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Yield‐Soil Water Relationships in Sorghum‐Soybean Cropping Systems with Different Fertilizer Regimes
Author(s) -
Roder W.,
Mason S. C.,
Clegg M. D.,
Kniep K. R.
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/agronj1989.00021962008100030015x
Subject(s) - agronomy , sorghum , loam , crop rotation , fertilizer , cropping system , manure , soil water , mathematics , environmental science , crop , biology , soil science
Crop rotation of soybean [ Glycine max (L.) Merr.] with grain sorghum [ Sorghum bicolor (L.) Moench], and application of N fertilizer or manure generally increases grain sorghum yield. Little is known about rotation and fertilization effects on soybean yield in the Great Plains. Grain yields were measured from 1981 to 1987 in a cropping experiment started in 1980 on a Sharpsburg silty clay loam (fine, montmorillonitic, mesic Typic Argiudoll). The cropping treatments included continuous soybean, continuous grain sorghum, and grain sorghum‐soybean rotation. Fertilizer treatments consisted of control, manure (15.8 Mg dry matter ha −1 yr −1 1) and N (45 kg ha −1 for soybean and 90 kg N ha −1 for sorghum). Volumetric soil water content was determined with a neutron probe in 1985, 1986, and 1987. Soil water content was unaffected by fertilizer treatment. Water content in the upper 30 cm was generally greatest with continuous grain sorghum and least with continuous soybean. Soil water depletion to 120 cm in September was 10 to 36 mm greater with soybean than with grain sorghum. Crop rotation increased soybean yield, but N application did not. Manure application reduced soybean yield in 1986, but had no effect in the other years. Rotation and fertilization increased sorghum grain yield. The soybean yield advantage from crop rotation decreased as 1 April to 31 May rainfall increased. Cropping‐system induced differences in soil water content early in the growing season may be partly responsible for higher soybean yield with crop rotation.