Nitrogen pools and processes in agricultural systems of Coastal British Columbia — A review of published research

2000 ◽  
Vol 80 (1) ◽  
pp. 1-10 ◽  
Author(s):  
C. G. Kowalenko

A significant amount of research on nitrogen (N) dynamics has been conducted within the past 20 yr in south coastal British Columbia. This succinct set of data has practical and environmental information on N cycling particularly focusing on gains to and losses from agricultural fields, and transformations of soil N pools. Coastal British Columbia fields have received large annual additions by application of fertilizer and manure. Some of the manure N from animals using locally grown forages is recycled within the farm operation, but a large amount of N is imported as feed especially for intensive animal production. Budget calculations estimated that there may be substantial losses of N through volatilization from manure, particularly from housing and storage areas, and during application to fields. Some of the volatilized ammonia in holding areas may be recycled to fields via precipitation. Direct measurements of these losses and returns of N have not been made. Studies have shown that there is limited risk of leaching of nitrate beyond the root zone during the growing season because most of the annual rainfall occurs over the winter and because nitrate can be adsorbed to soil particles. However, any extractable inorganic N (nitrate directly and ammonium after nitrification) in the profile at the end of the growing season will be lost over the winter. Most of that loss is due to nitrate leaching, but conditions are also favorable for denitrification. There is considerable (> 200 mg N k−1 in some soils) ammonium-N fixed in Fraser Valley soils, but the impact of this phenomenon to crop growth is still poorly understood. Wetting and drying cycles have a great influence on the dynamics of this pool of soil N. The response of spring growth of grass to the time of N application was influenced by the relative competitiveness of microorganisms and plants for available soil N. A study comparing short-season (broccoli) and long-season (sweet corn) crop responses to N applications showed that the rate at which the plants require N influences their response to N amendments. Raspberries were found to require relatively small quantities of N on a land area basis because of the wide inter-row distances. An autumn soil nitrate test has been proposed for making fertilizer N recommendations for raspberries. Although knowledge gained from this research has provided a basis for interpreting studies for the development of N management practices and for making interim recommendations, a method to predict the amount of N mineralized from soil organic matter is key to the development of soil-analysis-based N rate recommendations. Key words: N cycling, nitrate, ammonium, fixed ammonium, soil organic N, mineralization

Nitrogen ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 137-150
Author(s):  
Jacynthe Dessureault-Rompré ◽  
Alexis Gloutney ◽  
Jean Caron

Vegetable crop production, which is expanding worldwide, is managed extremely intensively and is therefore raising concerns about soil degradation. The objective of this study was to analyze the impact of using rye mulch as a conservation practice on nutrient availability for lettuce grown in histosols. The rye cover crop was established in the fall of 2018 at two cultivated peatland sites. The following summer, lettuce crops were planted at both sites on the rye mulch cover and on control plots. Lysimeters were used to extract the soil solution once a week during lettuce growth. Various soil properties were analyzed in the soil sampled at the end of the lettuce growing season. The rye yield was higher at site 1 than at site 2 and the lettuce growth was reduced at site 1 under the rye mulch treatment. The rye mulch reduced mineral N and dissolved organic N availability at both sites. The N dynamics in histosols might be fast enough to supply the lettuce needs; however, the implantation difficulties must first be overcome to confirm that hypothesis. At the end of the lettuce growth period, soil total and active C pools and soluble organic soil N in the rye mulch treatment sample were significantly higher at site 1 than at site 2. The presence of rye mulch improved the carbon pool over a single growing season. The use of rye mulch as a soil conservation practice for vegetable crop production appears promising for histosols; however, more work is needed to gain a better understanding on the long-term effects of decomposing rye mulch and roots on soil nutrient availability, soil health and C sequestration, and on the nitrogen uptake pathways and growth of cash crops. Future works which would include consecutive years of study at multiple sites are also needed to be able to confirm and generalize the observations found in the present work.


1994 ◽  
Vol 74 (4) ◽  
pp. 443-451 ◽  
Author(s):  
A. A. Bomke ◽  
W. D. Temple ◽  
S. Yu

Winter wheat, Triticum aestivum, is a new crop in south coastal British Columbia. The purposes of this study were to characterize plant development, dry matter accumulation and N uptake under low input and intensively managed systems as well as to assess the capability of some of the region’s soils to supply N to the crop. Grain yields, crop development and dry matter and N accumulation were similar to those reported from southern England. High amounts of winter rainfall (November–April precipitation ranged from 523 to 1111 mm) leach virtually all residual NO3 from south coastal B.C. soils and, without N fertilization, result in uniformly N deficient winter wheat. The low input N regime, 75 kg N ha−1 at Zadoks growth stage 31, plus soil N mineralized subsequent to the winter leaching period were sufficient in this study to maximize grain and total aboveground crop dry matter yields, but not to achieve adequate grain protein contents. The soils in the study were capable of supplying N in amounts sufficient to support only 30–53% of the maximum N uptake between growth stages 31 and 78. Appropriate quantities and timing of N are critical to successful production of high-yielding, good-quality wheat in south coastal British Columbia. Nitrogen management is likely to be most efficient when guided by the stage of crop development and demand and not by spring soil sampling and mineral N analysis. Key words: Winter wheat, N demand, soil N supply, crop development, intensive crop management, low input


