Premium
Plant Uptake, Microbial Immobilization, and Residual Soil Fertilizer of Urea‐Nitrogen in a Grass‐Legume Association
Author(s) -
Nannipieri Paolo,
Ciardi Carlo,
Palazzi Tiana
Publication year - 1985
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1985.03615995004900020036x
Subject(s) - agronomy , urea , topsoil , legume , fertilizer , forage , growing season , nitrogen , chemistry , biomass (ecology) , environmental science , zoology , soil water , biology , soil science , organic chemistry
A field experiment throughout three growing seasons was conducted to evaluate the fate of urea‐N in a grass‐legume association. The urea N removed by the forage accounted for 25.0, 2.7, and 1.4% of the total applied N in 1980, 1981 and 1982, respectively. The legume forage contained significantly less fertilizer N than the grasses and weeds. About 59% of the initially applied N was accounted for in the 0 to 40‐cm topsoil layer at the end of the first cropping season, and a large proportion of residual fertilizer N (about 86.5%) was present as organic forms. Of the processes following the spring application of urea, microbial immobilization was largely prevailing and limited downward movement, plant uptake and losses. Soil biomass C and N, determined by the chloroform fumigation‐incubation method, showed the highest values 29–59 d after the application of urea. Microbial biomass represented a considerable fraction of residual fertilizer N in soil accounting for 10.3, 11.9, and 19.3% of the total 59, 535, and 822 d after the application, respectively.