Effects of contrasting fertilization and moisture regimes on biomass, nutrients, and water relations of container grown red pine seedlings

Abstract

Application. Exponential fertilization of red pine seedlings grown under limited irrigation decreased shoot/root ratio, increased root nutrient reserves and enhanced drought avoidance properties when compared to conventional fertilization. Enhanced preconditioning from exponential fertilization may promote outplanting performance.Abstract. Red pine seedlings were grown for 16 weeks under contrasting fertilization (conventional, exponential) and moisture (wet, moist, dry) regimes to assess preconditioning effects of treatments on biomass production, nutrient uptake and allocation, and water relations. Growth, nutrient status, and water relations were affected more by moisture availability than by fertilization regime. Exponential fertilization under limited irrigation lowered shoot/root mass ratio, increased root nutrient reserves, and enhanced drought avoidance compared to conventional fertilization regimes. Drought treatments decreased nutrient uptake in the shoots of both fertilization regimes by 24%, but increased nutrient accumulation in the roots by 39% in the exponential regime compared to 17% in the conventional. These results may explain improved outplanting performance noted for exponentially fertilized container stock.

Effect of water stress conditioning on the water relations, root growth capacity, and the nitrogen and non-structural carbohydrate concentration of Pinus halepensis Mill. (Aleppo pine) seedlings

“…Several previous studies have also reported a positive effect of water stress on nutrient and starch concentration [20,28]. This response has been explained because growth is depressed earlier by drought than are photosynthesis or nutrient absorption [11,17] …”

Irrigation regime affects water and aeration conditions in peat growth medium and the growth of containerized Scots pine seedings

“…In contrast, the concentrations of P, Ca, S, Mn and Na were markedly lower in the -5 and -10 kPa irrigation treatments . This may have been due to reduced water supply, which resulted in lower concentrations of nutrients in the growth medium (Timmer and Miller 1991) and/or decreased water and ion conductivity from the peat medium to the roots (Orlander and Due 1986ab;Heiskanen 1993c) . On the other hand, the reduced concentrations of N in the wet irrigation treatment may indicate increased leaching or dilution of N due to high water content .…”

“…Lahde and Savonen 1983 ;Bassman et al . 1989 ;Timmer and Armstrong 1989 ;Timmer and Miller 1991) . In particular, little is known about the effects of contrasting irrigation regimes on the actual water and aeration conditions in peat media and subsequent influences on the development of containerized Scots pine (Pinus sylvestris L.) seedlings .…”

Croissance par rapport au stockage : réponses de semis de chênes méditerranéens aux changements de nutrition et de disponibilité en eau

“…We tested the following working hypotheses: (1) Under high nutrient availability, plant C/N balance decreases and plant growth will be enhanced until being carbon-limited; in such circumstances, carbohydrate reserves will be low, while nitrogen will be in excess and therefore stored. (2) As water stress limits both carbon and nitrogen uptake [42,44], larger water availability is expected to increase plant growth without altering plant C/N balance. (3) Under higher resource availability, the fastest-growing species (i.e.…”