1990 ◽  
Vol 20 (10) ◽  
pp. 1583-1592 ◽  
Author(s):  
Caroline M. Preston ◽  
Valin G. Marshall ◽  
Kevin McCullough ◽  
Donald J. Mead

Fertilizer was applied on snow in January 1981 at 100 kg N•ha−1 as [15N]urea, 15NH4NO3, and NH415NO3 to 11-year-old lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) at Spillimacheen in the British Columbia interior and as [15N]urea (200 kg N•ha−1) to 13-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) at Green Mountain, a coastal site in British Columbia. Recovery of labelled N after one growing season was determined in soil and biomass at both sites, and it was also monitored during the growing season in snow and soil at Spillimacheen. At Green Mountain, 5.5% of urea N was recovered in tree biomass, 10.8% in understory, and 33.4% in soil organic N (total recovery 49.7%). Leaching may have contributed to N losses at Green Mountain, but was probably not a direct consequence of the application on snow. At Spillimacheen, total recovery of [15N]urea was 93.3%, with 10.1% in tree biomass, 2.4% in understory, and 80.8% in soil. For 15NH4NO3, recoveries were 5.3% in tree biomass, 2.9% in understory, and 87.0% in soil, for a total of 95.2%. For NH415NO3, recoveries were 1.9% in tree biomass, 3.4% in understory, and 39.1% in soil, for a total of 44.4%. At Spillimacheen, the performance of 15NH4NO3 was comparable to that of urea in tree uptake and soil retention. There were large losses with the NH415NO3 source, however, most likely due to leaching and denitrification during snowmelt. For this reason, fertilization with nitrate on snow is not recommended because of nitrate's susceptibility to leaching, but urea and ammonium sources may be applied under these conditions.


2001 ◽  
Vol 16 (1) ◽  
pp. 26-30 ◽  
Author(s):  
K.D. Thomas ◽  
W.J. Reid ◽  
P.G. Comeau

Abstract This study was initiated in 1995 to gather information on the effectiveness of opaque polyethylene mats and glyphosate herbicide treatment on growth and yield of hybrid poplar plantations on south coastal British Columbia. Immediately after planting 40 cm tall hybrid poplar cuttings, 60 × 60 cm opaque polyethylene mats were installed. All treatment plots were mechanically cultivated in one direction twice yearly from 1995 to 1997. This practice left an uncultivated strip between trees running in the same direction as the cultivation. The uncultivated strip was approximately 1 m wide, and represented approximately one-third (0.04 ha) of the total plot area (0.13 ha). Glyphosate was applied at a rate of 2.1 kg active ingredient (ai)/ha in water to the uncultivated strips in the herbicide treatment plots in midsummer of the second and third growing seasons. The opaque polyethylene mats significantly improved poplar height growth only for the first growing season. After four growing seasons, hybrid poplars treated with glyphosate were significantly taller (983 cm) than those in either the mat (915 cm) or control treated plots (902 cm). Diameter at breast height (dbh) was also significantly greater in the herbicide treated plots (88 mm) than in either the mat (78 mm) or control (77 mm) treated plots. Total volume was also significantly greater in herbicide plots (23 ³/ha) than in either the mat (17 m³/ha) or control (17 m³/ha) plots. Basal area and total volume were 14% and 37%, respectively, greater in the herbicide plots than in the mat and control plots following the fourth growing season. West. J. Appl. For. 16(1):26–30.


2021 ◽  
Author(s):  
Neus Otero ◽  
Mathieu Sebilo ◽  
Bernhard Mayer ◽  
Daren Gooddy ◽  
Dan Lapworth ◽  
...  

