The ammonification and nitrification in soil of urea with and without biuret

Low, A. J.; Piper, F. J.

doi:10.1017/s0021859600016993

Cited by 13 publications

(8 citation statements)

References 14 publications

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“…Nitrogen recovered as NO?-N by the end of the 6th week, amounted to 70, 86, and 96% of the applied urea-N for the 30, 60 and 100% of WHC treatments, respectively. These findings are in agreement with those of Robinson (1957) and Low and Piper (1970). Under water-logging conditions, nitrate formation was completely inhibited.…”

Section: Nitrificationsupporting

confidence: 92%

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Effect of Rate of Urea Application and Soil Moisture on the Behaviour of Urea in Soil

Ibrahim

Awadalla

Eldin

et al. 1984

J Plant Nutrition & Soil

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A sandy clay loam soil was used to study the effect of (a) urea application at rates equivalent to 250, 500, 1000 and 2000 ppm‐N, at moisture content level of 100 % WHC, and (b) soil moisture levels of 30, 60 and 100 % of the WHC in addition to water‐logging conditions, when urea was applied at the rate of 500 ppm‐N, on urea‐N transformations. In both cases, the incubation took place at 30°C and lasted for 6 weeks. The experiments were carried out in a closed system daily aerated. Complete hydrolysis of the added urea was attained after 1, 2 and 3 weeks for 250, 500 and 1000 ppm urea‐N, respectively. Six weeks incubation period was not enough for full hydrolysis of the 2000 ppm urea‐N. The rate of urea hydrolysis increased linearly for urea concentration up to 1000 ppm N. This concentration must have been sufficient to saturate the urease present in the soil used. The peak of NO 2−N was higher the higher the rate of urea applied. Delay of the nitrate formation was always accompanied by the accumulation of nitrites. At the end of the experiment, the nitrate‐N formed represented 93,90,77 and only 20 % of the initially applied nitrogen for 250, 500, 1000 and 2000 ppm‐urea‐N, respectively. The rate as well as the total ammonia loss increased with increasing the rate of urea application. No appreciable differences were observed in urea hydrolysis due to the variations in moisture levels within the range of WHC. Under water‐logging conditions, urea hydrolysis was slower and extended to the 6th week, also the rate of urea hydrolysis was no more than 50 % of the rate produced in moisture treatments within WHC. NO 2−N accumulation persisted for one week in the moisture levels within the range of WHC, while it continued in the water‐logged treatment till the end of the experiment. Nitrate formation was slightly favoured at 100 % WHC and decreased somewhat with lowering the soil moisture levels. However, it was completely inhibited under water‐logging conditions. Ammonia volatilization was not markedly affected by moisture levels within WHC, however, the water‐logged treatment showed the highest total loss.

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Section: Nitrificationsupporting

confidence: 92%

“…2. Moisture content; the drier the soil, the slower will be ammonification and subsequent nitrification (Vofk, 1966;and Low and Piper, 1970). 3.…”

Section: Introductionmentioning

confidence: 99%

Effect of Rate of Urea Application and Soil Moisture on the Behaviour of Urea in Soil

Ibrahim

Awadalla

Eldin

et al. 1984

J Plant Nutrition & Soil

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“…Segundo Weber & Gainey (1962), o sulfato de amônio provoca uma redução do pH do solo, que pode até inibir a nitrificação em solos ácidos. Low & Piper (1970) observaram que o amônio proveniente da uréia nitrificou mais rapidamente do que o do sulfato de amônio e que em solo ácido, como o AQ, somente o amônio oriundo da uréia foi convertido a nitrato.…”

Section: Nitrificação Sob Efeito De Fontes E Doses De Nunclassified

Disponibilidade de nitrato em solos brasileiros sob efeito da calagem e de fontes e doses de nitrogênio

Silva

Vale

2000

Pesq. agropec. bras.

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Termos para indexação: matéria orgânica, pH do solo, urease, sulfato de amônio, nitrificação. NITRATE AVAILABILITY IN BRAZILIAN SOILS UNDER EFFECT OF LIMING AND SOURCES AND AMOUNTS OF NITROGENABSTRACT -The aim of this work was to evaluate the effect of liming and sources and doses of nitrogen on nitrate availability in Brazilian soils. Two experiments were carried out: one with five soils from Bahia State and the other with five soils from Minas Gerais State. Soil samples were previously moistened and incubated at 26°C in order to activate the microorganism population. Soil samples from Bahia State were incubated with 50, 100, 150 e 200 mg of N per kg of soil as ammonium sulfate or urea and in the Minas Gerais soils it was evaluated the effect of liming on nitrification. Soil samples were incubated at 26°C during 15 days. Urea nitrified faster than ammonium sulfate. The sandy soil did not exhibit net nitrification following ammonium application, but nitrification in this soil was significantly higher under urea. The nitrate availability increases with the liming of Minas Gerais soils. Nitrification rate showed to be highly correlated with base saturation whereas urea hydrolysis was correlated with organic matter content.

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“…The approach was based on the experimental finding that the average half life of ammonium under field conditions was ca 3 weeks for much of the year (Anderson and Purvis, 1955;Tyler et al, 1959;Low and Piper, 1970;Page, 1975;Bums, 1977). Assuming there are no losses of N from the soil, the release of nitrate for this half life loosely approximates to a step function in which half of the ammonium is present as nitrate for the The effective rooting depth (h cm) of each of the crops was calculated h = 6.082 W + 1.52 X 10-5p + (1.81 x 10-'/a2) -2.1…”

Section: Nitrate Present At the Onset Of Leachingmentioning

confidence: 99%

A Simple Model for Predicting the Effects of Leaching of Fertilizer Nitrate During the Growing Season on the Nitrogen Fertilizer Need of Crops

Burns¹

1980

Journal of Soil Science

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The model is based on the concept that there is an effective rooting depth above which all the inorganic N in the soil is equally available and below which all N is totally unavailable. The extent to which nitrate is leached below this depth is calculated from the excess rainfall over evapotranspiration and the water holding capacity of the soil.The model was tested against the results of N fertilizer experiments with lettuce, French beans and overwintered onions which had been camed out in at least 2 years (and often more) on adjacent sites of the same field. The yields from all of the experiments with each crop were plotted against the level of fertilizer applied and against the difference between that applied and that lost by leaching. Comparison of these graphs showed that correcting for leaching in this way greatly reduced the variability between the response curves. The model was also tested against the results of similar experiments with Brussels sprouts grown on different sites with different combinations of base and top dressing. The results showed that the poor response to top dressing could be explained by the relatively small amounts of N in the base dressing which were leached from the rooting zone of this crop.It appears that the model will enable worthwhile adjustments in N fertilizer dressings to be made for differences in rainfall, provided that leaching occurs during the early stages of crop growth when uptake is small.

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The ammonification and nitrification in soil of urea with and without biuret

Cited by 13 publications

References 14 publications

Effect of Rate of Urea Application and Soil Moisture on the Behaviour of Urea in Soil

Effect of Rate of Urea Application and Soil Moisture on the Behaviour of Urea in Soil

Disponibilidade de nitrato em solos brasileiros sob efeito da calagem e de fontes e doses de nitrogênio

A Simple Model for Predicting the Effects of Leaching of Fertilizer Nitrate During the Growing Season on the Nitrogen Fertilizer Need of Crops

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