SIMULATED AND MEASURED NITROGEN STATUS IN SOIL AND IN ONION CROPS

The Swedish simulation model SOIL-SOILN was extented to include coefficients to define the details of onion development.
Key coefficients were obtained from an experiment carried out in 1993. The ability of the model to calculate the dry weights and N contents of the leaves and bulbs, and the soil mineral nitrogen was assessed by comparison with the results of the 1993 experiment and also with those experiments carried out in 1989 and 1991.

Simulated bulb growth was generally in reasonable agreement with the measured data, but simulated leaf growth was often overestimated.
Nitrogen uptake was closely related to the growth of the plant organs and where simulation of growth fitted well to the measured values so did nitrogen uptake.
Measured soil mineral nitrogen was less than the simulated values until the period of high nitrogen uptake in July.

According to this work, SOIL-SOILN model can be used as a tool to investigate relationships between soil water, soil nitrogen, plant nitrogen and biomass production in onion crops.
However, effects of onion development stages on key coefficients should be included into the model in order to improve applicability of the model to onion production.

Ecological aspects of Vegetable Fertigation in Integrated crop Production in the Field

T. Salo

modelling, Allium cepa, nitrogen uptake, soil mineral nitrogen, yield

https://doi.org/10.17660/ActaHortic.1996.428.20