scholarly journals Soil nitrogen dynamics in canola agroecosystems of eastern Canada

Author(s):  
Leanne Ejack ◽  
Bineeta Gurung ◽  
Philippe Seguin ◽  
Baoluo Ma ◽  
Joann K. Whalen

Canola (Brassica napus L.) is a nitrogen (N)-demanding crop, so tissue N analysis should be related to soil N supply. We evaluated canola N uptake in relation to soil N pools in plots receiving 0, 50, 100 and 150 kg N ha-1 from urea at three sites in eastern Canada in 2012. Soil N pools varied significantly at the rosette, flowering, pod filling and maturity stages, but responded less predictably to urea. Canola N uptake was inconsistently related to soil N pools and urea input. This confirms the importance of site-specific N fertilizer management when growing canola in eastern Canada.

2012 ◽  
Vol 1 (2) ◽  
pp. 257
Author(s):  
Adrien N. Dayegamiye ◽  
Judith Nyiraneza ◽  
Johann K. Whalen ◽  
Michèle Grenier ◽  
Anne Drapeau

<p>Growing soybean (<em>Glycine max L.)</em> prior to corn (<em>Zea mays</em> L) can enhance corn grain and nitrogen (N) use efficiency compared to continuous corn. This two year study (2007-2008) was conducted at 62 sites in Quebec (Eastern Canada) to assess the effect of crop rotations [soybean-corn, soybean-wheat (<em>Triticum aestivum</em> L.,)-corn and corn-corn] on corn yield, N uptake, N fertilizer efficiency (NFE), and the economic optimum N rate (EONR). Plots within each crop rotation received N fertilizer rates from 0 to 250 kg N ha<sup>-1</sup> to assess the N contribution from the preceding soybean crop. Corn grain yields ranged from 8.4 to 10.8 Mg ha<sup>-1</sup> and were lower in continuous corn than in the crop rotations. Corn N uptake and NFE varied from 89 to 164 kg N ha<sup>-1</sup> and from 45 to 80 kg grain per kg N fertilizer, respectively. A significant interaction of crop rotation and year on corn N uptake and NFE was obtained implying that annual variations influenced soil N supply. The EONR for corn was lower under crop rotations than continuous corn in 2008 only. No difference in corn yield, NFE and EONR was observed for soybean-corn and soybean-wheat-corn crop sequences. In conclusion, crop rotations including soybean increased soil N availability and reduced EONR from 32 to 45 kg ha<sup>-1</sup> for corn grown in 2008.</p>


2017 ◽  
Vol 110 (1) ◽  
pp. 71-81 ◽  
Author(s):  
Arne M. Ratjen ◽  
Henning Kage
Keyword(s):  
Soil N ◽  

2020 ◽  
Vol 21 ◽  
pp. e00282
Author(s):  
Thais de Marchi Soares ◽  
Fabricio Silva Coelho ◽  
Vando Braz de Oliveira ◽  
Oscar Pontes ◽  
Paulo Sergio Pavinato

2014 ◽  
Vol 152 (S1) ◽  
pp. 82-95 ◽  
Author(s):  
N. T. MCDONALD ◽  
C. J. WATSON ◽  
R. J. LAUGHLIN ◽  
S. T. J. LALOR ◽  
J. GRANT ◽  
...  

SUMMARYMineralized soil nitrogen (N) is an important source of N for grassland production. Some soils can supply large quantities of plant-available N through mineralization of soil organic matter. Grass grown on such soils require less fertilizer N applications per unit yield. A reliable, accurate and user-friendly method to account for soil N supply potential across a large diversity of soils and growing conditions is needed to improve N management and N recommendations over time. In the current study, the effectiveness of chemical N tests and soil properties to predict soil N supply for grass uptake across 30 Irish soil types varying in N supply potential was investigated under controlled environmental conditions. The Illinois soil N test (ISNT) combined with soil C : N ratio provided a good estimate of soil N supply in soils with low residual mineral N. Total oxidized N (TON) had the largest impact on grass dry matter (DM) yield and N uptake across the 30 soil types, declining in its influence in later growth periods. This reflected the high initial mineral N levels in these soils, which declined over time. In the current study, a model with ISNT-N, C : N and TON (log TON) best explained variability in grass DM yield and N uptake. All three rapid chemical soil tests could be performed routinely on field samples to provide an estimate of soil N supply prior to making N fertilizer application decisions. It can be concluded that these soil tests, through their assessment of soil N supply potential, can be effective tools for N management on grassland; however, field studies are needed to evaluate this under more diverse growing conditions.


