scholarly journals The effect of work level and dietary intake on sweat nitrogen losses in a hot climate

1972 ◽  
Vol 27 (3) ◽  
pp. 543-552 ◽  
Author(s):  
J. S. Weiner ◽  
J. O. C. Willson ◽  
Hamad El-Neil ◽  
Erica F. Wheeler
Keyword(s):  
Normal Diet ◽  
Physical Work ◽  
N Loss ◽  
N Losses ◽  
Total N ◽  
Adequate Diet ◽  
N Concentration ◽  
Hot Climate ◽  
Rate Of Increase ◽  
Work Level

1. Nitrogen intakes, and N output in urine, faeces and sweat have been measured in six young Tanzanian men who were accustomed to a hot climate. The measurements were done while the subjects were receiving first a normal and then a low-N diet; and when they were performing moderate physical work, and had undergone a period of acclimatization.2. When the subject were acclimatized and working on a normal diet, their sweat output increased, with a fall in its N concentration. Total sweat N loss increased from an average of 0.10 to 0.71 g/d.3. The effect of the low-N diet was to decrease both the sweat N concentration, and the rate of increase of total N loss in sweat, as sweat volume increased.4. It is estimated that maximum sweat N losses would not exceed 1 g/d on an adequate diet, or 0.5 g/d on a low-protein diet. Our results provide no basis for recommending extra protein allowances to cover sweat N losses for workers in tropical climates.

scholarly journals Short-Term Effects of Pile Burn on N Dynamic and N Loss in Mediterranean Croatia

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1340
Author(s):  
Domina Delač ◽  
Paulo Pereira ◽  
Igor Bogunović ◽  
Ivica Kisić
Keyword(s):  
Sediment Yield ◽  
Principal Component ◽  
Extreme Rainfall ◽  
Mediterranean Area ◽  
Sediment Concentration ◽  
N Loss ◽  
N Losses ◽  
Extreme Rainfall Events ◽  
Total N ◽  
N Concentration

There is a lack of information in the rural Mediterranean area about agricultural pile burning impacts on soil nitrogen (N) dynamic and the N loss. Therefore, this research aims to study the impacts of moderate (MS), and high (HS) severity burn on N transformation and N losses, compared to an unburned (C) during the first year. The experimental plots (10 m2) were established in Croatia (43°58′ N 15°31′ E), in a slope ~18°, with a southwest exposition. Five days after the burn, C treatment had a significantly higher total N (TN) than MS and HS. Generally, the runoff was significantly different between burned and C treatments. Sediment yield, concentrations, and TN loss were significantly higher in MS than in C treatment. The concentrations of ammonium (NH4-N) and nitrate (NO3-N) in the runoff, and their losses were higher in burn treatments than in C treatment. These values were high in the first three months after burn, although the peaks in later periods correspond to extreme rainfall events. Principal component analysis showed that sediment yield was associated with sediment concentration, runoff, and TN loss (Factor 1). In addition, rainfall amount and intensity were inversely related to NH4-N concentration and losses (Factor 2). The NO3-N concentration was positively related to NO3-N losses. Overall, MS treatment had severe effects on N loss and, sediment yield can be used as an indicator of soil degradation after pile burns.

scholarly journals The interaction of seasonal rainfall and nitrogen fertiliser rate on soil N2O emission, total N loss and crop yield of dryland sorghum and sunflower grown on sub-tropical Vertosols

Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 604 ◽  
Author(s):  
G. D. Schwenke ◽  
B. M. Haigh
Keyword(s):  
Crop Yield ◽  
Crop Production ◽  
Field Experiments ◽  
N2o Emission ◽  
N2o Emissions ◽  
N Loss ◽  
N Losses ◽  
Total N ◽  
Tropical Regions ◽  
The Impact

