Effect of fertilization combination of nitrogen, phosphorus, and potassium on yield and quality of Salvia miltiorrhiza / 中草药

ABSTRACT

Objective: To study the effect of fertilization combination of nitrogen, phosphorus, and potassium on the yield and quality of Salvia miltiorrhiza in order to explore the optimal N, P, and K ratios and dosages in middle south of Shandong, and provide theoretical guidance for precision fertilization. Methods: Based on “3414” randomized block design, 14 fertilization combination treatments of N, P and K were designed to determine the yield, growth, and bioactive components of S. miltiorrhiza. The effects of different fertilization treatments on the yield and quality of S. miltiorrhiza were analyzed, and a fertilizer effect model of S. miltiorrhiza in middle south of Shandong was established by stepwise regression analysis. The maximum yield of fertilized S. miltiorrhiza and the best amount of economic fertilization were estimated. Results: Nitrogen, phosphorus, and potassium deficiency treatments reduced the yields by 27.29%, 22.09%, and 23.83%, respectively, and the optimal treatment for increasing yield was N2P2K2 with a yield of 16 740 kg/hm2. Single factor fertilizer effect analysis showed that the yield of S. miltiorrhiza showed a trend of increasing first and then decreasing with the increase in the application amount of these fertilizers. The main nutrient elements limiting yield and benefit of S. miltiorrhiza in middle south of Shandong were as follow N > K > P. The analysis of the interaction between the two factors showed that the nitrogen, phosphorus, and potassium fertilizers promoted each other at a certain application amounts, the interaction effect were as follow NP > NK > PK. Through the effects of fertilization combination of nitrogen, phosphorus, and potassium on growth, nitrogen significantly promoted the material accumulation in roots of S. miltiorrhiza. Potassium had a certain role in promoting the plant width and root width. The effect of fertilization on the content of active ingredients showed that potassium promoted the accumulation of phenolic acids and tanshinones, while potassium had the adverse effect. Conclusion: The quadratic function fitting result between the amount of fertilizer applied and the yield of S. miltiorrhiza is in line with the law of diminishing returns, which can better reflect the relationship between the amount of fertilizer and yield. The best fertilizer scheme in middle south of Shandong should be N 195.63 kg∙/hm2, P2O5 116.64 kg/hm2, and K2O 153.84 kg/hm2 estimated by ternary quadratic function fitting.