Stimulation of root growth and soil nitrogen uptake by foliar application of urea to wheat and sunflower

1996 ◽  
Vol 126 (2) ◽  
pp. 127-135 ◽  
Author(s):  
S. Sen ◽  
P. M. Chalk
Keyword(s):  
Soil Nitrogen ◽  
Root Biomass ◽  
Dry Matter ◽  
Foliar Application ◽  
Urea Solution ◽  
Soil N ◽  
Clay Loam ◽  
Limited Effectiveness ◽  
N Status ◽  
Stimulation Of

SUMMARYWheat and sunflower plants were grown in a temperature-controlled glasshouse in Melbourne, Australia (37° 50′ S, 145° 00′ E), from 9 August to 2 October 1991, in cylinders containing two soils (Walpeup loamy sand (LS) and Gombalin clay loam (CL)) of low and moderate N status, respectively. Nitrogen fertilizer was applied by immersion of leaves in 0·18 M urea solution (10·5 atom% 15N).Plants were N-deficient in the Walpeup LS but not in the Gombalin CL soils. Both species had higher root: shoot ratios, and higher proportions of foliar-absorbed N were transferred to the roots, in the Walpeup LS plants. Plant N derived from the fertilizer and root or shoot dry matter were significantly correlated only when plants were N-deficient.In the Walpeup LS soil, N-fertilized wheat harvested 33 days after sowing (DAS) took up significantly less soil N compared with unfertilized plants, whereas significantly more soil N was taken up by N-fertilized sunflower compared with unfertilized plants harvested at 54 DAS. The fertilizerinduced response in uptake of soil N was directly related to the observed response in production of root biomass for both species. The different responses were related to the severity of the N deficiency and the limited effectiveness of foliar applications of urea in ameliorating the deficiency.

scholarly journals Evaluation of legumes and poultry manure for the early protection of burnt soils .

2014 ◽  
Vol 2 ◽  
Author(s):  
Serafín González Prieto ◽  
Tarsy Carballas ◽  
Arturo Castro
Keyword(s):  
Root Biomass ◽  
N Uptake ◽  
Poultry Manure ◽  
Organic Amendments ◽  
Soil N ◽  
Plant N Uptake ◽  
N Losses ◽  
Lupinus Polyphyllus ◽  
N Status ◽  
Shoot And Root Biomass

Organic amendments combined with the sowing of gramineous grasses are effective for the early protection of burnt soils (BS) but cannot restore soil N status to pre-fire level; this has led to interest in combining their use with N<sub>2</sub> fixer legumes. The effectiveness of applying poultry manure (PM; 2 Mg ha<sup>-1</sup>) and sowing legumes (<em>Lotus corniculatus, Lupinus polyphyllus </em>and <em>Trifolium repens</em>) for the early protection of BS was compared with that of applying PM + <em>Lolium perenne</em> and growing these four species without PM in a 3-month pot experiment, which also included a control consisting of an unburnt soil (US). In US, the shoot and root biomass increased as follows: <em>Trifolium </em>~<em> Lotus </em>&lt;&lt; <em>Lolium </em>&lt; <em>Lupinus.</em> Compared with those grown in US, plants grown in BS were smaller and weaker in three species (<em>Lupinus, Lolium</em> and <em>Trifolium</em>). The reverse was true for the four species grown in BS+PM, which showed the benefits of PM addition. In all the treatments, plant N uptake, which prevents soil-N losses, increased as follows: <em>Trifolium </em>~ <em>Lotus</em> &lt; <em>Lupinus </em>&lt; <em>Lolium.</em> The lack of nodules observed suggested that none of the legumes fixed atmospheric-N<sub>2</sub>.

