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Nitrogen uptake and leaching under annual bluegrass ecotypes and bentgrass species: a lysimeter experiment.

GOLF COURSES may represent a significant environmental issue because of the potential for ground water contamination by N[O.sub.3.sup.-] from fertilizers (Petrovic, 1990). Putting greens are of particular concern because the root zone is often made of high-porosity sand mixtures to prevent compaction and water logging. Sandbased root zones have little capacity to retain nutrients or water, and frequent N applications and irrigations are required (Brown et al., 1982; Bigelow et al., 2001). Under these conditions, N[O.sub.3.sup.-] leaching can be high (Brown et al., 1982; Mancino and Troll, 1990; Shuman, 2001).

Management factors known to affect N[O.sub.3.sup.-] leaching under golf green conditions include irrigation volume, application rate and timing, and source of N fertilizers (Petrovic, 1990). Management practices need to optimize N uptake by turfgrasses to reduce the risk of N[O.sub.3.sup.-] leaching. Petrovic (1990) reported N uptake ranging from 5 to 74% of applied N. Differences in N uptake and utilization as well as differences in N leaching patterns have been reported among turfgrass species and cultivars (Cisar et al., 1989; Liu et al., 1997; Jiang and Hull, 1998; Jiang et al., 2000; Bowman et al., 2002). Some of the variations in N uptake efficiency may be due to morphological and physiological differences among grasses (Carrow et al., 2001). The morphology and the depth of root development appear to be important factors affecting N uptake (Bowman et al., 1998; Sullivan et al., 2000).

In Canada, creeping bentgrass (A. stolonifera L.) and annual bluegrass are cultivated on 53 and 36% of the golf greens, respectively (Royal Canadian Golf Association, 2003). However, little is known about N uptake efficiency and N leaching under golf greens cultivated with bentgrass or annual bluegrass. The objective of this research was to compare, in a greenhouse experiment, N uptake and potential mineral N leaching among various annual bluegrass ecotypes and bentgrass species grown in lysimeter columns simulating a golf-green profile.

MATERIALS AND METHODS

A lysimeter experiment was conducted in a greenhouse at the Univ. of Guelph, Guelph, ON, Canada. During the 57-d experimental period (October to December 2002), air and root zone temperatures were monitored with a data logger (HOBO, PRO series, Onset Computer Corporation, Bourne, MA). The mean daily air and root zone temperatures at the 5-cm depth were 22.8 [+ or -] 2.1[degrees]C and 17.0 [+ or -] 0.6[degrees]C, respectively. The photoperiod was 16 h [d.sup.-1] with supplemental high-pressure sodium lighting (PAR, 80 [micro]mol [m.sup.-2] [s.sup.-1]) for the duration of the experiment.

Plant Material and Culture

The plant material consisted of 11 annual bluegrass ecotypes and three bentgrass species. Six annual bluegrass ecotypes were grown from tillers selected from golf greens, at different geographical locations, on the basis of their potentially superior turf characteristics. Three ecotypes were selected in the province of Quebec, Canada (Bic, Quebec City, and Montebello; mean annual temperature, 4.7[degrees]C; mean annual precipitation, 1011 mm), and three were selected in the Guelph area in Ontario, Canada (mean annual temperature, 6.5[degrees]C; mean annual precipitation, 769 mm). Finally, five USA ecotypes were selected from tillers grown for 6 wk from seeds planted in 10-cm-diam. pots containing sand-peat root zone mixture. The seeds were provided by Dr. David Huff (Pennsylvania State Univ.) and the ecotypes were originally collected in the Mid-East region of the USA (mean annual temperature, 9.5[degrees]C; mean annual precipitation, 813 mm).

The bentgrass species were creeping bentgrass ('Penncross' and 'Penn-A4'), dryland bentgrass (A. castellana Boiss. & Reut. cv. 'Highland'), and velvet bentgrass (A. canina L. cv. 'Vesper'). As with the USA annual bluegrass ecotypes, the bentgrasses were selected from tillers grown from commercial seeds planted in 10-cm-diam. pots for a 6-wk period.

All individual tillers were transplanted into 3.8-cm-diam., 14.0-cm-high cylindrical containers (conetainers, RL C7 Stuby Cell, Stuewe and Sons, Inc., Corvallis, OR) filled with a 80:20 sand-peat mix (v/v) and were grown in a greenhouse. Plants were irrigated as needed, fertilized twice a week (20-8-20; 250 mg N [L.sup.-1], Plant-Prod, Plant Products Co. Ltd., Brampton, ON, Canada) and clipped weekly with scissors to approximately 1 cm.

