Premium
Spatial and Temporal Variability of Soil Nitrate and Corn Yield
Author(s) -
Eghball Bahman,
Schepers James S.,
Negahban Mehrdad,
Schlemmer Michael R.
Publication year - 2003
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/agronj2003.3390
Subject(s) - spatial variability , agronomy , leaching (pedology) , fertilizer , nitrogen , environmental science , grain yield , yield (engineering) , residual , soil science , mathematics , soil water , biology , chemistry , statistics , materials science , organic chemistry , algorithm , metallurgy
High levels of residual soil NO 3 –N can contaminate ground water by leaching through the soil. Our objective was to reduce the level and spatial variability of residual soil NO 3 –N while maintaining optimum corn ( Zea mays L.) production by variable rate N fertilizer application. The experiment was located on a 60‐ha sprinkler‐irrigated corn field in central Nebraska and included four N management practices: uniform rate, variable rate (VRAT), variable rate at 75% of recommended amount (VRAT @ 75%), and variable rate plus 10% (VRAT + 10%). VRAT @ 75% decreased the amount of residual NO 3 –N in the soil while maintaining similar grain yield to the other treatments, indicating over‐application of N with treatments receiving the recommended rate. Increasing the recommended rate by 10% (VRAT + 10%) did not increase corn yield or residual soil NO 3 –N. Based on multifractal spectrum, no consistent pattern of spatial variability of soil NO 3 –N was observed for each treatment across years. Spatial variability in corn grain yield was much lower than that for soil NO 3 –N, indicating noneffectiveness of using soil NO 3 –N spatial distribution for variable rate N application unless some areas in the field are severely N deficient. Variable rate N application did not reduce variability of residual soil NO 3 –N or corn grain yield as compared with uniform N. Multifractal analysis quantitatively characterized the extent and pattern of spatial and temporal variability in corn grain yield and residual soil nitrate.