Influence of Nitrogen Rates on Nitrate Accumulation and Distribution in Vegetables

In this paper, the influence of nitrogen rates on nitrate accumulation and distribution in four vegetables was studied through pot experiment. The results showed that nitrate concentrations in cabbage and garden sass are apparently higher than that of two kinds of spinach. Petiole is an organ in which nitrate concentration is the highest and accumulated nitrate of plant is mainly distributed for cabbage, garden sass and Ningxia spinach. Lateral root, blade and petiole are separately the organ in which nitrate concentration is the highest and accumulated nitrate of plant is mainly distributed under the low, medium and high nitrogen levels for Japanese spinach. With the increase of nitrogen rate, nitrate concentrations of different organs all significantly increase for four kinds of vegetable. The distribution percent of accumulated nitrate increase in blade and trend to decrease in main root and lateral root for cabbage, garden sass and Ningxia spinach as nitrogen rate increased, but this percent gradually decrease in main root and stem for Japanese spinach.