Meadow bromegrass response to coated and conventional urea fertilizers

1998 ◽  
Vol 78 (4) ◽  
pp. 589-595 ◽  
Author(s):  
S. S. Malhi ◽  
K. Heier ◽  
M. Zhang ◽  
M. Nyborg

In central Alberta, surface-broadcast urea is usually less effective in increasing grass forage yield than ammonium nitrate (AN) due to volatilization loss. A 2-yr field experiment was conducted in 1994 and 1995 on meadow bromegrass (Bromus bibersteinii Roem and Shult 'Regar') at Eckville, Alberta to compare a number of synthetic con-trolled-release urea fertilizers with conventional urea and AN fertilizers for their effect on dry matter yield (DMY), protein yield (PY), N-use efficiency (NUE) and percent N recovery (NR). The N fertilizers were applied at 100 kg N ha−1 in early June of 1994 and mid-April of 1995. The meadow bromegrass was harvested three times during the May to September growing season. In both years there was a significant forage yield response to applied N. In 1994, the DMY, PY, NUE and NR were similar for urea and AN, and most of the treated urea products were inferior to urea alone. This was most likely due to delayed application of N fertilizer until just before the start of summer rains. In 1995, urea had lower DMY (by 874 kg ha−1), PY (by 177 kg ha−1), NUE (by 8.8 kg DM kg−1 N ha−1) and NR (by 27.3%) than AN. Some of the coated urea products (e.g., Sh. 19, Sh. G) gave significantly greater DMY, PY, NUE and NR than urea alone, though still less than AN. These results suggest that under conditions when surface-applied urea is inferior to AN, its effectiveness can be improved by using Sh. 19 and Sh. G controlled-release urea fertilizers on grassland. The controlled-release fertilizers may be more expensive and therefore, additional cost must be considered as compared with AN before using on a commercial basis. Key words: Ammonium nitrate, bromegrass, controlled-release N fertilizers, forage yield, N recovery, urea

2017 ◽  
Vol 48 (1) ◽  
Author(s):  
Thais Antolini Veçozzi ◽  
Rogério Oliveira de Sousa ◽  
Walkyria Bueno Scivittaro ◽  
Cristiano Weinert ◽  
Victor Raul Cieza Tarrillo

ABSTRACT: A study was conducted to evaluate the solubilization and nitrogen (N) use efficiency (NUE) of controlled release nitrogen fertilizers in irrigated rice, compared to urea. It was developed under semi-controlled conditions, including five treatments: Control, Splitted Urea (pre-sowing and topdressing), Pre-sowing urea, and Polymer Coated Urea (PCU) with 60-day and 90-day release. PCUs did not maintain high NH4 + and NO3 - levels in solution over a longer period than urea. NUE of PCUs was similar to uncoated urea, not increasing nutrient release in irrigated rice field.


1988 ◽  
Vol 68 (2) ◽  
pp. 457-470 ◽  
Author(s):  
H. UKRAINETZ ◽  
C. A. CAMPBELL

