scholarly journals Soil nitrogen sequestration in a long-term fertilizer experiment in central China

2020 ◽  
Vol 18 (1) ◽  
pp. e1102 ◽  
Author(s):  
Xuemei Han ◽  
Cheng Hu ◽  
Yunfeng Chen ◽  
Yan Qiao ◽  
Donghai Liu ◽  
...  
Keyword(s):  
N Fertilizer ◽  
Inorganic Fertilizer ◽  
Total N ◽  
N Storage ◽  
Fertilizer Experiment ◽  
N Concentration ◽  
N Input ◽  
Sequestration Rate ◽  
Input Amount

Aim of study: To evaluate the effects of a long-term manuring and fertilization experiment on the soil total N concentration and its storage and sequestration rates in the rice-wheat cropping system.Area of study: A rice-wheat rotation area in central China.Material and methods: A 35-yr long-term fertilizer experiment was conducted with 9 treatments: unfertilized (Control), N, P, and K fertilizers, manure (M) and M combined with N, P, and K fertilizers treatments. Soil total N input amount, total N concentration, total N storage amount and N sequestration rate in soil were calculated.Main results: The soil total N input amount, N concentration, N storage amount and N sequestration rate were significantly influenced by M and chemical fertilizers. In total, 0.017-0.021 g N/kg soil accumulated in the organic M plots, whereas only 0.005-0.007 g in chemical fertilizer alone plots. The highest soil total N storage amount was 6.09 t/hain the M alone plot, and the lowest value was 4.46 tN/ha in the N fertilizer alone plot. The highest N sequestration rate in soil was 0.061 t N/ha/yr in the high amount M plus NPK fertilizers plot, and the lowest value was 0.002 tN/ha/yr in the N fertilizer alone plot. A significant nonlinear regression relationship existed between the total N sequestration rate in soil and annual total N input amount. Moreover, the average soil total N concentration was significantly positively correlated with the average grain yield of crop and soil organic C concentration. The soil total N sequestration rate in M alone or M combined with inorganic fertilizer treatments were increased compared with inorganic fertilizer alone treatments.Research highlights: Considering crop yields and total N sequestration rate in soil, the use of manure combined with inorganic fertilizer should be recommended in the rice-wheat cropping system.

scholarly journals Long-term effects of continuous cropping and different nutrient management practices on the distribution of organic nitrogen in soil under rice-wheat system

2014 ◽  
Vol 60 (No. 2) ◽  
pp. 63-68 ◽  
Author(s):  
J. Kaur ◽  
Singh JP
Keyword(s):  
Amino Acid ◽  
Management Practices ◽  
Nutrient Management ◽  
Amino Sugar ◽  
Inorganic Fertilizer ◽  
Inorganic Fertilizers ◽  
Total N ◽  
Organic Manures ◽  
Hydrolysable N

A long-term experiment was used to evaluate the effects of different nutrient management practices on the distribution of soil organic N fractions and their contribution to N nutrition of a rice-wheat system. Continuous rice-wheat cultivation for 13 years without any fertilization was unable to maintain total soil nitrogen level to its original level and resulted in a decrease at 8.3 mg N/kg/year. Likewise, amino acid N, amino sugar N, ammonia N, hydrolysable unknown N, total hydrolysable N and non-hydrolysable N decreased by 37.2, 29.6, 33.7, 10.4, 26.6 and 20.4%, respectively over their initial status. However, application of inorganic fertilizers alone or in combination with organic manures led to a marked increase in total N and its fractions. The increase in total N with the application of farmyard manure, press mud and green manure along with inorganic fertilizer over treatment with inorganic fertilizer alone was 23.1, 34.4 and 7.0%, respectively. These results imply that integrated use of inorganic fertilizers with organic manures represent a sound practice for sustaining N reserves in soil. On average, amino acid-N, amino sugar-N, ammonia-N and hydrolysable unknown-N constituted about 27.9, 10.7, 28.7 and 32.7% of the total hydrolysable-N, respectively.

scholarly journals Nitrogen Fertigation Rates Affect Stored Nitrogen, Growth, and Blooming in Iris germanica ‘Immortality’

HortScience ◽  
2016 ◽  
Vol 51 (2) ◽  
pp. 186-191 ◽  
Author(s):  
Xiaojie Zhao ◽  
Guihong Bi ◽  
Richard L. Harkess ◽  
Jac J. Varco ◽  
Tongyin Li ◽  
...  
Keyword(s):  
Plant Height ◽  
Dry Weight ◽  
Growing Season ◽  
N Fertilizer ◽  
N Content ◽  
Total N ◽  
N Concentration ◽  
Inflorescence Stems ◽  
Iris Germanica ◽  
N Rates

