Effect of post-emergence nitrogen application on the yield and protein content of wheat

2005 ◽  
Vol 85 (2) ◽  
pp. 327-342 ◽  
Author(s):  
R. E. Karamanos ◽  
N. A. Flore ◽  
J. T. Harapiak

Post-emergence application of N with wheat is contemplated as a practice for managing risk and reducing fertilizer N costs. An attempt was made to develop a comprehensive agronomic package relating to the practice of post-emergence applications by examining aspects relating to the rates of N, timing of post-emergence applications and products that might be used for that purpose. An extensive database of 49 trials conducted between 1995 and 1998 separated in five experimental plans was utilized to address the above issues. Nitrogen rates of up to 100 kg N ha-1 were employed as soil applied at seeding by side banding (0, 20, 40 and 60 kg N ha-1) plus topdressed (0, 20 and 40 kg ha-1) as post-emergence applications between Feekes growth stages 10.4 and 10.5. The effect of timing was explored in three different experimental designs that included rates up to 100 kg ha-1 applied at seeding or split, so that a post-emergence application of 20 kg N ha-1 was applied at Feekes growth stages 10 and 10.5, or up to 60 kg N ha-1, applied either all at seeding time or 20 or 40 kg N ha-1 at seeding time accompanied by 20 or 40 kg N ha-1 in a post-emergence application at Feekes growth stages 3–4, 6, 10.5 or 11. A number of products (ammonium nitrate, ammonium sulphate, urea, urea ammonium nitrate, Pro N and N serve) were also evaluated for their effectiveness in post-emergence applications. Two distinct trends emerged from all experiments depending on whether application of N at seeding corrected an N deficiency. If N deficiency was corrected by the application rate at seeding then the post-emergence N application increased grain protein concentrations; however, this practice was shown to result in no economic advantage. If N deficiency was not corrected by the N application at seeding, post-emergence applications at late growth stages increased grain protein of wheat at the expense of grain yield. This increase was greater in soils containing soil organic matter (SOM) concentrations less than 5% than those over 5%. Increases in grain protein ranged from 0.7 to 1.5% depending on initial fertilization regime, but they were not sufficient in any of the circumstances to economically compensate for the loss in grain yield caused by insufficient application of N at seeding. The performance of a number of products used for post-emergence application on the protein of hard red spring wheat was mixed with none proving to be consistently superior. Post-emergence application of N to enhance either the grain yield or protein of hard red spring wheat could be effective under high moisture or irrigated conditions; however, this practice represents a relatively high-risk practice under dryland conditions in the western Canadian prairies. Key words: Economics, growth stage, N rates, N products, timing

2014 ◽  
Vol 94 (2) ◽  
pp. 329-335 ◽  
Author(s):  
C. A. Grant

Grant, C. A. 2014. Use of NBPT and ammonium thiosulphate as urease inhibitors with varying surface placement of urea and urea ammonium nitrate in production of hard red spring wheat under reduced tillage management. Can. J. Plant Sci. 94: 329–335. Field studies were conducted at two locations over 3 yr to evaluate the effect of surface placement of urea ammonium nitrate (UAN) and urea fertilizers, with and without the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) on straw and grain yield of hard red spring wheat (Triticum aestivum L.) grown under reduced tillage management. Ammonium thiosulphate (ATS) was also evaluated as a urease inhibitor with UAN. Surface sprayed applications of UAN were frequently less effective than dribble-banded UAN applications or broadcast or dribble-banded urea in increasing grain or straw yield of hard red spring wheat. Use of NBPT with the sprayed UAN increased its effectiveness, so that grain and straw yields were similar to those with urea or with surface dribble-banded UAN. Addition of NBPT to broadcast or banded urea did not increase straw or grain yield under the conditions of this study. While there was some indication that use of ATS with UAN may have had a limited effect on fertilizer efficiency, it did not increase final grain yield as compared with dribble-banded or spray UAN applied alone or with NBPT. If surface nitrogen (N) applications are used in reduced tillage systems, spray applications of UAN should be avoided in favour of dribble-band applications, or the use of urea. Alternately, NBPT may be effective in improving the efficacy of spray UAN.


