RELATIVE EFFICIENCY OF POINT-INJECTION AND SURFACE APPLICATIONS FOR N FERTILIZATION OF WINTER WHEAT

1990 ◽  
Vol 70 (2) ◽  
pp. 189-201 ◽  
Author(s):  
H. H. JANZEN ◽  
C. W. LINDWALL ◽  
C. J. ROPPEL
Keyword(s):  
Winter Wheat ◽  
Ammonium Nitrate ◽  
Fertilizer N ◽  
N Application ◽  
Fertilizer Use Efficiency ◽  
Fertilizer Use ◽  
Point Injection ◽  
Use Efficiency ◽  
Urea Ammonium Nitrate ◽  
Methods Of Application

Conventional methods of N application for winter wheat often exhibit low fertilizer use efficiency. The comparative effectiveness of a new method, point-injection of N solution, was evaluated in two similar microplot field experiments established in southern Alberta. The first experiment, conducted over three site-year combinations in 1985 and 1986, compared yield response and fertilizer uptake in four spring-applied fertilizer treatments: broadcast urea-ammonium nitrate (UAN), broadcast urea, broadcast ammonium nitrate, and point-injected UAN, all applied in solution form. The second experiment, conducted at five sites in 1987, compared four spring-applied fertilizer treatments: surface-banded UAN, broadcast urea (granular), broadcast ammonium nitrate (granular), and point-injected UAN. All fertilizers were labeled with 15N to permit direct estimation of fertilizer uptake. The experiments demonstrated significant increases in fertilizer efficiency with point-injection under some conditions. In five of eight comparisons conducted over a 3-yr period, point-injection treatments exhibited significantly higher fertilizer use efficiency than conventional broadcast methods of application. Average fertilizer-N recovery by the crop at all eight sites was 37% in the point-injection treatments compared with only 26% in the broadcast ammonium nitrate treatment, the next most effective method of N application. When one site was excluded, because of possible confounding effects of application time, average recoveries were 34 and 26%, respectively. The increased efficiency of point-injected fertilizers was attributed to the direct placement of fertilizer N into the active rooting zone of the crop. The advantage of point-injection over conventional methods of application was highly variable, ranging from approximately 0 to over 100%, in part because of variations in precipitation patterns. The results of these microplot studies suggest that point-injection has potential for significant enhancement of fertilizer use efficiency in winter wheat, particularly in semi-arid production regions. Key words: 15N, nitrogen, urea, ammonium nitrate, fertilizer placement

Response of no-till winter wheat to nitrogen fertilization and drought stress

1992 ◽  
Vol 72 (4) ◽  
pp. 1075-1089 ◽  
Author(s):  
A. M. Johnston ◽  
D. B. Fowler
Keyword(s):  
Winter Wheat ◽  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Fertilizer N ◽  
N Application ◽  
Early Season ◽  
No Till ◽  
Crop Development ◽  
Use Efficiency

The yield of recrop winter wheat (Triticum aestivum L.) is a function of the interaction between agronomic management and the prevailing environment. Eight field trials were conducted over 2 yr on Dark Brown and Black Chernozemic soils in Saskatchewan to determine the influence of fertilizer-N rate and time of application on the early-season crop development and water use of no-till seeded winter wheat. Ammonium nitrate was surface broadcast on one of three schedules: as early as possible (early); 67% early and 33% at the beginning of stem elongation (split): or 3 wk after early (late), at rates of 0, 67, 134 and 202 kg N ha−1. In 1987, N fertilization resulted in the development and maintenance of a larger leaf-area index (LAI) and increased leaf conductance, leading to higher dry matter (DM) yield at anthesis and harvest. High air temperatures increased evaporative demand in 1988 and hastened crop development. Early-season response of both LAI and tiller number to fertilizer-N were abruptly terminated, followed by rapid pre-anthesis senescence in 1988. On average, 43% of harvest DM had accumulated by anthesis in 1987, compared with 78% in 1988. Although early N application increased and maintained LAI over late N in three of the eight trials, tiller responses to early N application were lost before anthesis under the environmental stress encountered. Increases in water-use efficiency of DM production with added N were a reflection of DM responses and not water use. Most of the soil water was extracted pre-anthesis, with on average 98% of post-anthesis evapotranspiration (ET) coming from rainfall. Maximum ET was associated with periods of high rainfall. Pre-anthesis DM yield increases associated with fertilizer-N, and dependence of post-anthesis ET on rainfall, resulted in increased plant stress and reduced leaf conductance during grain filling with fertilizer-N additions. Early correction of N deficiencies were required to efficiently utilize rainfall and stored soil water for biomass production under the recrop conditions used to produce no-till winter wheat in Saskatchewan’s semi-arid environment.Key words: Winter wheat, N application time, drought, water-use efficiency

scholarly journals Effect of nitrogen fertilizer application timing on nitrogen use efficiency and grain yield of winter wheat in Ireland

2016 ◽  
Vol 55 (1) ◽  
pp. 63-73 ◽  
Author(s):  
A. Efretuei ◽  
M. Gooding ◽  
E. White ◽  
J. Spink ◽  
R. Hackett
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Plant Density ◽  
Fertilizer Application ◽  
Yield Reduction ◽  
Growth Stages ◽  
Fertilizer N ◽  
N Application ◽  
Application Timing ◽  
Use Efficiency

