[Effects of nitrogen, phosphorus and potassium fertilizers on the yield, quality and nutrient uptake of Pulsatilla cernua].

Objective: To study the effects of nitrogen (N), phosphorus (P2O5) and potassium (K2O) fertilizers on the growth, yield total saponins content and nutrient absorption of Pulsatilla cernua and provide a theoretical basis for good agriculture practice.

Methods: Field plot experiments was conducted, based on the D-saturation optimal design with three factors of nitrogen, phosphorus and potassium. Samples collected periodically were used for determination the contents of nutrient and total saponins, and for measurement of yield and agronomic characters.

Results: Nutrient contents in Pulsatilla cernua varied with growth stage and part under the same growth stage. Nutrient contents in aerial part were higher than that in root, while the proportion of nutritional absorption from seedling stage to the middle growth stage was larger than that at the late growth stage. Yield and total saponins content of Pulsatilla cernua were significantly influenced by the N1P2O5 and K2O applications, among three factors, N had the greatest effects, the next was K2O and P5O2.

Conclusion: Pulsatilla cerntua under field cultivation should be fertilized properly, top-dressing with these fertilizers during the early growth stage and increasing the proportion of potassium. According to total saponin production of Pulsatilla cernua, the optimum fertilization model for high yield and good quality is 180 kg/hm2 of N, 79.74 kg/hm2 of P2O5, and 225 kg/hm2 of K20, with a N : P2O : K2O ratio of approximately 2.3 : 1 : 2.8.