Fig. 6From: Experimental archaeological study in China: implications for reconstruction of past manuring and dietary practices indicated by δ15N values of Setaria italica and Panicum miliaceumδ15N 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 testBack to article page