Diagnostic nitrogen concentrations for tomatoes grown in sand culture

1988 ◽  
Vol 28 (3) ◽  
pp. 401 ◽  
Author(s):  
DO Huett ◽  
G Rose
Keyword(s):  
Critical Values ◽  
Sand Culture ◽  
Nutrient Concentrations ◽  
Total N ◽  
Nitrate N ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Petiole Sap ◽  
N Status ◽  
Leaf N

The tomato cv. Flora-Dade was grown in sand culture with 4 nitrogen (N) levels of 1.07-32.14 mmol L-1 applied as nitrate each day in a complete nutrient solution. The youngest fully opened leaf (YFOL) and remaining (bulked) leaves were harvested at regular intervals over the 16-week growth period. Standard laboratory leaf total and nitrate N determinations were conducted in addition to rapid nitrate determinations on YFOL petiole sap. The relationships between plant growth and leaf N concentration, which were significantly affected by N application level, were used to derive diagnostic leaf N concentrations. Critical and adequate concentrations in petiole sap of nitrate-N, leaf nitrate-N and total N for the YFOL and bulked leaf N were determined from the relationship between growth rate relative to maximum at each sampling time and leaf N concentration. YFOL petiole sap nitrate-N concentration, which can be measured rapidly in the field by using commercial test strips, gave the most sensitive guide to plant N status. Critical values of 770-1 120 mg L-I were determined over the 10-week period after transplanting (first mature fruit). YFOL (leaf + petiole) total N concentration was the most consistent indicator of plant N status where critical values of4.45-4.90% were recorded over the 4- 12 week period after transplanting (early harvests at 12 weeks). This test was less sensitive but more precise than the petiole sap nitrate test. The concentrations of N, potassium, phosphorus, calcium and magnesium in YFOL and bulked leaf corresponding to the N treatments producing maximum growth rates are presented, because nutrient supply was close to optimum and the leaf nutrient concentrations can be considered as adequate levels.

Diagnostic nitrogen concentrations for cabbages grown in sand culture

1989 ◽  
Vol 29 (6) ◽  
pp. 883 ◽  
Author(s):  
DO Huett ◽  
G Rose
Keyword(s):  
Growth Rate ◽  
Growth Period ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Sand Culture ◽  
Total N ◽  
Rate Range ◽  
Nitrate N ◽  
N Concentration ◽  
Petiole Sap

The cabbage cv. Rampo was grown in sand culture with 5 nitrogen (N) levels, between 2 and 43 mmol/L, applied as nitrate each day in a complete nutrient solution. The youngest fully opened leaf (YFOL), which became the wrapper leaf at heading, the youngest fully expanded leaf (YFEL) and the oldest green leaf (OL) were harvested at a minimum of 2-week intervals over a 12-week growth period. Standard laboratory leaf total N and nitrate-N determinations and rapid petiole sap nitrate-N determinations were conducted on YFOL, YFEL and OL. Total N was also determined in bulked leaves. The relationship between growth rate relative to the maximum at each sampling time and leaf N concentration was used to derive diagnostic petiole sap nitrate-N, leaf nitrate-N and total N in YFOL, YFEL and OL and bulked leaf total N concentrations. Critical concentration corresponded to 90% maximum growth rate and adequate concentration corresponded to 9 1-1 00% maximum growth rate. Petiole sap nitrate-N concentration, which can be measured rapidly in the field, and leaf nitrate-N concentration were very responsive to N application where positive growth responses were recorded. Critical N concentrations are presented for all leaves at most sampling times throughout the growth period. Critical total N concentrations in YFOL, YFEL and bulked leaves were higher during the pre-heading growth stage (weeks 2-6) than the post-heading growth stage (weeks 8-12). Critical N concentrations were inconsistent over the growth period and it was not possible to present single values to represent the full growth period, with 2 exceptions. A critical petiole sap nitrate-N concentration for OL of 3.0 g/L can be recommended for the full growth period because it represents a percentage of maximum growth rate range of 88-95%. Similarly, for YFEL, a critical total N concentration of 4.10% pre-heading (range 4.10-4.38%) represents a percentage maximum growth rate range of 62-90% and a post-heading critical total N concentration of 3.10% (range 3.10-3.50%) represents a percentage maximum growth rate range of 76-90%. The concentrations of potassium, phosphorus, calcium, magnesium and sulfur in YFOL, YFEL, OL and bulked leaf corresponding to N treatments producing maximum growth rates are also presented.