Summer crop production on slow-draining Vertosols in a sub-tropical climate has the potential for large emissions of soil nitrous oxide (N2O) from denitrification of applied nitrogen (N) fertiliser. While it is well established that applying N fertiliser will increase N2O emissions above background levels, previous research in temperate climates has shown that increasing N fertiliser rates can increase N2O emissions linearly, exponentially or not at all. Little such data exists for summer cropping in sub-tropical regions. In four field experiments at two locations across two summers, we assessed the impact of increasing N fertiliser rate on both soil N2O emissions and crop yield of grain sorghum (Sorghum bicolor L.) or sunflower (Helianthus annuus L.) in Vertosols of sub-tropical Australia. Rates of N fertiliser, applied as urea at sowing, included a nil application, an optimum N rate and a double-optimum rate. Daily N2O fluxes ranged from –3.8 to 2734g N2O-Nha–1day–1 and cumulative N2O emissions ranged from 96 to 6659g N2O-Nha–1 during crop growth. Emissions of N2O increased with increased N fertiliser rates at all experimental sites, but the rate of N loss was five times greater in wetter-than-average seasons than in drier conditions. For two of the four experiments, periods of intense rainfall resulted in N2O emission factors (EF, percent of applied N emitted) in the range of 1.2–3.2%. In contrast, the EFs for the two drier experiments were 0.41–0.56% with no effect of N fertiliser rate. Additional 15N mini-plots aimed to determine whether N fertiliser rate affected total N lost from the soil–plant system between sowing and harvest. Total 15N unaccounted was in the range of 28–45% of applied N and was presumed to be emitted as N2O+N2. At the drier site, the ratio of N2 (estimated by difference)to N2O (measured) lost was a constant 43%, whereas the ratio declined from 29% to 12% with increased N fertiliser rate for the wetter experiment. Choosing an N fertiliser rate aimed at optimum crop production mitigates potentially high environmental (N2O) and agronomic (N2+N2O) gaseous N losses from over-application, particularly in seasons with high intensity rainfall occurring soon after fertiliser application.

scholarly journals Protein requirements in tropical countries: nitrogen losses in sweat and their relation to nitrogen balance

1967 ◽  
Vol 21 (4) ◽  
pp. 833-843 ◽  
Author(s):  
Ann Ashworth ◽  
A. D. B. Harrower
Keyword(s):  
Initial Period ◽  
Tropical Climate ◽  
The Body ◽  
N Balance ◽  
Nitrogen Losses ◽  
Whole Body ◽  
Physical Work ◽  
N Loss ◽  
Total N ◽  
Protein Requirements

1. An experiment was undertaken to determine whether high rates of sweating in a tropical climate affect protein requirements by increasing the total nitrogen losses from the body.2. Six fully acclimatized volunteers were given a diet supplying 50 g protein (= 8 g N) daily. They performed strenuous physical work of a normal nature for an average of 6½ h a day for two 5-day periods. During control periods the subjects took minimal exercise and lived in a cool environment. N balance was measured throughout.3. Rates of sweating were measured by weighing. Whole body sweat was collected and the concentrations were measured of nitrogen, sodium and potassium. During 6½ h work approximately 3 l. of sweat were lost, containing on average 0·49 g N, 64 m-equiv. Na and 22 m-equiv. K.4. The N concentration in sweat was 0·20 mg/g, which is lower than that found by most other workers. It is suggested that acclimatization is an important factor in reducing N loss by sweating.5. There was a marked decrease in urinary Na excretion during sweating, which compensated fully for the loss of Na in sweat. Renal compensation for loss of K was less efficient.6. Because the total N loss in sweat was small, it was not possible to establish with certainty whether it was compensated for by a reduced renal excretion of N. However, after the initial period the subjects were in N balance in spite of the relatively low protein intake.7. It is concluded that there is no evidence to suggest that heavy sweating under natural conditions in a tropical climate causes a significant increase in protein requirements.

Diurnal variation in urine nitrogen and creatinine concentrations from lactating cows grazing ryegrass-dominant pasture in autumn and late spring–summer

2017 ◽  
Vol 57 (7) ◽  
pp. 1297 ◽  
Author(s):  
G. P. Cosgrove ◽  
A. Jonker ◽  
K. A. Lowe ◽  
P. S. Taylor ◽  
D. Pacheco
Keyword(s):  
Diurnal Variation ◽  
Urine Volume ◽  
Late Spring ◽  
Urine Samples ◽  
Creatinine Ratio ◽  
Sample Collection ◽  
N Losses ◽  
Total N ◽  
Once Daily ◽  
N Concentration