<p>Stable isotope fingerprinting is widely applied to plant-soil-groundwater systems in an aim to identify and even quantify the sources of nitrates found in groundwater. Frequently, in such studies, the <em>δ</em><sup>15</sup>N and <em>δ</em><sup>18</sup>O values of nitrogen sources, such as inorganic fertilizers and manure, are directly compared to the isotope signatures of nitrate encountered in groundwater bodies below agricultural watersheds. We submit that the underlying assumptions (conservative behavior of isotope composition, rapid transfer from surface to groundwater) may only be realistic under very specific conditions whereas, in most cases, significant isotope effects exerted by the soil-microbial-plant system on the <em>δ</em><sup>15</sup>N and <em>δ</em><sup>18</sup>O values of nitrate need to be taken into account when attempting a quantitative apportionment of sources of groundwater nitrate.</p><p>We hypothesise that the isotopic signature of nitrate exported from below the root zone and migrating towards the groundwater will reflect the nitrogen isotope composition of the soil organic N pool, rather than the isotope composition of source fertilizer or organic amendments, due to processes that reset source isotope compositions within soil N pools. We test this hypothesis using empirical observations from a diversity of settings, in France, Spain and Canada with a relatively constant historic anthropogenic N source or a simple and well constrained landuse history. Furthermore, through the use of a process-based model (SIMSONIC, Billy et al., 2010) we estimate to what extent the isotopic composition of the predominant N input to the soil-microbial-plant system and the soil N pool has been modified in an attempt to consider these changes in source apportionment studies elucidating the sources of groundwater nitrate.</p><p>This research was supported through the Consortium award MUTUAL, by the LE STUDIUM® Loire Valley Institute for Advanced Studies via its SMART LOIRE VALLEY (SLV) fellowship programme, co-funded by the H2020 Marie Sklodowska-Curie programme, Contract No. 665790.</p><p> </p><p>Billy C., Billen G., Sebilo M., Birgand F., Tournebize J. (2010) Nitrogen isotopic composition of leached nitrate and soil organic matter as an indicator of denitrification in a sloping drained agricultural plot and adjacent uncultivated riparian buffer strips. Soil Biology and Biochemistry, 42, 108-117.</p>


1997 ◽  
Vol 75 (5) ◽  
pp. 799-814 ◽  
Author(s):  
Marlow G. Pellatt ◽  
Rolf W. Mathewes ◽  
Ian R. Walker

Surficial sediment samples from 42 lakes, distributed from sea level to alpine elevations of coastal British Columbia and northwest Washington, were analyzed for pollen and spores. Pollen analysis revealed characteristic differences among the assemblages of the Coastal Western Hemlock, Mountain Hemlock, and Engelmann Spruce – Subalpine Fir biogeoclimatic zones (the Alpine zone is less clearly identifiable). Cluster analysis and detrended correspondence analysis (DCA) correctly group the sites according to their biogeoclimatic zones and also by geographic origin. DCA indicates a high correlation between the biogeoclimatic zones of the sample sites and annual precipitation (−0.89), January temperature (−0.77), annual temperature (−0.64), and growing-season precipitation (−0.68). Further analysis of the samples and eight environmental gradients using canonical correspondence analysis groups the pollen assemblages from the study sites into biogeoclimatic zones in relation to annual precipitation, growing-season precipitation, annual snowfall, annual temperature, and growing degree-days. These data are useful for testing whether or not postglacial pollen assemblages have modern analogues. Key words: modern pollen analysis, vegetation, ordination, multivariate statistical analysis, biogeoclimatic zones, British Columbia.


1986 ◽  
Vol 16 (1) ◽  
pp. 36-41 ◽  
Author(s):  
R. E. Carter ◽  
A. M. Scagel ◽  
K. Klinka

Nutritional problems, deficiencies of B and Zn in particular, have been tentatively identified as the cause of specific distorted growth symptoms in several young stands of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), western hemlock (Tsugaheterophylla (Raf.) Sarg.), and Pacific silver fir (Abiesamabilis (Dougl.) Forbes) in southwestern coastal British Columbia. The most common symptoms associated with these apparent micronutrient deficiencies include leader dieback and discolouration, multileadered and bushy crowns, and, in severely deficient trees, swollen and distorted stems. Visual symptoms of apparent B deficiency become obvious when foliar concentrations are <5.0 ppm; visual symptoms of apparent Zn deficiency are less easily recognized, usually occurring when foliar Zn levels are less than approximately 9.0 ppm. Low foliar concentrations of B were often associated with low levels of Ca and Mg. Foliar B concentration was also correlated with total foliar S. Temporal variation in foliar nutrient levels, examined over 3 years, was quite high with an apparent strong relationship to growing season precipitation. This suggests that deficiencies of B and (or) Zn may be acute rather than chronic, with the appearance of periodic acute deficiencies being influenced by growing season soil moisture supply.


