RESPONSE OF AN ORCHARDGRASS-PERENNIAL RYEGRASS SWARD TO RATE AND METHOD OF UREA AND AMMONIUM NITRATE APPLICATION

1983 ◽  
Vol 63 (4) ◽  
pp. 719-725 ◽  
Author(s):  
A. A. BOMKE ◽  
R. A. BERTRAND

Urea and ammonium nitrate were applied at rates of 75, 150 and 300 kg N/ha as either a single application in April or split into three equal increments, one applied in April and the second and third following cuts one and two. The orchardgrass-perennial ryegrass sward responded significantly to applied N in each year; however, the yield produced by the two sources differed in only one of the three years. In that year split applied ammonium nitrate gave 8% higher yields than similarly applied urea. The sources were found to be equivalent when applied in the spring. Split application of the N rates increased total annual dry matter yields in one of the three years regardless of N source. In all three years split application of N shifted forage production from cut one to cuts two and three. Key words: N uptake, split N application, orchardgrass-perennial ryegrass sward

1976 ◽  
Vol 12 (2) ◽  
pp. 189-193 ◽  
Author(s):  
A. Hamid ◽  
G. Sarwar

SUMMARYThe effect of split application of N on the uptake of N by wheat from N15 labelled ammonium nitrate and urea was studied in the field. Nitrogen fertilizers were applied at 120 kg N/ha in a single application (at seeding); two split applications (at seeding and tillering); and six split applications (at seeding, tillering, boot, heading, flowering and the milky stage). Nitrogen applied in two splits was most productive for grain yield for both the N sources, but six split applications significantly increased the protein content in grain compared with single or two split applications. The utilization of N from ammonium nitrate in grain was significantly higher than from urea when applied in six split applications.


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


1989 ◽  
Vol 69 (3) ◽  
pp. 841-859 ◽  
Author(s):  
R. P. ZENTNER ◽  
C. A. CAMPBELL ◽  
H. UKRAINETZ

A 5-yr study on a Dark Brown Loam at Scott and a 9-yr study on a Gray Luvisolic loam at Loon Lake, Saskatchewan, were used to determine the effect of rate of urea (46-0-0) and ammonium nitrate (34-0-0) fertilization on net returns from bromegrass (Bromus inermis Leyss.) production when the N was broadcast annually or as a single application at the start of the experiment. Each N source was applied at annual rates of 0, 50, 100, and 200 kg N ha−1 and at single application rates of 0, 100, 200, 400, and 800 kg ha−1. The ammonium nitrate was also applied at rates of 600 and 1000 kg ha−1. Comparisons of the discounted present value of net returns (NPV) over the study periods showed that N fertilization was highly profitable for all treatments under most forage price, N cost, and interest rate situations. The application of ammonium nitrate was consistently more profitable than urea despite its higher unit cost. At Scott, the 5-yr economic advantage of ammonium nitrate over urea averaged $53–$117 ha−1 for annual applications and $34–$72 ha−1 for single applications when forage price was varied from $0.05 to $0.09 kg−1; at Loon Lake, the corresponding 9-yr advantage of ammonium nitrate averaged $48–$121 ha−1 for annual and $25–$59 ha−1 for single applications. When price was adjusted to reflect forage N and P composition, the economic advantage of using ammonium nitrate over urea was enhanced. For treatments receiving similar rates of total applied N by both methods of application, NPV was generally higher when the N was applied in smaller doses annually compared to all at one time. At Scott, this effect was consistent at all N rates and for both N sources, but at Loon Lake, where moisture was more favorable, single applications at lower N rates often provided similar NPV as for annual N applications. The most profitable fertilizer treatments at Scott and Loon Lake were the 100- and 200-kg ha−1 rates of ammonium nitrate-N applied annually. When forage yields were related to N rate, moisture, and stand age for the annual N application treatments the economic optimum N rates depended greatly on the expectations for moisture, level of risk aversion, and on the ratio of fertilizer N cost to forage price. The optimum application rates of ammonium nitrate-N averaged 7–14 kg ha−1 higher at Scott and 8–27 kg N ha−1 higher at Loon Lake compared to those for urea. Further, the optimum N rates were higher than the general recommendation for bromegrass grown in these regions; thus producers should consider using higher N rates than has been the tradition for maximum economic return.Key words: Net returns, bromegrass hay, N source, N rates, application method