Determination of critical nitrogen concentrations of lettuce (Lactuca sativa L. cv. Montello) grown in sand culture

1992 ◽  
Vol 32 (6) ◽  
pp. 759 ◽  
Author(s):  
DO Huett ◽  
E White
Keyword(s):  
Dry Matter ◽  
Growth Period ◽  
Sand Culture ◽  
N Application ◽  
Total N ◽  
N Supply ◽  
Nitrate N ◽  
N Concentration ◽  
Nitrate Concentrations ◽  
Petiole Sap

A gamma x cubic response surface model was used to predict the dry matter yield of lettuce cv. Montello over the 8-week growth period in sand culture with nitrogen (N) levels of 2, 5, 11, 18 and 36 mmol/L. At 1, 2, 3, 5, 7 and 8 weeks after transplanting, dry matter yield relative to maximum was plotted against tissue N concentration to derive diagnostic concentrations of petiole sap nitrate-N and leaf total N in youngest fully opened leaf (YFOL), youngest fully expanded leaf (YFEL) and oldest green leaf (OL), and total N in bulked leaf samples. Critical concentrations corresponding to 90% maximum yield are presented. Growth was consistently depressed at 2 mmol N/L due to N deficiency, and at 36 mmol N/L due to salt toxicity. Petiole sap nitrate concentrations were more responsive than leaf total N concentrations to N application levels. Leaf N concentrations at N application levels of 18 and 36 mmol/L were often similar. Critical leaf total N concentrations in YFOL and YFEL decreased from 2 weeks after transplanting to maturity, whereas the opposite trend occurred for petiole sap nitrate concentrations. Critical total N concentration ranges in YFEL were 0.30-0.95 g/L for petiole sap nitrate-N, and 4.00-5.30% for leaf total N concentration. Critical leaf total N and petiole sap nitrate concentrations clearly differentiated between inadequate and adequate N application rates. Critical values in most cases, differentiated toxic concentrations. Nitrogen application levels of 2 and 36 mmol N/L reduced (P<0.05) potassium, calcium and magnesium concentrations in all leaves. This confirms the importance of optimising N supply when determining critical levels of these nutrients for lettuce. Petiole sap nitrate-N concentrations, which can be determined rapidly in the field, can be used to distinguish between a deficient and an adequate N supply. The marked increase in critical concentration over the growth period requires consecutive determinations to verify the N status of lettuce.

scholarly journals Estimating Plant Nitrogen Concentration of Maize Using a Leaf Fluorescence Sensor across Growth Stages

2020 ◽  
Vol 12 (7) ◽  
pp. 1139
Author(s):  
Rui Dong ◽  
Yuxin Miao ◽  
Xinbing Wang ◽  
Zhichao Chen ◽  
Fei Yuan ◽  
...  
Keyword(s):  
Precision Agriculture ◽  
Fluorescence Sensor ◽  
Accurate Estimation ◽  
Growth Stages ◽  
Fluorescence Sensors ◽  
N Application ◽  
N Concentration ◽  
Leaf N Concentration ◽  
N Status ◽  
Leaf N

Nitrogen (N) is one of the most essential nutrients that can significantly affect crop grain yield and quality. The implementation of proximal and remote sensing technologies in precision agriculture has provided new opportunities for non-destructive and real-time diagnosis of crop N status and precision N management. Notably, leaf fluorescence sensors have shown high potential in the accurate estimation of plant N status. However, most studies using leaf fluorescence sensors have mainly focused on the estimation of leaf N concentration (LNC) rather than plant N concentration (PNC). The objectives of this study were to (1) determine the relationship of maize (Zea mays L.) LNC and PNC, (2) evaluate the main factors influencing the variations of leaf fluorescence sensor parameters, and (3) establish a general model to estimate PNC directly across growth stages. A leaf fluorescence sensor, Dualex 4, was used to test maize leaves with three different positions across four growth stages in two fields with different soil types, planting densities, and N application rates in Northeast China in 2016 and 2017. The results indicated that the total leaf N concentration (TLNC) and PNC had a strong correlation (R2 = 0.91 to 0.98) with the single leaf N concentration (SLNC). The TLNC and PNC were affected by maize growth stage and N application rate but not the soil type. When used in combination with the days after sowing (DAS) parameter, modified Dualex 4 indices showed strong relationships with TLNC and PNC across growth stages. Both modified chlorophyll concentration (mChl) and modified N balance index (mNBI) were reliable predictors of PNC. Good results could be achieved by using information obtained only from the newly fully expanded leaves before the tasseling stage (VT) and the leaves above panicle at the VT stage to estimate PNC. It is concluded that when used together with DAS, the leaf fluorescence sensor (Dualex 4) can be used to reliably estimate maize PNC across growth stages.