Abstract The objectives of this work were to determine the effects of initiating application of fertilizer nitrogen (N) to winter wheat at different growth stages (GSs) on grain yield and N use efficiency (NUE). A factorial experiment was carried out in two growing seasons (2011 and 2012) with five timings of first N application (GS 24/26 [tillering], GS 30, GS 31, GS 32 or GS 37) and an unfertilized control, two sowing densities (100 and 400 seeds/m2) and a cattle slurry treatment (with or without slurry). The latter was included to simulate variation in soil N supply (SNS). Delaying the first application of N from the tillering stage until GS 30 had no significant effect on grain yield in either year. Further delaying the initial N application until GS 31 caused a significant yield reduction in 2011, in comparison to GS 30 application, but not in 2012. Differences in efficiency of recovery and use of fertilizer N by the crop among the first three application timings were small. There was no evidence to support alteration in the timing of the first application of N in response to low plant density. Slurry application did not influence SNS, so the interaction between SNS and fertilizer N application timing could not be determined. It is concluded that in order to maximise yield and NUE, the first N application should be applied to winter wheat between late tillering and GS 30 and that delaying the first N until GS 31 can lead to yield reductions compared to the yield obtained with earlier application.

Effects of spray application of urea fertilizer at stem extension on winter wheat: N recovery and nitrate leaching

2002 ◽  
Vol 139 (1) ◽  
pp. 11-25 ◽  
Author(s):  
R. J. READMAN ◽  
C. P. BECKWITH ◽  
P. S. KETTLEWELL
Keyword(s):  
Winter Wheat ◽  
Ammonium Nitrate ◽  
Nitrate Leaching ◽  
Nitrate Concentration ◽  
N Use Efficiency ◽  
Urea Solution ◽  
N Recovery ◽  
Fertilizer N ◽  
Use Efficiency ◽  
N Use

A field experiment was carried out at Harper Adams in Shropshire to investigate the effect of supplying the spring N application to winter wheat as different proportions of urea as a solution, rather than as conventional soil-applied solid urea, on N recovery in the above-ground crop, autumn soil mineral N and nitrate leaching over the subsequent winter. A solid ammonium nitrate treatment was also included to represent alternative commercial practice to solid urea. Treatments were repeated on the same plots over the 3 years 1992, 1993 and 1994. N recovery was measured in all 3 years by difference in N uptake between fertilized and unfertilized plots, and in 1993 for selected treatments, N was applied as 15N-labelled fertilizer to determine direct uptake of fertilizer N in the crop and soil. Both urea sprays and solid soil N applications were labelled with 15N. Urea sprays were split over several days to reduce scorch, whereas solid fertilizer was applied as a single dressing. For some urea spray treatments, apparent N recovery in the above-ground crop in 1992 and 1994 was less compared with soil-applied N treatments. These urea spray treatments were applied in the morning rather than the evening, and gaseous losses, most likely by volatilization, are suggested. In 1992 application of a large proportion of N as urea sprays, such that application of some N as urea solution was delayed to around GS 37, was associated with an increase in physiological N use efficiency. In 1993, there was no difference in direct or apparent recovery of fertilizer N in the crop or soil for N applied as ammonium nitrate, solid urea or as urea sprays. Mean nitrate concentration in the drainage water at 1 m was elevated for all N treatments in all years, but only in 1992 did nitrate concentration and leaching loss decrease with increasing proportion of N applied as urea sprays. It may therefore be possible to reduce gaseous losses by application of urea sprays under cool conditions in the evening and exploit the increased physiological N use efficiency for urea sprays applied later, such that total fertilizer N applied and N losses are reduced.

Grain protein responses to nitrogen applied to wheat growing on a red earth

1991 ◽  
Vol 42 (5) ◽  
pp. 735 ◽  
Author(s):  
JF Angus ◽  
RA Fischer
Keyword(s):  
Ammonium Nitrate ◽  
Theoretical Background ◽  
Yield Response ◽  
Grain Protein ◽  
Fertilizer N ◽  
South Wales ◽  
Eastern Australia ◽  
Red Earth ◽  
Subsequent Crop ◽  
Urea Ammonium Nitrate

Dryland wheat was fertilized with ammonium nitrate or liquid urea-ammonium nitrate at the time of sowing or about 3 months later (generally at the terminal-spikelet stage) on a well-drained site near Harden on the south-west slopes of New South Wales. The experiments continued from the second to the fifth year (1981-1984) of the cropping phase of a crop-pasture rotation. The maximum agronomic efficiencies for yield in the four consecutive years were 19, 4, 23 and 25 kg grain per kg of applied nitrogen (N). The three large responses were obtained in wetter than average seasons and the small response was obtained during drought. In the last three years of the study the yield response to nitrogen at the terminal-spikelet stage was found to be close to but slightly less than that for N applied at sowing. In those years the agronomic efficiencies for the late-applied N were 0, 22 and 22. The apparent recovery of fertilizer N in the above-ground parts of the crop at maturity was up to 70% of the fertilizer applied in the year of sowing, and, after the drought during which there was little uptake of fertilizer N, up to 62% by the subsequent crop. The fertilizer efficiencies in the non-drought years were higher than generally reported in south-eastern Australia, and indicate potential for profitable delayed application of N fertilizer to wheat. Grain-protein responses were variable from year to year and are discussed against a simple theoretical background of the amount of N applied and grain-yield response.

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