EFFECTS OF DESICCATED THYROID ON NON-ESTROGENIZED AND ESTROGENIZED SEXUALLY IMMATURE PULLETS

1960 ◽  
Vol 40 (2) ◽  
pp. 119-125 ◽  
Author(s):  
A. J. Moo-Young ◽  
K. A. McCully ◽  
R. H. Common
Keyword(s):  
Intramuscular Injection ◽  
Crude Protein ◽  
Dry Matter ◽  
Estradiol Benzoate ◽  
Kidney Weight ◽  
Total Crude Protein ◽  
Stimulation Of ◽  
Liver Tissues

Inclusion of 0.5 per cent desiccated thyroid in the food of unestrogenized immature pullets for 14 days reduced thyroid weight, reduced serum Ca slightly but significantly, increased liver total crude protein, liver total DNAP and total RNAP, but did not alter the ratio RNAP:DNAP in the liver. These results are regarded as indicative of stimulation of growth of liver tissues by the thyroidal treatment.Daily intramuscular, injection of 1.0 mg. estradiol benzoate for 14 days greatly increased serum Ca and liver total crude protein, increased slightly liver total DNAP and increased greatly liver total RNAP and ratio RNAP: DNAP in the liver. The thyroidal treatment reduced estrogen-induced increase of serum Ca and of liver crude protein but did not alter significantly the effects of estrogen on liver DNAP and RNAP.The thyroidal treatment increased kidney weight in both unestrogenized and estrogenized pullets.Estrogen treatment increased kidney weight and the percentage of dry matter in the kidney.The thyroidal treatment did not affect the degree of estrogen-induced hypertrophy of the oviduct.

Vegetation recovery alters soil N status in subtropical karst plateau area: Evidence from natural abundance δ15N and δ18O

2021 ◽  
Author(s):  
Jing Wang ◽  
Xuefa Wen ◽  
Sidan Lyu ◽  
Xinyu Zhang ◽  
Shenggong Li ◽  
...  
Keyword(s):  
Natural Abundance ◽  
Vegetation Recovery ◽  
Soil N ◽  
Plateau Area ◽  
N Status

scholarly journals Agriculture Model Comparison Framework and MyGeoHub Hosting: Case of Soil Nitrogen

Inventions ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 25
Author(s):  
Anupam Bhar ◽  
Benjamin Feddersen ◽  
Robert Malone ◽  
Ratnesh Kumar
Keyword(s):  
Soil Nitrogen ◽  
Field Data ◽  
Model Comparison ◽  
Test Model ◽  
Soil N ◽  
N Dynamics ◽  
Benchmark Model ◽  
C Dynamics ◽  
Comparison Results ◽  
Speed Up

To be able to compare many agricultural models, a general framework for model comparison when field data may limit direct comparison of models is proposed, developed, and also demonstrated. The framework first calibrates the benchmark model against the field data, and next it calibrates the test model against the data generated by the calibrated benchmark model. The framework is validated for the modeling of the soil nutrient nitrogen (N), a critical component in the overall agriculture system modeling effort. The nitrogen dynamics and related carbon (C) dynamics, as captured in advanced agricultural modeling such as RZWQM, are highly complex, involving numerous states (pools) and parameters. Calibrating many parameters requires more time and data to avoid underfitting. The execution time of a complex model is higher as well. A study of tradeoff among modeling complexities vs. speed-up, and the corresponding impact on modeling accuracy, is desirable. This paper surveys soil nitrogen models and lists those by their complexity in terms of the number of parameters, and C-N pools. This paper also examines a lean soil N and C dynamics model and compares it with an advanced model, RZWQM. Since nitrate and ammonia are not directly measured in this study, we first calibrate RZWQM using the available data from an experimental field in Greeley, CO, and next use the daily nitrate and ammonia data generated from RZWQM as ground truth, against which the lean model’s N dynamics parameters are calibrated. In both cases, the crop growth was removed to zero out the plant uptake, to compare only the soil N-dynamics. The comparison results showed good accuracy with a coefficient of determination (R2) match of 0.99 and 0.62 for nitrate and ammonia, respectively, while affording significant speed-up in simulation time. The lean model is also hosted in MyGeoHub cyberinfrastructure for universal online access.

scholarly journals Effects of nitrogen and phosphorus additions on nitrous oxide emission in a nitrogen-rich and two nitrogen-limited tropical forests

2016 ◽  
Vol 13 (11) ◽  
pp. 3503-3517 ◽  
Author(s):  
Mianhai Zheng ◽  
Tao Zhang ◽  
Lei Liu ◽  
Weixing Zhu ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Tropical Forests ◽  
N2o Emission ◽  
N Deposition ◽  
Soil N ◽  
N Addition ◽  
Old Growth ◽  
Old Growth Forest ◽  
P Addition ◽  
Stimulation Of