scholarly journals LEAF TOTAL NITROGEN CONCENTRATION AS AN INDICATOR OF NITROGEN STATUS FOR PLANTLETS AND YOUNG PLANTS OF EUCALYPTUS CLONES

2015 ◽  
Vol 39 (4) ◽  
pp. 1127-1140 ◽  
Author(s):  
Eric Victor de Oliveira Ferreira ◽  
Roberto Ferreira Novais ◽  
Bruna Maximiano Médice ◽  
Nairam Félix de Barros ◽  
Ivo Ribeiro Silva
Keyword(s):  
Total Nitrogen ◽  
Block Design ◽  
Nitrogen Concentration ◽  
Soil N ◽  
Total N ◽  
Chlorophyll Meter ◽  
N Concentration ◽  
Total Nitrogen Concentration ◽  
N Status ◽  
Leaf N

The use of leaf total nitrogen concentration as an indicator for nutritional diagnosis has some limitations. The objective of this study was to determine the reliability of total N concentration as an indicator of N status for eucalyptus clones, and to compare it with alternative indicators. A greenhouse experiment was carried out in a randomized complete block design in a 2 × 6 factorial arrangement with plantlets of two eucalyptus clones (140 days old) and six levels of N in the nutrient solution. In addition, a field experiment was carried out in a completely randomized design in a 2 × 2 × 2 × 3 factorial arrangement, consisting of two seasons, two regions, two young clones (approximately two years old), and three positions of crown leaf sampling. The field areas (regions) had contrasting soil physical and chemical properties, and their soil contents for total N, NH+4-N, and NO−3-N were determined in five soil layers, up to a depth of 1.0 m. We evaluated the following indicators of plant N status in roots and leaves: contents of total N, NH+4-N, NO−3-N, and chlorophyll; N/P ratio; and chlorophyll meter readings on the leaves. Ammonium (root) and NO−3-N (root and leaf) efficiently predicted N requirements for eucalyptus plantlets in the greenhouse. Similarly, leaf N/P, chlorophyll values, and chlorophyll meter readings provided good results in the greenhouse. However, leaf N/P did not reflect the soil N status, and the use of the chlorophyll meter could not be generalized for different genotypes. Leaf total N concentration is not an ideal indicator, but it and the chlorophyll levels best represent the soil N status for young eucalyptus clones under field conditions.

scholarly journals Fertilization Rate and Growth of `Hamlin' Orange Trees Related to Preplant Leaf Nitrogen Levels in the Nursery

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 613e-614
Author(s):  
Laura Guazzelli ◽  
Frederick S. Davies ◽  
James J. Ferguson
Keyword(s):  
N Fertilizer ◽  
Soil Nitrate ◽  
Growth Responses ◽  
Fertilizer Rate ◽  
Trunk Diameter ◽  
Nitrate N ◽  
N Concentration ◽  
Leaf N Concentration ◽  
N Fertilizer Rate ◽  
Leaf N

Our objectives were to determine if leaf N concentration in citrus nursery trees affected subsequent growth responses to fertilization for the first 2 years after planting and how N fertilizer rate affected soil nitrate-N concentration. `Hamlin' orange [Citrus sinensis (L.) Osb.] trees on `Swingle' citrumelo rootstock [C. paradisi Macf. × P. trifoliata (L.) Raf.] were purchased from commercial nurseries and grown in the greenhouse at differing N rates. Three to five months later trees were separated into three groups (low, medium, high) based on leaf N concentration and planted in the field in Oct. 1992 (Expt. 1) or Apr. 1993 (Expt. 2). Trees were fertilized with granular material (8N–2.6P–6.6K) with N at 0 to 0.34 kg/tree yearly. Soil nitrate-N levels were also determined in Expt. 2. Preplant leaf N concentration in the nursery varied from 1.4% to 4.1% but had no effect on trunk diameter, height, shoot growth, and number or dry weight in year 1 (Expt. 1) or years 1 and 2 (Expt. 2) in the field. Similarly, N fertilizer rate had no effect on growth during year 1 in the field. However, trunk diameter increased with increasing N rate in year 2 and reached a maximum with N at 0.17 kg/tree yearly. Shoot number during the second growth flush in year 2 was much lower for nonfertilized vs. fertilized trees. Leaf N concentrations increased during the season for trees with initially low levels even for trees receiving low fertilizer rates. Soil nitrate-N levels were highest at the 0.34-kg rate, and lowest at the 0.11-kg rate. Nitrate-N levels decreased rapidly in the root zone within 2 to 3 weeks of fertilizing.

