Effects of nitrogen addition on soil inorganic N content and soil N mineralization of a cold-temperate coniferous forest in Great Xing'an Mountains

2015 ◽  
Vol 35 (5) ◽  
pp. 130-136 ◽  
Author(s):  
Wenlong Gao ◽  
Wei Zhao ◽  
Hao Yang ◽  
Haijun Yang ◽  
Gaoqi Chen ◽  
...  
Keyword(s):  
N Mineralization ◽  
Coniferous Forest ◽  
Nitrogen Addition ◽  
Soil N ◽  
Inorganic N ◽  
N Content ◽  
Soil N Mineralization ◽  
Great Xing’An Mountains ◽  
Soil Inorganic N ◽  
Soil Inorganic

scholarly journals Effect of soil covering on nitrogen availability of vineyards soils in Champagne area

OENO One ◽  
2005 ◽  
Vol 39 (4) ◽  
pp. 163
Author(s):  
Pascal Thiebeau ◽  
Christian Herré ◽  
Anne-France Doledec ◽  
André Perraud ◽  
Laurent Panigai ◽  
...  
Keyword(s):  
Organic Matter ◽  
N Mineralization ◽  
Farmyard Manure ◽  
N Availability ◽  
Soil N ◽  
Inorganic N ◽  
Growing Period ◽  
Soil Inorganic N ◽  
Soil Inorganic

<p style="text-align: justify;">We studied the effect of soil cover (bare soil, mulch of barks or composted organic materials, grass cover) on soil N dynamics in various experimental vineyards located in Champagne area (France). Soil cores were sampled periodically to measure water and mineral N in soil profile during autumn and winter. These measurements were used in a simple dynamic model (LIXIM) to calculate nitrate leaching and N mineralization. N mineralization potential of soils were also determined in laboratory incubations in controlled conditions. In most sites, soil inorganic N contents (0-75 cm) varied between 20 and 60 kg N ha-1, depending of the season. Soil inorganic N in plots receiving barks or composted barks or covered with grass did not differ significantly from control plots. Higher amounts of inorganic N were found in soils amended with refuse compost, peat or mixed compost (barks + farmyard manure) or composted farmyard manure. The model indicated that N leached varied from 8 to 77 kg N ha-1 and that the mean nitrate concentration in drained water was less than 50 mg NO3- L-1 except for plots receiving refuse compost or bark + farmyard manure compost. The calculated N mineralization varied from 9 to 45 kg N ha-1 over the autumn-winter period, i.e. 118 to 182 days. The N mineralization rate (Vp), expressed per 'normalised day' i.e. day at 15°C and field capacity, varied from 0.15 to 0.82 kg N ha-1 nd-1, including all sites and experimental treatments. Effect of organic matter addition on Vp was only observed for long-term experimental sites where large amounts of organic nitrogen had been added to soil using peat, refuse compost or compost mixtures with barks and farmyard manure. The Vp values measured in laboratory incubations showed the same trends and were in the same order of magnitude than those calculated with LIXIM model using in situ data. In average, the values measured in laboratory incubations underestimated the actual N mineralization in field conditions. The model was used to predict N mineralization and inorganic N in soil during the vegetative period using Vp values. It allowed to estimate the N uptake by vine: 10 ± 5 kg N ha-1 at flowering and 57 ± 5 kg N ha-1 over the whole growing period. These results show that soil N availability was sufficient to feed the vine during the whole growing period and that no inorganic N fertilisation was necessary, even in the grass covered soil. In this soil, water availability is probably the limiting factor when depressive effects are observed. On the long-term, it is necessary to manage the amount and quality of added organic matter since organic inputs may modify N availability and therefore vine behaviour, wine quality and environmental risks.</p>

scholarly journals The effect of long-term CO2 enrichment on carbon and nitrogen content of roots and soil of natural pastureland

2021 ◽  
Vol 48 (2) ◽  
pp. 180-190
Author(s):  
Manal Al-Traboulsi ◽  
Brian Wilsey ◽  
Catherine Potvin
Keyword(s):  
N Mineralization ◽  
Co2 Enrichment ◽  
Net N Mineralization ◽  
Soil N ◽  
N Content ◽  
Total N ◽  
Soil C ◽  
Soil N Mineralization ◽  
C And N ◽  
The Impact