Tall bearded (TB) iris (Iris germanica L.) has great potential as a specialty cut flower due to its fragrance and showy, multicolor display; however, limited research has been reported on optimal nitrogen (N) nutrient management for TB iris. The objectives of this study were to investigate the effects of N fertilizer rate on plant growth and flowering of ‘Immortality’ iris and determine the influence of both stored N and spring-applied N fertilizer on spring growth and flowering. On 14 Mar. 2012, rhizomes of ‘Immortality’ iris were potted in a commercial substrate with no starter fertilizer. Plants were fertigated with 0, 5, 10, 15, or 20 mm N from NH4NO3 twice per week from 28 Mar. to 28 Sept. 2012. In 2013, half of the plants from each of the 2012 N rate were supplied with either 0 or 10 mm N from 15NH415NO3 twice per week from 25 Mar. to 7 May 2013. Growth and flowering data including plant height, leaf SPAD, number of fans and inflorescence stems, and length of inflorescence stem were collected during the growing season. Plants were harvested in Dec. 2012 and May 2013 to measure dry weight and N concentration in leaves, roots, and rhizomes. Results showed higher 2012 N rates increased plant height, leaf SPAD reading, and number of inflorescence stems at first and second blooming in 2012. Greater 2012 N rates also increased plant dry weight and N content in all structures, and N concentration in roots and rhizomes. Rhizomes (58.8% to 66.3% of total N) were the dominant sink for N in Dec. 2012. Higher 2012 N rates increased plant height, number of fans, and the number of inflorescence stems at spring bloom in 2013. In May 2013, N in leaf tissue constituted the majority (51% to 64.3%) of the total plant N. Higher 2012 N rates increased total dry weight, N concentration, and N content in all 2013 15N rates; however, leaf dry weight in all plants was improved by 2013 15N rate. Percentage of tissue N derived from 2013 15N (NDFF) decreased with increasing 2012 N rate. New spring leaves were the dominant sink (56.8% to 72.2%) for 2013 applied 15N. In summary, ‘Immortality’ iris is capable of a second blooming in a growing season, this second blooming dependent on N fertilization rate in current year. A relatively high N rate is recommended to produce a second bloom.

Long-term effects on soil-water nitrogen and pH of clearcutting and simulated disc trenching of previously nitrogen-fertilised pine plots

2018 ◽  
Vol 48 (10) ◽  
pp. 1115-1123
Author(s):  
Eva Ring ◽  
Lars Högbom ◽  
Staffan Jacobson ◽  
Gunnar Jansson ◽  
Hans-Örjan Nohrstedt
Keyword(s):  
Soil Water ◽  
Site Preparation ◽  
Low Fertility ◽  
N Leaching ◽  
Soil N ◽  
Long Term Effects ◽  
Total N ◽  
N Concentration ◽  
Experimental Plots

Forest fertilisation with nitrogen (N) typically increases N leaching for 1–2 years. Some studies have reported effects also after clearcutting. This study presents an analysis of soil-water chemistry data from the 3rd to the 15th year after clearcutting of fertilised experimental plots on a low-fertility site in Sweden. Before clearcutting in 1987, study plots had been fertilised with NH4NO3 in 1967, 1974, and 1981, resulting in total applications ranging from 0 to 1800 kg N·ha−1. In 1989, disc trenching was simulated by manual digging on small subplots within the fertilised main plots. Soil-water samples were collected at a depth of 50 cm. Previous N fertilisation and site preparation, respectively, affected (p < 0.05) the total N and NO3–-N concentrations and pH of soil water, but no statistical interaction between fertilisation and site preparation was found. The NO3–-N concentration was elevated for total N applications above 720 kg·ha−1 (mean NO3–-N concentration of 0.93 mg·L−1 for 1080 kg N·ha−1, 1.6 mg·L−1 for 1440 kg N·ha−1, and 2.4 mg·L−1 for 1800 kg N·ha−1 compared with 0.20 mg·L−1 for the control) and lower after simulated disc trenching (0.63 mg·L−1) than in nontrenched soil (1.3 mg·L−1). The elevations in the soil-water NO3–-N concentration for the fertiliser treatments seemed to be related to changes in the soil N store created by previous fertilisation.

