Nitrogen dynamics under corn fields in the Red River Valley of North Dakota

Abstract

Excessive applications of fertilizer N in corn (Zea mays L.) has profound environmental and economic consequences. Corn grain yield, N losses, N 2 O denitrification, NH 3 volatilization, and soil water NO 3 concentration at 60-cm depth were collected for eight corn fields in the Red River Valley of North Dakota. Relationships of soil and management factors with cumulative N 2 O and NH 3 losses were studied. Grain yield varied from 3.58 to 5.66 Mg ha -1 . Cumulative NH 3 and N 2 O losses were ranged between 1.0-2.4 kg ha -1 and 24.7-150 g N 2 O-N ha -1 , respectively. Soil organic matter (SOM; r = .94, p = .001), clay (r = .94, p = .001), and initial inorganic N (0-60 cm) content (r = .83, p = .01) had a positive relationship with cumulative N 2 O losses. Cumulative NH 3 had a negative relationship with soil pH (r 2 = .63, p = .01).Results indicate that soil properties such as, SOM, clay concentration, and initial profile N had a control over N losses.