Abstract

VILLAFANE, Roberto; JASPE, Alcides; D'LIMA, Jesús  and  BASSO, Carmen. Behaviour of fertilizers discharge in close and distant emitters to injector. Bioagro [online]. 2016, vol.28, n.3, pp.209-214. ISSN 1316-3361.

In fertigation of crops, the time of injector operation is usually calculated based on the water requirements without considering the travel time of fertilizer from the injector to the farthest emitters. The objective of this research is to propose a way to estimate the operating time of the injector to ensure full and uniform application of fertilizers. In two systems of fertigation in stevia [Stevia rebaudiana (Bertoni) Bertoni] the travel times of water from the injector to the closest and the farthest emitters were calculated under two irrigation treatments (80 and 100 % of the crop evapotranspiration), using the conservation mass law. The water discharged by those emitters was collected at constant intervals from the start of fertigation to the end of watering. Electrical conductivity was measured in each water sample, which allowed drawing curves of fertilizer discharge for both emitters, and determining the amount of fertilizer applied based on the calibration equation. The time from the start of fertigation till the total discharge of fertilizers by the last emitter was compared with the summation of the fertilizer injection time and the water travel time from the injector to the last emitter in order to propose a method of splitting the irrigation time.

Keywords : Advection; dispersion; fertigation; fertilizer transport in pipelines.

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