Long-term tillage influences on soil physical properties under dryland conditions in northeastern Montana
2009
Jabro, Jay D. | Sainju, Upendra M. | Stevens, William B. | Lenssen, Andrew W. | Evans, Robert G.
We evaluated the effect of long-term (>20 years) tillage (no-till [NT], spring till [ST], and fall and spring till [FST]) under continuous spring wheat on soil penetration resistance (PR), bulk density (ρb), water content (θm) and saturated hydraulic conductivity (Ks) under dryland cropping systems. Soil PR was significantly greater in the NT than in ST and FST treatments at 0–10 cm depth, but was greater in FST than in NT and ST at a depth deeper than 10 cm. Soil PR generally increased to a depth of 10–15 cm and then decreased beyond this depth. Long-term tillage reduced soil compaction in the surface (0–10 cm), but increased in the subsurface at a depth >10 cm due to the traffic intensity induced by tillage mechanism. Soil ρb was not affected by tillage and averaged 1.59, 1.58, and 1.61 Mg m−3 for NT, ST, and FST, respectively. Similarly soil θm was not influenced by tillage and generally decreased with increased intensity of soil manipulation and tillage frequency. Soil Ks generally decreased with increased tillage frequency. The results showed that soil ρb, θm, and Ks were minimally influenced by tillage intensity after 22 years of treatment imposition.
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