sprinkler systems, manually operated, presents the environmental outcome of water or residual solution disposal from the fertigation. The generated wastewater is generally discarded directly in the soil with the risk to reach the groundwater and contaminate the watershed water resources where the property is located. Looking for a feasible technical alternative to solving this problem, this research aimed to develop an irrigation system that applied water by capillary action to be employed in the production of citrus rootstocks in the seedling stage that would allow the appropriate water resources use in this sector. Initially, it was carried on the assessment of the characteristics of irrigation used by citrus nurseries growers by fill in a feedback form. In the second stage of the study it was evaluated the irrigation system performance used by producers, estimating the efficiency of irrigation and water and salt losses, using a field methodology developed specifically for this purpose. With the results of the previous steps, it was developed and design equipment proposals, followed by construction of prototypes with preliminary testing. Afterwards, the chosen prototype was hydraulically characterized with the determination of the flow rate and pressure relationship for three operating pressures (10 kPa, 15 kPa and 20 kPa), estimating the time and filling volume of the equipment. The substrate subsidence and material loss were monitored during the hydraulic trails, estimating the substrate water storage in the four water applications. Finally, a field simulation of the equipment was performed to compare with the conventional irrigation. The survey results confirmed that the producer of citrus rootstocks characteristic of the state of Sao Paulo in 2007, had a production area from 1001 m2 to 3000 m2, producing up to 80,000 seedlings annually, used pine husk as substrates; employed showers or perforated pipes and irrigation with fertigation, not using techniques for irrigation. Performance appraisals of irrigation in the production of citrus rootstocks in the seedlings stage confirmed that the irrigation activity in the citrus rootstock production during the seedling phase is performed without effective control of the applied depth, generating low irrigation efficiencies with significant losses of water and fertilizers. The developed capillarity equipment, despite showing a low performance, has shown potential to improve the management and automation of the process, proving to be a viable alternative technology for this production system

ASSUNTO(S)

frutas citricas - cultivo viveiros de mudas citrus - irrigação irrigation engineering estufas - uso - agricultura nursy stock citrus fruit cultivation greenhouse use agriculture engenharia de irrigação irrigation citrus

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