Fig. 6

δ15N values of grains treated with different types of animal manure. Bars indicate mean values ± 1 standard error (n = 9). Within millet varieties in one period, letters denote statistical significance at P < 0.05 with the LSD test

δ15N values of grains treated with different types of animal manure. Bars indicate mean values ± 1 standard error (n = 9). Within millet varieties in one period, letters denote statistical significance at P < 0.05 with the LSD test