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An empirical model for estimating nitrate leaching as affected by crop type and the long‐term N fertilizer rate
Author(s) -
Simmelsgaard S. E.,
Djurhuus J.
Publication year - 1998
Publication title -
soil use and management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.709
H-Index - 81
eISSN - 1475-2743
pISSN - 0266-0032
DOI - 10.1111/j.1475-2743.1998.tb00608.x
Subject(s) - loam , leaching (pedology) , fertilizer , nitrate , human fertilization , environmental science , agronomy , soil water , drainage , nitrogen , soil science , chemistry , ecology , biology , organic chemistry
. An empirical model was developed for prediction of annual average nitrate leaching as affected by the long‐term rate of N fertilization and crop type. The effect of N fertilization was estimated from annual values of nitrate leaching obtained from two Danish investigations of drainage from pipe drains with four rates of N fertilization on a loamy sand and sandy clay loam from 1973‐89. The effect of crop at normal N fertilization was estimated from 147 observations of annual nitrate leaching obtained from field measurements. The nitrate leaching model consists of a relative N fertilization submodel and an absolute submodel for specific combinations of crop, soil and drainage at the normal rate of N fertilization. The relative submodel is Y/Y lN = exp[0.7l(N/ N 1 – I)], where Y is the nitrate leaching (kg N/ha per year) at fertilization rate N , and Y IN and N 1 are the corresponding values at the normal rate of N fertilization. The relative submodel is valid for cereals, root crops and grass leys fertilized with mineral fertilizer at N/N 1 < 1.5, and on the prerequisite that the fertilization rate N has been constant for some years. To illustrate the use of the relative leaching submodel, estimated values of Y IN corrected to mean annual drainage for 1970 to 1990 in Denmark for spring cereals and grass on sandy and loamy soils are given as input to the relative leaching submodel. The model can be used for sandy to loamy soils to estimate the mean nitrate leaching over a number of years.