Lysimeter Columns and Plant Establishment

Lysimeters were constructed using opaque polyvinyl chloride columns (10-cm diam., 40-cm depth). A cone collector was sealed to the bottom of each lysimeter and was connected to a 500-mL bottle by a tygon tube. The cone collector section of each lysimeter was filled with 10 cm of pea gravel ([approximately equal to] 6- to 10-mm diam.) overlaid with 30 cm of a 80:20 (v/v) sand-peat root zone mixture. Materials used in the root zone mixture (Table 1) were selected to meet the standards of a golf green profile as stipulated by the United State Golf Association (USGA Green Section Staff, 1993). After [approximately equal to] 2 mo of growth, turfgrass from seven containers of the same species, cultivar, or ecotype were transplanted into each lysimeter (experimental unit); four lysimeter columns (replications) were prepared for each turfgrass. In addition, four unplanted root zone lysimeters were included as a control treatment for a total of 64 lysimeter columns.

At initiation of the experiment the turf was approximately 3.5 mo old; that is, 2 mo of growth in containers and a 6-wk establishment period to obtain a solid stand of grass in the lysimeters. During the 6-wk establishment period, plants were irrigated twice a day with 150 mL of deionized water, fertilized twice a week with 75 mL of a fertilizer solution (20-8-20, equivalent to 24 kg N [ha.sup.-1]), and clipped once a week to [approximately equal to] 1 cm. Two weeks before starting the experiment, fertilization was stopped and the lysimeters were irrigated with 150 mL of deionized water twice a day to leach residual fertilizer N from the lysimeters.

Fertilizer Application, Irrigation, and Leachate Sampling

One hundred fifty milliliters of a water-soluble fertilizer was applied every 14 d, and the lysimeters were manually irrigated with 150 mL of deionized water poured from a beaker every other day. This is equivalent to a depth of 1.9 cm [lysimeter.sup.-1] per application. Nitrogen was applied as ammonium nitrate (34-0-0; 25 kg N [ha.sup.-1]) and P and K were supplied using monopotassium phosphate (0-52-34; 5.5 kg P [ha.sup.-1] and 6.8 kg K [ha.sup.-1]) and potassium chloride (0-0-62; 8.8 kg K [ha.sup.-1]). This would compare to yearly application rates of 350 kg N [ha.sup.-1], 77 kg P [ha.sup.-1], and 218.4 kg K [ha.sup.-1] based on a 7-mo growing season, which is typical of golf green management in the Quebec and Ontario areas. Micronutrients were supplied according to the manufacturer's (Micronutrient Mix For Turf, Plant Products Co. Ltd., Brampton, ON, Canada) recommendation (21 g Micronutrient Mix 100 [m.sup.-2]; Fe 7.0%, Mg 2.9%, Mn 2.0%, B 1.0%, Cu 0.1%, Zn 0.4%, and Mo 0.06%). For each lysimeter, the total volume of leachate was measured the day following each irrigation and a subsample was collected and stored in a 15-mL-polypropylene tube at 4[degrees]C for later quantification of mineral N concentration.

Plant and Root Zone Sampling

Plants were clipped once a week to approximately 1 cm; only a few millimeters of shoot tissues were removed at each clipping. The harvested clippings were dried at 60[degrees]C (48-72 h), weighed, and pooled over the duration of the experiment for analysis. At the end of the experiment, the root zone core in each lysimeter column was divided into three sections: 0- to 5-, 5- to 10-, and 10- to 40-cm depth; the last section included the gravel layer. Roots were manually separated from the root zone in each section and then gently washed with tap water to remove any adhering material, which was discarded. Shoots were cut to the crown, weighed after drying at 60[degrees]C (48-72 h), and combined with the clippings for analysis; the crown was included with roots in the 0- to 5-cm section. Root dry weight was measured for each section after drying at 60[degrees]C (48-72 h). A root zone sample was also collected from each section and air-dried for later N analysis.

