Foliar Phosphorus Research Articles

Foliar nutrient dynamics, growth, and nutrient use efficiency of Hamamelis virginiana in three forest microsites

To determine the relative importance of soil moisture and soil nutrient availability in determining levels of nutrient use efficiency, seasonal nutrient dynamics and growth rates were determined for individuals of Hamamelis virginiana L., an understory tree, in three forest microsites. The mixed oak site had the lowest levels of soil nutrients and moisture, the mixed mesophytic site the highest nutrient availability, and the valley bottom the highest moisture levels. Foliar nitrogen and phosphorus levels declined over the season in all trees, while calcium levels increased with time. Relative growth rates did not differ significantly among sites, though growth varied inversely with tree mass. Proportional nitrogen resorption was highest in trees at the fertile mesophytic site. Phosphorus and calcium use efficiency were higher at the infertile mixed oak site than the others, and phosphorus resorption was highest in trees from the mixed oak site. Projected nitrogen uptake needs for the next growing season were least at the mixed mesophytic site, while projected phosphorus uptake needs were least at the mixed oak site. Within the ranges of moisture and soil pH – nutrient availability present, growth and nitrogen dynamics seemed most closely correlated to soil moisture, and phosphorus dynamics to phosphorus availability. This differential dependence among elements on moisture levels is suggested to be the underlying reason for differences in the form of the relationship between proportional resorption and soil availability of N and P for a variety of woody species.

Changes in needle morphology, anatomy, and mineral content during the recovery of protected balsam fir trees initially defoliated by the spruce budworm

Morphological, anatomical, and chemical changes in foliage of 25- to 30-year-old balsam fir trees (Abiesbalsamea (L.) Mill.) that had been completely defoliated in 1977 by the spruce budworm (Choristoneurafumiferana (Clem.)) and then protected for 5 years by insecticide, were compared with foliage from adjacent undefoliated trees. The comparison showed that in 1978, the 1st year of refoliation, needle length, weight, and width were greater in the defoliated trees, while in 1979 they were less. In 1980, needle length was again less, but no difference was observed in needle weight and width. Needle length, weight, and width were similar in the defoliated and undefoliated trees in 1981 and 1982. Needle density in the defoliated trees was lower in 1978, but greater in 1979, while no difference occurred in 1980–1982. Foliar nitrogen content was higher in the defoliated trees in 1978–1980. Foliar phosphorus and potassium content were higher in the defoliated trees only in 1978. Needle and mesophyll cross-sectional areas in the defoliated trees were larger in 1978, but were smaller in 1979. There were no differences during 1980–1982. Mesophyll and needle cross-sectional areas were positively correlated throughout 1978–1982. Relative amounts of total protein were higher, whereas those of total insoluble carbohydrates were lower in 1978–1980 needles from undefoliated trees.

Nitrogen and Phosphorus Resorption Dynamics of Five Tree Species in a Kansas Gallery Forest

The foliar nitrogen and phosphorus contents of 25 gallery forest trees on the Konza Prairie Research Natural Area were measured 1 month before, and immediately after autumnal abscission in 1979. Leaves from five trees each of bur oak (Quercus macrocarpa), chinquapin oak (Q. muhlenbergii), green ash (Fraxinus pensylvanica), hackberry (Celtis occidentalis) and red elm (Ulmus rubra), ranging in diam from 3-77 cm, were sampled. Total leaf contents varied from 47-219 gg nitrogen cm-2 and 4.3-23.8 Ag phosphorus cm-2. Preto postabscission decreases of nitrogen and phosphorus were statistically significant in all species except red elm. Mean foliar nitrogen decreases varied from 13.2-54.2 %o among species and followed the order, chinquapin oak> bur oak> hackberry> green ash> red elm. Mean foliar phosphorus decreases varied from 7.9-36.7% and followed the order, bur oak>chinquapin oak>green ash > hackberry> red elm. Phosphorus reductions were much lower than reductions reported for other hardwood forests in the United States. This may be a function of the availability of soil phosphorus at the various sites. Tree age and diameter were positively correlated with the magnitude of nitrogen reductions. However, stepwise regression models based on all species combined indicated that age and diameter accounted for little of the variance in nitrogen decreases. The measured reductions in foliar nitrogen and phosphorus were not caused by leaching or insect herbivory, but rather were the result of biologically controlled nutrient resorption.

Soil nutrient-vegetation relationships in the Eden area, N.S.W.:III. Foliage nutrient relationships with particular reference toEucalyptussubgenera

Summary Foliar nutrient concentrations were determined for the dominant tree species occurring on plots established during a previously reported soil survey in the Eden area. Generally, within-species nutrient variation was low and few significant correlations were found between soil nutrient levels and foliar concentrations for individual species. However, foliar nutrient concentrations differed significantly between species and when the data for all species were pooled, significant relationships were found between foliar phosphorus, nitrogen, calcium, potassium and sulphur levels and soil chemical properties. The species with the higher foliage nutrient concentrations were clearly associated with the more fertile soils. Eucalypt subgenera are considered in relation to their ecology and nutrition, and distinctive relationships are concluded to exist between site nutrition and the distribution of Eucalyptus subgeneric groups.

