Effects of two controlled-release fertilizers with different proportions of N, P and K on the nutrient uptake and growth of Chrysanthemum morifolium Ramat.

A pot experiment was conducted to study the effects of two controlled-release fertilizers CRFA (4% resin-coated, N: P₂O₅: K₂O = 14: 14: 14) and CRFB (4% resin-coated, N: P₂O₅: K₂O = 20: 8:10) on the nutrient uptake and growth of Chrysanthemum morifolium, with common compound fertilizer CCF (N: P₂O₅: K₂O = 15: 15: 15) as the control. Six treatments were installed, i. e., CCF1 (CCF, 6 g N · pot^-1), CCF2 (CCF, 3 g N · pot^-1), CRFA1 (CRFA, 6 g · pot^-1), CRFA2 (CRFA, 3 g · pot(-1)), CRFB1 (CRFB, 6 g · pot^-1), and CRFB (CRFB, 3 g · pot^-1). On the 30th day of applying common compound fertilizer CCF1 and CCF2, soil available N, P and K contents were 163.29 and 145.26 mg · kg^-1, 180.39 and 163.13 mg · kg^-1, and 300.08 and 213.15 mg · kg^-1, respectively, and decreased rapidly since then. In treatments CRFA1, CRFB1, CRFA2, and CRFB, soil available N content increased slowly, and reached the peak on the 60th day after fertilizing, being 129.51, 138.65, 118.36, and 126.31 mg · kg^-1, respectively. Soil available P content had the same variation trend. Its maximum concentration was 169.54 and 133.46 mg · kg^-1 in treatments CRFA1 and CRFA2 on the 30th day after fertilizing, and 137.13 and 84.68 mg · kg^-1 in treatments CRFB1 and CRFB2 on the 60th day after fertilizing, and decreased slowly then. The agronomic traits such as leaf area, leaf area index, branch number, flowering rate, flower number, and flower diameter, etc., in treatments CRFA and CRFB were obviously better than those of the control, and CRFB was better than CRFA, suggesting that CRFB more matched the nutrient demand of C. morifolium. Under the conditions of present experiment, applying CRFB2 obtained the highest yield. [ABSTRACT FROM AUTHOR]