A comparison of slow-release and conventional nitrogenous fertilizers for an established pangola grass pasture in a sub-tropical environment

1978 ◽  
Vol 18 (92) ◽  
pp. 415 ◽  
Author(s):  
KF Lowe ◽  
JF Cudmore

Three slow-release nitrogen fertilizers, urea formaldehyde, nitrogen-enriched coal (NEC) and corea (a coal-urea formulation) were compared with conventional nitrogenous fertilizers (urea, ammonium nitrate and ammonium sulphate) in a small-plot cutting experiment. The slow-release fertilizers were applied in one 672 kg N ha-1 dressing to an established Digitaria decumbens (pangola grass) pasture on wallum heath in south-east Queensland. Conventional fertilizers were applied in one, two or four applications in one, two or three years respectively, all treatments receiving a total of 672 kg N ha-1. Dry matter production, nitrogen yield and nitrogen recovery were compared over four summer periods. Over four years, pangola grass produced highest dry matter yields when fertilized with urea formaldehyde, the residual effect disappearing in the fourth summer. Annual yield distribution was equivalent to that from regular applications of conventional fertilizers. NEC released little nitrogen for grass growth in four years while corea had little effect on yield after the first summer. Nitrogen recovery from urea formaldehyde was equivalent to that from ammonium nitrate and urea (applied in four dressings of 168 kg N ha-1). Where 672 kg ha-1 of nitrogen was applied in one dressing, nitrogen recovery was in the order urea formaldehyde >> ammonium nitrate > urea >> ammonium sulphate.

2009 ◽  
Vol 19 (1) ◽  
pp. 16-19 ◽  
Author(s):  
E.A. Guertal

Slow-release nitrogen (N) fertilizers offer many potential benefits for vegetable production. In sandy soils, their use may lessen N leaching. If the slow-release fertilizer has a release pattern that matches crop needs, N uptake by the growing crop may become more efficient. Additionally, if slow-release fertilizers can be applied as a preplant application, production costs could be lessened, eliminating the need for multiple applications of soluble N fertilizer. Synthetic slow-release fertilizers can be separated into two general groups: those that are slow release as a byproduct of a chemical reaction (such as urea-formaldehyde), and those that are slow release via a sulfur, wax, or resin coating around the fertilizer prill. In vegetable crop research, much of the available literature has focused on use of sulfur coat urea and urea-formaldehyde, as they have been in the fertilizer market for 40 years. Newer research has evaluated resin-coated products. In most studies, use of slow-release N fertilizers as a preplant treatment did not decrease crop yield, but yield was rarely increased when compared with standard split applications of soluble N. Based on available research, the benefits of using slow-release N fertilizers in vegetable crop production will come from reduced environmental risk and savings in production costs.


1987 ◽  
Vol 23 (2) ◽  
pp. 167-179 ◽  
Author(s):  
J. Halevy

SummaryTwo slow-release nitrogen fertilizers, isobutylidene diurea (IBDU) and sulphur-coated urea (SCU), and urea plus nitrapyrin were compared with urea alone for their effect on the growth and nitrogen uptake of ryegrass in a greenhouse experiment.The IBDU and the SCU were applied in one dressing before sowing and the urea in five dressings (one after each cut). Dry matter yield and nitrogen uptake of the six cuts at the optimum levels of 3 and 6 g N pot−1 (equivalent to 1120 and 2240 kg N ha−1 on a weight basis) were similar for the slow-release fertilizers and urea, showing that SCU and IBDU can be effective sources of nitrogen for ryegrass at rates far above those regarded as safe for conventional nitrogen fertilizers when applied in a single dose.Nitrapyrin at 20 ppm effectively inhibited nitrification for 12 weeks, then its effect rapidly declined, disappearing after 18 weeks. Ryegrass growth was retarded by nitrapyrin treatment, probably as a result of an accumulation of NH4-N in the soil.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 844
Author(s):  
Carlos Martín Sastre ◽  
Ruth Barro ◽  
Yolanda González-Arechavala ◽  
Ana Santos-Montes ◽  
Pilar Ciria

Nitrogen fertilizers have been identified in energy crops LCAs as the main contributors to global warming, as well as to many other environmental impacts. The distinct production process and application emissions of nitrogen fertilizer types for top dressing produce different GHG savings when energy crops value chains are compared to fossil energy alternatives. In this study, three types of fertilizers (calcium ammonium nitrate, urea and ammonium sulphate) at N top dressing rates of 80 kg N/ha are used to grow rye for electricity generation under the conditions of the Continental Mediterranean climate of central-northern Spain. Complete LCAs for the whole value chain based on real data were performed in conjunction with soil nitrogen balances (SNBs) to assess the accomplishment of European Union (EU) GHG savings sustainability criteria, as well as the sustainability of fertilization practices for soil nitrogen stocks. The results obtained can provide interesting insights for policy making, since calcium ammonium nitrate, the most common fertilizer for rye crops, led to 66% GHG savings, as opposed to the 69% achieved when applying urea and 77% when ammonium sulphate was used. Nevertheless, the three fertilizers produced annual soil deficits greater than 50 kg N/ha. In order to ensure savings above 80%, as required by the EU sustainability criteria, and sustainable SNBs, additional optimization measures should be taken at key points of the value chain.


