ISSN:
1573-0867
Keywords:
Ammonia volatilization
;
large granular urea
;
penetration in soil
;
puddled soil
;
urea granules
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract The efficiency of urea in wetland rice cultivation is known to be increased by placement below the soil surface. The penetration of broadcast urea into puddled soil might be a way to achieve placement of urea in soil. This paper combines an analysis of the free fall of urea granules in the atmosphere and a layer of water on the soil surface with measurements of granule penetration into puddled soils. The process of free fall can be described in terms of the height of fall in air, the depth of the water layer, and the terminal velocities and characteristic distances for free fall in air and water. The penetration depth of a particular granule with a particular velocity at the water/soil interface depends on the type of soil and its physical condition. Granule mass ranged from 0.1 to 0.5 g, granule velocity from 1 to 10 m s−1, depth of the water layer from 0 to 30 mm and penetration depth from 0 to 35 mm. There is some indication that the penetration depth is proportional to the square root of the kinetic energy at the water/soil interface.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01080683
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