INVESTIGATIONS ON NITROGEN NUTRITION INDICES OF CABBAGE AND CUCUMBER

The present investigations were based on field experiments carried out in 1966–1968 with increasing nitrogen fertilization levels.

For the investigations vegetables with different nitrogen requirements, viz.: late cabbage and cucumber, were selected The nitrogen fertilizer rates, from 0 to 900 kg N/ha, were applied against a uniformly high phosphorus-potassium fertilization level.
In the growing season plant and soil samples were taken with the purpose of:

1. establishing the indicative part of the given plant ilustrating most exactly nitrogen nutrition degree;

2. determining the range of the indicative nitrogen form content in the growing season depending on the nitrogen fertilization level;

3. determining critical levels of mineral nitrogen in the soil.

It has been assumed that the nitrogen nutrition status of plants will be estimated by means of analyzing plants for N-NO₃ content and soil for nitrate and ammonium nitrogen content in arable layer.

N-NO₃ was determined in air-dry matter of plants and in dry soil using the methods with brucine (soil and cucumbers) or brucine and phenol-disulphonic acid application (cabbage). N-NH₄ in soil was determined using the Nessler’s reagent.

The investigations have shown that:

1. This selection has been made on a basis of the

Symposium on Nutrition and Fertilization of Vegetables

M. Mijas, O. Nowosielski

https://doi.org/10.17660/ActaHortic.1973.29.6