Abstract Increasing levels of atmospheric CO2 may change C and N dynamics in pasture ecosystems. The present study was conducted to examine the impact of four years of CO2 enrichment on soil and root composition and soil N transformation in natural pastureland. Plots of open-top growth chambers were continuously injected with ambient CO2 (350 µL L–1) and elevated CO2 (625 µL L–1). Soil cores exposed to ambient and elevated CO2 treatment were incubated and collected each year. Net N-mineralization rates in soil (NH4 +-N plus NO3ˉ–-N), in addition to total C and N content (%) of soil and root tissues were measured. Results revealed that elevated CO2 caused a significant reduction in soil NO3 (P < 0.05), however, no significant CO2 effect was found on total soil C and N content (%). Roots of plants grown under elevated CO2 treatment had higher C/N ratios. Changes in root C/N ratios were driven by changes in root N concentrations as total root N content (%) was significantly reduced by 30% (P < 0.05). Overall, findings suggest that the effects of CO2 enrichment was more noticeable on N content (%) than C content (%) of soil and roots; elevated CO2 significantly affected soil N-mineralization and total N content (%) in roots, however, no substantial change was found in C inputs in CO2-enriched soil.

Whole-season grass response to and recovery of nitrogen applied at various rates and distributions in a high rainfall environment

1998 ◽  
Vol 78 (3) ◽  
pp. 445-451 ◽  
Author(s):  
S. Bittman ◽  
C. G. Kowalenko
Keyword(s):  
Crude Protein ◽  
Forage Yield ◽  
Soil N ◽  
Inorganic N ◽  
High Rainfall ◽  
Yield And Quality ◽  
Soil Inorganic N ◽  
Herbage Yield ◽  
Nitrate Concentrations ◽  
Soil Inorganic

High rates of nitrogen (N) fertilizer are often used on perennial grass in the coastal region of British Columbia and the Pacific Northwest, but there is little information on optimum rates for abundant high-quality yields and on their environmental implications. A field trial was conducted in each of 3 yr to determine the effect of rates and distributions of N on whole-season herbage yield and quality, and pre- and post-season extractable inorganic N in the soil. Yearly rates were 100, 200 and 400 kg N ha−1 applied to each of four cuts in the following distributions: 1.00/0/0/0, 0.50/0.25/0.25/0 and 0.25/0.25/0.25/0.25. Whole-season yield was increased by increasing rates of N in all three trials, but the increase varied from 17% (Trial 1) to 127% (Trial 3). Distributing the N uniformly through the season resulted in only a 5% increase in yield compared with applying all of the N at the beginning of the season. Rate of N had a substantial effect on average herbage crude protein and nitrate concentrations, but the distribution effect was greater on herbage N constituents than on yield. Increasing rates of N consistently increased average herbage nitrate concentrations, and crude protein in two of three trials. Applying all of the N at the beginning of the season increased average herbage crude protein and nitrate concentrations more than distributing it evenly through the season. Extractable inorganic N in the soil at the end of the season increased only at 400 kg N ha−1 rate and was not affected by distribution. Although distribution pattern influenced herbage yield and nitrogen concentrations, distribution did not influence total herbage N uptake or recovery in herbage plus soil. Rates and distributions of N on grass influenced herbage yield and quality, and soil extractable inorganic N in different ways; therefore, compromises in N management are required to optimize forage yield and quality, and soil nitrate concentrations. Autumn soil inorganic N testing may be useful as feedback information for fertilizer recommendations in the subsequent season. Spring soil inorganic N testing was a poor predictor of crop response to fertilizer in the high rainfall environment of the study. Key words: Nitrogen, plant crude protein, plant nitrate, forage yield, forage quality, apparent N recovery, residual soil N, soil N test

scholarly journals Abiotic versus biotic controls on soil nitrogen cycling in drylands along a 3200 km transect