scholarly journals Variations of leaf N, P concentrations in shrubland biomes across northern China: phylogeny, climate and soil

2015 ◽  
Vol 12 (22) ◽  
pp. 18973-18998 ◽  
Author(s):  
X. Yang ◽  
X. Chi ◽  
C. Ji ◽  
H. Liu ◽  
W. Ma ◽  
...  
Keyword(s):  
Soil Nutrient ◽  
Northern China ◽  
Nutrient Concentrations ◽  
Soil P ◽  
P Concentration ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Chemical Traits ◽  
Leaf P ◽  
Leaf N

Abstract. Concentrations of leaf nitrogen (N) and phosphorus (P) are key leaf traits in ecosystem functioning and dynamics. Foliar stoichiometry varies remarkably among life forms. However, previous studies have focused on trees and grasses, leaving the knowledge gap for the stoichiometric patterns of shrubs. In this study, we explored the intra- and interspecific variations of leaf N and P concentration in relation to climate, soil property and evolutionary history based on 1486 samples composed of 163 shrub species from 361 shrubland sites in northern China expanding 46.1° (86.7–132.8° E) in longitude and 19.8° (32.6–52.4° N) in latitude. The results showed that leaf N concentration decreased with precipitation, leaf P concentration decreased with temperature and increased with precipitation and soil P concentration. Both leaf N and P concentrations were phylogenetically conserved, but leaf P concentration was less conserved than leaf N concentration. At community level, climates explained more interspecific, while soil nutrient explained more intraspecific, variation of leaf nutrient concentrations. These results suggested that leaf N and P concentrations responded to climate, soil, and phylogeny in different ways. Climate influenced the community chemical traits through the shift in species composition, whereas soil directly influenced the community chemical traits.

Determination of critical nitrogen concentrations of zucchini squash (Cucurbita pepo L.) cv. Blackjack grown in sand culture

1991 ◽  
Vol 31 (6) ◽  
pp. 835 ◽  
Author(s):  
DO Huett ◽  
E White
Keyword(s):  
Growth Rate ◽  
Growth Period ◽  
Sand Culture ◽  
Total N ◽  
N Supply ◽  
Nitrate N ◽  
Fruit Harvest ◽  
Petiole Sap ◽  
Leaf Nitrate

A gamma x quadratic response surface model was used to predict the growth rate over the 14-week growth period of zucchini squash (Cucurbita pepo L.) cv. Blackjack in sand culture with nitrogen (N) levels of 2, 7, 14, 29 and 43 mmol/L. Growth rate relative to maximum was plotted against tissue N concentration every 2 weeks, to derive diagnostic petiole sap; leaf nitrate-N and leaf total-N in youngest fully opened leaf, youngest fully expanded leaf and oldest green leaf; and total N in bulked leaf samples. Critical concentrations corresponding to 90% maximum growth rate for deficiency and toxicity are presented. Petiole sap and leaf nitrate-N were much more responsive than leaf total N concentrations over the 2-14 mmol N/L range where positive growth responses were recorded. At 2 mmol N/L, plants were severely N-deficient and growth rate was low (1.6 g/plant.week at fruit set). Tissue nitrate concentrations were negligible, while leaf total N concentrations exceeded 2.6%. Salt toxicity occurred at 29 and 43 mmol N/L, and at the highest N level, tissue N concentrations were sometimes reduced so that concentration ranges for adequacy and toxicity overlapped. Critical tissue N concentrations always exceeded (P<0.05) levels recorded in plants receiving a marginally deficient N level (7 mmol/L). Critical petiole sap and leaf nitrate-N concentrations were much more variable between sampling periods than leaf total N concentrations. Adequate concentration ranges (values between critical concentrations for deficiency and toxicity) were determined for the pre-fruit harvest (weeks 2-6) and fruit harvest (weeks 8-14) growth stages where values were common for consecutive weeks within each sampling period. It was only possible to determine adequate concentrations over the entire growth period for bulked leaf total N (4.30440% prefruit harvest and 4.15-4.45% fruit harvest). Concentrations of potassium (K), phosphorus and sulfur were affected (P<0.05) by N application level, with the largest effect being recorded for K. This confirms the importance of optimising N supply when determining critical levels of these nutrients for zucchini squash. Determination of petiole sap nitrate-N concentrations in the field can be used to distinguish between a deficient and an adequate N supply, but the large variation in values between sampling periods renders this technique less reliable than leaf total N. Tissue N concentrations which exceed critical deficient levels can be interpreted as such because they were recorded when growth was depressed at high N levels. This will rarely occur under field conditions.