Leachate, Plant, and Root Zone Analyses

All leachate samples were analyzed for N[O.sub.3]-N and N[H.sub.4]-N concentration with a segmented flow colorimeter (Technicon Model Traacs 800, Pulse Instrumentation, Ltd., Saskatoon, SK, Canada). Ammonium N concentration in leachates was typically below the detection limit (<0.5 mg [L.sup.-1]). Total amount of N[O.sub.3]-N in each leachate sample was calculated by multiplying N[O.sub.3]-N concentration by the total volume of leachate. Cumulative N[O.sub.3]-N losses were calculated by summing the amounts of N[O.sub.3]-N collected from each lysimeter. For each lysimeter, a linear regression curve was fitted to the cumulative N[O.sub.3]-N data and the slope of the curve was used as an estimate of the mean daily rate of N[O.sub.3]-N leaching.

Root zone, plant aboveground biomass (clippings plus shoots), and roots were analyzed for total N content by dry combustion with an elemental analyzer (Model LECO CNS-1000, Leco Corp., St. Joseph, MI). Nitrogen concentration in the root zone samples was below the detection limit (<0.05% dry wt.) for all lysimeter columns. N uptake was calculated by multiplying the dry weight of the clippings plus shoots and roots by their respective N concentrations. Total plant N uptake was not corrected for N in shoots and roots at the beginning of the experiment.

Experimental Design and Statistical Analyses

The experiment consisted of 16 treatments (11 annual bluegrasses, four bentgrasses, and one unplanted root zone control) and four replicates arranged as a randomized complete-block design. All statistical analyses were performed using SAS v. 8 (SAS Institute, 1999). Slopes of the cumulative N[O.sub.3]-N losses were obtained by linear regression using the REG procedure. An ANOVA was performed using the GLM procedure. Treatment means were compared using a priori contrasts with the CONTRAST option of the GLM procedure. Type I error rate was set at P = 0.05 for all statistical tests.

RESULTS AND DISCUSSION

Nitrate and Ammonium Leaching

Nitrate N accounted for >99% of total mineral N found in leachates. Ammonium N leaching was negligible under all grasses studied, most likely because of plant assimilation and rapid microbial immobilization and nitrification in the root zone. This is consistent with results from other greenhouse and field studies (Brown et al., 1982; Mancino and Troll, 1990; Bowman et al., 2002). In a laboratory experiment, Bigelow et al. (2001) found that sand amended with 20% by volume of sphagnum peat (the same sand-peat mixture used in our experiment) reduced N[H.sub.4]-N leaching loss by 59% when compared with a pure sand root zone.

The concentration of N[O.sub.3]-N in leachates fluctuated during each 14-d fertilizer application period (Fig. 1). In general, including the unplanted control, N[O.sub.3]-N concentration in the leachate increased 3 d after fertilizer application, peaked after 7 d ([approximately equal to] 1-15, 20-40, and 40-55 mg N[O.sub.3]-N [L.sup.-1] for the bentgrasses, annual bluegrasses, and unplanted control, respectively) and then decreased to [approximately equal to] 3 and 10 mg [L.sup.-1] for the grasses and unplanted control, respectively, until the next fertilizer application. This cyclic pattern in N[O.sub.3]-N leaching is reflected in the sigmoidal shapes of the cumulative N[O.sub.3]-N leaching curves (Fig. 2). Total N[O.sub.3]-N leaching losses, using single degree of freedom contrasts, were in the following order: unplanted control > Quebec P. annua > Ontario P. annua > USA P. annua > Agrostis spp. (Table 2).

[FIGURES 1-2 OMITTED]

As expected, the unplanted control resulted in the greatest N[O.sub.3]-N leaching with losses representing 116% of the N applied (Table 2). Although some experimental error might have occurred in measuring total N[O.sub.3]-N leaching, cumulative losses > 100% of the applied N in the control lysimeters could also be attributed to mineralization and subsequent leaching of organic N present in the lysimeters at initiation of the experiment. Chapman (1994) and Brauen and Stahnke (1995) found N[O.sub.3]-N leachate concentrations > 15 mg [L.sup.-1] under a sand-based putting green during bentgrass seedling establishment. This demonstrates the importance of N uptake in regulating fertilizer N leaching and stresses the need for careful adjustment of N fertilization during the establishment period of grasses to prevent excessive N[O.sub.3] leaching when N uptake is low.

