不同施肥量对辣木幼苗生长、光合和养分特征的影响

Effect of Fertilization on Photosynthetic and Nutrient Characteristics of Moringa oleifera Seedlings

以辣木(Moringa oleifera)品种云南极品27号为材料,采用盆栽试验研究不同施肥量处理对辣木幼苗生长指标、光合参数和养分吸收利用的影响。结果表明:随施肥量增多,辣木幼苗的株高、地径、生物量、根长、根直径、根体积、根表面积等生长指标基本表现为先升高后降低的趋势,施肥量为N9P4.5K4.5 g·株^(-1)时达到最高,单株生物量和壮苗指数分别为对照的3.99和1.53倍;适量施肥能显著提高辣木幼苗的光合能力,有利于生物量的积累。随着施肥量的增加,辣木幼苗叶片的叶绿素含量、净光合速率、水分利用效率先升高后降低,而蒸腾速率、气孔导度则随施肥量的增加而加大;辣木幼苗根、茎、叶组织中N、P、K含量随施肥量的增加先增多后减少,表观吸收率和施肥效率随施肥量增加显著降低,施肥量增加对根系的影响最大;施肥量为N12P6K6 g·株^(-1)时辣木幼苗各生长、光合、养分含量指标均有所降低,根冠比最低,壮苗指数显著低于对照水平,明显抑制辣木幼苗的生长。总之,辣木幼苗最适施肥量为N9P4.5K4.5 g·株^(-1),施肥量为N12P6K6 g·株^(-1)时抑制辣木幼苗的生长。

In order to provide theoretical basis for precise fertilization of Moringa oleifera seedling, different amounts of fertilization were treated on M. oleifera No.27 Yunnan Jipin of seedlings, and the growth index, photosynthetic parameters and nutrient characteristics were studied. The results showed that the growth indexes such as plant height, ground diameter, biomass, root length, root diameter, root volume and root surface area of M. oleifera seedlings increased and then decreased with the increasing of fertilization. These indexes reached the highest level in the treatment (N9P4.5K4.5 g), as it’s biomass and seedling index were 3.99 time and 1. 53 time higher than the control respectively. Moderate fertilization significantly increased photosynthetic capacity and biomass accumulation of M. oleifera seedlings. With the increasing of fertilization, the leaves chlorophyll content, net photosynthetic rate and water using efficiency of M. oleifera seedlings were increased, which following by decreased. Meanwhile, the leaves transpiration rate and stomatal conductance were increased with the increasing of fertilization. The contents of N, P and K in roots, stems and leaves of M. oleifera seedlings were increased at first and then decreased with the increasing of fertilization. The apparent absorption rate and fertilization efficiency decreased significantly with the increase of fertilization, and the greatest effect of fertilization was on the roots.The growth, photosynthesis and nutrient content of M. oleifera seedlings were all decreased in the treatment ( N12P6K6 g), for the root-shoot ratio was the lowest and the strong seedling index was significantly lower than the control level. Apparently, the treatment ( N12P6K6 g) inhibited the growth of M. oleifera seedlings. In conclusion, the optimum fertilization rate of M. oleifera seedlings was N9P4.5K4.5 g for each plant. Moreover, the growth of M. oleifera seedlings was inhibited with the fertilization of N12P6K6 g for each plant.