指数施肥对白桦容器苗生物量及形态特征的影响

Effect of Exponential Fertilization on Biomass and Morphological Characteristics of Betula platyphylla Seedlings

采用常规施肥、指数施肥、1/2指数施肥、2倍指数施肥以及不施肥(对照)5种不同施氮肥处理,研究其对白桦1年生播种苗生物量动态变化及苗木形态的影响。研究结果表明:(1)苗木达到生长高峰期时,生物量净增速率顺序为:2倍指数施肥>指数施肥>1/2倍指数施肥>常规施肥>对照。(2)生长结束后,2倍指数施肥处理苗木年单株生物量为13.32 g,显著高于其他处理。(3)在苗木生长高峰期(施肥后第10周)测定苗木叶面积,指数施肥和2倍指数施肥处理对苗木叶面积增加效果最为明显,达到53.36、53.39 cm2。(4)在苗木生长结束后,2倍指数施肥处理苗木最高为98.89 cm;而指数施肥处理苗木地茎最大,达到7.53 mm。指数施肥处理为最佳施肥方式,有效促进了白桦播种苗生长,改善了苗木形态结构。

We studied the dynamic changes of the biomass and seedling morphology of Betula platyphylla one year old seedling under constant （CF）, exponential （EF）, half （HEF） and doubled exponential fertilization （DEF）, and no fertilization （CK） regimes in the first growing season. In the fast-growing periods of seeding, the net increase rate order of biomass in different treatment is DEF〉EF〉HEF〉CFCK. At the end of the growing season, the biomass accumulation of seedlings under DEF treatment is 13.32 g stem-1 , significantly greater than that in others treatment. Seedling leaf area significantly increases under EF and DEF treatments in the fast-growing periods of seedling, and the leaf area of seedlings under EF and DEF treatment are 53.36 cm and 53.39 cm, respectively. Seedlings height under DEF treatment is the highest （98.89 cm）, and the ground diameter under EF treatment is 8.53 ram, most in all treatments. Exponential fertilization regimes is the opti mum treatment and it can promote biomass accumulation and improve seedling morphology in B. platyphylla seedlings.