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.


1981 ◽  
Vol 11 (2) ◽  
pp. 414-422
Author(s):  
C. Camiré ◽  
B. Bernier

Six nitrogen fertilizers (urea, sulfur-coated urea, urea-formaldehyde, ammonium nitrate, ammonium sulfate, and ammonium nitrate) were individually applied, either in fall or in spring, at a rate of 224 kg N/ha and compared for nitrogen retention in the different horizons of a podzol under jack pine. Despite its susceptibility to nitrogen losses through ammonia volatilization, urea was by far, among readily available nitrogen fertilizers, the one whose nitrogen is best retained in soil surface horizons. Retention varied with weather conditions that prevailed immediately after fertilizer application. With the other fertilizers used, nitrogen retention followed this order: ammonium sulfate > ammonium nitrate > calcium nitrate. After four seasons, about 50% of the nitrogen applied as sulfur-coated urea and urea-formaldehyde was still found in its original form. Ammonium sulfate is next to urea among the recommended nitrogen sources for similar jack pine sites, considering that fertilizers with nitrate are prone to leaching and the sulfur-coated urea and urea-formaldehyde used presented problems of nitrogen availability.


Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1549
Author(s):  
Bruno Maia Abdo Rahmen Cassim ◽  
Antonio Pedro Martins Machado ◽  
Daniel Fortune ◽  
Fernando Rodrigues Moreira ◽  
Éder Júnior De Oliveira Zampar ◽  
...  

The objective of the study was to evaluate the effect of foliar application of urea and urea-formaldehyde, triazone-based fertilizers on soybean and corn crops. Four experiments were carried out, two on soybeans, one on first season corn, and the other on second season corn. The experiments were conducted using a randomized block design, with 5 treatments studied: T1—control without application of foliar nitrogen (N); T2—foliar application of conventional urea solution and three treatments with Hexion foliar fertilizers based on urea-formaldehyde and triazone (N-Hexion®), with varying levels of N and slow-release components; T3—Hexion 1; T4—Hexion 2; and T5—Hexion 3. The foliar application of conventional urea showed no statistically significant difference in relation to the control for the yield components and grain yield for the soybean crops in seasons 2018–2019 and 2019–2020. Urea-formaldehyde/triazone treatments showed a significant increase in yield for soybeans in the 2018–2019 season compared to the control and to conventional urea. Nitrogen fertilizers with high percentages of slow-release compounds promote nitrogen release more slowly, which led to no significant increase in yield for Hexion 1. No statistical differences were observed in the corn yield for the first and second crop.


1970 ◽  
Vol 75 (3) ◽  
pp. 523-532 ◽  
Author(s):  
D. Reid ◽  
M. E. Catle

SUMMARYTwo 1-year experiments are described in which a single dressing of 120 lb N/acre (134 kg/ha) was applied to a grass sward as anhydrous ammonia (82% N), ammonium nitrate (34·5% N) or sulphate of ammonia (21% N) at various dates from December to April. The pattern of primary growth from each of the treatments was recorded from early April until mid-June by frequent sampling of the herbage to determine the dry matter and crude protein yields. At every date of fertilizer application from late January to mid-April the growth rate of the herbage was markedly lower with anhydrous ammonia than with ammonium nitrate. With the December applications the spring growth rate of herbage from the anhydrous ammonia treatment was similar to that from the ammonium nitrate treatment. Applications of sulphate of ammonia gave results almost identical with those obtained from ammonium nitrate. The calculation of the dates on which a yield of 2000 lb dry matter/acre (2242 kg/ha) would have been available for dairy cow grazing showed clearly a delay of 12–15 days where anhydrous ammonia rather than ammonium nitrate was applied. The response to anhydrous ammonia was improved by applying it early in the year but solid nitrogen fertilizers, applied either early in the season or when growth was starting, gave higher yields of herbage than anhydrous ammonia.