Differences in mean daily rate and total (cumulative value at 57 d) N[O.sub.3]-N leaching losses were observed among the grasses (Table 2). Total N[O.sub.3]-N leaching varied from 5 to 56 mg [lysimeter.sup.-1], representing 6 to 71% of the N applied. In a 3-yr N leaching study on a golf green at Coeur d'Alene, ID, 48% of the applied N was recovered in creeping bentgrass clippings and 11% was recovered in the leachate (Johnston et al., 2001). This is in agreement with our work where 10 to 11% of the applied N was recovered in the leachates under creeping bentgrass (Table 2). P. annua Quebec ecotype 2 had the greatest numerical mean daily rate and total N[O.sub.3]-N leaching, while A. canina had the smallest values. Mean daily rate and total N[O.sub.3]-N leaching were greater under annual bluegrasses than under bentgrasses (Table 2). In addition, intraspecific differences were found among annual bluegrass ecotypes. Both the mean daily rate and total N[O.sub.3]-N leaching were as follows: Quebec P. annua > Ontario P. annua > USA P. annua. Differences in N[O.sub.3]-N leaching observed among the annual bluegrass ecotype groups could be a consequence of their adaptation to climatic conditions in their region of origin. Poole et al. (2005) reported that differences in P. annua morphology were related to regional climatic conditions. Interspecific differences were also observed among the bentgrasses. Both the mean daily rate and total N[O.sub.3]-N leaching under A. canina were smaller than under A. castellana and A. stolonifera; there were no differences between A. castellana and A. stolonifera (Table 2).

Plant Growth Characteristics and Nitrogen Uptake

Differences in growth characteristics were observed among the grasses (Table 3). Overall, annual bluegrasses had less clipping, shoot, and root dry weight when compared with the bentgrass species. The only exceptions were found with the Ontario and USA ecotypes, which had shoot dry weight similar to Agrostis spp. In addition, Ontario ecotypes had a root dry weight in the 0- to 5-cm depth similar to Agrostis spp. Total biomass production was as follows: A. canina > A. stolonifera = A. castellana > Ontario P. annua > USA P. annua > Quebec P. annua. For all grasses evaluated, the major portion of the total root biomass (65-90%) was located in the top 5 cm of the root zone; this is partly due to the inclusion of the crown with root materials at this depth. Total root biomass of the bentgrasses was also larger than the annual bluegrasses and developed deeper in the root zone (Table 3). Overall, total root biomass was in the following order: A. canina > A. stolonifera = A. castellana > Ontario P. annua = USA P. annua > Quebec P. annua.

The bentgrasses had a greater N uptake than annual bluegrasses for all parameters (Table 4). The only exceptions were for P. annua from Ontario and USA, which demonstrated N uptake in the roots similar to Agrostis spp. Quebec P. annua ecotypes had the smallest N uptake. This intraspecific and interspecific variability in N uptake agrees with the different N uptake efficiencies previously found among various grass species and cultivars (Liu et al., 1997; Jiang and Hull, 1998; Jiang et al., 2000).

Total N uptake was closely and positively correlated to total biomass (Fig. 3a), whereas it was closely and negatively correlated to total N[O.sub.3]-N leaching (Fig. 3b). Thus, interspecific and intraspecific differences in N[O.sub.3]-N leaching were mainly attributed to differences in plant biomass. Grasses with a greater aboveground biomass generally had a greater root biomass (Table 3). In putting greens, where grass is mowed at short heights on a daily basis and exposed to stresses such as traffic and pests, the root system plays an important role in plant maintenance, recovery, and survival. It is logical to believe that plants with a larger root system exploit a greater root zone volume and have a greater potential to absorb nutrients. Sullivan et al. (2000) found that root morphological traits, such as length, surface, and volume are positively correlated with N[O.sub.3.sup.-] uptake rate in Kentucky bluegrass (Poa pratensis L.). In our experiment, the extensive root development in bentgrasses, compared to annual bluegrasses, was critical to reduce potential N[O.sub.3]-N leaching. Similarly, in a greenhouse experiment, Bowman et al. (1998) found that a deep-rooted creeping bentgrass genotype had half as much N[O.sub.3]-N leaching when compared with a shallow-rooted one. Since Lehman and Engelke (1991) found rooting characteristics to be a heritable trait in turfgrass, selection of ecotypes or cultivars with superior root development should be possible and could be used in turfgrass breeding programs.

[FIGURE 3 OMITTED]

CONCLUSIONS

Bentgrasses were more efficient at preventing N[O.sub.3]-N leaching losses under sand-based root zones than annual bluegrasses, which could be explained by a greater aboveground biomass and root development (both total root biomass and its distribution deeper in the profile). Interspecific differences in N[O.sub.3]-N leaching were also found among bentgrasses; A. canina had less N[O.sub.3]-N leaching than A. castellana or A. stolonifera. In addition, intraspecific differences in N[O.sub.3]-N leaching were found within annual bluegrasses; Quebec P. annua > Ontario P. annua > USA P. annua. Consequently, identification of annual bluegrass ecotypes or bentgrass cultivars with improved root development is possible and can be used in breeding programs along with management practices to reduce N leaching under sand-based putting greens.

