Zhou, K., Liu, X., Zhang, X., Sui, Y., Herbert, S. J. and Xia, Y. 2012. Corn root growth and nutrient accumulation improved by five years of repeated cattle manure addition to eroded Chinese Mollisols. Can. J. Soil Sci. 92: 521-527. The use of fertilizers with additional cattle manure application on eroded soil has been reported to improve cereal yields. Limited research exists on the long-term effect of cattle manure on root growth and nutrient uptake by corn (Zea mays L.) grown on eroded soils. A field experiment was established in Hailun city, Northeast China to determine the impact of long-term cattle manure addition on corn production in eroded Mollisols. There were five levels of simulated-erosion, which removed 0, 5, 10, 20, 30 cm of topsoil. Two soil amendments were: (1) chemical fertilizer at the rate normally used by farmers in the region and (2) chemical fertilizer plus 15 000 kg ha^-1 (dry weight basis) of cattle manure. Root growth (length, surface area and dry weight) was assessed at the three-leaf stage. Nitrogen (N), phosphorus (P) and potassium (K) uptake and accumulation by corn were evaluated at the three-leaf stage and at harvest. Compared with chemical fertilizer alone, 5 yr of repeated cattle manure addition significantly increased root surface area by 18-35%, and root dry weight by 45-129% in soil with simulated-erosion. The improvement of root growth by manure application was mainly correlated with the changes in larger size aggregate. N content increased by 12-59%, P by 31-129%, and K by 297-494% in corn at the three-leaf stage, and the same trend was found at harvest. Long-term cattle manure addition increased corn yield by 7% in soils with 5 cm topsoil removal, and gave similar yields in soils with 10 and 20 cm topsoil removal as non-eroded plots receiving chemical fertilizer only. Our results suggest that the increased corn yield in manure-amended soils was related to greater N, P and K accumulation due to larger root surface area and biomass. Addition of cattle manure with chemical fertilizer would be a practical and effective approach to restore soil productivity and improve corn yields in eroded Chinese Mollisols.