Vertical distribution of soil organic matter, N, and soil C/N ratio for different N treatments (mean ± SD)

<p>The lines indicate the vertical distributions of soil organic matter, N, and soil C/N for different levels of N treatment at soil depths of 0–50 cm in July and September 2010 and 2013, and the error bars indicate the standard deviations of the means (n = 3). CK denotes the control treatment (no nitrogen added), L denotes the low-concentration N treatment (37.5 kg·N·ha^-1·yr^-1), and H denotes the high-concentration N treatment (112.5 kg·N·ha^-1·yr^-1). <i>P</i>. <i>euphratica</i> samples were selected in an arid area of the Ebinur Lake Area of China.