ACKNOWLEDGMENTS

The authors would like to recognize assistance of Ms. Johanne Tremblay, Agriculture and Agri-food Canada, and Dr. David R. Huff, Pennsylvania State Univ. The Natural Sciences and Engineering Council of Canada, Royal Canadian Golf Assoc. Foundation, and Canadian Turfgrass Research Foundation provided financial support for this project.

REFERENCES

Bigelow, C.A., D.C. Bowman, and D.K. Cassel. 2001. Nitrogen leaching in sand-based rootzones amended with inorganic soil amendments and sphagnum peat. HortScience 126:151-156.

Bowman, D.C., C.T. Cherney, and T.W. Rufty, Jr. 2002. Fate and transport of nitrogen applied to six warm-season turfgrasses. Crop Sci. 42:833-841.

Bowman, D.C., D.A. Devitt, M.C. Engelke, and T.W. Rufty, Jr. 1998. Root architecture affects nitrate leaching from bentgrass turf. Crop Sci. 38:1633-1639.

Brauen, S.E., and G.K. Stahnke. 1995. Leaching of nitrate from sand putting greens. USGA Green Sect. Rec. 33:29-32.

Brown, K.W., J.C. Thomas, and R.L. Duble. 1982. Nitrogen source effect on nitrate and ammonium leaching and runoff losses from greens. Agron. J. 74:947-950.

Carrow, R.N., D.V. Waddington, and EE. Rieke. 2001. Tuffgrass soil fertility and chemical problems: Assessment and management. Ann Arbor Press, Chelsea, MI.

Chapman, J.E. 1994. The effects of nitrogen fertilizer rate, application timing, and root-zone modification on nitrate concentrations and organic matter accumulation in sand-based putting greens. M.S. thesis. Washington State Univ., Pullman.

Cisar, J.L., R.J. Hull, and D.T. Duff. 1989. Ion uptake kinetics of cool season turfgrasses, p. 233-235. In H. Takatoh (ed.) Proc. Int. Turfgrass Res. Conf., 6th, Tokyo, Japan. 31 July-5 Aug. 1989. Int. Turfgrass Soc. and the Japanese Soc. of Turfgrass Sci., Tokyo.

Jiang, Z., and R.J. Hull. 1998. Interrelationships of nitrate uptake, nitrate reductase, and nitrogen use efficiency in selected Kentucky bluegrass cultivars. Crop Sci. 38:1623-1632.

Jiang, Z., W.M. Sullivan, and R.J. Hull. 2000. Nitrate uptake and nitrogen use efficiency by Kentucky bluegrass cultivars. HortScience 35:1350-1354.

Johnston, W.J., C.T. Golob, C.M. Kleene, W.L. Pan, and E.D. Miltner. 2001. Nitrogen leaching through a floating sand-based golf green under golf course play and management. Int. Turfgrass Soc. Res. J. 9:19-24.

Lehman, V.G., and M.C. Engelke. 1991. Heritability estimates of creeping bentgrass root systems grown in flexible tubes. Crop Sci. 31:1680-1684.

Liu, H., R.J. Hull, and D.T. Duff. 1997. Comparing cultivars of three cool-season tuffgrasses for soil water nitrate concentration and leaching potential. Crop Sci. 37:526-534.

Mancino, C.E, and J. Troll. 1990. Nitrate and ammonium leaching losses from N fertilizers applied to 'Penncross' creeping bentgrass. HortScience 25:194-196.

Petrovic, A.M. 1990. The fate of nitrogenous fertilizers applied to turfgrass. J. Environ. Qual. 19:124-130.

Poole, G.J., W.J. Johnston, and R.C. Johnson. 2005. Regional climatic characterization of Pacific Northwest, USA, green-type Poa annua. Int. Turfgrass Soc. Res. J. 10:565-571.

Royal Canadian Golf Association. 2003. Canadian golf course operations survey report. Royal Canadian Golf Association, Oakville, ON, Canada.

SAS Institute. 1999. SAS systems for Windows. v. 8. SAS Inst., Cary, NC.

Shuman, L.M. 2001. Phosphate and nitrate movement through simulated golf greens. Water Air Soil Pollut. 129:305-318.