Abstract. Nitrogen (N) deposition is generally considered to increase soil nitrous oxide (N2O) emission in N-rich forests. In many tropical forests, however, elevated N deposition has caused soil N enrichment and further phosphorus (P) deficiency, and the interaction of N and P to control soil N2O emission remains poorly understood, particularly in forests with different soil N status. In this study, we examined the effects of N and P additions on soil N2O emission in an N-rich old-growth forest and two N-limited younger forests (a mixed and a pine forest) in southern China to test the following hypotheses: (1) soil N2O emission is the highest in old-growth forest due to the N-rich soil; (2) N addition increases N2O emission more in the old-growth forest than in the two younger forests; (3) P addition decreases N2O emission more in the old-growth forest than in the two younger forests; and (4) P addition alleviates the stimulation of N2O emission by N addition. The following four treatments were established in each forest: Control, N addition (150 kg N ha−1 yr−1), P addition (150 kg P ha−1 yr−1), and NP addition (150 kg N ha−1 yr−1 plus 150 kg P ha−1 yr−1). From February 2007 to October 2009, monthly quantification of soil N2O emission was performed using static chamber and gas chromatography techniques. Mean N2O emission was shown to be significantly higher in the old-growth forest (13.9 ± 0.7 µg N2O-N m−2 h−1) than in the mixed (9.9 ± 0.4 µg N2O-N m−2 h−1) or pine (10.8 ± 0.5 µg N2O-N m−2 h−1) forests, with no significant difference between the latter two. N addition significantly increased N2O emission in the old-growth forest but not in the two younger forests. However, both P and NP addition had no significant effect on N2O emission in all three forests, suggesting that P addition alleviated the stimulation of N2O emission by N addition in the old-growth forest. Although P fertilization may alleviate the stimulated effects of atmospheric N deposition on N2O emission in N-rich forests, this effect may only occur under high N deposition and/or long-term P addition, and we suggest future investigations to definitively assess this management strategy and the importance of P in regulating N cycles from regional to global scales.

scholarly journals Effects of elevated CO2 on fine root biomass are reduced by aridity but enhanced by soil nitrogen: A global assessment

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Juan Piñeiro ◽  
Raúl Ochoa-Hueso ◽  
Manuel Delgado-Baquerizo ◽  
Silvan Dobrick ◽  
Peter B. Reich ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Soil Nitrogen ◽  
Root Biomass ◽  
Global Assessment ◽  
Fine Root ◽  
Fine Root Biomass

Comparison of rotations in which barley for grain follows woollypod vetch or forage barley

1987 ◽  
Vol 108 (3) ◽  
pp. 609-615 ◽  
Author(s):  
I. Papastylianou ◽  
Th. Samios
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Nitrogen Concentration ◽  
N Balance ◽  
Dry Matter Yield ◽  
Soil N ◽  
Fertilizer N ◽  
Total Soil ◽  
Using Data ◽  
Total Soil N

SummaryUsing data from rotation studies in which barley or woollypod vetch were included, both cut for hay and preceding barley for grain, it is shown that forage barley gave higher dry-matter yield than woollypod vetch (3·74 v. 2·92 t/ha per year). However, the latter gave feedingstuff of higher nitrogen concentration and yield (86 kg N/ha per year for vetch v. 55 kg N/ha per year for barley). Rainfall was an important factor in controlling the yield of the two forages and the comparison between them in different years and sites. Barley following woollypod vetch gave higher grain yield than when following forage barley (2·36 v. 1·91 t/ha). Rotation sequences which included woollypod vetch had higher output of nitrogen (N) than input of fertilizer N with a positive value of 44–60 kg N/ha per year. In rotations where forage barley was followed by barley for grain the N balance between output and input was 5–6 kg N/ha. Total soil N was similar in the different rotations at the end of a 7-year period.

