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Effect of Nitrogen Supply on Maize Yield: II. Field and Model Analysis
Author(s) -
Muchow Russell C.,
Sinclair Thomas R.
Publication year - 1995
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/agronj1995.00021962008700040006x
Subject(s) - interception , agronomy , yield (engineering) , fertilizer , environmental science , soil fertility , nitrogen , mineralization (soil science) , crop yield , crop , field experiment , soil water , soil science , chemistry , biology , ecology , materials science , organic chemistry , metallurgy
Experiments investigating the yield response of maize ( Zea mays L.) to applications of fertilizer N are generally analyzed empirically. While the nature of the yield response can be characterized, information on the effects of various components influencing the soil and crop N budgets are unresolved. The objective of this study was to examine the results of a series of N fertility experiments with the aid of a mechanistically based crop model. The experiments resulted in grain yields ranging from 99 to 1102 g m −2 , and these yields were well simulated by the model ( r 2 = 0.97). Under high fertility conditions, temperature and solar radiation interception explained the variation in yield among environments. Under low fertility conditions, mineralization of soil organic N was especially important in explaining yield variations among environments. Management practices preceding the experimental crops were hypothesized to have large effects on the N availability in the soil, and consequently influence observed and simulated yields. Sensitivity tests confirmed the importance of defining the initial soil organic N levels in simulating crop growth and yield when there is little or no applied N fertilizer.