Accumulation of nitrate in spinach depending on forms and doses of nitrogen

Abstract

Nitrogen, as one of the most important element of nutrition, has lots of specifics. Its adsorption by plants directly depends on its content in the soil, as well as from the form and doses of nitrogen fertilizers. Spinach belongs to the group of nitrophillic vegetables. Since nitrogen overdoses can jeopardize spinach nutritive value, a special attention should be given to its nitrogen fertilization. The experimental part of this research was conducted during spring of 2009 and 2010 by applying two types of nitrogen fertilizers (CAN and urea) in three variants (80, 160 and 240 kg/ha N). The testing was performed on commercial variety Matador (Institute for Vegetable Crops, Smederevska Palanka). The results show that the use of high doses of nitrogen caused higher accumulation of nitrate in spinach. Statistically significant higher level of nitrogen was found in leaves treated with CAN comparing to urea. Spinach yield was directly dependent from the nitrogen doses supplied, but no statistically significant difference was found among nitrogen forms.