In dairy production systems based on grazed pasture, urine patches are the main source of nitrogen (N) losses via leaching and gaseous emission pathways. The volume and N concentration of urine influences the amount of N in a urine patch. We conducted systematic urine sampling to determine the diurnal variation in concentrations of N and creatinine (a proxy for urine volume), and the N : creatinine ratio, to identify the sampling required for accurately estimating the daily mean concentrations of N and creatinine. Nine groups (n = 6) of multiparous Friesian and Friesian × Jersey cows in autumn (220 ± 26 days-in-milk, milked twice daily) and nine groups (n = 6) in late spring–summer (228 ± 24 days-in-milk, milked once daily) were sequentially withdrawn from the farm herd at approximately weekly intervals and each group was offered a fresh allocation of ryegrass-dominant pasture twice daily after milking for 3 days (including at the equivalent time in the afternoon in late spring–summer when they were milked once daily). For each of the 18 different groups of cows, individual urine samples were collected on Day 3 at 1100 hours, 1500 hours (afternoon milking), 1800 hours and 0700 hours (the following morning milking), and, subsequently, analysed for total N and creatinine concentrations. In autumn, urine-N concentrations were higher (P = 0.0002) at 1800 hours (5.8 g N/L) than they were at 1500 hours or 0700 hours (mean of 4.2 g N/L). In late spring–summer, the concentrations were higher (P < 0.001) at 1100 hours (8.0 g N/L) than they were at 1500 hours, 1800 hours or 0700 hours (mean of 6.3 g N/L). The urine N : creatinine ratio was 214 mol/mol in autumn and 148 mol/mol in late spring–summer, but did not vary among sampling times during the day. The highest concentrations of N were in urine samples collected ~3 h post-allocation of fresh feed when cows had grazed actively and consumed the majority of the herbage available. For accurate estimates of the daily mean urine N concentration, sample collections should be timed to encompass this diurnal variation. For the N : creatinine ratio, which was more stable through the day, the timing of sample collection is less important for estimating a daily mean.

scholarly journals Ammonia volatilization losses in Tanzania grass fertilized with urea

2015 ◽  
Vol 16 (1) ◽  
pp. 253-264 ◽  
Author(s):  
Cecílio Viega SOARES FILHO ◽  
Ulysses CECATO ◽  
Ossival Lolato RIBEIRO ◽  
Cláudio Fabrício da Cruz ROMA ◽  
Tatiane BELONI
Keyword(s):  
Ammonia Volatilization ◽  
Repeated Measurements ◽  
N Loss ◽  
N Losses ◽  
Total N ◽  
Factors Affecting ◽  
Randomized Design ◽  
Different Seasons ◽  
Completely Randomized Design ◽  
N Volatilization

<p>Gaseous losses are the main factors affecting the efficiency of nitrogenous fertilizers in pastures. To evaluate NH<sub>3</sub>-N volatilization losses in Tanzania grass fertilized with urea in autumn, spring and summer, a completely randomized design with repeated measurements over time and fifteen replicates was used. Plots were represented by urea levels (50; 100 and 150 kg ha<sup>-1</sup> N) and subplots by time after fertilization (1; 2; 3; 6; 9; 12 and 15 days). The interaction between fertilization leveland time after urea application was significant for the accumulated NH<sub>3</sub>-N volatilization. Urea application leads to higher percentage N losses in the first three days after application. The average cumulative NH<sub>3</sub>-N loss for the three occasions (different seasons of the year) was 28%, 20% and 16% of N applied for fertilizer doses of 50; 100 and 150 kg ha<sup>-1</sup>of N, respectively. The season of the year influenced NH<sub>3</sub>-N loss pattern and volume, with the lowest values recorded in spring, followed by summer and autumn. The cumulative NH<sub>3</sub>-N volatilization loss varies from 78 to 90% up to the third day after application of the total N-NH3 loss.</p>

scholarly journals Nitrogen and phosphorus losses by surface runoff and soil microbial communities in a paddy field with different irrigation and fertilization managements

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254227
Author(s):  
Limin Wang ◽  
Dongfeng Huang
Keyword(s):  
Surface Runoff ◽  
Soil Microbial Communities ◽  
Chemical Properties ◽  
High Water ◽  
Chemical Fertilizer ◽  
Impact Factors ◽  
N Loss ◽  
Nitrogen And Phosphorus ◽  
N Losses ◽  
Total N

Rice cultivation usually involves high water and fertilizer application rates leading to the nonpoint pollution of surface waters with phosphorus (P) and nitrogen (N). Here, a 10-year field experiment was conducted to investigate N and P losses and their impact factors under different irrigation and fertilization regimes. Results indicated that T2 (Chemical fertilizer of 240 kg N ha−1, 52 kg P ha−1, and 198 kg K ha−1 combined with shallow intermittent irrigation) decreased N loss by 48.9% compared with T1 (Chemical fertilizer of 273 kg N ha−1, 59 kg P ha−1, and 112 kg K ha−1 combined with traditional flooding irrigation). The loss ratio (total N loss loading/amount of applied N) of N was 9.24–15.90%, whereas that of P was 1.13–1.31% in all treatments. Nitrate N (NO3-−N) loss was the major proportion accounting for 88.30–90.65% of dissolved inorganic N loss through surface runoff. Moreover, the N runoff loss was mainly due to high fertilizer input, soil NO3-−N, and ammonium N (NH4+−N) contents. In addition, the N loss was accelerated by Bacteroidetes, Proteobacteria, Planotomycetes, Nitrospirae, Firmicutes bacteria and Ascomycota fungi, but decreased by Chytridiomycota fungi whose contribution to the N transformation process. Furthermore, T2 increased agronomic N use efficiency (AEN) and rice yield by 32.81% and 7.36%, respectively, in comparison with T1. These findings demonstrated that T2 might be an effective approach to ameliorate soil chemical properties, regulate microbial community structure, increase AEN and consequently reduce N losses as well as maintaining rice yields in the present study.

