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Soybean Effects on Soil Nitrogen Availability in Crop Rotations
Author(s) -
Vanotti Matias B.,
Bundy Larry G.
Publication year - 1995
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/agronj1995.00021962008700040012x
Subject(s) - agronomy , crop rotation , loam , crop , avena , legume , fertilizer , biology , soil water , ecology
Soybean [ Glycine max (L.) Merr.] production contributes significantly to the N supply for a following corn ( Zea mays L.) crop, even though soybean N budget studies indicate that N removed in grain may substantially exceed biological fixation. Information on the N status of cereal crops during the 2nd yr following soybean may help resolve this issue. This study reports on N effects of soybean on yield response of succeeding cereal crops and soil N availability based on data from a 15‐yr crop rotation experiment (1977–1991) on a Rozetta silt loam soil (Typic Hapludalfs) at Lancaster, WI. We evaluated the yields of corn and oat ( Avena sativa L.) succeeding soybean and alfalfa ( Medicago sativa L.) in corn‐soybean‐corn‐oat‐alfalfa (CSCOM) and corn‐corn‐oat‐alfalfa‐alfalfa (CCOMM) crop rotations. Fertilizer N (0, 56, ll2, and 224 kg ha −1 ) was applied only to corn, but NO 3 ‐N carryover usually affected oat yields as well. The legume fertilizer N replacement values based on check plot yields and the response function of 3rd‐yr corn in a corn‐corn‐corn‐alfalfa‐alfalfa sequence, were equivalent to 153 and 36 kg N ha −1 for the 1st and 2nd yr after alfalfa, respectively, and 75 kg N ha −1 for the 1st yr after soybean. In the 2nd yr after soybean (CSC O M), oat yields were significantly lower than following corn in the CC O MM rotation. Preplant soil NO 3 and oat N uptake (1987–1991) indicated that oat yield differences were due to lower soil N availability in the CSCOM rotation. The average soybean effect on soil N availability in the 2nd yr was equal to a soil N debit of 36 kg N ha −1 . This indicates that part of the N contribution of soybean to 1st‐yr corn is realized at the expense of subsequent reductions in soil N availability.