Nursery and field fertilization of 2 + 0 ponderosa pine seedlings: the effect on morphology, physiology, and field performance

Abstract

Ponderosa pine (Pinusponderosa Laws.) from two seed zones in central Oregon were grown at two nurseries where they were subjected to fall applications of N, N + K, or no fertilizer. For one seed zone, foliar N concentration increased from 1.47 to 1.53% for the N application and to 1.57% for N + K application. For the other seed zone, seedlings did not show any differences in foliar N after nursery fertilization. Seedlings that received the N application appeared to be less susceptible to frost damage, but nursery fertilization had little or no effect on seedling morphology or bud break. One month after outplanting 2 + 0 seedlings back to their respective seed-zone sites, slow-release fertilizer pellets were placed 10–13 cm from half the trees. Soils at the outplanting sites differed in mineral content, percent organic matter, and pH. The nursery-fertilized seedlings with increased N concentration grew more than control seedlings during the first season. Field-fertilized seedlings at the less fertile field site grew more in the second and third growing seasons, indicating that field fertilization after outplanting is more effective on nutrient-poor sites. Soil fertility had a greater impact on seedling performance than did nursery- and field-fertilizer treatments. At the less fertile site, N concentration decreased by 14% during the first growing season and increased by 22% during the second season, whereas at the more fertile site it increased during both the first season (12%) and the second season (6%). Seedlings at the more fertile site almost doubled in height in the 3rd year and were more than 20 cm taller than those at the other site.

Fall fertilization of Pinus resinosa seedlings: nutrient uptake, cold hardiness, and morphological development

“…Application of N to dormant slash pine (Irwin et al, 1998), ponderosa pine (Gleason et al, 1990), and Douglas-fir (Margolis and Waring, 1986) seedlings increased N concentration. In our study, six weeks after applying fertilizer to red pine seedlings with dormant terminal buds, shoot and root N concentrations in seedlings receiving 89 kg N ha −1 were 40% and 68% greater than for the control.…”

“…For example, Timmis (1974) reported Douglas-fir seedlings with low foliar N concentration (i.e., 0.8%) had a LT 50 of -13 • C and those with a higher concentration (i.e., 1.6%) had a LT 50 of -30 • C. Gleason et al (1990) reported that fall fertilized ponderosa pine seedlings with a N concentration of 1.55% were more cold hardy than control seedlings with 1.47% N. Fernández et al (2007) observed that N fertilized plants with more than 1.25% N better tolerated freezing than those that had less than 1%. Similarly, Luoranen et al (2008) observed poor autumn cold hardiness for Picea abies seedlings with lower (i.e., 1.1%) compared to higher (i.e., > 1.6%) foliar N concentrations.…”

“…Additionally, N application during fall increased cold hardiness in Douglas-fir, whereas phosphorus (P) applied without N decreased hardiness (Thompson, 1983). Furthermore, 2-year old ponderosa pine (Pinus ponderosa C. Lawson) seedlings showed enhanced cold hardiness with increasing N concentrations (Gleason et al, 1990). Cold hardiness was unaffected by three different rates of N and P application in Douglas-fir and western redcedar (Thuja plicata Donn ex D. Donn) seedlings (Hawkins et al, 1995).…”

Fertilization at planting impairs root system development and drought avoidance of Douglas-fir (Pseudotsuga menziesii) seedlings

“…Fertilizer may be applied to the planting hole, to an adjacent hole, or surface broadcast [8]. To facilitate nutrient uptake, many researchers have recommended applying CRF directly in the planting hole, such that nutrients are released in the immediate vicinity of the root system [2,12,14,23,52]. However, fertilization in the planting hole may limit root system expansion because roots tend to proliferate in areas 644 D.F.…”

Late-season fertilization of Picea mariana seedlings under greenhouse culture: biomass and nutrient dynamics

“…Nutrient loading before hardening may counter late-season dilution [39], although some growers are reluctant to adopt this practice because of concerns that high N fertilization may jeopardize frosthardiness development in seedlings prior to winter storage [2,17,43]. More recent studies, however, have shown that high N supply does not affect cold tolerance of conifers [4] and may actually increase frost-hardiness [7,14,16,27,35]. Presumably autumnal accumulation of free amino acids and proteins may lessen cellular freezing damage by reducing the symplastic water volume [3,26,38].…”