Sullivan, W.M., Z. Jiang, and R.J. Hull. 2000. Root morphology and its relationship with nitrate uptake in Kentucky bluegrass. Crop Sci. 40:765-772.

USGA Green Section StafL 1993. USGA recommendations for a method of putting green construction. USGA Green Section Rec. 31:1-3.

doi: 10.2135/cropsci2005.07.0200

K. Pare, M. H. Chantigny, K. Carey, W. J. Johnston, and J. Dionne *

K. Pare and W.J. Johnston, Dep. of Crop and Soil Sciences, Washington State Univ., Pullman, WA 99164-6420; M.H. Chantigny, Agriculture and Agri-Food Canada, Sainte-Foy, QC, Canada G1V 2J3; K. Carey, Dep. of Plant Agriculture, Univ. of Guelph, Guelph, ON, Canada N1G 2W1; J. Dionne, Royal Canadian Golf Assoc., Golf House, 1333 Dorval Dr., Oakville, ON, Canada L6M 4X7. Received 12 July 2005. * Corresponding author (jdionne@rcga.org).
Table 1. Physical properties of the root zone mix used in lysimeter
columns. ([dagger])

Mix analysis, % v/v
  Sand                                   80.0
  Peat                                   20.0
Pore space, % v/v
  Total                                  48.0
    Capillary                            21.0
    Noncapillary                         27.0
Infiltration rate, cm [h.sup.-1]         26.4
Bulk density, g [cm.sup.-3]               1.5
Organic matter content, g [kg.sup.-1]    12.0
Particle size distribution, %
  Fine gravel (2.0-9.4 mm)                0.1
  Sand
    Very coarse (1.0-2.0 mm)              5.2
    Coarse (0.5-1.0 mm)                  26.3
    Medium (0.25-0.5 mm)                 46.9
    Fine (0.15-0.25 mm)                  15.6
    Very fine (0.05-0.15 mm)              4.5
Silt (0.002-0.05 mm)                      1.0
Clay (<0.002 mm)                          0.4

([dagger]) Values provided by Hutcheson Sand and Mixes, Huntsville, ON,
Canada.

Table 2. Mean daily rate and total nitrate N (N[O.sub.3]-N) leaching
under annual bluegrass ecotypes and bentgrass species grown in
lysimeter columns for 57 d with fertilizer application every 14 d
during 2002 at Guelph, ON, Canada.

                                                           Ecotype
Grass                                       Origin       or cultivar

P. annua                              Canada   Ontario        1
                                                              2
                                                              3
                                               Quebec         1
                                                              2
                                                              3
                                      USA                     1
                                                              2
                                                              3
                                                              4
                                                              5
A. canina                                                 'Vesper'
A. castellana                                            'Highland'
A. stolonifera                                            'Penn-A4'
                                                         'Penncross'
Unplanted control                                            --
SEM ([double dagger])                                        --
Contrasts ([section])
  Unplanted control vs. all grasses
  P. annua vs. Agrostis
  P. annua: Ontario vs. Quebec
  P. annua: Ontario vs. USA
  P. annua: Quebec vs. USA
  A. canina vs. A. castellana
  A. canina vs. A. stolonifera
  A. castellana vs. A. stolonifera
  P. annua Quebec vs. Agrostis
  P. annua Ontario vs. Agrostis
  P. annua USA vs. Agrostis

                                          N[O.sub.3]-N leaching

                                                    Mean
Grass                                            daily rate

                                      mg [d.sup.-1] [lysimeter.sup.-1]

P. annua                                            0.57
                                                    0.82
                                                    0.53
                                                    0.97
                                                    1.04
                                                    0.87
                                                    0.49
                                                    0.59
                                                    0.41
                                                    0.63
                                                    0.52
A. canina                                           0.08
A. castellana                                       0.15
A. stolonifera                                      0.14
                                                    0.16
Unplanted control                                   1.70
SEM ([double dagger])                               0.05
Contrasts ([section])                             P value
  Unplanted control vs. all grasses                <0.001
  P. annua vs. Agrostis                            <0.001
  P. annua: Ontario vs. Quebec                      0.001
  P. annua: Ontario vs. USA                        <0.001
  P. annua: Quebec vs. USA                         <0.001
  A. canina vs. A. castellana                      <0.001
  A. canina vs. A. stolonifera                     <0.001
  A. castellana vs. A. stolonifera            ns ([paragraph])
  P. annua Quebec vs. Agrostis                     <0.001
  P. annua Ontario vs. Agrostis                    <0.001
  P. annua USA vs. Agrostis                        <0.001

