Regularity of absorption and distribution of nitrogen, phosphorus, potassium, calcium, and magnesium in Artemisia annua / 中草药

ABSTRACT

Objective: To study the regularity of dry matter accumulation and its absorption and distribution of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) in Artemisia annua, and to provide a scientific fertilizer application for the standardized cultivation. Methods: The sampling was carried out in the different growing periods of A. annua under field condition, and the amount of dry matter and the contents of N, P, K, Ca, and Mg in all parts of the plant were determined, respectively. Results: The dry matter mainly distributed in leaves within 40 d after transplanting, and this period could be defined as seedling period. The period within 40-100 d could be defined as vegetative growth period and the dry matter mainly distributed in leaves and branches. The period within 100-180 d could be defined as reproductive growth period. And the period of 100-140 d could be defined as earlier reproductive growth period, and the dry matter mainly distributed in branches and flower buds during this time. The period of 140-180 d could be defined as later reproductive growth period, the dry matter mainly distributed in branches and seeds during this time. The accumulation of nutrition was the lowest in seedling period; but the uptake of nutrition increased in vegetative growth period, and mainly distributed in leaves and branches. Nutrition mainly distributed in leaves earlier reproductive growth period, but transferred to flower buds gradually. Nutrition mainly distributed in seeds in the later reproductive growth period. The dry matter accumulation lineally increased with the assimilation and accumulation of N, K, Mg, Ca, and P. The uptake proportion of them was 4.214.170.740.630.24 in the whole growth period. Conclusion: Low nutrition should be applied during seedling stage to controlling the loss of nutrition. During the period of 40-140 d after transplanting, A. annua grows quickly, and mineral nutrition must be supplied especially N and K. The maximum uptake period of P, Ca, and Mg is in 100-120 d, so Ca, Mg, and P fertilizers should be applied earlier or by foliage spray to promote the formation of flower buds and seeds.