Nutrient Translocation in the Outer Canopy and Understory of an Eastern Deciduous Forest

The translocation of nutrients into and out of outer canopy leaves of ten eastern deciduous forest species was calculated from the temporal patterns of foliar nutrient pools sampled through a growing season. The calculations accounted for average chemical leaching effects due to rainfall. There were no significant differences in translocation rate between species within the evergreen, understory, or overstory-deciduous tree groups. Evergreen species had lower translocation rates than deciduous trees. Translocation rates into leaves of deciduous species showed a very rapid increase during spring; however, by late May, foliar phosphorus was being translocated at a slow rate back to stems. A similar trend was established for nitrogen by mid-June. An internal storage pool is suggested as the major source of foliar nitrogen during the spring flush since a simulation of nitrogen uptake from soil could only account for one-fourth of the quantity of nitrogen transported to leaves by the end of May. Simulation further showed that trace levels of soluble nitrogen (0.01 ppm) in soil were sufficient to supply a deciduous forest with an estimated nitrogen uptake of 100 kg N ha/sup -1/ year/sup -1/.

Influence of Glomus fasciculatus mycorrhizae on some physical and chemical characteristics of Platanus occidentalis seedlings

Inoculation of Platanus occidentalis seedlings with Glomus fasciculatus significantly increased plant dry weight and foliar phosphorus (P) concentration when compared with the uninoculated control. After 12 weeks inoculated seedlings were 73% taller and 200% greater in total dry weight. The largest dry weight increase was recorded for foliage (212%) followed in order by stem (202%) and root (171%). Averaged overall nutrient treatments, foliar P concentration was 22% greater for the inoculated seedlings. Nutrient regimes representing 1×, 2×, and 4× Hoagland's No. 2 solution and a control significantly influenced seedling height, dry weight, percentage of foliar N, P, and K, and the degree of root colonization. Maximum growth and foliar nutrient concentrations were associated with the 2× Hoagland's nutrient regime followed in order by the 4× and 1× nutrient treatments and the control. Degree of root colonization by G. fasciculatus increased from 42% of the root length in the unfertilized control to 48% at the 1× Hoagland's regime and sharply declined at the 2× and 4× levels. Total dry weight of inoculated seedlings was significantly greater than the noninoculated control at each nutrient level. Incremental differences were 2.71, 4.03, 4.37, and 3.08 g for the control, 1×, 2×, and 4× Hoagland's nutrient regimes, respectively. Seedling growth attributed to G. fasciculatus is directly related to degree of mycorrhizal colonization and inversely related to the amount of extractable soil P.

The role of boron in plant response to mycorrhizal infection

In a Morrison sandy loam marginal in boron, fertilization with 1.1 ppm boron increased the shoot dry weight of mycorrhizal red clover (Trifolium pratense L.) an average of 16%, but did not affect nonmycorrhizal clover weight. Root colonization and foliar phosphorus concentrations were not significantly affected by B deficiency. With alfalfa (Medicago sativa L.) and Morrison soil in which B deficiency had been intensified by the addition of 100 ppm nitrogen as NH4NO3, inadequate B reduced the shoot dry weight of mycorrhizal plants 71%vs a reduction of 35% for nonmycorrhizal plants. Boron deficiency was more severe in the earlier cuttings and delayed the onset of mycorrhizal infection and the subsequent spread of mycorrhizal fungi within the roots. This delay may contribute to the lower concentrations of P and Cu seen by others during early developmental stages of B-deficient alfalfa.

Stunting of Citrus Seedlings in Fumigated Soils in Texas and its Correction by Phosphorus Fertilization and Inoculation with Mycorrhizal Fungi1

Abstract Stunting of sour orange seedlings was observed in seedbeds which had been fumigated chemically, heat-treated, or planted in soil-less media. Mycorrhizae were consistently absent from stunted seedlings and present in vigorous seedlings in seedbeds and nurseries and also present in orchards. Inoculation with Glomus fasciculatus (Thaxter) Gerd. & Trappe increased seedling height more than 300% and increased foliar phosphorus concentrations in greenhouse experiments on sour orange seedlings grown in sand culture with complete nutrient solution. Preplant application of P at 200 mg/liter did not increase growth or foliar P concentrations under the same conditions. Inoculation of seedlings receiving 0 to 800 mg P/liter with G. fasciculatus increased growth where 0 or 100 mg P/liter was added, but not where higher rates of P were used. Application of high rates of P induced copper deficiency symptoms, which were more severe on non-mycorrhizal than on mycorrhizal plants.