Grass                                              Total

                                             mg                %
                                      [lysimeter.sup.-1]   ([dagger])]

P. annua                                      32                40
                                              45                57
                                              28                36
                                              53                68
                                              56                71
                                              48                61
                                              27                34
                                              32                41
                                              22                28
                                              34                44
                                              28                36
A. canina                                      5                 6
A. castellana                                  8                11
A. stolonifera                                 8                10
                                               9                11
Unplanted control                              9               116
SEM ([double dagger])                          2.8              --
Contrasts ([section])                       P value
  Unplanted control vs. all grasses         <0.001
  P. annua vs. Agrostis                     <0.001
  P. annua: Ontario vs. Quebec               0.001
  P. annua: Ontario vs. USA                 <0.001
  P. annua: Quebec vs. USA                  <0.001
  A. canina vs. A. castellana               <0.001
  A. canina vs. A. stolonifera              <0.001
  A. castellana vs. A. stolonifera            ns
  P. annua Quebec vs. Agrostis              <0.001
  P. annua Ontario vs. Agrostis             <0.001
  P. annua USA vs. Agrostis                 <0.001

([dagger]) Cumulative N[O.sub.3]-N leached (mg [lysimeter.sup.-1]) per
78.5 mg N applied x 100.

([double dagger]) Standard Error of the means, n = 4.

([section]) Single degree of freedom contrast.

([paragraph]) ns, not significant.

Table 3. Dry weight characteristics of annual bluegrass ecotypes and
bentgrass species grown in lysimeter columns for 57 d with fertilizer
application every 14 d during 2002 at Guelph, ON, Canada.

                                                       Ecotype
Grass                                    Origin       or cultivar

Poa annua                          Canada   Ontario        1
                                                           2
                                                           3
                                            Quebec         1
                                                           2
                                                           3
                                    USA                    1
                                                           2
                                                           3
                                                           4
                                                           5
A. canina                                              'Vesper'
A. castellana                                         'Highland'
A. stolonifera                                         'Penn-A4'
                                                      'Penncross'
SEM ([dagger])
Contrasts ([double dagger])
P. annua vs. Agrostis
P. annua: Ontario vs. Quebec
P. annua: Ontario vs. USA
P. annua: Quebec vs. USA
A. canina vs. A. castellana
A. canina vs. A. stolonifera
A. castellana vs. A. stolonifera
P. annua Quebec vs. Agrostis
P. annua Ontario vs. Agrostis
P. annua USA vs. Agrostis

                                                  Root

                                             Soil depths, cm

Grass                              Clipping   Shoot     0-5      5-10

                                           g [lysimeter.sup.-1]

Poa annua                            0.69      1.72     1.14     0.13
                                     0.33      0.92     0.89     0.13
                                     0.64      1.58     1.84     0.10
                                     0.38      0.76     0.61     0.07
                                     0.33      1.07     0.98     0.09
                                     0.38      0.91     0.69     0.12
                                     0.5       1.25     1.01     0.16
                                     0.48      1.46     0.97     0.17
                                     0.44      1.52     1.30     0.21
                                     0.45      1.14     0.78     0.14
                                     0.46      1.25     0.97     0.14
A. canina                            0.98      1.99     2.27     0.20
A. castellana                        1.19      1.23     1.02     0.15
A. stolonifera                       1.15      1.42     1.25     0.22
                                     1.03      1.34     1.29     0.24
SEM ([dagger])                       0.04      0.05     0.06     0.01
Contrasts ([double dagger])                         P value
P. annua vs. Agrostis               <0.001    0.004    <0.001   <0.001
P. annua: Ontario vs. Quebec        <0.001    <0.001   <0.001     ns
P. annua: Ontario vs. USA            0.012      ns      0.004    0.008
P. annua: Quebec vs. USA             0.004    <0.001    0.011   <0.001
A. canina vs. A. castellana          0.002     0.001   <0.001     ns
A. canina vs. A. stolonifera         0.043     0.001   <0.001     ns
A. castellana vs. A. stolonifera      ns        ns       ns      0.004
P. annua Quebec vs. Agrostis        <0.001    <0.001   <0.001   <0.001
P. annua Ontario vs. Agrostis       <0.001      ns       ns     <0.001
P. annua USA vs. Agrostis           <0.001      ns     <0.001    0.009

                                                Root

                                           Soil depths, cm

Grass                              10-40    Total    Total biomass

                                       g [lysimeter.sup.-1]