Long term effects of rotation, tillage and stubble management on wheat production in southern NSW

1994 ◽  
Vol 45 (1) ◽  
pp. 93 ◽  
Author(s):  
DP Heenan ◽  
AC Taylor ◽  
BR Cullis ◽  
WJ Lill
Keyword(s):  
Grain Yield ◽  
N Uptake ◽  
N Fertilizer ◽  
Yield Response ◽  
Wheat Crop ◽  
Wagga Wagga ◽  
Grain Protein ◽  
Total N ◽  
Grain Yields

A long term field experiment began in 1979 at Wagga Wagga, N.S.W., to compare the sustainability of a range of rotation, tillage and stubble management systems on a red earth. This paper reports yield, yield components and grain protein of wheat for 1979-90. Rotations considered were alternating lupin-wheat (LW), lupin-wheat-wheat (LWW), continuous wheat (WW) with and without N fertilizer (100 kg N/ha), and alternating sub-clover-wheat (CW). Soil N supply at the start of the experiment was high following many years of sub-clover based pasture. From 1979 to 1983, there was a negative grain yield response to N fertilizer and no response to a legume in rotation except in the drought of 1982 when low yields were recorded from LW. Thereafter, a positive grain yield response was usually produced to N fertilizer in WW rotations, until 1989 and 1990, when these crops displayed aluminium toxicity sym ptoms. Overall, average grain yields from legume rotations were higher than WW with added N fertilizer. Since 1983, LW rotations consistently produced higher mean grain yields than CW, but mean grain protein and total N uptake were lower. Yields and N uptake by the second wheat crop in a LWW rotation indicated little carryover of benefits from the lupins. Slightly higher mean grain yield and harvest index, but lower mean grain protein, were produced by direct drilling, compared with cultivation before sowing, following lupins or sub-clover. However, retaining stubble rather than burning in autumn consistently reduced grain yields. There was no evidence that early burial of wheat stubble following summer rain, rather than incorporation in autumn, improved grain yield or total N uptake. The build-up of giant brome grass and diseases, particularly where stubble was retained and crops direct-drilled, casts some doubt on the long term sustainability of these short term rotations in this environment.

Nitrogen inputs and losses from clover/grass pastures grazed by dairy cows, as affected by nitrogen fertilizer application

1999 ◽  
Vol 132 (2) ◽  
pp. 215-225 ◽  
Author(s):  
S. F. LEDGARD ◽  
J. W. PENNO ◽  
M. S. SPROSEN
Keyword(s):  
Dairy Cows ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
Organic N ◽  
Total N ◽  
Nitrogen Inputs ◽  
N Input ◽  
Maize Grain ◽  
Intensively Managed ◽  
N Pool

Nitrogen (N) inputs and outputs were measured over 3 years in a trial with four farmlets (each with 16 randomly-allocated 0·4 ha paddocks) on permanent white clover/ryegrass pastures which were grazed throughout the year by dairy cows near Hamilton, New Zealand. Three farmlets were stocked at 3·3 cows/ha and received nominal rates of N fertilizer (urea in 8–10 split applications) of 0, 200 or 400 kg N/ha per year. A fourth farmlet with 4·4 cows/ha received 400 kg N/ha per year and was supplemented with maize grain during the first two years.Nitrogen balances were calculated, with [sum ]N inputs[ape ][sum ]N outputs. Annual inputs from N2 fixation were 99–231 kg N/ha in the 0 N farmlet, but declined to 15–44 kg N/ha in the 400 N farmlets. The main N outputs (in kg N/ha per year) were in milk (72–126), nitrate leaching (20–204), and transfer of N via cow excreta from pastures to lanes and milking shed (54–92). Gaseous losses by denitrification (3–34) and volatilization (15–78) were smaller than the other N outputs but increased significantly with N fertilizer application. In the maize-supplemented farmlet, N outputs in milk were 31% higher than in the corresponding non-supplemented 400 N farmlet, whereas leaching losses averaged 17% lower during the 2 years of supplementation.In the N-fertilized farmlets, estimated N balances were influenced by inclusion of the transitional N processes of immobilization of fertilizer N into the soil organic N pool (estimated using 15N at 42–94 kg N/ha per year) and the contribution from mineralization of residual clover-fixed N in soil not accounted for in the current estimates of N2 fixation (estimated at up to 70% of measured N2 fixation or 46 kg N/ha per year). However, these processes were counteracting and together were calculated to have only a small net effect on total N balances.The output of N in products (milk, meat and feed) relative to the total N input averaged 26% in the 400 N farmlets, and is compared to that measured for commercial intensively-managed dairy farms in England and the Netherlands (14–20%). The 0 N farmlet, which was reliant on N2 fixation as the sole N input, was relatively very N-efficient with the milk production being 83% of that in the 400 N farmlet (at 3·3 cows/ha) and the N output in products relative to total N input averaging 52%.