A 5–yr study was conducted on a Dark Brown loam at Scott, Saskatchewan to determine the effect of rate of ammonium nitrate-N (34–0–0) and urea-N (46–0–0) on bromegrass (Bromus inermis Leyss.) production and quality, N recovery and N use efficiency when the N was applied either annually or as a single application at the start of the experiment. The effect of phosphorus (P) on the above listed parameters was also assessed. Each N source was applied at once-only rates of 0, 100, 200, 400, and 800 kg ha−1 and annual rates were 0, 50, 100 and 200 kg ha−1. Phosphorus was applied in 1976, 1979 and 1981 at 100 kg ha−1 P2O5. Forage dry matter was positively related to precipitation received in April–June (r = 0.91**) and in April of the crop year plus the previous September (r = 0.80**). Dry matter response to N rates generally increased at a decreasing rate in early years but linearly in later years. Over the first 4 yr, annual applications of N resulted in up to 37% more dry matter than the single applications. Dry matter production was generally greater when ammonium nitrate was applied than when urea was used; these differences were more consistent at medium N rates. Dry matter was increased by P only when N was applied. Nitrogen concentration in forage was directly related to N rate in years of good precipitation, was greater in dry than wet years, and when N was applied annually, but was unaffected by N source. Phosphorus fertilization increased P concentration of forage but heavy dry matter production reduced P concentration. Annual N applications increased P concentration in forage only in the first year and N source had no effect. Toxic concentrations of NO3–N in the forage occurred in the first year only at N rates [Formula: see text] and were directly related to the amount of N applied. Except for the 800 kg ha−1 N rate in the second year, there were no further indications of NO3–N toxicity. Accumulated N use efficiency decreased linearly with increasing N rate and was greater for ammonium nitrate than for urea except at very high N rates. Accumulated N recovery was inversely related to N rate for the single method of application but unaffected by N rate applied annually. Over the first 4 yr, accumulated N recovery was greater for the single application at low N rates, but was greater for annual applications of N at high N rates. P fertilization increased N recovery.Key words: N source, bromegrass, N recovery, yield, quality, application method


1988 ◽  
Vol 68 (3) ◽  
pp. 687-703 ◽  
Author(s):  
H. UKRAINETZ ◽  
C. A. CAMPBELL ◽  
R. P. ZENTNER ◽  
M. MONREAL

A 9-yr study was conducted on a Gray Luvisolic loam at Loon Lake, Saskatchewan to determine the effect of ammonium nitrate-N (34–0–0) and urea-N (46–0–0) on bromegrass (Bromus inermis Leyss.) production and nutrient quality, N recovery, and N use efficiency when the N was applied either annually or as a single application at the start of the experiment. The effects of phosphorus (P) and sulphur (S) were also assessed. Each N source was applied at single rates of 0, 100, 200, 400 and 800 kg ha−1 N and annual rates of 0, 50, 100 and 200 kg ha−1 N. The ammonium nitrate was also applied as a single dose at rates of 600 and 1000 kg ha−1 N. Phosphorus and S were applied every second year at 224 kg ha−1 P2O5 and 45 kg ha−1 S. Forage dry matter yields were positively related to precipitation received in May and July, and April–May, but negatively related to June precipitation. Forage dry matter production was greater over the first 8-yr period for annual N applications than for a single application receiving an equivalent amount of N; but fertilizer N recovered in forage over the same period was similar (about 30%) for the two methods of application. Dry matter yields were 19% greater after 4 yr and 26% greater after 8 yr when ammonium nitrate was used compared to urea. Recovery of fertilizer N in forage also favored the ammonium nitrate source. The application of low to moderate N rates depressed forage N and P concentrations when yield response was high but concentrations were increased by the highest rates of N fertilizer and by repeated annual applications of N. Toxic concentrations of NO3-N occurred in bromegrass in the first year when N was applied at or above 400 kg ha−1 as one application and also in the second year when N was applied at 800 kg ha−1. When N was applied annually at 200 kg ha−1, NO3-toxicity became a potential problem in later years as soil mineral N accumulated. Phosphorus and S fertilizers increased dry matter yields of forage; P fertilizer increased and S decreased forage P concentration. Annual N applications resulted in more uniform year-to-year yields and N uptake response compared to a single application and provided greater dry matter production without loss of nutritive quality. It was concluded that, in contrast to reports in the literature, the response of forage grasses to N is not site specific.Key words: N source, N recovery, N application method, N use efficiency, phosphorus, sulfur


2002 ◽  
Vol 139 (1) ◽  
pp. 11-25 ◽  
Author(s):  
R. J. READMAN ◽  
C. P. BECKWITH ◽  
P. S. KETTLEWELL

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.