scholarly journals High Carbon Amendments Increase Nitrogen Retention in Soil After Slurry Application—an Incubation Study with Silty Loam Soil

2021 ◽  
Author(s):  
Xinyue Cao ◽  
Rüdiger Reichel ◽  
Holger Wissel ◽  
Sirgit Kummer ◽  
Nicolas Brüggemann
Keyword(s):  
Wheat Straw ◽  
Application Rate ◽  
N Recovery ◽  
High Carbon ◽  
N Loss ◽  
N Losses ◽  
Total N ◽  
N Retention ◽  
Incubation Study ◽  
Loam Soil

AbstractExcess nitrogen (N) after animal slurry application is a persistent problem of intensive agriculture, with consequences such as environmental pollution by ammonia (NH3) and nitrous oxide (N2O) emissions and nitrate (NO3−) leaching. High-carbon organic soil amendments (HCAs) with a large C:N ratio have shown the potential of mitigating unintended N losses from soil. To reduce gaseous and leaching N losses after the application of slurry, a laboratory incubation study was conducted with silt loam soil. We tested the potential of three different types of HCA—wheat straw, sawdust, and leonardite (application rate 50 g C L−1 slurry for each of the three HCAs)—to mitigate N loss after amendment of soil with pig and cattle slurry using two common application modes (slurry and HCA mixed overnight with subsequent addition to soil vs. sequential addition) at an application rate equivalent to 80 kg N ha−1. Compared to the control with only soil and slurry, the addition of leonardite reduced the NH3 emissions of both slurries by 32–64%. Leonardite also reduced the total N2O emissions by 33–58%. Wheat straw reduced N2O emissions by 40–46%, but had no effect on NH3 emission. 15 N labeling showed that the application of leonardite was associated with the highest N retention in soil (24% average slurry N recovery), followed by wheat straw (20% average slurry N recovery). The mitigation of N loss was also observed for sawdust, although the effect was less consistent compared with leonardite and wheat straw. Mixing the slurry and HCA overnight tended to reduce N losses, although the effect was not consistent across all treatments. In conclusion, leonardite improved soil N retention more effectively than wheat straw and sawdust.

scholarly journals Effects of Changing Fertilization since the 1980s on Nitrogen Runoff and Leaching in Rice–Wheat Rotation Systems, Taihu Lake Basin

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 886
Author(s):  
Yaqin Diao ◽  
Hengpeng Li ◽  
Sanyuan Jiang ◽  
Xinyan Li
Keyword(s):  
Algal Blooms ◽  
Field Experiments ◽  
Taihu Lake ◽  
Crop Yields ◽  
Fertilization Rate ◽  
Freshwater Ecosystems ◽  
Lake Basin ◽  
N Loss ◽  
N Losses ◽  
Total N

The nitrogen (N) loss associated with intensive agricultural activities is a significant cause of eutrophication and algal blooms in freshwater ecosystems. Taihu Lake has experienced serious surface water quality deterioration and eutrophication problems since the 1980s. The objective of this study is to examine the effect of fertilization changes since the 1980s on the N loss with runoff and leaching in the rice–wheat cropping rotation system. According to the results published in the literature since the 1980s, we set up four fertilization scenarios—N1980s: a fertilization rate of 350 kg N·ha−1·year−1 with 30% in manure fertilization to simulate fertilization in the 1980s; NA1990s: a fertilization rate of 500 kg N·ha−1·year−1 with 10% in manure fertilization to simulate fertilization in the early 1990s; NL1990s: fertilization rate of 600 kg N·ha−1·year−1 with 10% in manure fertilization to simulate fertilization in the late 1990s; and N2000s: fertilization rate of 550 kg N·ha−1·year−1 with all chemicals to simulate fertilization in the 2000s. Then, we calibrated and validated the DNDC (denitrification–decomposition) model through field experiments in two rice–wheat rotation seasons from November 2011 to October 2013 and simulated the N loss with runoff and leaching since the 1980s. The results show that N losses with leaching in the four periods (N 1980s, NA1990s, NL1990s, and N2000s) were 5.2 ± 2.1, 9.4 ± 3.2, 14.4 ± 4.6 and 13.5 ± 4.6 kg N·ha−1·year−1, respectively. N losses with surface runoff were 7.9 ± 3.9, 18.3 ± 7.2, 25.4 ± 10.2, and 26.5 ± 10.6 kg N·ha−1·year−1, respectively. The total N loss through runoff and leaching showed an increasing trend from 1980 to the late 1990s, when it reached its peak. The increase in N export to water due to fertilizer application occurs mainly during the rainy season from March to August, and especially from June to August, when rainfall events and intensive rice fertilization activities are frequent. After the 1990s, when the fertilizer rate was above 500 kg N·ha−1·year−1, the crop yields no longer increased significantly, which indicates that the optimized fertilization rate to balance crop yields and N loss to water is lower than 500 kg N·ha−1·year−1. The increase in fertilizer use has been unnecessary since the early 1990s, and at least about 30% of the N loss could have been prevented without reducing crop yields.

