A. Meiri
N. Bernstein
U. Yanai
R. Strul
M. Zilberstaine
Optimal Avocado fertigation should satisfy the crop nitrogen (N) requirements and minimize deep percolation of N that pollutes the ground water. A field study conducted in an avocado orchard in Israel, with the CV. Ettinger grafted on the salt tolerant VC51 rootstock, tested the effect of 20, 40 and 60 ppm N on temporal changes of N in the soil-solution. Nitrogen concentration of the soil-solution increased with increased levels of N fertilization with clear seasonal interaction. N-level of the soil solution was lowest at the beginning of the irrigation season and increased with time. It remained relatively steady in the midst of the summer and later increased with time until the end of the irrigation season (in the fall). The N/Cl ratio in of the soil solutions increased as well towards the end of the irrigation season suggesting a reduced N-uptake capacity at that time. Our results suggest temporal changes in N uptake by the crop. Most important is the slow uptake toward the end of the summer that needs to be taken into account in the seasonal fertigation planing to avoid increased N percolation and ground water contamination. We recommend in-situ monitoring of soil N and salinity as feedback for managing fertigation of avocado.
A. Meiri
N. Bernstein
U. Yanai
R. Strul
M. Zilberstaine
Optimal Avocado fertigation should satisfy the crop nitrogen (N) requirements and minimize deep percolation of N that pollutes the ground water. A field study conducted in an avocado orchard in Israel, with the CV. Ettinger grafted on the salt tolerant VC51 rootstock, tested the effect of 20, 40 and 60 ppm N on temporal changes of N in the soil-solution. Nitrogen concentration of the soil-solution increased with increased levels of N fertilization with clear seasonal interaction. N-level of the soil solution was lowest at the beginning of the irrigation season and increased with time. It remained relatively steady in the midst of the summer and later increased with time until the end of the irrigation season (in the fall). The N/Cl ratio in of the soil solutions increased as well towards the end of the irrigation season suggesting a reduced N-uptake capacity at that time. Our results suggest temporal changes in N uptake by the crop. Most important is the slow uptake toward the end of the summer that needs to be taken into account in the seasonal fertigation planing to avoid increased N percolation and ground water contamination. We recommend in-situ monitoring of soil N and salinity as feedback for managing fertigation of avocado.