Premium
Crop Yield as Affected by Rotation and Nitrogen Rate. II. Grain Sorghum
Author(s) -
Peterson Todd Andrews,
Varvel G. E.
Publication year - 1989
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/agronj1989.00021962008100050006x
Subject(s) - sorghum , agronomy , crop rotation , loam , avena , sweet sorghum , fertilizer , crop , biology , soil water , ecology
Crop rotation is reported to increase grain sorghum [ Sorghum bicolor (L.) Moench] yield in some, but not all cases. This study compares yield of continuous grain sorghum with that of sorghum grown (i) in a 2‐yr rotation with soybean [ Glycine max (L.) Merr.]; (ii) in a 4‐yr oat + clover [ Avena sativa (L.) + 80% Melilotus officinalis (L.) Lam., 20% Trifolium pratense ]‐corn ( Zea mays L.)‐soybean—grain sorghum rotation; and (iii) in a 4‐yr soybean—corn—oat + clover—grain sorghum rotation. Interactions between crop rotation and N rate were also determined. The study was conducted for 4 yr on a Sharpsbury silty clay loam (fine, montmorillonitic, mesic Typic Arguidoll). Continuous grain sorghum showed a greater response to fertilizer N than sorghum in rotation. Sorghum following legumes in rotation did not respond to applications of more than 90 kg N ha− 1 , while continuous sorghum increased with all levels of N applied. Yield of continuous sorghum was 3.4, 5.0, and 5.3 Mg ha− 1 with 0, 90, and 180 kg N ha− 1 , respectively, while sorghum in rotation averaged 5.0, 5.4, and 5.3 Mg ha− 1 at the same N rates. Differences between continuous and rotated sorghum were large without applied N, but were minimized or removed with N applications. Sorghum in the 2‐yr sorghum‐soybean rotation produced sustained high yields (5.0 Mg ha− 1 ) without additions of N fertilizer.