2007 ◽  
Vol 87 (4) ◽  
pp. 709-718 ◽  
Author(s):  
B. J. Zebarth ◽  
E. J. Botha ◽  
H. Rees

Use of an in-season measurement of crop nitrogen (N) status to optimize fertilizer N management has been proposed as a means of optimizing yield of spring wheat while minimizing environmental N losses. This study determined the effect of the rate and time of fertilizer N application on the grain yield, grain protein, and apparent recovery of fertilizer N in grain and in the above-ground plant for spring wheat (Triticum aestivum L.) in 2001–2003, and evaluated the use of a SPAD-502 meter to measure crop N status in spring wheat. Sixteen N fertility treatments were used, including application of different rates of fertilizer N (0–160 kg N ha-1) applied pre-seeding (ZGS 0), at tillering (ZGS 21) and at shooting (ZGS 32) as ammonium nitrate. Split N application provided no benefit in terms of grain yield or apparent recovery of fertilizer N. Application of fertilizer N at ZGS 32 reduced crop yield and apparent recovery of fertilizer N compared with N application at ZGS 0. Application of fertilizer N at ZGS 21 reduced yield and apparent recovery of fertilizer N in grain in 2 of 3 yr, but had no effect on apparent recovery of fertilizer N in the above-ground plant. Delayed fertilizer N application generally increased grain protein. Fertilizer N can be applied at ZGS 21 as required to optimize grain yield provided at least some fertilizer N is applied prior to seeding; however, crop N status cannot reliably be assessed at this time using a SPAD-502 meter. Crop N status can be assessed at ZGS 32 using a SPAD-502 meter; however, fertilizer N application at this time primarily influences grain protein rather than grain yield. These results highlight the need for a means of predicting soil N mineralization potential in order to optimize grain yield in humid environments where carry-over of soil nitrate from the previous growing season is limited. Key words: Triticum aestivum; N mineralization; soil N supply; SPAD-502 meter, leaf chlorophyll index


1998 ◽  
Vol 49 (4) ◽  
pp. 695 ◽  
Author(s):  
S. Boonchoo ◽  
S. Fukai ◽  
Suzan E. Hetherington

Two types of experiments were conducted with the malting barley cv. Grimmett to examine how assimilate and nitrogen (N) availability at different growth stages determined yield and grain protein concentration (GPC) in south-east Queensland. In one series of experiments, plants were sown in April, June, and August so that they would experience different growing conditions, and responses to N application rate were examined. Another experiment examined response of growth, yield, and GPC to variation of assimilate production pre and post anthesis, caused by the canopy manipulation treatments of opening, closure, and 50% shading at 3 different growth stages. Without N application all 3 sowings produced similar yields (1·9-2·3 t/ha), but when N was applied, yield was higher and responded more to applied N in the June sowing than in the other sowings.The different responses of grain yield to N application rate among the 3 sowing dates were not due to differences in N uptake but to the efficiency of N use; with favourable temperatures throughout crop growth, the crop sown in June utilised N most eciently to develop a large number of grainsand to produce sufficient as similates to fill these grains. When yield had a positive response to low N application rates, then there was generally no response of GPC, whereas when there was no response of grain yield to further rate of N application then GPC increased. The results of the second experiment show that N uptake depended on plant N demand at early stages of growth when N was still available in the soil, but total N content of tops at maturity was similar among canopy manipulation treatments. Canopy opening at any stage of growth tended to increase tiller number, leaf area index, and above-ground dry matter, but the effect was greater attillering stage which produced the highest yield because of the greatest number of heads. Shading reduced yield at all stages, but particularly at pre-anthesis. Shading and canopy closure during grain filling reduced grain yield, but with similar N uptake these treatments significantly increased GPC .These results indicate that GPC depends on both assimilate and N availability to grain, and GPC can increase sharply when grain yield is reduced with low assimilate availability as a result of adverse growing conditions. Responses of grain yield to applied N depended on environmental conditions, particularly the patterns of air temperature during growth, and the crop utilised N more efficiently to produce higher yield when it was not exposed to extreme temperatures during the latter stages of growth.


Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 171
Author(s):  
Tao Sun ◽  
Xin Yang ◽  
Xiaoli Tan ◽  
Kefeng Han ◽  
Sheng Tang ◽  
...  

