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Nitrate in Deep Soil Profiles in Relation to Fertilizer Rates and Leaching Volume
Author(s) -
Pratt P. F.,
Jones W. W.,
Hunsaker V. E.
Publication year - 1972
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1972.00472425000100010024x
Subject(s) - soil water , dns root zone , environmental science , drainage , fertilizer , nitrate , water table , leaching (pedology) , saturation (graph theory) , lessivage , denitrification , soil science , hydrology (agriculture) , nitrogen , chemistry , mathematics , groundwater , geology , ecology , geotechnical engineering , organic chemistry , combinatorics , biology
The NO 3 ‐ ‐N concentration in saturation extracts and soil solutions was determined in 30‐m profiles in six treatments of a longterm fertility trial with citrus and in four commercial citrus groves in which the depth of sampling was 15 m or to the top of the water table. Drainage volumes and excess N in the soil, calculated as N input minus crop removal, provided a reasonable estimate of the NO 3 ‐ concentration of water in the unsaturated zone in open‐porous soils when inputs were about 150 kg/ha per year. However, at higher rates of inputs to porous soils or at low rates with soils with profiles which had textural discontinuities, denitrification had to be assumed to obtain a reasonable N balance. Calculated transit times for water to move 30 m in the unsaturated zone varied from 12 to 49 years.