Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 9, 1998
Publication Date: N/A
Interpretive Summary: No-till and chisel are two conservation tillage practices that are used in the Midwest. Soils in both systems are subject to wheel traffic compaction from tractors, grain wagons and combines. Driving on the same wheel track for all field operations (controlled traffic) results in areas of the field with wheel traffic compaction, and areas without wheel traffic compaction. Not controlling wheel traffic patterns eventually results in most of the field being compacted by wheel tracks. This study compared soil properties from no-till and chisel plots in the top foot of soil, both for a study with controlled wheel traffic, and for a study without controlled wheel traffic. For the controlled traffic study, the no-till plots had lower soil density in the top inch, but the chisel plots had lower soil density from 2.5 to 7 inches. There were no soil density differences between no-till and chisel for the treatments without controlled wheel traffic. Comparisons of corn and soybean yields between no-till and chisel plots were inconsistent, but were caused by factors other than soil density differences. In summary, chiseling only loosens the soil if wheel-traffic is controlled; if traffic is not controlled, the chiseled soil is as dense as no-till soil. This information is useful to scientists, farmers, and county and state personnel interested in maintaining crop yield and soil quality.
Technical Abstract: Compaction in no-till has remained a concern, but comparisons of bulk density between no-till and chisel have produced mixed results. The objective of this study was to examine the vertical incremental density and other soil properties for no-till and chisel on a controlled-traffic site and on a site without controlled-traffic. Soil samples were collected in fine (2 cm) increments in soybean (Glycine max (L.) Merr.) and corn (Zea mays L.) plots. On controlled-traffic plots, soil bulk density was less for no-till only from 0 to 2 cm deep. Soil was less dense for chisel than no-till generally from 6 to 18 cm deep, but only in untracked areas of controlled traffic plots. There was no significant density difference between tillage treatments for plots without controlled traffic. No-till had significantly more incorporated residue than chisel for 0 to 2 cm deep, and for some soils and depths, no-till had significantly more organic carbon and total nitrogen than chisel. Soil bulk density did not explain yield differences between no-till and chisel during the 3-year study.