Previous studies have revealed that the japonica/indica hybrid rice has a higher yield potential, biomass production, and nitrogen (N) accumulation than japonica rice in China, however, at a single N application rate. It remains unclear whether it also occurs at a higher or lower N application rate under the same field condition. To investigate the effects of nitrogen application rates on grain yield, N uptake, dry matter accumulation, and agronomic N use efficiency, field experiments were conducted in Jinhua City, Zhejiang Province during three consecutive growth seasons in 2016, 2017, and 2018. Two japonica/indica hybrid varieties (Yongyou 12 and Yongyou 538) and two japonica varieties (Xiushui 134 and Jia 58) were exposed to five N application rates (0, 150, 225, 300, and 375 kg ha−1). The results showed that grain yields of all the varieties increased with increasing nitrogen application rates, except for Jia 58 whose optimum nitrogen level was 225 kg ha−1, because no significant difference was observed between N225 and N300. Across the four rice varieties, N uptake increased significantly with increased N-fertilizer rates at all the growth stages (p < 0.05). Across the three planting years, the average grain yield of japonica/indica hybrid rice was higher than that of japonica rice by 75.6% at N0, 57.2% at N150, 41.1% at N225, 38.3% at N300, and 45.8% at N375. We also found that as compared with japonica rice, the japonica/indica hybrid rice had more grain yield, higher dry matter, and higher N uptake at all growth stages, regardless of the N application rate.


2001 ◽  
Vol 81 (4) ◽  
pp. 631-636 ◽  
Author(s):  
F. Selles ◽  
R. P. Zentner

Results from fertilizer trials with hard red spring wheat (Triticum aestivum L.) conducted throughout southwestern Saskatchewan under fallow and cereal stubble cropping conditions were used to determine if grain prote in concentration (GPC) could be used as an index of N sufficiency to the crop. Critical GPC were determined using the Cate-Nelson R2 procedure. Grain yield and protein concentration were negatively correlated under stubble and for fallow cropping when yields were below 2858 kg ha–1 ± 179, with grain protein decreasing by 15 mg g–1 for every 1000kg ha–1 yield increase. In these two groups of observations, water and N availability, N yield and grain produced per unit N available suggested that water availability was the dominant factor limiting grain yield. For the portion of fallow observations in which grain yields were higher than 2858 kg ha–1, water availability was not limiting, and N availability controlled grain yield and protein concentration. In this group, a GPC of 128 mg g–1 (range of 123 to 135 mg g–1) marked the transition between N deficiency and sufficiency. Under stubble cropping and for the lower-yielding portion of the fallow cropping system, where water stress was predominant, the Cate-Nelson analysis identified critical protein concentrations of 160 and 154 mg g–1, respectively. However, these critical concentrations separated populations into moderately and severely water-stressed crops, rather than providing a separation based on N availability. We concluded that GPC as a post-harvest index of N sufficiency must be used with caution in southwestern Saskatchewan. Grain protein concentration below the critical limit of 128 mg g–1 is a reliable indicator of low N sufficiency, but high grain protein does not necessarily imply N sufficiency because, frequently, grain yield and protein concentration are negatively correlated due to water stress. Key words: Yield, protein, N availability, critical levels, water stress


2001 ◽  
Vol 81 (3) ◽  
pp. 399-404 ◽  
Author(s):  
P. M. Carr ◽  
G. B. Martin ◽  
W. W. Poland

Continuous wheat (Triticum aestivum L. emend. Thell.) and other intensive cropping systems are replacing t he wheat-fallow (WF) system in the semiarid prairie region of Canada and the northern USA. However, most wheat cultivar recommendations are based on performance in a WF system. Our objective was to determine if cultivar ranking for grain yield, grain protein concentration, and kernel weight changed for hard red spring wheat in WF compared with continuous wheat (WW) systems. Ten cultivars were seeded on a Dark Brown Chernozem loam following fallow and wheat over 3 consecutive years at Dickinson, ND, USA. Fertilizer was applied for equivalent yields in both systems based on soil test results. More grain and heavier kernels were produced during the crop phase of the WF system than the WW system, in part because soil-water content was greater after fallow than wheat in 2 of 3 yr. Grain protein concentration was unaffected by cropping system. Grain yield, grain protein concentration, and kernel weight differed among cultivars. Interactions did not occur between cropping systems and cultivars for any grain parameter. Results of this study support the hypothesis that wheat cultivar ranking based on performance in a WF system can be extended to a WW system. Key words: Crop rotation, cropping systems, fallow, monoculture, wheat


2006 ◽  
Vol 86 (3) ◽  
pp. 737-742 ◽  
Author(s):  
R. M. DePauw ◽  
R. E. Knox ◽  
F. R. Clarke ◽  
T. N. McCaig ◽  
J. M. Clarke ◽  
...  