1997 ◽  
Vol 77 (1) ◽  
pp. 9-19 ◽  
Author(s):  
Thi Sen Tran ◽  
Marcel Giroux ◽  
Michel P. Cescas

The main objective of this study was to compare the recovery of 15N-labelled fertilizer by different methods of N application and N rates. Field experiments were carried out for 3 yr at Saint-Hyacinthe (Saint-Damase, Du Contour, Sainte-Rosalie soils) and at Saint-Lambert, Lévis (Le Bras soil). Grain corn (cv. Pride K228, 2700 CHU) and silage corn (cv. Hyland 3251, 2300 CHU) were grown at Saint-Hyacinthe and Saint-Lambert, respectively. In 1988 and 1989, field trials were arranged in a randomized complete bloc design consisting of five treatments in three replications: control 0 N and four split application methods of N fertilizer. Labelled 15NH4 15NO3 fertilizer was applied either banded at planting as starter (D), broadcast and incorporated before planting (Vs) or sidedressing between rows at V6 to V8 stages of corn (Bp). In 1990 field trials, treatments consisted of four N rates (0, 60, 120 and 180 kg N ha−1) labelled with 15NH4 15NO3. The effect of N rates on yield and N uptake by corn was significant in all years. However, the effect of application methods was significant only on the soil Du Contour in 1989 where corn grain yield was highest when N fertilizer was split as starter and sidedress band. The CUR of N fertilizer applied broadcast before planting (42 to 48%) was generally lower than sidedressing band application (43 to 54%). N fertilizer recovery in the starter showed also high CUR values (45 to 60%). Consequently, it is recommended to split N fertilizers and apply in band to increase efficiency for grain corn. The CUR values decreased with N rates only in Le Bras soil in 1990. Residual N fertilizer increased from 27 to 103 kg N ha−1 for 60 and 180 kg N ha−1 rates, respectively. Consequently, the environmental impact of N fertilization may increased with high N rate. Key words: Grain corn, silage corn, 15N recovery, fertilizer N split application


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


1975 ◽  
Vol 55 (4) ◽  
pp. 949-954 ◽  
Author(s):  
M. C. J. VAN ADRICHEM ◽  
J. N. TINGLE

The effects of spring-applied nitrogen (0, 56, 112 and 224 kg/ha) and phosphorus (0 and 27.4 kg/ha) on the dry matter (DM) yield and forage quality of successive harvests of meadow foxtail (Alopecurus pratensis L.) were investigated. Nitrogen increased DM yield, crude protein, Cu, K and Zn contents and decreased P, Ca, Mg and Mn contents. Application of P in combination with N increased K content in the first cut and arrested the decline of P content due to N application in all cuts. The levels of dry matter digestibility and Cu declined in successive cuts whereas Mn content increased. At low N rates, Ca and Mg contents increased as the season advanced.