1987 ◽  
Vol 108 (1) ◽  
pp. 17-23 ◽  
Author(s):  
M. E. Castle ◽  
D. Reid

SummaryIn a 3-year plot experiment on a perennial ryegrass plus white clover sward the pH of the soil on the main plots was adjusted to, and maintained as nearly as possible at, target levels of 5·25, 6·00 and 6·75 by applying either sulphur or lime. Within the main plots the effects on herbage yield, clover content and crude-protein content of applying four fertilizers were compared at nitrogen rates of 225 and 450 kg/ha annually. The fertilizers were liquid manure (urine plus water), prilled urea, a urea solution and an ammonium-nitrate fertilizer. The applications of the urea and the ammonium-nitrate fertilizers were accompanied by dressings of a potassium fertilizer which supplied the same weights of potassium as in the liquid manure. On average the smallest yields of dry matter and crude protein were associated with the lowest soil pH with no significant interactions between pH and fertilizer treatment. The liquid manure gave slightly smaller total yields of mixed herbage dry matter than the other fertilizers, particularly at the low nitrogen rate. The herbage from the liquid manure treatment had a higher clover content and produced a greater total yield of clover dry matter. The effects of the liquid manure on the clover agree with those noted in previous experiments, but no evidence was found that these effects resulted from the liquid manure increasing the pH of the soil and improving the conditions for clover growth. Similarly, no proof was obtained that the clover effects were due to the nitrogen in the liquid manure being wholly in the ammonium form. However, the value of liquid manure as a fertilizer for grassland was demonstrated clearly.


1970 ◽  
Vol 42 (2) ◽  
pp. 123-130
Author(s):  
Armi Kaila ◽  
Paavo Elonen

The effect of irrigation and fertilizer placement on the accumulation of nitrogen in the aerial parts of spring wheat was studied in the relatively dry summer 1969, on the basis of plant samples collected at various stages of development from a field trial on silty clay soil. In addition to 16 kg/ha of nitrogen in the basal dressing, 120 kg/ha of nitrogen was applied as ammonium nitrate limestone, as urea, or as Ureaform, either on the surface, or in rows at the depth of 8 cm. 60 mm of water was applied by sprinkler irrigation, one half about three, and the other half about four weeks after sprouting. Under the conditions of this trial, spring wheat only slightly responded to Ureaform. No significant difference in the effect of urea and ammonium nitrate limestone could be detected. Placement of these two fertilizers tended to increase both the amount of dry matter and its content of nitrogen; these effects were more significant without irrigation. Though irrigation, usually, markedly increased the total amount of nitrogen in the aerial parts of the plants, this was in the later stages of development due only to higher yields of dry matter, since in July the positive effect of irrigation on the percentage of nitrogen in plant dry matter changed to a negative effect. In the grain yields the apparent recovery of nitrogen in urea or ammonium nitrate limestone was estimated to be only about 30 per cent of the 120 kg N/ha applied as surface dressing. Irrigation increased this recovery to 54 per cent, placement of the fertilizer to 42 per cent, and both placement and irrigation resulted in an apparent recovery of 61 per cent. On the basis of plant samples collected two days before harvest, the apparent recovery of nitrogen in urea or ammonium nitrate limestone by the aerial parts of wheat was estimated to be, on the average, 36 per cent from the surface-dressing, and 60 per cent when the fertilizers were placed. Irrigation increased the apparent recovery in the first case to 76 per cent and in the latter case to 96 per cent. Thus, in the field experiment the uptake of fertilizer nitrogen by spring wheat was markedly increased by irrigation and to a lesser extent by fertilizer placement. Both treatments together are recommended.


1968 ◽  
Vol 8 (32) ◽  
pp. 301 ◽  
Author(s):  
JR Simpson

A comparison was made of the responses to, and nitrogen recoveries from, ammonium sulphate, sodium nitrate, and urea when broadcast on a ryegrass sward in a favourable growing season. A second comparison was made, in a drier season on the same sward, between ammonium sulphate, sodium nitrate, urea, calcium ammonium nitrate, and ammonium nitrate. In both comparisons urea was an inefficient source of nitrogen, but its efficiency depended on the time of application. Differences in the rainfall shortly after application probably caused this variation in efficiency, by affecting the amounts of ammonia lost to the atmosphere. With sources other than urea, variation in the length of time during which the fertilizer remained at the soil surface, awaiting effective rainfall and plant uptake, had little effect on the final recovery of nitrogen. Ammonium sulphate, calcium ammonium nitrate, and ammonium nitrate showed similar efficiencies during the relatively dry season in which they were compared. Sodium nitrate was the most efficient source in both seasons.


Sign in / Sign up

Export Citation Format

Share Document