Soil bulk density, penetration resistance, and hydraulic conductivity under controlled traffic conditions

Abstract

Adverse soil physical conditions that limit soil water infiltration, root development, and crop yield could develop when using a no-tillage system, especially in humid regions or for irrigated crops. This study determined the effects of tillage treatments and controlled traffic on soil bulk density ( BD), penetration resistance ( PR), hydraulic conductivity ( HC), water content, and organic matter concentration. Treatments were no-tillage with residues left standing (NT-ResSt) or shredded (NT-ResSh), and no-tillage after wheat and conventional tillage after sorghum (NT-CT). Determinations were made at traffic furrow, non-traffic furrow, and row positions after grain sorghum ( Sorghum bicolor (L.) Moench) harvest in 1992. The grain sorghum had been grown in rotation with winter wheat ( Triticum aestivum L.) under limited irrigation conditions on Pullman clay loam (Torrertic Paleustoll) at Bushland, Texas, from 1986 to 1992. Tillage treatments did not significantly ( P = 0.05) affect any determined variable. Mean PR was greates (1.23 MPa) in the traffic furrow, but sampling position did not affect BD. Differences in HC were significant ( P = 0.05) only due to sampling depth, but tended to be greater in row than in furrow positions and with the NT-CT treatment than with other treatments. These results show that adverse soil physical condition (increased BD and PR) development is limited to designated traffic zones when using no-tillage for irrigated crop production.