Abstract:To investigate the effects of different proportions of chicken manure and nitrogen fertilizer on the fractal characteristics of soil water stable aggregates and the carbon pool management index in the forage triticale/maize rotation, a field experiment was conducted from 2010 to 2017 (successive eight years) with five treatments: C0N0 (no fertilizer, CK), C0N10 (chicken manure nitrogen:urea nitrogen=0:10), C2N8 (chicken manure nitrogen:urea nitrogen=2:8), C4N6 (chicken manure nitrogen:urea nitrogen=4:6), C5N5 (chicken manure nitrogen:urea nitrogen=5:5). Soil water stable aggregate composition and organic carbon (SOC), total organic carbon (TOC), active organic carbon (AOC), soil mass fractal dimension (Dm) and soil carbon management index (CPMI) were assayed in triticale/maize rotation. The results showed that different fertilization measures had significant influence on the composition of soil water stable aggregates in triticale/maize rotation. The soil water stable aggregate composition was less than 0.25 mm particle size, its content was the highest in C0N0 treatment, followed by C0N10, C2N8 and C5N5 treatments, and C4N6 treatment was the lowest. Compared with CK, aggregate SOC content of each treatment were significantly increased (p< 0.05), and the increase order from large to small was C4N6 > C5N5> C2N8 > C0N10, and SOC of C4N6 treatment was significantly higher than those of other treatments (p< 0.05), the Dm of soil water stable aggregates from large to small was C0N0 > C0N10 > C2N8 > C5N5 > C4N6. Soil TOC, AOC and CPMI of each treatment in order was C4N6 > C5N5 > C2N8 > C0N10 > C0N0, and the AOC, CPMI and TOC contents of the same treatment decreased gradually with the increasing soil depth. The pearson correlation analysis showed that Dm had a very significant negative correlation with TOC, AOC and aggregate SOC (p< 0.01), and CPMI was significantly positively correlated with TOC, AOC and aggregate SOC (p< 0.01). Comprehensively, the combined application of chicken manure with nitrogen fertilizer was not only beneficial to improving the stability of the soil structure, but also to enhancing soil fertility in triticale/maize rotation system, which C4N6 was the best treatment.