Assessment of the nitrogen and potassium status of irrigated Brussels sprouts (Brassica oleracea L. var. gemmifera) by plant analysis

1996 ◽  
Vol 36 (7) ◽  
pp. 887 ◽  
Author(s):  
CMJ Williams ◽  
NA Maier
Keyword(s):  
Total Yield ◽  
Leaf Age ◽  
Plant Analysis ◽  
Total N ◽  
Brussels Sprouts ◽  
Critical Concentrations ◽  
N Supply ◽  
Nitrate N ◽  
N Concentration ◽  
N Status

Four field experiments were carried out during 1992-93 (sites 1 and 2) and 1993-94 (sites 3 and 4) to assess the effects of nitrogen (N), at rates up to 600 kgha, and potassium (K), at rates up to 300 kgha, on total N, nitrate-N and K concentrations in petioles of the youngest fully expanded leaves (P-YFEL) of Brussels sprouts (Brassica oleracea var. gemmifera). The experiments were located in commercial plantings in the Mt Lofty Ranges, South Australia. Plant samples were collected at 2-4-week intervals from 4 to 28 weeks after the plants were transplanted. Temporal or seasonal variation, and the effects on concentrations of total N, nitrate-N and K of sampling leaves next in age (YFEL-1 to YFEL+2) to the index leaf, were also studied. Total N concentration in P-YFEL was more sensitive to variations in N supply than nitrate-N at all sites. Total N and nitrate-N concentrations in petioles also varied with the age of the leaf sampled. Total N concentrations in petioles of leaves sampled 4-16 weeks after transplanting decreased with increasing leaf age. In contrast, nitrate-N concentrations in petioles sampled 4-8 weeks after transplanting increased with leaf age. Potassium concentrations in petioles did not vary consistently between leaves of different age. From 4 to 6 weeks after transplanting, relationships between total N or nitrate-N concentrations in P-YFEL and relative total yield were not significant (P>0.05), therefore, critical concentrations could not be determined. Linear and quadratic models were used to study the relationships between total N and nitrate-N concentration in P-YFEL and relative total yield during 8-28 weeks after transplanting. Total N concentrations accounted for a greater amount of variation in relative total yield at 10, 12, 14, 16, 18, 20, 24 and 28 weeks after transplanting compared with nitrate-N. Coefficients of determination (r2) were in the range 0.52-0.93. Relationships between nitrate-N concentration in P-YFEL and relative total yield were only significant 8, 10, 14 and 16 weeks after transplanting and 9 values were in the range 0.49-0.82. Critical concentrations for total N decreased from 3.13-3.44% at 10 weeks to 1.22-1.38% at 28 weeks after transplanting. This decrease highlights the importance of carefully defining sampling time to ensure correct interpretation of plant test data. Potassium concentrations also decreased between 4 and 28 weeks after transplanting. Critical concentrations were not determined for K, because the crops at all sites did not respond significantly (P>0.05) to applied K. Based on sensitivity (as indicated by the range in tissue concentrations in response to variations in N supply) and on the correlations between total N and nitrate-N concentrations and relative total yield, we concluded that total N was better than nitrate-N as an indicator of plant N status and yield response of Brussels sprouts. We suggested that growers sample P-YFEL several times during the growing season, starting 10 weeks after transplanting. Plant analysis can be used to monitor N status and to detect N deficiencies which may arise during the growing season of Brussels sprouts which may be up to 9 months duration. Growers can adjust their fertiliser N program to ensure deficiencies are quickly corrected.