2011 ◽  
Vol 91 (4) ◽  
pp. 493-501 ◽  
Author(s):  
K. Liu ◽  
A. M. Hammermeister ◽  
P. R. Warman ◽  
C. F. Drury ◽  
R. C. Martin

Liu, K., Hammermeister, A. M., Warman, P. R., Drury, C. F. and Martin, R. C. 2011. Assessing soil nitrogen availability in contrasting cropping systems at the end of transition to organic production. Can. J. Soil Sci. 91: 493–501. Quantifying soil nitrogen (N) availability at the end of a transition period for converting conventional fields to organic fields could enhance N management during the subsequent organic crop production phase. Soil total N (Ntot), KCl extractable N (KCl N) and potentially mineralizable N (No) were determined at the end of a 3-yr transition period. A complementary greenhouse ryegrass N bioassay was conducted using soils collected from the treated field plots. The field experiment consisted of six cropping systems comprising two N inputs (legume-based vs. manure-based) and three forage cropping treatments (0, 1 or 2 yr of forage in 4-yr rotations). The N input treatments consisted of alfalfa meal in the legume-based cropping system (LBCS) and composted beef manure in the manure-based cropping system (MBCS). Orthogonal contrasts suggested no differences in Ntot or KCl N either between LBCS and MBCS or between no-forage and forage cropping systems. However, in the greenhouse study, high cumulative N inputs in the MBCS resulted in significantly higher ryegrass N uptake and potentially mineralizable soil N than in the LBCS. Ryegrass N uptake ranged from 101 to 139 kg ha−1, which should be an adequate N supply for the succeeding potato crop. In the greenhouse, a ryegrass N bioassay effectively identified the differences in soil N availability. Ryegrass N uptake was linearly related to cumulative soil amendment N inputs but had no apparent relationship with N o. A systems approach provided a good assessment of N availability at the end of the transition period to organic production.


1987 ◽  
Vol 67 (3) ◽  
pp. 521-531 ◽  
Author(s):  
M. GIROUX ◽  
T. SEN TRAN

The objective of this study was to compare several methods of estimating the availability of soil nitrogen to plants. Total soil N, organic matter content, mineralized N during a 2 wk incubation at 35 °C, organic N in 6 N HC1, 0.01 M NaHCO3 and 1 N KCl extracts, and finally mineral N extracted by 2 N KCl were evaluated and contrasted with N uptake by sugar beets cultivated on 19 soils in a greenhouse experiment. The relative yield or plant N uptake gave the highest correlation coefficients when both mineral and organic N fractions in soil extract were considered. The incubation methods gave the best correlation coefficient with relative yield (R2 = 0.85**). N contents in NaHCO3 extract were more correlated with relative yield or N uptake than total N, organic matter contents or N extracted by 6 N HCl or 1 N KCl. The UV absorbance values obtained at 205 nm with 0.01 M NaHCO3 extract were also well correlated with relative yield (R2 = 0.78**) and plant N uptake (R2 = 0.66**). At this wavelength, as well as at 220 nm, the absorbance was affected by mineral and organic N contents in the extract. However, at 260 nm, the UV absorbance was only related to organic N in the extract; consequently these absorbance values were less correlated with relative yield (R2 = 0.49**) or N uptake (R2 = 0.27*). Furthermore, the absorbance measured at 205 nm was too sensitive to NO3-N and organic N concentration and this relationship was not linear in the high-N concentration range. The UV absorbance at 220 nm in the 0.01M NaHCO3 extract seemed to be a promising method to evaluate the availability of soil N. Key words: Soil nitrogen, incubation, ultraviolet absorbance, hydrolyzable nitrogen


2015 ◽  
Vol 24 (3) ◽  
pp. 433 ◽  
Author(s):  
Jian-jian Kong ◽  
Jian Yang ◽  
Haiyan Chu ◽  
Xingjia Xiang

Both topography and wildfire can strongly affect soil nitrogen (N) availability. Although many studies have examined the individual effects of fire and topography on N, few have investigated their combined influences and relative importance. In this study, we measured soil extractable inorganic N concentrations, N mineralisation rates, and in situ soil inorganic N supply rates at 36 plots in three topographic positions (north-facing, south-facing and flat valley bottom) of burned and unburned sites in a boreal larch forest of northeastern China. Our data showed that wildfire significantly increased soil N availability, with mean soil extractable inorganic N concentrations, N mineralisation rates and N supply rates being 63, 310 and 270% higher in the burned site 1 year following fire. Additionally, soil N availability in the unburned site was significantly greater on the north-facing slope than on the south-facing slope, though this pattern was reversed at the burned site. Wildfire and topography together explained ~50% of the variance in soil N availability, with wildfire explaining three times more than topography. Our results demonstrate that wildfire and topography jointly affected spatial variations of soil N availability, and that wildfire decreased the influence of topography in the early successional stage of this boreal larch ecosystem.