scholarly journals Nitrogen fertilizer value of animal slurries with different proportions of liquid and solid fractions: A 3-year study under field conditions

2021 ◽  
pp. 1-11
Author(s):  
Betina Nørgaard Pedersen ◽  
Bent T. Christensen ◽  
Luca Bechini ◽  
Daniele Cavalli ◽  
Jørgen Eriksen ◽  
...  
Keyword(s):  
Solid Fraction ◽  
Liquid Fraction ◽  
N Fertilizer ◽  
Organic N ◽  
First Year ◽  
Net N Mineralization ◽  
Pig Slurry ◽  
Total N ◽  
Plant Availability ◽  
Loamy Sand Soil

Abstract The plant availability of manure nitrogen (N) is influenced by manure composition in the year of application whereas some studies indicate that the legacy effect in following years is independent of the composition. The plant availability of N in pig and cattle slurries with variable contents of particulate matter was determined in a 3-year field study. We separated cattle and a pig slurry into liquid and solid fractions by centrifugation. Slurry mixtures with varying proportions of solid and liquid fraction were applied to a loamy sand soil at similar NH4+-N rates in the first year. Yields and N offtake of spring barley and undersown perennial ryegrass were compared to plots receiving mineral N fertilizer. The first year N fertilizer replacement value (NFRV) of total N in slurry mixtures decreased with increasing proportion of solid fraction. The second and third season NFRV averaged 6.5% and 3.8% of total N, respectively, for cattle slurries, and 18% and 7.5% for pig slurries and was not related to the proportion of solid fraction. The estimated net N mineralization of residual organic N increased nearly linearly with growing degree days (GDD) with a rate of 0.0058%/GDD for cattle and 0.0116%/GDD for pig slurries at 2000–5000 GDD after application. In conclusion NFRV of slurry decreased with increasing proportion of solid fraction in the first year. In the second year, NFRV of pig slurry N was significantly higher than that of cattle slurry N and unaffected by proportion between solid and liquid fraction.

scholarly journals Public acceptance of COVID-19 vaccines: cross-national evidence on levels and individual-level predictors using observational data

BMJ Open ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. e048172
Author(s):  
Marie Fly Lindholt ◽  
Frederik Jørgensen ◽  
Alexander Bor ◽  
Michael Bang Petersen
Keyword(s):  
Health Communication ◽  
Herd Immunity ◽  
Geographical Location ◽  
Vaccine Acceptance ◽  
Total N ◽  
Individual Level ◽  
Health Authorities ◽  
Personal Consequences ◽  
Western Democracies

ObjectivesThe management of the COVID-19 pandemic hinges on the approval of safe and effective vaccines but, equally importantly, on high vaccine acceptance among people. To facilitate vaccine acceptance via effective health communication, it is key to understand levels of vaccine scepticism and the demographic, psychological and political predictors. To this end, we examine the levels and predictors of acceptance of an approved COVID-19 vaccine.Design, setting and participantsWe examine the levels and predictors of acceptance of an approved COVID-19 vaccine in large online surveys from eight Western democracies that differ in terms of the severity of the pandemic and their response: Denmark, France, Germany, Hungary, Sweden, Italy, UK and USA (total N=18 231). Survey respondents were quota sampled to match the population margins on age, gender and geographical location for each country. The study was conducted from September 2020 to February 2021, allowing us to assess changes in acceptance and predictors as COVID-19 vaccine programmes were rolled out.Outcome measureThe outcome of the study is self-reported acceptance of a COVID-19 vaccine approved and recommended by health authorities.ResultsThe data reveal large variations in vaccine acceptance that ranges from 83% in Denmark to 47% in France and Hungary. Lack of vaccine acceptance is associated with lack of trust in authorities and scientists, conspiratorial thinking and a lack of concern about COVID-19.ConclusionMost national levels of vaccine acceptance fall below estimates of the required threshold for herd immunity. The results emphasise the long-term importance of building trust in preparations for health emergencies such as the current pandemic. For health communication, the results emphasise the importance of focusing on personal consequences of infections and debunking of myths to guide communication strategies.