Agriculture ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 541
Author(s):  
Gerhard Moitzi ◽  
Reinhard W. Neugschwandtner ◽  
Hans-Peter Kaul ◽  
Helmut Wagentristl

Improvements in nitrogen (N) use efficiency in crop production are important for addressing the triple challenges of food security, environmental degradation and climate change. The three fertilizers, calcium ammonium nitrate (CAN), urea (Urea) and stabilized urea (Ureastab), were applied at a rate of 160 kg N ha−1 with two or three splits to winter wheat (Triticum aestivum L.) in the Pannonian climate region of eastern Austria. On average, over all fertilization treatments, the grain yield (GY) increased by about a quarter and the grain N concentration (GNC) doubled compared to the control without fertilization. Consequently, the grain N yield (NYGRAIN) was increased with N fertilization by 154%. The GY increased due to a higher grain density with no differences between N fertilizers but with a tendency of a higher grain yield with three compared to two splits. Three splits also slightly increased the GNC and consequently the NYGRAIN of CAN and Ureastab in one year. The removal of N fertilizer with the NYGRAIN (N surplus) was higher than the amount of applied fertilizer. Fertilization decreased the N use efficiency (NUE), the N uptake efficiency (NUpE) and the N utilization efficiency (NUtE) but increased the soil mineral nitrate (NO3-N) at harvest and the apparent N loss (ANL). Three compared to two applications resulted in a higher NO3-N at harvest but also a lower N surplus due to partly higher NYGRAIN. Consequently, the ANL was lower with three compared to two splits. Also, the NUpE and the apparent N recovery efficiency (ANRE) were higher with three splits. The best N treatment regarding highest above-ground biomass yield with lowest N surplus, N balance and ANL was the three-split treatment (50 CAN, 50 CAN, 60 liquid urea ammonium nitrate). Three splits can, under semi-arid conditions, be beneficial when aiming high-quality wheat for bread-making and also for reducing the N loss. Whereas, two splits are recommended when aiming only at high GY, e.g., for ethanol-wheat production.


2010 ◽  
Vol 90 (2) ◽  
pp. 363-372 ◽  
Author(s):  
S S Malhi ◽  
Y K Soon ◽  
C A Grant ◽  
R. Lemke ◽  
N. Lupwayi

Field experiments were conducted on Dark Gray Luvisolic soils (Typic Cryoboralf) from 2004 to 2006 (wheat-canola-barley rotation) near Star City, Saskatchewan, and from 2004 to 2007 (barley-canola-wheat-barley rotation) near Beaverlodge, Alberta. The aim was to compare the effects of controlled-release urea (CRU) vs. conventional urea (hereafter called urea) on seed yield and N (i.e., protein) concentration, and N use efficiency (NUE). The treatments were combinations of tillage system [conventional tillage (CT) and no tillage (NT)], and N source (urea, CRU and a blended mixture), placement method (spring-banded, fall-banded and split application) and application rate (0-90 kg N ha-1). There was no tillage × fertilizer treatment interaction on the measured crop variables. Seed yield and crop N uptake and, to a lesser degree, seed N concentration generally increased with N application to 90 kg N ha-1. Fall-banded CRU or urea generally produced lower crop yield and N uptake than spring-banded CRU or urea. Split application of urea (half each at seeding and tillering) resulted in higher seed yield and N concentration in at least 3 of 7 site-years than did CRU and urea applied at a similar rate. A blend of urea and CRU was as effective as spring-banded CRU (at Star City only). Seed yield, N recovery and NUE were higher with spring-banded CRU than urea in 2 site-years, and similar to urea in other site-years. We conclude that for boreal soils of the Canadian prairies, spring-banded CRU is as effective as urea, and in some years more effective, in increasing crop yield and N recovery; however, urea split application can be even more effective in addition to having an advantage in managing risk.Key words: Controlled-release urea, Gray Luvisol, nitrogen source, nitrogen recovery, nitrogen use efficiency, tillage systems


Author(s):  
Bernardo Melo Montes Nogueira Borges ◽  
Fernanda Ribeiro Peixoto ◽  
Marilena de Melo Braga ◽  
Barbara de Brito Brunozzi ◽  
Maria Lucia Silveira ◽  
...  

