Thermal Autoignition of Aqueous Urea Ammonium Nitrate as a Function of Equivalence Ratio, Water Content, and Nitrogen Pressure

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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Volatilization of ammonia from urea-ammonium nitrate solutions as influenced by organic and inorganic additives

Fertilizer Research ◽

10.1007/bf01063338 ◽

1990 ◽

Vol 23 (2) ◽

pp. 113-119 ◽

Cited By ~ 6

Author(s):

T. AL-Kanani ◽

A. F. MacKenzie ◽

H. Blenkhorn

Keyword(s):

Ammonium Nitrate ◽

Urea Ammonium Nitrate ◽

Nitrate Solutions

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Response of Navy Bean (Phaseolus vulgaris) and Wheat (Triticum aestivum) Grown in Rotation to Clomazone, Imazethapyr, Bentazon, and Acifluorften

Weed Science ◽

10.1017/s0043174500057088 ◽

1992 ◽

Vol 40 (1) ◽

pp. 127-133 ◽

Cited By ~ 29

Author(s):

Karen A. Renner ◽

Gary E. Powell

Keyword(s):

Triticum Aestivum ◽

Phaseolus Vulgaris ◽

Nonionic Surfactant ◽

Ammonium Nitrate ◽

Wheat Yield ◽

Bean Seed ◽

Navy Bean ◽

Visible Injury ◽

Seed Moisture ◽

Urea Ammonium Nitrate

The response of ‘C-20’ navy bean and ‘Frankenmuth’ soft white winter wheat grown in rotation to clomazone, imazethapyr, bentazon, and acifluorfen was examined. Clomazone at 560 and 430 g ai ha−1plus 800 g ai ha−1pendimethalin and 2000 g ai ha−1chloramben visibly injured navy bean in 1 of 2 yr. However, navy bean seed moisture at harvest and yield was not reduced compared to the weed-free control. PPI and PRE treatments of 70 g ai ha−1imazethapyr did not injure navy bean or reduce yield. Imazethapyr applied POST at 70 g ha−1plus nonionic surfactant visibly injured navy bean. The addition of urea ammonium nitrate to imazethapyr enhanced visible injury and seed moisture compared to nonionic surfactant alone in 1 of 2 yr. However, seed yield was not reduced. Seed moisture at harvest was greater following treatment with 430 g ai ha−1acifluorfen plus nonionic surfactant or urea ammonium nitrate and 140 and 280 g ha−1acifluorfen plus 840 g ai ha−1bentazon in 1 of 2 yr compared to the weed-free control, but yield was not reduced. Wheat yield was reduced in 2 of 2 and 1 of 2 yr by 560 g ha−1and 430 g ha−1clomazone, respectively, plus pendimethalin plus chloramben compared to the weed-free control. Wheat yield was not reduced by imazethapyr, bentazon, or acifluorfen.

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