1968 ◽  
Vol 71 (2) ◽  
pp. 195-203 ◽  
Author(s):  
D. R. Hodgson ◽  
A. P. Draycott

SUMMARYField experiments with Italian ryegrass cut four times a year compared aqueous ammonia with ammonium sulphate and with a mixture of ammonium nitrate and urea (equal parts by weight). In 1963 four rates of nitrogen, 224, 448, 672 and 896 lb/acre, were applied as single and split dressings of injected aqueous ammonia, as solid ammonium sulphate and as injected solution of ammonium sulphate. There was little difference in total dry-matter yield between a single injection of aqueous ammonia and the split dressing of solid. Injecting ammonium sulphate solution eliminated scorch caused by single applications of solid supplying 448 lb N/acre or more and gave significantly greater dry-matter yields. A single application of 448 lb N/acre provided enough nitrogen to sustain the response of the grass to the end of the season.In 1964 a single injection of aqueous ammonia was compared with ammonium nitrate/urea applied as solid or solution at 280, 560 and 840 lb N/acre. There was no difference in total dry-matter yield between aqueous ammonia and ammonium nitrate/urea at rates of 560 and 840 lb/acre. At 280 lb/acre a split dressing of solid produced most dry matter. More than 280 lb N/acre was required, therefore, as a single application in spring to last the whole season, but this rate of nitrogen applied as a split dressing was almost sufficient to give maximum yield.In both experiments the seasonal distribution of dry matter was similar for single and split applications except in 1963 when large single injections of ammonium sulphate produced greater yields at the third cut than the split applications. The percentage of nitrogen recovered in the harvested grass decreased as nitrogen rate was increased and was greater from single than split applications. Recovery of nitrogen from aqueous ammonia was less efficient from four injections than one, and was greater in 1964 than 1963 due to better penetration of the sward by injector tines. Least nitrogen was recovered from surface-applied solutions of ammonium nitrate/urea. Regressions of dry-matter yield on nitrogen yield showed that single injections of aqueous ammonia were as efficient as other fertilizers tested.


HortScience ◽  
2012 ◽  
Vol 47 (12) ◽  
pp. 1768-1774 ◽  
Author(s):  
Thomas G. Bottoms ◽  
Richard F. Smith ◽  
Michael D. Cahn ◽  
Timothy K. Hartz

As concern over NO3-N pollution of groundwater increases, California lettuce growers are under pressure to improve nitrogen (N) fertilizer efficiency. Crop growth, N uptake, and the value of soil and plant N diagnostic measures were evaluated in 24 iceberg and romaine lettuce (Lactuca sativa L. var. capitata L., and longifolia Lam., respectively) field trials from 2007 to 2010. The reliability of presidedressing soil nitrate testing (PSNT) to identify fields in which N application could be reduced or eliminated was evaluated in 16 non-replicated strip trials and five replicated trials on commercial farms. All commercial field sites had greater than 20 mg·kg−1 residual soil NO3-N at the time of the first in-season N application. In the strip trials, plots in which the cooperating growers’ initial sidedress N application was eliminated or reduced were compared with the growers’ standard N fertilization program. In the replicated trials, the growers’ N regime was compared with treatments in which one or more N fertigation through drip irrigation was eliminated. Additionally, seasonal N rates from 11 to 336 kg·ha−1 were compared in three replicated drip-irrigated research farm trials. Seasonal N application in the strip trials was reduced by an average of 77 kg·ha−1 (73 kg·ha−1 vs. 150 kg·ha−1 for the grower N regime) with no reduction in fresh biomass produced and only a slight reduction in crop N uptake (151 kg·ha−1 vs. 156 kg·ha−1 for the grower N regime). Similarly, an average seasonal N rate reduction of 88 kg·ha−1 (96 kg·ha−1 vs. 184 kg·ha−1) was achieved in the replicated commercial trials with no biomass reduction. Seasonal N rates between 111 and 192 kg·ha−1 maximized fresh biomass in the research farm trials, which were conducted in fields with lower residual soil NO3-N than the commercial trials. Across fields, lettuce N uptake was slow in the first 4 weeks after planting, averaging less than 0.5 kg·ha−1·d−1. N uptake then increased linearly until harvest (≈9 weeks after planting), averaging ≈4 kg·ha−1·d−1 over that period. Whole plant critical N concentration (Nc, the minimum whole plant N concentration required to maximize growth) was estimated by the equation Nc (g·kg−1) = 42 − 2.8 dry mass (DM, Mg·ha−1); on that basis, critical N uptake (crop N uptake required to maintain whole plant N above Nc) in the commercial fields averaged 116 kg·ha−1 compared with the mean uptake of 145 kg·ha−1 with the grower N regime. Soil NO3-N greater than 20 mg·kg−1 was a reliable indicator that N application could be reduced or delayed. Neither leaf N nor midrib NO3-N was correlated with concurrently measured soil NO3-N and therefore of limited value in directing in-season N fertilization.


