Efectos del volumen de riego y el número de emisores por maceta sobre la distribución de raíces y sales en el sustrato en "Ficus benjamina"

Resumo

Potted weeping fig were grown in a greenhouse with one, two, or four emitters (1.2 L·h-1) per pot and irrigated (3 dS/m-1) with two volumes of irrigation water (control-590 mL and high-650 mL). The aim was to determine whether the factors affect the distribution of roots and salts in the substrate. We determined the electrical conductivity (EC) distribution at three heights (upper, middle, and lower), and the roots and EC horizontal distribution in four quadrants (south, west, north, and east). We also studied the effects on growth, average substrate EC, total applied water and drainage. Under control-volume irrigation, using four emitters per pot decreased the total applied water compared to one or two, which did not occur with high-volume irrigation. High-volume irrigation increased the leaching fraction compared with that observed in the control, while the number of emitters per pot reduced it. Both the number of emitters per pot and the irrigation volume increased the shoot/root ratio. The substrate EC was higher in the upper layer than in the underlying layers. When a high-irrigation volume was applied, using more than one emitter per pot attenuated this gradient. The substrate EC and the presence of roots in the horizontal quadrants were heterogeneous. Both of these behaviours decreased as the number of emitters per pot increased.