Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/5/1998
Publication Date: N/A
Technical Abstract: No-tillage management reduces soil disturbance and, therefore, may improve soil organic matter and soil structure leading to enhanced soil quality and sustained crop production. We determined changes in soil aggregation, soil organic carbon, carbohydrates, and soil microbial biomass carbon in a loam and silt loam soil (Luvisols) managed for 8-16 yr under conventional and no tillage. No tillage under continuous spring cropping resulted in a significant improvement in surface soil structure, organic matter, and total carbohydrates. Improvement of total soil organic C under no tillage compared with conventional tillage occurred only near the soil surface. Water-stable aggregation improved under no tillage compared with conventional tillage with more soil organic C sequestered within macroaggregates that helped to stabilize these aggregates. Water-stable macroaggregates (> 0.25 mm) and aggregate mean weight diameter were greater under no tillage than under conventional tillage. Concentration of soil organic C and soil microbial biomass C tended to be greatest in macroaggregates and lowest in microaggregates (<0.25 mm). Our results suggest that long-term no-tillage can significantly improve soil structure, and potentially increase soil organic C sequestration and enhance soil quality.