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Nitrous Oxide Emission in Three Years as Affected by Tillage, Corn‐Soybean‐Alfalfa Rotations, and Nitrogen Fertilization
Author(s) -
MacKenzie A. F.,
Fan M. X.,
Cadrin F.
Publication year - 1998
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/jeq1998.00472425002700030029x
Subject(s) - loam , tillage , agronomy , chemistry , nitrogen , conventional tillage , no till farming , crop rotation , zoology , crop , environmental science , soil water , biology , soil fertility , soil science , organic chemistry
Nitrous oxide (N 2 O) produced from agricultural activities must be determined if management procedures to reduce emissions are to be established. From 1994 to 1996, N 2 O emissions were determined using a closed chamber technique. Continuous corn ( Zea mays L.) at four N rates of 0, 170, 285, and 400 kg of N ha −1 was used on a Ste. Rosalie heavy clay (a very‐fine‐silty, mixed, nonacid, frigid Typic Humaquept) and a Chicot sandy loam (a fine‐loamy, frigid, Typic Hapludalf). On two additional sites, a Ste. Rosalie clay and an Ormstown silty clay loam (a fine‐silty, mixed, nonacid, frigid Humaquept) no‐till (NT) and conventional tillage (CT); monocultural corn (CCC), monocultural soybean ( Glycine max L.) (SSS); corn‐soybean (SSC, CCS); and soybean‐corn‐alfalfa ( Medicago sativa L.) phased rotations (SAC, CSA, and ACS) were used. Nitrogen rates of 0, 90, and 180 kg of N ha −1 for corn and 0, 20, and 40 kg of N ha −1 for SSS were used. Rates of N 2 O emission were measured from April to November in 1994 and 1995, and from mid‐March to mid‐November in 1996. Maximum N 2 O emissions reached from 120 to 450 ng of N m −2 s −1 at the Ormstown site to 50 to 240 ng of N m −2 s −1 at the Ste. Rosalie soil. Generally, N 2 O emissions were higher in the NT systems, with corn, and increased linearly with increasing N rates, and amounted to 1.0 to 1.6% of fertilizer N applied. The N 2 O emission rates were significantly related to soil denitrification rates, water‐filled pore space, and soil NH 4 and NO 3 concentrations. A corn system using conventional tillage, legumes in rotation, and reduced N fertilizer would decrease N 2 O emission from agricultural fields.