2016 ◽  
Author(s):  
Dongwei Liu ◽  
Weixing Zhu ◽  
Xiaobo Wang ◽  
Yuepeng Pan ◽  
Chao Wang ◽  
...  
Keyword(s):  
Arid Zone ◽  
N Cycling ◽  
Mean Annual Precipitation ◽  
N Availability ◽  
Soil N ◽  
Inorganic N ◽  
N Transformations ◽  
Soil Inorganic N ◽  
Soil Inorganic ◽  
Biotic Controls

Abstract. Nitrogen (N) cycling of drylands under changing climate is not well understood. Our understanding about N cycling over larger scales to date relies heavily on the measurement of bulk soil N, and the information about soil internal N transformations remains limited. The 15N natural abundance (δ15N) of ammonium and nitrate can serve as a proxy record for the N processes in soils. To better understand the patterns and mechanisms of water availability on soil N cycling in drylands, we collected soils along a 3200 km dryland transect at about 100 km intervals in northern China, with mean annual precipitation (MAP) from 36 mm to 436 mm. We analysed N pools and δ15N of ammonium, dual isotopes (15N and 18O) of nitrate, and the microbial gene abundance associated with soil N transformations. We found that the N status and their driven factors were different on the two sides of MAP = 100 mm. In the arid zone with MAP below 100 mm, soil inorganic N accumulated, with a large fraction being of atmospheric origin. Ammonia volatilization was strong because of the higher soil pH. The abundance of microbial genes associated with soil N transformations was also significantly low. In the semiarid zone with MAP above 100 mm, soil inorganic N concentrations were low and controlled mainly by biological processes, e.g., plant uptake and denitrification. The preference of soil ammonium to nitrate by the dominant plant species may enhance the possibility of soil nitrate loss via denitrification. Overall, our study suggest that the shifting from abiotic to biotic controls on soil N biogeochemistry under global climate changes would greatly affect N losses, soil N availability, and other N transformation processes in these drylands in China.

Nitrogen release from field pea residues and soil inorganic N in a pea-wheat crop rotation in northwestern Canada

2009 ◽  
Vol 89 (2) ◽  
pp. 239-246 ◽  
Author(s):  
N. Z. Lupwayi ◽  
Y. K. Soon
Keyword(s):  
N Mineralization ◽  
Block Design ◽  
Wheat Crop ◽  
Net N Mineralization ◽  
Inorganic N ◽  
Rhizobium Inoculation ◽  
Soil Inorganic N ◽  
N Release ◽  
Over Time ◽  
Soil Inorganic

Pea (Pisum sativum L.) varieties can differ in morphology, N2 fixation and straw N content. A study was conducted over 3 site-years to evaluate the influence of pea variety and inoculation with Rhizobium on N release from decomposing pea residues. The litterbag technique was used to measure N release over a 52-wk period starting from the time of pea harvest in one season through part of the following season when wheat was grown. Experimental treatments comprised factorial combinations of three pea varieties and either inoculation with 5 kg ha-1 of a granular inoculant or none, arranged in a randomized complete block design. Neither pea variety nor inoculation affected amounts or patterns of N released. Patterns of N release over time showed mostly net N mineralization in two of 3 site-years, and some net N immobilization in one site-year. The percentages (up to 19 to 24% over time) and amounts (up to 2.3 to 7.5 kg N ha-1) of N released were low, probably due to the combination of low N concentrations (mostly < 1%) in the residues and below-normal rainfall in all 3 site-years. Soil NO3-N and NH4-N (0- to 80-cm depth) in the fall after pea harvest (20 to 39 and 27 to 55 kg N ha-1, respectively) and in spring before wheat seeding (23 to 51 and 16 to 40 kg N ha-1, respectively) were not affected by pea variety or inoculation. However, soil NO3-N was mostly higher after peas than after barley (the control). There is need to measure patterns of N release over several subsequent crops to check if more N is released in the long term. Key words: Crop residue, N mineralization, Rhizobium inoculation, soil inorganic N

scholarly journals Abiotic versus biotic controls on soil nitrogen cycling in drylands along a 3200 km transect