Determination of critical nitrogen concentrations of potato (Solanum tuberosum L. cv. Sebago) grown in sand culture

1992 ◽  
Vol 32 (6) ◽  
pp. 765 ◽  
Author(s):  
DO Huett ◽  
E White
Keyword(s):  
Dry Matter ◽  
Maximum Yield ◽  
Growth Period ◽  
Sand Culture ◽  
N Application ◽  
Total N ◽  
Nitrate N ◽  
Nitrate Concentrations ◽  
Petiole Sap ◽  
Leaf Nitrate

A gamma x cubic response surface model was used to predict the dry matter yield of potato cv. Sebago over the 12-week growth period in sand culture with nitrogen (N) levels of 2, 7, 14, 29 and 43 mmol N/L. At each 2-week sampling period after emergence, dry matter yield relative to maximum was plotted against tissue N concentration to derive diagnostic petiole, petiole sap, leaf nitrate-N and leaf total N in youngest fully opened leaf (YFOL), youngest fully expanded leaf (YFEL) and oldest green leaf (OL) and for total N in bulked leaves. Critical concentrations corresponding to 90% maximum yield are presented. Tissue nitrate was much more responsive than leaf total N to applied N over the 2-14 mmol/L range where positive growth responses to N were recorded. Plants grown with 2 mmol N/L were severely N deficient and growth was depressed. Tissue nitrate concentrations in these plants from 4 weeks after emergence onwards were negligible, while leaf total N concentrations exceeded 2.36%. Salt toxicity occurred at 29 and 43 mmol NIL, and it sometimes reduced tissue N concentrations so that adequacy and toxicity concentrations overlapped. Critical tissue N concentrations declined over the growth period, the largest decline occurring for nitrate. Critical tissue N concentrations for YFEL, from 2 weeks after emergence to final harvest were: petiole sap nitrate-N, 1.2-0.2 g/L; petiole nitrate-N, 2.1-0.1%; leaf nitrate-N, 0.44-0.08%. Critical tissue nitrate concentrations clearly differentiated between inadequate and adequate N application levels. Critical leaf total N concentrations only differentiated between inadequate and marginal N application rates, except for OL when inadequate and marginally adequate (80-90% maximum yield) concentrations were not different (P>0.05). Nitrogen application level affected (P<0.05) leaf potassium, phosphorus, calcium (Ca), magnesium (Mg) and sulfur concentrations. The largest effects were recorded for Ca and Mg where increasing N application level reduced leaf nutrient concentration. Petiole sap nitrate concentrations can be used as a rapid field test for distinguishing between a deficient and an adequate N supply. Where concentrations exceed critical values, they can be interpreted as such because N fertiliser toxicity rarely occurs under field conditions.

First-year growth response of four Populus trichocarpa × Populus deltoides clones to fertilizer placement and level

1999 ◽  
Vol 29 (5) ◽  
pp. 554-562 ◽  
Author(s):  
R van den Driessche
Keyword(s):  
Populus Deltoides ◽  
Populus Trichocarpa ◽  
Hybrid Poplar ◽  
Stem Volume ◽  
First Year ◽  
Total N ◽  
Organic C ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Leaf N

Fertilizer (18:40:0, N:P:K) was applied by two methods, each at different levels, following establishment of a hybrid poplar (Populus trichocarpa Torr. & Gray × Populus deltoides Bartr. ex Marsh.) plantation, containing four clones, on central Vancouver Island. Nitrogen and P were supplied at 0, 100, and 200 kg·ha-1 by banding, and at 0, 25 and 50 kg·ha-1 by placing in holes adjacent to cuttings. After one season, response to placed treatments (mean height 182 cm) was greater than to banded treatments (mean height 149 cm). The 50 kg·ha-1 placed treatment increased stem volume 4.3-fold above control, and the 200 kg·ha-1 banded treatment increased stem volume 2.4-fold above control. Uptake of N and P was about 10-fold greater per kilogram of fertilizer nutrient for placed than banded treatments. Fertilizer increased leaf N concentration, but concentrations of most other nutrients declined despite increased uptake. Significant increases in stem volume occurred when leaf N concentration was about 29 g·kg-1 in clone 1, but 23-25 g·kg-1 in the other clones. Clone 2 tolerated foliage P concentrations below 1.4 g·kg-1 at the greatest growth rates. Stem volume was positively correlated with soil total N% and organic C% in the 16-30 cm horizon.

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