scholarly journals Reduced tillage: Influence on erosion and nutrient losses in a clayey field in southern

2002 ◽  
Vol 11 (1) ◽  
pp. 37-50 ◽  
Author(s):  
J. KOSKIAHO ◽  
S. KIVISAARI ◽  
S. VERMEULEN
Keyword(s):  
Surface Runoff ◽  
Quality Data ◽  
Reduced Tillage ◽  
Nutrient Losses ◽  
N Loss ◽  
Drainage Flow ◽  
N Losses ◽  
Water Quality Data ◽  
Total N ◽  
Total P

Reduced tillage was compared with traditional ploughing in terms of erosion and phosphorus (P) and nitrogen (N) losses in an experimental field in southern Finland. One part of the field has been ploughed (treatment PF) and the other part harrowed (treatment NPF) every autumn since 1986. Flow volume and water quality data was collected separately from surface runoff and subsurface drainage waters during 1991-1995 (surface runoff volume since 1993). Erosion was higher in PF (on average 234 kg ha-1yr-1 in drainage flow and 479 kg ha-1 yr-1 in surface runoff) than in NPF (158 kg ha-1yr-1 in drainage flow and 160 kg ha-1yr-1 in surface runoff). Total N loss in drainage flow was also higher in PF (7.2 kg ha-1yr-1) than in NPF (4.6 kg ha-1yr-1). Total P losses did not differ much

Nitrogen turnover and loss during storage of slurry and composting of solid manure under typical Vietnamese farming conditions

2010 ◽  
Vol 149 (3) ◽  
pp. 285-296 ◽  
Author(s):  
M. T. TRAN ◽  
T. K. V. VU ◽  
S. G. SOMMER ◽  
L. S. JENSEN
Keyword(s):  
Animal Feed ◽  
Plant Nutrients ◽  
Pig Manure ◽  
Pig Slurry ◽  
N Loss ◽  
N Losses ◽  
N Content ◽  
Total N ◽  
Available N ◽  
Slurry Storage

SUMMARYA high proportion of plant nutrients present in animal feed are excreted and therefore animal manure can be an important source of nitrogen (N) for crop production if losses of plant nutrients to the environment during storage and processing are minimized. The present study examines gaseous N losses from stored pig slurry and during composting of solid manure as affected by protein and fibre content in the feed and manure management. Two slurry storage treatments (with and without cover) and three additives to solid manure composting (straw only, straw+lime and straw+superphosphate) were examined for three common types of pig feed in Vietnam (low-protein high-fibre, medium-protein medium-fibre and high-protein low-fibre).Feed type was found to affect the N content in pig slurry or manure and thus potential N losses. The fraction of N loss caused by N emission from covered slurry storage was 0·25–0·30 of initial N content, while that from uncovered slurry was 0·60–0·70. After 90 days of storage, 1·15–1·20 times the initial ammonium-N (NH4-N) was found in the covered slurry and 0·40–0·50 in the uncovered. The fraction of N lost during composting with superphosphate was 0·25–0·35 of initial total N, while with lime or straw the total N loss was 0·45–0·55. With added superphosphate, 1·25–1·60 times the initial NH4-N in manure was found in the compost after 80 days compared with only 0·11–0·22 for lime and 0·22–0·36 for straw only. Covering stored slurry and addition of superphosphate when composting solid pig manure are thus important methods for Vietnamese farmers to minimize N losses and produce compost with a high content of plant-available N.

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