The nitrogen contents and nitrogen forms were studied in albic soil with long-term crop rotation and soybean

maize

wheat continuous cropping. The results indicated that under no fertilization condition

the decreasing range of total nitrogen

alkaline-hydrolyzable nitrogen were largest

but hydrolizable nitrogen

amino acid nitrogen

amino sugar nitrogen were least in the wheat continuous cropping plot. Under applying manure condition

the increasing range of total nitrogen

alkaline-hydrolyzable nitrogen were least in the wheat continuous cropping plot

but were largest in the maize continuous cropping plot. The increasing range of amino acid nitrogen and amino sugar nitrogen were largest in crop rotation plot

and the variation of the other nitrogen forms could not been found law in the two cultivations.