Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 5, 2000
Publication Date: N/A
Technical Abstract: Understanding long-term management effects on soil quality indicators is necessary to determine the relative sustainability of cropping systems. The status of soil quality indicators was determined in a long-term cropping system study in the Western Corn Belt. Indicators were evaluated 16 years after initiation of the study in four crop rotations (Cont. Corn; Corn/Soybean; Corn/Oats-Clover/Sorghum/Soybean, and Corn/Soybean/Sorghum/ Oats-Clover) at three nitrogen rates (ZERO, LOW, and HIGH) for two depths (0-7.6 and 0-30.5 cm) on a Sharpsburg silty clay loam (fine, smectitic, mesic Typic Argiudoll). On average, management effects on soil quality indicators were most pronounced at 0-7.6 cm. Increased nitrogen rate resulted in higher pre-plant soil nitrate, organic carbon, total nitrogen, and particulate organic matter, but lower microbial biomass and soil pH. Four-year rotations possessed significantly lower soil bulk density, but higher available water-holding capacity, particulate organic matter, and potentially mineralizable nitrogen (anaerobic incubation). Management practices of fertilization and inclusion of leguminous crops in rotation were primarily responsible for differences in soil quality indicators among cropping systems.