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Modeling Long‐Term Crop Response to Fertilizer Phosphorus. II. Comparison with Field Results 1
Author(s) -
Janssen B. H.,
Lathwell D. J.,
Wolf J.
Publication year - 1987
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1987.00021962007900030009x
Subject(s) - sorghum , fertilizer , agronomy , oryza sativa , residual , phosphorus , crop , field experiment , poaceae , mathematics , environmental science , chemistry , biology , biochemistry , organic chemistry , algorithm , gene
Results obtained using a simple model for computing the residual effect of applied fertilizer P were compared with results of long‐term field trials with maize ( Zea mays L.), sorghum [ Sorghum bicolor (L.) Moench], and rice ( Oryza sativa L.), carried out in Brazil, Australia, and Madagascar, respectively. The calculated and experimentally found residual effects of fertilizer P were in close agreement, provided the applications rates were not too high and seasonal effects not too strong. At all locations the same values for the time constants of P transfer between the labile and stable pools could be used, irrespective of the method of application and the type of fertilizer. As a consequence, the residual effect of fertilizer P is directly related to the first‐year recovery fraction. For given recovery fractions, the residual effects are calculated for different types of P fertilizers.