Soil-tree relationships in a forest of Pinus radiata with micronutrient deficiencies

Multiple regressions of tree height and diameter on foliar nutrient contents of a second rotation 9-yearold Pinus radiata forest in an area with a history of micronutrient problems at Clover Hill (S.A.), showed low levels of copper and manganese and high chloride in trees with less height and larger diameter than normal. Areas which were swampy and had failed in the first rotation were better stocked than their surroundings in the second. Such areas were, however, more subject to disorder symptoms. The soils of the forest integraded and were: yellow podzolic, podzol, solodized solonetz and terra rossa. Swampy phases were observed in the podzol and particularly the solodized solonetz soils. Trees on the various soils had different foliar levels of copper, zinc, manganese, potassium, phosphorus, nitrogen, sodium and chloride. On increasingly swampy phases of the podzol, foliar copper and manganese decreased but nitrogen and sodium increased. The multiple regressions differed for the various soils; tree height increased and diameter decreased with higher foliar copper, manganese and nitrogen, whereas both increased with higher foliar zinc and sodium. On some soils the multiple regressions contained quadratic terms, enabling an estimate to be made for a 20% reduction in height (less than 1.5 ppm copper) or a similar increase in diameter due to tree malformation (less than 1.8 ppm copper). A similar reduction in height was also indicated when the foliar chloride was greater than 0.68 to 0.8%. Foliar phosphorus was unusually high at about 2.5 times the levels found in healthy trees in other forests. Statistical interactions between foliar nutrients did not contribute to the multiple regressions. Soil surveys to delineate saline and previously swampy areas should be part of future forestry investigations in the south-east of South Australia.

The Relationship of Red Pine Site Index to Soil Phosphorus Extracted by Several Methods

AbstractPhosphorus was extracted by 10 methods from soils in Minnesota supporting stands of red pine (Pinus resinosa Ait.) to find those methods most suitable for estimating site index. The amount of phosphorus extracted from the surface 25 cm of mineral soil by H2O, 0.002N H2SO4, or 0.01N HCl was related at the 1% level (r2 = .47 to .53) to site index. Considerably weaker relationships with site index were obtained with organic P, total P, and phosphorus extracted by 0.5N NaHCO3, 0.4N HCl, 0.025N HCl + 0.03N NH4F, 0.10N HCl + 0.03N NH4F, or 0.05N HCl + 0.025N H2SO4. No improvement in the estimation of site index was made by including phosphorus extracted from deeper layers of the soil. Foliar phosphorus concentration was significantly related to site index and to the amount of phosphorus extracted from the surface soil by H2O, 0.002N H2SO4, or 0.01N HCl.

Principles and practice of foliar analysis as a basis for crop-logging in pine plantations

Progress towards the introduction of crop-logging as a management tool is illustrated by the development of multiple regression equations relating basal area increment to various stand parameters including foliar phosphorus levels. Mixed mode regression analysis was used, removing foliar P variables first and adding other variables stepwise. The model which best described the relationships sought was of the form: $$\log B = a_1 P + a_2 P^2 + a_3 \frac{{BA.SI}}{{Age}} + a_4 \frac{{SI}}{{BA.Age}}$$ where B = average annual basal area increment for the three-year period preceding or subsequent to foliar sampling; P = percentage phosphorus in foliage; BA = basal area standing at the time of sampling; SI = site index, defined as predominant height (predicted or actual) in feet at age 25 years; and Age = age of plantation in years at time of sampling. Using this equation, the critical level of phosphorus in slash pine (Pinus elliottii Engelm.) is set at 0.075–0.080 per cent and in loblolly pine (P. taeda L.) at 0.095–0.105 per cent. Critical level is here defined as the foliar P concentration associated with 90 per cent of maximum basal area increment. Over the range of parameters examined, the critical levels so determined are, for all practical purposes, independent of age, site index and stand density. Utilization of critical foliar nutrient levels in crop-logging requires a know-ledge of fertilizer — soil — plant interactions which can be derived in part from the fertilizer trials used to establish critical levels in the first instance.

Annual changes in foliar nitrogen, phosphorus, and potassium levels of loblolly pine (pinus taeda L.) with site, and weather factors

The study investigated the fluctuation in foliar nutrient levels (over a period of approximately three years) on two sites of widely differing productivity for loblolly pine. Preliminary analysis at the end of the first year indicated large variations in foliar levels with time which were attributed to weather factors, and further sampling was initiated to evaluate the influence of weather. A lack of a stable period during any portion of the year was attributed to the indeterminate growth habit of loblolly pine, and this aspect, together with a strong statistical correlation of weather factors with foliar levels, suggests that if foliar nutrient levels are obtained by the method used in this study, results could not be recommended for use in site differentiation of this species. The weather factors most commonly correlated with foliar levels were average maximum and average minimum temperatures for certain periods preceeding the sampling date.