玄参不同生长期氮、磷、钾的积累与分配特点研究

摘要

OBJECTIVE:To study the accumulation and distribution characteristics of nitrogen(N),phosphorus(P)and potas-sium(K)in Scrophularia ningpoensis at different growth stages,in order to provide theory evidence for the establishment of scien-tific fertilization technique for S. ningpoensis. METHODS:In field testing,through the dynamic sampling of S. ningpoensis at seed-ling stage,stem and leaves growth stage,root enlargement stage and root enrichment stage,the contents of N,P and K were mea-sured,and the accumulation and distribution regularity of N,P and K in stem,leaves,root,rhizome and bud were also studied. RESULTS:The accumulation of mineral elements in seedling stage of S. ningpoensis was less,the absorptive capacity of N,P and K accounted for 13.8%,13.2%,14.0% of the whole growth periods;the plants grew vigorously at stem and leaves growth stage, root enlargement stage,and the absorptive capacity of N,P and K accounted for 86.2%,85.2%,86.0% of the whole growth peri-ods;the plants drooped and languished at root enrichment stage,and the absorptive capacity of N,P and K appeared a downward trend. The allocation proportion of N,P and K at seedling stage,stem and leaves growth stage and root enlargement stage were al-ways leaf>stem>root>rhizome>bud,especially focusing on stem and leaves. In the later period of root enlargement,roots re-placed the aerial part of plants to be the center of growth,and the accumulation of N,P and K shifted from the stem and leaves to the roots. During growth period,the demand of N and K were the highest,followed by P. The dry weight of S. ningpoensis was positively correlated with the total accumulation of N,P and K(R2 were 0.844,0.959,0.827). CONCLUSIONS:The stem and leaves growth stage and root enlargement stage are the most crucial period of the absorption of N,P and K. It should be paid more attention to the supply of mineral nutrition to meet the requirement of plant. Under medium nutrition condition,the average N,P and K absorption amount per 100 kg try medicine are 7,0.73 and 6.5 kg respectively.%目的：研究玄参不同生长期氮、磷、钾的积累与分配特点，以期为玄参科学施肥技术的建立提供理论依据。方法：通过田间试验，在玄参苗期、茎叶生长期、块根膨大期、块根充实期4个不同生长期进行动态采样，测定各样品中氮、磷、钾含量，计算积累量，研究茎、叶、根、芦头、子芽各器官中的氮、磷、钾分配和积累规律。结果：苗期氮、磷、钾的积累量较少，氮、磷、钾的积累量占整个生长期的13.8％、13.2％、14.0％；茎叶生长期和块根膨大期植株生长旺盛，氮、磷、钾的积累量占整个生长期的86.2％、85.2％、86.0％；块根充实期茎叶逐渐枯萎凋零，氮、磷、钾积累量呈明显下降趋势。氮、磷、钾的分配比例排序在苗期、茎叶生长期及块根膨大期始终为叶＞茎＞根＞芦头＞子芽，生长中心集中在茎叶中。块根膨大期后期，根代替植株地上部分成为玄参的生长中心，氮、磷、钾的积累也由茎叶转为根部。整个生长期对氮和钾需求量最高，磷次之。干物质积累量与氮、磷、钾积累量呈显著正相关（R2分别为0.844、0.959、0.827）。结论：茎叶生长期和块根膨大期是玄参对氮、磷、钾吸收的主要时期，要注意及时追肥以满足植株对养分的需求。中等肥力条件下，每生产100 kg玄参需吸收氮7 kg、磷0.73 kg、钾6.5 kg。