ISSN:
1432-0789
Keywords:
Spatial nitrogen distribution
;
Prilled urea
;
Urea supergranules
;
Neem cake coated urea
;
Submerged rice soil
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Field experiments were conducted on transplanted rice (Oryza sativa L., var. Ratna) in a submerged soil, in order to study the distribution of N applied at 100 kg/ha. N was introduced as prilled urea or neem cake coated urea broadcast on the soil, and as urea supergranules, 1 or 2.5 g in size, point-placed at 5 cm depth. The surface-broadcast N was found mostly in the top 0–5 cm layer of soil and there was only a small vertical movement of applied N to 5–10 cm depth. With point placement of 1-g urea granules, the fertilizer N was found mostly at 5–10 cm depth and within 2.5 cm horizontal distance from the point of placement, compared with 5–10 cm depth and within 5 cm horizontal distance from the point of placement for the 2.5-g granules. With the two broadcast applications, the NH4 +-N content reached peaks of 40–68 mg/kg soil in the top 0–5 cm of soil within the first 3–6 days, decreased at a faster rate from the 6th to 12th day and then at a slower rate up to the 32nd day. In contrast, the NH4 +-N content around the points of placement of the urea supergranules reached peaks of 570–900 mg/kg soil during the first 3–12 days after placement, then decreased rapidly during the next 6–9 days, after which the values remained more or less unchanged but were still higher than the untreated control value.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00257928
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