Corn root growth and nutrient accumulation improved by five years of repeated cattle manure addition to eroded Chinese Mollisols

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.