Poa annua                           0.06     1.3         3.7
                                    0.05     1.1         2.3
                                    0.04     2.0         4.2
                                    0.01     0.7         1.8
                                    0.03     1.1         2.5
                                    0.07     0.8         2.1
                                    0.10     1.3         3.0
                                    0.10     1.2         3.2
                                    0.15     1.7         3.6
                                    0.09     1.0         2.6
                                    0.10     1.2         2.9
A. canina                           0.29     2.8         5.7
A. castellana                       0.38     1.6         4.1
A. stolonifera                      0.30     1.8         4.3
                                    0.30     1.8         4.2
SEM ([dagger])                      0.02     0.08        0.15
Contrasts ([double dagger])                 P value
P. annua vs. Agrostis              <0.001   <0.001      <0.001
P. annua: Ontario vs. Quebec         ns     <0.001      <0.001
P. annua: Ontario vs. USA          <0.001     ns         0.038
P. annua: Quebec vs. USA           <0.001   <0.001      <0.001
A. canina vs. A. castellana        <0.001   <0.001      <0.001
A. canina vs. A. stolonifera         ns     <0.001      <0.001
A. castellana vs. A. stolonifera   <0.001     ns          ns
P. annua Quebec vs. Agrostis       <0.001   <0.001      <0.001
P. annua Ontario vs. Agrostis      <0.001   <0.001      <0.001
P. annua USA vs. Agrostis          <0.001   <0.001      <0.001

([dagger]) Standard error of the means, n = 4.

([double dagger]) Single degree of freedom contrasts.

Table 4. Nitrogen uptake of annual bluegrass ecotypes and bentgrass
species grown in lysimeter columns for 57 d with fertilizer application
everv 14 d durine 2002 at Guelph, ON, Canada.

                                                       Ecotype
Grass                                  Origin         or cultivar

P. annua                           Canada   Ontario        1
                                                           2
                                                           3
                                            Quebec         1
                                                           2
                                                           3
                                   USA                     1
                                                           2
                                                           3
                                                           4
                                                           5
A. canina                                              'Vesper'
A. castellana                                         'Highland'
A. stolonifera                                         'Penn-A4'
                                                      'Penncross'
SEM ([dagger])
Contrasts ([section])
P. annua vs. Agrostis
P. annua: Ontario vs. Quebec
P. annua: Ontario vs. USA
P. annua: Quebec vs. USA
A. canina vs. A. castellana
A. canina vs. A. stolonifera
A. castellana vs. A. stolonifera
P. annua Quebec vs. Agrostis
P. annua Ontario vs. Agrostis
P. annua USA vs. Agrostis

                                          N uptake ([dagger])

                                   Clipping and
Grass Origin                          shoot        Root    Total

                                       mg N [lysimeter.sup.-1]

P. annua                               72.5        27.7     100
                                       43.6        23.4      67
                                       60.4        30.7      91
                                       30.0        15.7      46
                                       41.3        18.9      60
                                       43.5        19.1      63
                                       57.3        27.2      84
                                       62.1        26.7      89
                                       64.3        34.1      98
                                       52.5        22.2      75
                                       58.4        26.1      84
A. canina                              84.0        36.2     120
A. castellana                          75.6        27.7     106
A. stolonifera                         80.1        28.8     109
                                       71.5        30.0     101
SEM ([dagger])                          2.3         1.0       3.1
Contrasts ([section])                             P value
P. annua vs. Agrostis                 <0.001      <0.001   <0.001
P. annua: Ontario vs. Quebec          <0.001      <0.001   <0.001
P. annua: Ontario vs. USA             <0.001      <0.001   <0.001
P. annua: Quebec vs. USA
A. canina vs. A. castellana             ns        0.026      ns
A. canina vs. A. stolonifera            ns         0.04     0.046
A. castellana vs. A. stolonifera      <0.001      <0.001   <0.001
P. annua Quebec vs. Agrostis          <0.001        ns     <0.001
P. annua Ontario vs. Agrostis         <0.001        ns     <0.001
P. annua USA vs. Agrostis

([dagger]) Tissue N concentration x mg of dry matter produced.

([double dagger]) Standard error of the means, n = 4.

[(section]) Single degree of freedom contrasts.
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Author:Pare, K.; Chantigny, M.H.; Carey, K.; Johnston, W.J.; Dionne, J.
Publication:Crop Science
Geographic Code:1CANA
Date:Mar 1, 2006
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