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ARS Home » Plains Area » Brookings, South Dakota » Integrated Cropping Systems Research » Research » Publications at this Location » Publication #99669


item Pikul Jr, Joseph
item Aase, J

Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/19/1999
Publication Date: N/A
Citation: Pikul Jr, J.L., Aase, J.K. 1999. Wheat response and residual soil properties following subsoiling of a sandy loam soil. Soil & Tillage Research.

Interpretive Summary: Occasional deep tillage to fracture shallow tillage pans may improve water storage and consequently wheat yield in parts of the semiarid west. We conducted a tillage experiment to 1) determine if subsoiling with a paratill improved wheat yield and 2) determine longevity of soil properties altered by tillage. Water infiltration was consistently greater on paratill treatments compared with no paratill treatment. These measurements provided evidence that soil structure created by subsoiling was not destroyed after one winter. But, we also found that even one tillage for seedbed preparation was enough to destroy vertical continuity of macropore channels important for improved water infiltration. Evidence of improved soil physical condition on plots that were subsoiled were found 2.5 yr after subsoiling, but we found no differences in wheat yield due to subsoiling. Based on wheat yield alone, subsoiling was of little value, but we cannot discount the benefits of improved water infiltration on plot that were paratilled. Tillage methods that improve water infiltration are a benefit towards reducing water runoff and combating soil erosion by water.

Technical Abstract: Shallow tillage pans resulting from the use of the same tillage tools may lead to wheat (Triticum aestivum L.) yield reductions. Objectives were to test deep tillage as a method to improve water storage and increase wheat yield. Our hypothesis was tested by comparing paired crop and soil responses on plots that were subsoiled using a paratill (PT) or not subsoiled (NOPT). Soil was a Dooley sandy loam near Culbertson, MT. Effects of PT or NOPT were compared in a study that included annual wheat using fall and spring tillage (FST) and what rotated with fallow (FWCT). Subsoil treatments were paratilled once in autumn 1992 to about 0.3 m deep. Cone index of the top 0.3 m of soil 2.5 years afer subsoiling was 891 kPa on PT and 981 kPa on NOPT. Soil bulk density was 1.34 Mg/cubic m on PT and 1.36 Mg/cubic m on NOPT plots. Final water infiltration rate averaged 15 mm/h on PT and 6 mm/h on NOPT plots nine months after subsoiling. Average water content of the top 1.2 m of soil in the spring of the year was 21 mm greater on PT than on NOPT plots. There were no differences due to treatment in wheat yield. Residual effects of subsoiling on soil properties were detected 2.5 yr after subsoiling, but soil changes attributed to subsoiling had no effect on wheat yield.