Growth and nutrient uptake dynamics ofMytilaria laosensisseedlings under exponential and conventional fertilizations

Abstract

The growth characteristics and nutrient uptake dynamics of Mytilaria laosensis Lec. seedlings treated weekly with conventional and exponential fertilizations were investigated at intervals of 3 weeks for 12 weeks in a greenhouse. Leaf area and pigment compositions were also examined at the final harvest. The fertility treatments (mg nitrogen seedling -1 ) included two conventional (50C and 100C) and four exponential (50E, 100E, 200E and 400E) fertilizations, and no fertilization (0) as control. The biomass and nutrient contents of M. laosensis seedlings increased exponentially with time. Steady-state nutrition of nitrogen (N) and phosphorus (P) were achieved under exponential fertilization treatment of 50 mg N seedling À1 (50E) and conventional fertilization treatment of 100 mg N seedling -1 (100C), resulting from simultaneous increase of their biomass and nutrient contents. The nutrient uptake efficiency continuously increased over time in conventionally fertilized seedlings, but it increased initially and declined or remained stable from 11 weeks after transplanting in the exponentially fertilized seedlings. At the end of the experiment, the conventionally fertilized seedlings performed remarkably better than all exponentially fertilized seedlings except for seedlings in the exponential treatment of 200 mg N seedling -1 (200E) in height, root collar diameter and biomass. The optimum N and P uptake occurred in 200E seedlings because their N and P contents were 71%/60% and 14%/9% higher than both conventionally fertilized seedlings (50C/100C) without significant differences in growth performance between them. The leaf areas and chlorophyll contents of seedlings increased significantly with the increase of fertilizer levels and nearly peaked at the range from 100 to 200 mg N seedling -1 , whereas the delivery schedule (conventional and exponential) had little effect on leaf areas and chlorophyll contents of seedlings at the same nutrient level (50 or 100 mg N seedling -1 ). These findings will provide evidence to make guidelines on fertilization for nursery production of M. laosensis, and help understand the nutrient demands for this species and further benefit the development of its plantations.

Effect of exponential fertilization on growth and nutritional status in Buddhist pine (Podocarpus macrophyllus[Thunb.] D. Don) seedlings cultured in natural and prolonged photoperiods

“…Nitrogen (N) dilution has been found to impact the performance of some transplanted tree stocks, whose size, however, was evaluated to be of high morphological quality . Exponential fertilization (EF) applied at a proper rate has been proven to counter nutrient dilution effectively by inducing steady-state luxury consumption of nutrients in tree seedlings (Salifu and Timmer 2003;Salifu et al 2009;Chen et al 2012;Duan et al 2013). However, nearly all of the current studies have only detected the effect of EF on seedlings exposed to a unique photoperiod.…”

Growth and nutrient efficiency of Betula alnoides clones in response to phosphorus supply

“…The whole plants were emerged in tap water and washed carefully by hand to remove the fine roots from the peat mixture. Leaf area was measured for each plant according to Chen et al (2012). After that, these components were separately composited for each subplot, and dried at 80℃ for 48 h to determine root, stem and leaf dry weight, and ground by a portable crusher for subsequent chemical analysis.…”

“…Plant material was wet-digested in a block digester using H 2 SO 4 -HClO 4 mixture solutions. The digests were analyzed for total N by the titration method, total P by the molybdenum blue method and total K by atomic absorption spectroscopy (Chen et al 2012).…”

“…Each subplot had 12 plants, thus a total of 288 plants (12 plants × 6 P treatments × 4 replications) for each clone. The plants were watered with equal amounts of deionized water by the method of Chen et al (2012 Just prior to fertilization, 10 representative plants were chosen from each clone and combined to determine the initial dry weight (0.07g plant -1 on average), and then for analyzing the initial plant concentrations of total nitrogen (12.83 g kg -1 ), phosphorus (7.83 g kg -1 ) and potassium (15.79 g kg -1 ). One week after the last fertilization, the height, root collar diameter and number of branches were measured.…”

Diagnosis of macronutrient deficiency in Erythrophleum fordii, a nitrogen-fixing rosewood species

“…Up to present, no information has been reported on nutrient defi ciency diagnosis for E. fordii, even for Erythrophleum genus although a number of tree species have been studied in this fi eld. However, tree species were usually specifi c in their nutrient demands and nutrient use effi ciency (Bigelow & Canham 2007, Chen et al 2012, Millner & Kemp 2012, and interactions among nutrient elements such as antagonism, compensate etc. were even complicated.…”