Nitrogen fertilization is an important input for crop yield; however, it can result in detrimental environmental effects due to low use efficiency of regular N sources. This study evaluated the effects of N fertilizers and application strategies (single vs. split application) on bermudagrass (Cynodon spp.) responses and release pattern and rate in controlled and field incubations. The bermudagrass study was arranged in a two-way factorial scheme of 6 N fertilizers, urea, Polymer Coated Urea (PCU), PCU-6 (6 months), PCU-4 (4 months), PCU-2 (2 months) and urea + urease inhibitor (U-NBPT) applied as a single (400 kg N ha-1 yr-1) or two split applications of 200 kg N ha-1 (400 kg N ha-1 yr-1). The controlled experiment was a two-way factorial of PCU-6, PCU-4, PCU-2 and 15, 45 and 90% water hold capacity (WHC), sampling period of 170 days, the field incubation used the same sources sampled up to 220 days. Enhanced-efficiency fertilizers (EEF) increased herbage accumulation (HA) by 1.3 Mg ha-1 compared to untreated urea, on average. Nitrogen use efficiency (NUE) was greater for EEFs (44%) than urea (36%). Results showed that increased soil moisture inferred positive responses in release pattern and a minimum of 45% WHC was necessary for optimum release. Fertilizers at field conditions resulted in an earlier release than expected, ~20 days.


Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1505
Author(s):  
Amritbir Riar ◽  
Gurjeet Gill ◽  
Glenn K. McDonald

Canola has a high nitrogen requirement and optimal nitrogen (N) management in environments with variable rainfall is a challenge. This study investigated the impact of timing of N as a single or split application at different growth stages on seed yield, N uptake and water-use efficiency in canola. Nitrogen rates of 100 and 200 kg ha−1 were applied after sowing when two leaves were unfolded or equally split between the rosette, green bud and first flower stages. The experiments were conducted at two sites with contrasting rainfall and a supplementary irrigation treatment at the low rainfall site, generating a third environment. Nitrogen application increased seed yield by up to 20% at a high rainfall site and by up to 77% at a medium rainfall site, but the timing of N did not significantly affect the yield response to N. Seed yield was closely associated with total dry matter production and seed m−2. N-use efficiency was influenced more by N recovery and uptake efficiency, rather than physiological efficiency, which highlights the importance of soil moisture availability and the ability of the crop to exploit soil water and N reserves. The results suggest that better use of subsoil moisture by overcoming some of the subsoil constraints may be an avenue for further improvements in yield and nitrogen-use efficiency (NUE) of canola in this environment.


2001 ◽  
Vol 1 ◽  
pp. 114-121 ◽  
Author(s):  
Lenz Haderlein ◽  
T.L. Jensen ◽  
R.E. Dowbenko ◽  
A.D. Blaylock

Controlled release nitrogen (N) fertilizers have been commonly used in horticultural applications such as turf grasses and container-grown woody perennials. Agrium, a major N manufacturer in North and South America, is developing a low-cost controlled release urea (CRU) product for use in field crops such as grain corn, canola, wheat, and other small grain cereals. From 1998 to 2000, 11 field trials were conducted across western Canada to determine if seed-placed CRU could maintain crop yields and increase grain N and N use efficiency when compared to the practice of side-banding of urea N fertilizer. CRU was designed to release timely and adequate, but not excessive, amounts of N to the crop. Crop uptake of N from seed-placed CRU was sufficient to provide yields similar to those of side-banded urea N. Grain N concentrations of the CRU treatments were higher, on average, than those from side-banded urea, resulting in 4.2% higher N use efficiency across the entire N application range from 25 to 100 kg ha-1. Higher levels of removal of N in grain from CRU compared to side-banded urea can result in less residual N remaining in the soil, and limit the possibility of N losses due to denitrification and leaching.


Author(s):  
Chuang Ba ◽  
Songling Chen ◽  
Ming Yang ◽  
Na Yu ◽  
Yuling Zhang ◽  
...  

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