Growth and N status of Populus in mixture with red alder on recent volcanic mudflow from Mount Saint Helens

1990 ◽  
Vol 20 (1) ◽  
pp. 84-90 ◽  
Author(s):  
Paul E. Heilman
Keyword(s):  
Late Summer ◽  
Height Growth ◽  
Phosphorus Fertilization ◽  
Cross Sectional ◽  
Red Alder ◽  
Total N ◽  
Foliar N ◽  
N Concentration ◽  
The Mean ◽  
Foliar N Concentration

Eleven months after the May 1980 eruption of Mount Saint Helens in southeastern Washington, United States, three Populus clones were planted in an experiment on the Toutle River mudflow deposit. The trees grew at an abnormally slow rate and by 3 years were overtopped by a dense stand (14 600 ± 3600 trees/ha) of red alder seeded naturally onto the site. Over the 6-year period of the study, the total N content of the soil increased an average of 56 kg•ha−1•year−1•. Foliar N concentration in Populus increased significantly from a mean late summer – early autumn value in the 2nd year (1982) of 0.69% N to a value of 2.06% N at the end of the seventh growing season. The mean annual height growth of the largest Populus averaged <0.5 m/year in the first 3 years, increasing to an average of over 1.0 m/year in the 5th and 6th years. Fertilizer treatments with N (as urea) and N + P (as urea plus treble superphosphate) placed in the soil near the individual Populus at a maximum rate of 5.3 g N/tree increased height growth in the year of fertilization (1982) and the following year (the response in height growth for the 2 years totaled 64%). After 1984, no significant effects of fertilizer on height growth, total height, or diameter were evident. Nitrogen fertilization significantly increased foliar N concentration (1.54% N with the highest N treatment vs. 0.69% N in the control) in the year of treatment only. Phosphorus fertilization had no significant effect on growth or foliar P concentration. At 6 years, only 2% of the Populustrichocarpa Torr. & Gray clone and 13% of the tallest Populus hybrid were equal to or above the mean height of alder dominants and codominants (6.2 m). Additionally, the diameter growth of Populus was severely limited: the trees had only 8% of the cross-sectional area of "normal" trees for their height. Results indicated that on sites of low N such as the mudflow, Populus may not compete satisfactorily in mixture with alder. Such behavior is in sharp contrast to sites of high N, where red alder cannot compete with Populus.

Nitrogen form, time and rate of application, and nitrification inhibitor effects on crop production

2014 ◽  
Vol 94 (2) ◽  
pp. 425-432 ◽  
Author(s):  
R. E. Karamanos ◽  
K. Hanson ◽  
F. C. Stevenson
Keyword(s):  
Crop Production ◽  
Protein Concentration ◽  
Wheat Yield ◽  
Nitrification Inhibitor ◽  
N Fertilizer ◽  
Nitrogen Form ◽  
Anhydrous Ammonia ◽  
N Concentration ◽  
Fertilizer Rates ◽  
Better Than

Karamanos, R., Hanson, K. and Stevenson, F. C. 2014. Nitrogen form, time and rate of application, and nitrification inhibitor effects on crop production. Can. J. Plant Sci. 94: 425–432. Nitrogen management options for anhydrous ammonia (NH3) and urea were compared in a barley–wheat–canola–wheat cropping sequence (2007–2010) at Watrous and Lake Lenore, SK. The treatment design included a factorial arrangement of N fertilizer form (NH3versus urea), nitrification inhibitor application, time of N application (mid-September, mid- to late October, and spring) and four N fertilizer rates (0, 40, 80 and 120 kg ha−1). Anhydrous ammonia applications at 40 kg N ha−1in 2008 (fall) and in 2010 (all times of application) resulted in wheat yield reductions relative to the same applications for urea. For wheat years, yield was reduced for both fall versus spring N fertilizer applications, when no nitrification inhibitor was applied and the inclusion of nitrification inhibitor maintained wheat yield at similar levels across all times of N fertilizer applications, regardless of form. Protein concentration was approximately 2 g kg−1greater with urea compared with NH3at both sites in 2008 and only at Watrous in 2010. Also, early versus late fall N fertilizer applications consistently increased N concentration of grain only for the 40 and/or 80 kg N ha−1rates. Effects of nitrification inhibitor on N concentration were not frequent and appeared to be minimal. Urea had greater agronomic efficiency (AE) than NH3at the lower N fertilizer rates. The nitrification inhibitor had a positive effect on wheat AE only for early fall N fertilizer applications. It can be concluded that for maximum yields NH3or urea will be suitable if applied at rates of 80 kg N ha−1and greater. If N fertilizer is applied at 40 kg N ha−1, especially in fall without inhibitor, urea is better. In terms of protein concentration for wheat, urea seemed to better than NH3and fall was better than spring application.

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