2004 ◽  
Vol 34 (3) ◽  
pp. 754-761 ◽  
Author(s):  
Ryan D Hangs ◽  
Ken J Greer ◽  
Catharine A Sulewski

During the early establishment phase, outplanted white spruce (Picea glauca (Moench) Voss) and jack pine (Pinus banksiana Lamb.) seedlings are vulnerable to lethargic growth or mortality because of interspecific competition for soil nutrients, particularly N. Accurately quantifying the degree of N competition is essential for supporting effective vegetation management (VM) decisions. This study evaluated the use of in situ burials of ion-exchange membrane (IEM; Plant Root SimulatorTM-probes) for quantifying differences in soil N supply rate between different VM treatments and the relationship of this N availability index to early growth of conifer seedlings at four boreal forest sites. At most sites, the effect of noncrop N uptake on soil N availability was apparent, with smaller NH4+-N, NO3–-N, and total dissolved inorganic N (DIN) supply rates in control plots than in VM plots. Total DIN supply rate was correlated (R2 = 0.60 to 0.73, P < 0.01) with seedling height, root-collar diameter, and stem volume growth. Ammonium-N supply rate was better correlated than NO3–-N supply rate with conifer seedling growth, which is in agreement with preferential NH4+-N uptake by conifer species. The results of this study support the use of in situ burials of IEM for measuring soil N availability during the early establishment phase.


1998 ◽  
Vol 49 (3) ◽  
pp. 487 ◽  
Author(s):  
W. J. McGhie ◽  
D. P. Heenan ◽  
D. Collins

Soil nitrogen (N), N uptake, and wheat production in relation to rotation with wheat, lupin,or subterranean clover, mulched or grazed, were examined on a red earth at Wagga Wagga, New South Wales. Data over 4 years (1992{95) are presented from a long-term trial commenced in 1979. The effects of the various rotations on wheat productivity changed with seasonal rainfall duringthe wheat and the previous legume growing year. Generally, low rainfall (1991 and 1994) during thelegume growing season resulted in lower N uptake, grain protein, and grain yield by wheat grown ina following season. The addition of N fertiliser (100 kg N/ha) to continuous wheat increased soil N supply, N uptake, grain yield, and grain protein. Yields from continuously cropped wheat fertilisedwith N were usually lower than those after a lupin growing season, although total soil N levels weresimilar. Subterranean clover produced higher total soil N and grain protein than lupin but yields werenormally less. Lodging and take-all diseases were higher after a growing season with subterraneanclover than after lupins and most likely reduced grain yields. Grazing, as opposed to mowing andmulching subterranean clover, increased soil total N, grain protein, and usually soil mineral N, butnot grain yield. The addition of lime at 1·5 t/ha raised the soil pH(CaCl2) (0-10 cm) of the mostacidified treatment, continuously cropped wheat fertilised with N, from 4·04 to a mean of 4·7, andincreased yields and N uptake in 1993 and 1995.


2009 ◽  
Vol 89 (2) ◽  
pp. 113-132 ◽  
Author(s):  
B J Zebarth ◽  
C F Drury ◽  
N Tremblay ◽  
A N Cambouris

There is increasing public pressure to reduce the environmental impacts of agricultural production. Therefore, one key challenge to producers is to manage their crop production systems in order to minimize losses of nitrogen to air or water, while achieving crop yield and quality goals. Many strategies have been developed in recent years to meet this challenge. These include: development of new tools to measure crop N status in order to refine in-season fertilizer N management, development of new soil N tests to improve prediction of soil N supply, development of new fertilizer N products with release patterns more closely matched to crop N uptake patterns, and development of site-specific N management strategies. We review the opportunities and limitations to these new strategies within different arable crop production systems under the humid and sub-humid soil moisture regimes present in eastern Canada. Future research opportunities to improve the efficiency of fertilizer N utilization include development of practical methods to predict the magnitude of soil N mineralization; refinement of decision-making processes which take into consideration the crop N status and soil properties as a basis for variable rate fertilizer N application; development of affordable controlled-release fertilizer N products with improved N release characteristics; development of practical methods for capturing and recycling nutrient-laden drainage water; development of gene expression profiling based techniques to identify crop N stress; and application of crop genomics and molecular breeding techniques to accelerate the development of new cultivars with increased N use efficiency. Key words: Soil N tests, plant N tests, nitrogen fertilizers, nitrogen cycling


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