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Soil Nitrogen Balance in selected Row‐Crop Sites in Southern California
Author(s) -
Adriano D. C.,
Takatori F. H.,
Pratt P. F.,
Lorenz O. A.
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/jeq1972.00472425000100030015x
Subject(s) - drainage , soil water , environmental science , irrigation , mineralization (soil science) , nitrogen balance , water table , manure , agronomy , water balance , hydrology (agriculture) , nitrogen , fertilizer , dns root zone , soil science , groundwater , chemistry , geology , ecology , geotechnical engineering , organic chemistry , biology
Nine row‐crop sites, where data for nitrogen fertilizer use, crop yields, and amounts of irrigation water used were available for a number of years, were studied to estimate the N balance as related to NO 3 − in water in the unsaturated zone from below the zone of root influence to the water table or to the 15‐m depth. The system of predicting NO 3 − concentrations in drainage waters based on the difference between N inputs and N removal in harvested crop sand the drainage volume in which the excess N, converted to NO 3 − , is dissolved, was valid in open‐porous soils containing no layers that restrict water movement within the soil profile (0‐ to 2‐m depth). A combination of losses plus net immobilization of up to 56% had to be assumed in some soils to account for all the N loss. In two soils that had been used for disposal of feedlot manure, net mineralization of N from the organic N pool had to be assumed to explain the data obtained. The current fertilization and irrigation practices used for some row crops in southern California leave varying amounts of NO 3 − in the drainage water. The amounts depend on the total N added, crop removal, drainage volume, net mineralization, and losses.