Natural abundance 15N determinations.

(A) δ15N values from Sierra Mixe maize, a conventional maize variety (Maiz Blanco Conasupo), and reference plants grown in Sierra Mixe, 3 months after planting. Values are given as mean and standard deviation. Statistical comparisons were made between the means of the reference plants, Maiz Blanco Conasupo, and Z. mays S. Mixe, using Student t tests (p 15N values from Sierra Mixe maize plants grown in Fields 1 and 2 in Sierra Mixe during 2011 and 2012 at 2, 3, 4, 5, and 6 months after planting. Values are given as mean and standard deviation. Statistical comparisons were made between the reference plants mean and Z. mays S. Mixe means at each time point using Student t tests (p S3 Table. (Data at DOI: 10.6084/m9.figshare.6534545).