施磷量对黑木相思苗木生长的影响

为探究黒木相思苗木生长变化对磷肥的反映机制,本研究对1a生黑木相思(Acacia melanoxylon)苗木采用随机区组设计,设置了7个不同施肥量处理(0、50、75、100、125、150、200 mg P/株),测定并分析其苗高、地径、生物量及根系形态指标。结果表明：不同施磷量对苗木高生长、地径、生物量(地上部分、地下部分生物量)以及根系的生长都起促进作用,随时间和施磷量的增加,黑木相思根长、根平均直径、根表面积、根体积、苗高、地径、生物量总体表现均有所增加,总量为100 mg/株的等量施磷量对苗木生长促进作用效果最佳,试验结束时(即施肥第12 wk),该处理的根长、根表面积、根平均直径、根体积、苗高、地径、生物量(地上、地下部分)分别为417.09 cm、35.16 cm2、0.46cm、0.48cm3、36.2mm、2.30mm、1.236g(地上部分)、0.227g(地下部分),其中根长、根表面积、根平均直径、根体积分别比对照增加了81.2%、110.7%、61.2%和127.1%。

Effects of Phosphorus Application Amounts on Seedling Growth of Acacia melanoxylon

The randomized block design was used to study the reaction mechanism of Acacia melanoxylon on different phosphorous fertilizer levels. Seven phosphorous fertilizer treatments (0, 50, 75, 100, 125, 150, 200 mg P/plant) were set up to measure and analyze the index of seedling height, ground diameter, biomass and root morphology. The results showed that all treatments had promoting effects on seedling growth, ground diameter, aboveground and underground biomass and root growth of Acacia melanoxylon. With the increase of time and phosphorous application amount, the root length, average root diameter, root surface area, root volume, seedling height, ground diameter and biomass of Acacia melanoxylon increased. The treatment of 100 mg P/plant had the best promoting effect, the root length, surface area, average root diameter, root volume, seedling height, ground diameter and aboveground and underground biomass of Acacia melanoxylon were 417.10 cm, 35.17 cm2, 0.47 cm, 0.48 cm3, 36.2 mm, 2.30 mm, 1.236 g (aboveground) and 0.227 g (underground), respectively. Meanwhile, the root length, average root diameter, root surface area and root volume increased by 81.2%, 110.7%, 61.1% and 127.2% compared with that of CK.