1996 ◽  
Vol 121 (1) ◽  
pp. 105-114 ◽  
Author(s):  
John D. Lea-Cox ◽  
James P. Syvertsen

We examined how N supply affected plant growth and N uptake, allocation and leaching losses from a fine sandy soil with four Citrus rootstock species. Seedlings of `Cleopatra' mandarin (Citrus reticulata Blanco) and `Swingle' citrumelo (C. paradisi × P. trifoliata) were grown in a glasshouse in 2.3-liter pots of Candler fine sand and fertilized weekly with a complete nutrient solution containing 200 mg N/liter (20 mg N/week). A single application of 15NH415NO3(17.8% atom excess 15N) was substituted for a normal weekly N application when the seedlings were 22 weeks old (day O). Six replicate plants of each species were harvested at 0.5, 1.5, 3.5, 7, 11, and 30 days after 15N application. In a second experiment, NH4 NO3 was supplied at 18,53, and 105 mg N/week to 14-week-old `Volkamer' lemon (C. volkameriana Ten. & Pasq.) and sour orange (C. aurantium L.) seedlings in a complete nutrient solution for 8 weeks. A single application of 15NH415NO3 (23.0% 15N) was substituted at 22 weeks (day 0), as in the first experiment, and seedlings harvested 3,7, and 31 days after 15N application. Nitrogen uptake and partitioning were similar among species within each rate, but were strongly influenced by total N supply and the N demand by new growth. There was no 15N retranslocation to new tissue at the highest (105 mg N/week) rate, but N supplies below this rate limited plant growth without short-term 15N reallocation from other tissues. Leaf N concentration increased linearly with N supply up to the highest rate, while leaf chlorophyll concentration did not increase above that at 53 mg N/week. Photosynthetic CO2 assimilation was not limited by N in this study; leaf N concentration exceeded 100 mmol·m-2 in all treatments. Thus, differences in net productivity at the higher N rates appeared to be a function of increased leaf area, but not of leaf N concentration. Hence, N use efficiency decreased significantly over the range of N supply, whether expressed either on a gas-exchange or dry weight basis. Mean plant 15N uptake efficiencies after 31 days decreased from 60% to 47% of the 15N applied at the 18,20, and 53 mg N/week rates to less than 33% at the 105 mg N/week rate. Leaching losses increased with N rate, with plant growth rates and the subsequent N requirements of these Citrus species interacting with residual soil N and potential leaching loss.


HortScience ◽  
2000 ◽  
Vol 35 (2) ◽  
pp. 192-195 ◽  
Author(s):  
Michael W. Smith ◽  
Becky L. Carroll ◽  
Becky S. Cheary

`Giles' pecan [Carya illinoinensis (Wangenh.) K. Koch] seedlings were either not mulched or mulched with wood chips arranged in a 1- or 2-m-wide square that was 30 cm deep. Mulch treatments were in factorial combination with two N rates applied as either a single application at budbreak or as a split application at budbreak and 3 weeks later. Tree height was positively related to mulch width each year of the 3-year study, and trunk diameter was positively related to mulch width during the second and third years of the experiment. Leaf P and K concentration during 2 years and leaf N during 1 year of the study were positively related to mulch width. Trees receiving the higher N rate were taller during 2 of 3 years, but leaf N concentration was not affected by N rate. No differences in the parameters measured were observed whether N was applied as a single or as a split application.


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