Effect of split applications of nitrogen fertilizer on the growth and nitrogen composition of Chinese mustard

Abstract

We assessed the effect of split applications of nitrogen (N) fertilizer on the growth and N composition of Chinese mustard. There were six treatments in which various rates of N fertilizer were applied as a basal dressing and two top dressings. The plants were harvested 40 days after seeding and the N composition of the plants determined. The soil was also sampled and the pH, electrical conductivity (EC) of 1:1 soil:water ratio extract, organic matter, nitrate‐nitrogen (NO₃‐N), Bray Pl‐extractable phosphorus (P) as well as 1N neutral ammonium acetate‐extractable potassium (K), calcium (Ca), and magnesium (Mg) concentrations after harvesting of the plants determined. The results show that there was no significant difference in yield from the various treatments. Total N concentration in shoots receiving the 1–2–1 fertilizer treatment was higher than that of the other treatments. However, NO₃‐N, soluble reduced N, and insoluble N concentrations in shoots as well as NO₃‐N, soluble reduced N, insoluble N, and total N concentrations of roots were not significantly different due to the treatments.