2021 ◽  
Author(s):  
Greta Formaglio ◽  
Edzo Veldkamp ◽  
Muhammad Damris ◽  
Aiyen Tjoa ◽  
Marife D. Corre

AbstractIntensive management practices in large-scale oil palm plantations can slow down nutrient cycling and alter other soil functions. Thus, there is a need to reduce management intensity without sacrificing productivity. The aim of our study was to investigate the effect of management practices on gross rates of soil N cycling and soil fertility. In Jambi province, Indonesia, we established a management experiment in a large-scale oil palm plantation to compare conventional practices (i.e. high fertilization rates and herbicide weeding) with reduced management intensity (i.e. reduced fertilization rates and mechanical weeding). Also, we compared the typical management zones characterizing large-scale plantations: palm circle, inter-row and frond-stacked area. After 1.5 years of this experiment, reduced and conventional management showed comparable gross soil N cycling rates; however, there were stark differences among management zones. The frond-stacked area had higher soil N cycling rates and soil fertility (high microbial biomass, extractable C, soil organic C, extractable organic N, total N and low bulk density) than inter-row and palm circle (all p ≤ 0.05). Microbial biomass was the main driver of the soil N cycle, attested by its high correlation with gross N-cycling rates (r = 0.93–0.95, p < 0.01). The correlations of microbial N with extractable C, extractable organic N, soil organic C and total N (r = 0.76–0.89, p < 0.01) suggest that microbial biomass was mainly regulated by the availability of organic matter. Mulching with senesced fronds enhanced soil microbial biomass, which promoted nutrient recycling and thereby can decrease dependency on chemical fertilizers.


2021 ◽  
Author(s):  
Xiang Zheng ◽  
Qi Liu ◽  
Minmin Cao ◽  
Xiaofang Ji ◽  
Jianbing Lu ◽  
...  

Abstract BackgroundContinuous increasing nitrogen (N) deposition interferes with soil nitrogen cycle of forests, which highly impacts soil N2O emissions and accelerates global warming. Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) is one of the most widely planted species in southern China which locates in the high N deposition area. However, the impact of N deposition on soil N2O emissions in subtropical Chinese fir plantations and the potential risk of increasing N deposition still remain elusive. Here, we conducted an in situ study in a subtropical Chinese fir plantation at Fengyang Mountain Nature Reserve, China, from 2019-2020 with four different levels of N enrichment: control (CK: ambient N deposition), low-N (LN: 50 kg N ha−1 yr−1), medium-N (MN: 100 kg N ha−1 yr−1), and high-N (HN: 200 kg N ha−1 yr−1). ResultsWe found that soil N2O emission rates increased with N enrichment from an average of 5.89 ± 3.66 to 20.11 ± 3.44 μg N m−2 h−1. The N enrichment in general showed no significant effect on the abundance of nitrate-reducing bacteria, but it tended to raise the abundance of ammonia oxidizing archaea and bacteria, and to decrease the abundance of N2O-reducing bacteria, which likely provided the microbial basis for accelerating soil N2O emissions along with increasing N deposition. However, the relationship of soil N2O emissions with N input did not match an exponential increase, but it matched a logarithmic increase, illustrating that the risk of increasing N deposition on soil N2O emissions was attenuated. It is found that N enrichment significantly decreased soil moisture and tended to increase the fir leaf N concentrations and soil CO2 emission rates. Besides, soil microbial biomass was significantly suppressed by N enrichment during the mid-growing season, while not in end of growing season. These may suggest that N enrichment stimulated plant growth with more N and water uptake, which competed with microorganisms for N and therefore alleviated further increasing N2O emissions under N enrichment. ConclusionThis study deepen our understanding of the impacts of increased N deposition on the greenhouse gas (GHG) balance in the Chinese fir plantations, and highlight that plants need to be incorporated as an important explanatory variable when predicting GHG fluxes in the background of global increasing N deposition.


2015 ◽  
Vol 2 (2) ◽  
pp. 1135-1160
Author(s):  
A. F. Charteris ◽  
T. D. J. Knowles ◽  
K. Michaelides ◽  
R. P. Evershed

Abstract. A compound-specific nitrogen-15 stable isotope probing (15N-SIP) technique is described which allows investigation of the fate of inorganic- or organic-N amendments to soils. The technique uses gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) to determine the δ15N values of individual amino acids (AAs; determined as N-acetyl, O-isopropyl derivatives) as proxies of biomass protein production. The δ15N values are used together with AA concentrations to quantify N assimilation of 15N-labelled substrates by the soil microbial biomass. The utility of the approach is demonstrated through incubation experiments using inorganic 15N-labelled substrates ammonium (15NH4+) and nitrate (15NO3-) and an organic 15N-labelled substrate, glutamic acid (15N-Glu). Assimilation of all the applied substrates was undetectable based on bulk soil properties, i.e. % total N (% TN), bulk soil N isotope composition and AA concentrations, all of which remained relatively constant throughout the incubation experiments. In contrast, compound-specific AA δ15N values were highly sensitive to N assimilation, providing qualitative and quantitative insights into the cycling and fate of the applied 15N-labelled substrates. The utility of this 15N-AA-SIP technique is considered in relation to other currently available methods for investigating the microbially-mediated assimilation of nitrogenous substrates into the soil organic N pool. This approach will be generally applicable to the study of N cycling in any soil, or indeed, in any complex ecosystem.


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