Dynamics of nitrogen and dry-matter partitioning and accumulation in broccoli (Brassica oleracea var. italica) in relation to extractable soil inorganic nitrogen

1999 ◽  
Vol 79 (2) ◽  
pp. 277-286 ◽  
Author(s):  
P. A. Bowen ◽  
B. J. Zebarth ◽  
P. M. A. Toivonen
Keyword(s):  
Dry Matter ◽  
N Fertilization ◽  
N Fertilizer ◽  
Organic N ◽  
Soil N ◽  
Inorganic N ◽  
N Accumulation ◽  
Spring Planting ◽  
Extractable Soil ◽  
Soil Inorganic

The effects of six rates of N fertilization (0, 125, 250, 375, 500 and 625 kg N ha−1) on the dynamics of N utilization relative to extractable inorganic N in the soil profile were determined for broccoli in three growing seasons. The amount of pre-existing extractable inorganic N in the soil was lowest for the spring planting, followed by the early-summer then late-summer plantings. During the first 2 wk after transplanting, plant dry-matter (DM) and N accumulation rates were low, and because of the mineralization of soil organic N the extractable soil inorganic N increased over that added as fertilizer, especially in the top 30 cm. From 4 wk after transplanting until harvest, DM and N accumulation in the plants was rapid and corresponded to a rapid depletion of extractable inorganic N from the soil. At high N-fertilization rates, leaf and stem DM and N accumulations at harvest were similar among the three plantings. However, the rates of accumulation in the two summer plantings were higher before and lower after inflorescence initiation than those in the spring planting. Under N treatments of 0 and 125 kg ha−1, total N in leaf tissue and the rate of leaf DM accumulation decreased while inflorescences developed. There was little extractable inorganic soil-N during inflorescence development in plots receiving no N fertilizer, yet inflorescence dry weights and N contents were ≥50 and ≥30%, respectively, of the maxima achieved with N fertilization. These results indicate that substantial N is translocated from leaves to support broccoli inflorescence growth under conditions of low soil-N availability. Key words: N translocation, N fertilizer

Effect of in-season application methods of fertilizer nitrogen on grain yield and nitrogen use efficiency in maize

2004 ◽  
Vol 84 (2) ◽  
pp. 169-176 ◽  
Author(s):  
B. L. Ma ◽  
M. Li ◽  
L. M. Dwyer ◽  
G. Stewart
Keyword(s):  
Grain Yield ◽  
Nitrogen Use Efficiency ◽  
Dry Matter ◽  
Foliar Spray ◽  
Soil N ◽  
Nitrogen Use ◽  
N Application ◽  
Maize Hybrids ◽  
Use Efficiency ◽  
Application Methods

Little information is available comparing agronomic performance and nitrogen use efficiency (NUE) for N application methods such as foliar spray, soil application, and ear injection in maize (Zea mays L.). The objective of this study was to investigate the effects of various N application methods on total stover dry matter, grain yield, and NUE of maize hybrids using a 15N-labeling approach. A field experiment was conducted on a Dalhousie clay loam in Ottawa and a Guelph loam in Guelph for 2 yr (1999 and 2000). Three N application methods were tested on two maize hybrids, Pioneer 3893 and Pioneer 38P06 Bt. At planting, 60 kg N ha-1 as ammonium nitrate was applied to all treatments. In addition, 6.5 kg N ha-1 and 13.5 kg N ha-1 as 15N-labeled urea were applied to either foliage (Treatment I) or soil (Treatment II) at V6 and V12 stages, respectively. In Treatment III, 20 kg N ha-1 as 15N-labeled urea was injected into space between ear and husks at silking. The results showed that compared with soil N application neither foliar spray nor injection through ear affected grain yield or stover dry matter. The NUE values ranged from 12 to 76% for N fertilizer applied at V6 a nd V12 stages, or at silking for all treatments. There was no interaction of hybrid × N application methods on any variables measured with the only exception that for soil N application, grain NUE in Pioneer 38P06 Bt was significant higher than in Pioneer 3893. The difference in total N and NUE of grain and stover between soil N application and foliar N spray was inconsistent. However, NUE was substantially higher for N injection through the ear than for foliar or soil application without differential responses between the two hybrids. Nitrogen injection through the ear at silking might have altered N redistribution within the plant and improved NUE. Hence, it can potentially enhance grain protein content. Foliar N spray is not advocated for maize production in Ontario. Key words: Maize, Zea mays, nitrogen application methods, nitrogen-15, yield, nitrogen use efficiency

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