2017 ◽  
Vol 14 (4) ◽  
pp. 989-1001 ◽  
Author(s):  
Dongwei Liu ◽  
Weixing Zhu ◽  
Xiaobo Wang ◽  
Yuepeng Pan ◽  
Chao Wang ◽  
...  
Keyword(s):  
Arid Zone ◽  
N Cycling ◽  
Mean Annual Precipitation ◽  
N Availability ◽  
Soil N ◽  
Inorganic N ◽  
N Transformations ◽  
Soil Inorganic N ◽  
Soil Inorganic ◽  
Biotic Controls

Abstract. Nitrogen (N) cycling in drylands under changing climate is not well understood. Our understanding of N cycling over larger scales to date relies heavily on the measurement of bulk soil N, and the information about internal soil N transformations remains limited. The 15N natural abundance (δ15N) of ammonium and nitrate can serve as a proxy record for the N processes in soils. To better understand the patterns and mechanisms of N cycling in drylands, we collected soils along a 3200 km transect at about 100 km intervals in northern China, with mean annual precipitation (MAP) ranging from 36 to 436 mm. We analyzed N pools and δ15N of ammonium, dual isotopes (15N and 18O) of nitrate, and the microbial gene abundance associated with soil N transformations. We found that N status and its driving factors were different above and below a MAP threshold of 100 mm. In the arid zone with MAP below 100 mm, soil inorganic N accumulated, with a large fraction being of atmospheric origin, and ammonia volatilization was strong in soils with high pH. In addition, the abundance of microbial genes associated with soil N transformations was low. In the semiarid zone with MAP above 100 mm, soil inorganic N concentrations were low and were controlled mainly by biological processes (e.g., plant uptake and denitrification). The preference for soil ammonium over nitrate by the dominant plant species may enhance the possibility of soil nitrate losses via denitrification. Overall, our study suggests that a shift from abiotic to biotic controls on soil N biogeochemistry under global climate changes would greatly affect N losses, soil N availability, and other N transformation processes in these drylands in China.

scholarly journals Plant and soil nitrogen in oligotrophic boreal forest habitats with varying moss depths: does exclusion of large grazers matter?

Oecologia ◽  
2021 ◽  
Author(s):  
Maria Väisänen ◽  
Maria Tuomi ◽  
Hannah Bailey ◽  
Jeffrey M. Welker
Keyword(s):  
Boreal Forest ◽  
Vascular Plant ◽  
Soil N ◽  
Inorganic N ◽  
N Dynamics ◽  
N Content ◽  
Feather Moss ◽  
Foliar N ◽  
Plant Soil ◽  
Plant Soil Interactions

AbstractThe boreal forest consists of drier sunlit and moister-shaded habitats with varying moss abundance. Mosses control vascular plant–soil interactions, yet they all can also be altered by grazers. We determined how 2 decades of reindeer (Rangifer tarandus) exclusion affect feather moss (Pleurozium schreberi) depth, and the accompanying soil N dynamics (total and dissolvable inorganic N, δ15N), plant foliar N, and stable isotopes (δ15N, δ13C) in two contrasting habitats of an oligotrophic Scots pine forest. The study species were pine seedling (Pinus sylvestris L.), bilberry (Vaccinium myrtillus L.), lingonberry (V. vitis-idaea L.), and feather moss. Moss carpet was deeper in shaded than sunlit habitats and increased with grazer exclusion. Humus N content increased in the shade as did humus δ15N, which also increased due to exclusion in the sunlit habitats. Exclusion increased inorganic N concentration in the mineral soil. These soil responses were correlated with moss depth. Foliar chemistry varied due to habitat depending on species identity. Pine seedlings showed higher foliar N content and lower foliar δ15N in the shaded than in the sunlit habitats, while bilberry had both higher foliar N and δ15N in the shade. Thus, foliar δ15N values of co-existing species diverged in the shade indicating enhanced N partitioning. We conclude that despite strong grazing-induced shifts in mosses and subtler shifts in soil N, the N dynamics of vascular vegetation remain unchanged. These indicate that plant–soil interactions are resistant to shifts in grazing intensity, a pattern that appears to be common across boreal oligotrophic forests.

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