Infinity hard red spring wheat (Triticum aestivum L.) has exhibited adaptation to a wide range of growing season temperatures and moisture availability. Infinity averaged significantly more grain yield than most other presently registered cultivars, and its grain protein concentration was significantly higher than that of Superb in the Saskatchewan Advisory Council trials. It matured significantly earlier than Superb. The straw length and strength, and volume weight of Infinity was intermediate to the check cultivars. Its seed size was smaller than that of AC Barrie and Superb. Infinity expressed resistance to prevalent races of stem rust and loose smut, moderate resistance to leaf rust and common bunt, and susceptibility to fusarium head blight. Infinity is eligible for all grades of the Canada Western Red Spring (CWRS) wheat class. Key words: Triticum aestivum L., cultivar description, adaptation, grain yield, grain protein, disease resistance


2021 ◽  
Vol 12 ◽  
Author(s):  
Karansher S. Sandhu ◽  
Paul D. Mihalyov ◽  
Megan J. Lewien ◽  
Michael O. Pumphrey ◽  
Arron H. Carter

Genomics and high throughput phenomics have the potential to revolutionize the field of wheat (Triticum aestivum L.) breeding. Genomic selection (GS) has been used for predicting various quantitative traits in wheat, especially grain yield. However, there are few GS studies for grain protein content (GPC), which is a crucial quality determinant. Incorporation of secondary correlated traits in GS models has been demonstrated to improve accuracy. The objectives of this research were to compare performance of single and multi-trait GS models for predicting GPC and grain yield in wheat and to identify optimal growth stages for collecting secondary traits. We used 650 recombinant inbred lines from a spring wheat nested association mapping (NAM) population. The population was phenotyped over 3 years (2014–2016), and spectral information was collected at heading and grain filling stages. The ability to predict GPC and grain yield was assessed using secondary traits, univariate, covariate, and multivariate GS models for within and across cycle predictions. Our results indicate that GS accuracy increased by an average of 12% for GPC and 20% for grain yield by including secondary traits in the models. Spectral information collected at heading was superior for predicting GPC, whereas grain yield was more accurately predicted during the grain filling stage. Green normalized difference vegetation index had the largest effect on the prediction of GPC either used individually or with multiple indices in the GS models. An increased prediction ability for GPC and grain yield with the inclusion of secondary traits demonstrates the potential to improve the genetic gain per unit time and cost in wheat breeding.


2006 ◽  
Vol 86 (1) ◽  
pp. 121-131 ◽  
Author(s):  
M. J. Wiens ◽  
M. H. Entz ◽  
R. C. Martin ◽  
A. M. Hammermeister

Field experiments were established at two locations in Manitoba in 2002 and 2003 to determine N contribution, moisture conservation, and weed suppression by alfalfa mulch applied to spring wheat (Triticum aestivum L). Mulch treatments included mulch rate (amount harvested from an area 0.5×, 1× and 2× the wheat plot area), and mulch application timing (at wheat emergence or at three-leaf stage). Positive relationships were observed between mulch rate and wheat N uptake, grain yield, and grain protein concentration. At Winnipeg, the 2× mulch rates (3.9 to 5.2 t ha-1) produced grain yields equivalent to where 20 and 60 kg ha-1 of ammonium nitrate-N was applied in 2002 and 2003, respectively. Where mulch and ammonium nitrate produced equivalent grain yield, grain protein in mulch treatments was often higher than where chemical fertilizer was used. N uptake was also observed in the following oat (Avena sativa L.) crop. The highest mulch rate (2×) produced higher N uptake and grain yield of second-year oat compared with ammonium nitrate treatments. N use efficiency of mulch-supplied N by two crops over 2 yr [calculated as (treatment N uptake – control N uptake)/total N added] was between 11 and 68%. Mulch usually suppressed annual weeds, with greater suppression with late- than early-applied mulch. Increased soil moisture conservation was observed with high mulch rates (≥ 4.3 t ha-1) at three sites. Alfalfa mulch holds promise for low-input cropping systems when used on wheat at the 2× rates. Key words: Legume N, low-input farming, integrated weed management, wheat protein


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