关键词: 高效液相色谱法, 高效液相色谱法, β-胡萝卜素, 茶叶, 含量测定

Abstract: The field experiment were conducted in semi-humid region to investigation the characteristics of N, P and K uptake of spring millet at different growth stages. Two fertilization treatments were set up (N 150 kg/ha、P2O5 75 kg/ha、K2O 90 kg/ha and CK) with four replicates. The results showed that application of N,P,K fertilizers remarkably increased grain yields ,weights of dry matters, and N, P and K contents and accumulates. Whatever fertilization levels, the above-ground dry matter accumulate increased with the growth stages and showed a typical S-shape. There were a peaks of dry matter accumulation occurred at filling stages and account for about 50% of total accumulation. The content of N in plants showed a downward tendency with growth stages; the content of P law of spring millet appeared“W”model; the content of K in plants showed a unimodal curve during the growing stage ,and reached the maximum at jointing stages. Under all experimental condition, N, P and K accumulation increased with both growth stages and fertilization rates, and the proportion of nutrient accumulate at different growth stages was almost same. On average, N,P,K uptake accounted for 1%-3% of the total uptake at seedling stages. During jointing period, the absorbed rates accounted for 30%, 20%, 37%, respectively, which the K uptake was highest at this stages comparing with the others. The absorbed rates accounted for 22%, 21%, 34% at pregnant ear stage, for 43%、53%、23% at heading and filling stages which the N, P uptake was highest at this stages comparing with the others, for 3%~5% at ripening stages. The uptake rates of N, P, K by plants were significantly positive correlated with the accumulated rates of dry matters, but were significantly negative correlated with the contents of N, K in plants either high fertility or low fertility.