Practices that combine stubble management for snow catch and contour-ripping for snowmelt infiltration have potential to reduce water runoff and increase soil water storage. A randomized design with 3 replications of ripped and non-ripped soil was used to test whether tillage improved water infiltration into frozen soil. Studies were conducted during 4 years on annually grown spring wheat (Triticum aestivum L.) near Culbertson, Montana. Soil was a Dooley sandy loam (fine-loamy, mixed Typic Argiboroll). Ripping was with a single chisel or rigid tine subsoiling shank at regular intervals on the contour in the fall of the year. Soil water change overwinter was measured at three slope positions using neutron attenuation and volumetric determinations. Final infiltration rate averaged 18 mm h^-1 on the rip treatment and 2 mm h^-1 on the no-rip treatment even when the soil was frozen deeper than 0.6 m. In spring, average water content of the top 1.2 m of soil, to a distance 1.5 m downslope from the rip, was 3.2 cm greater on ripped plots compared to non-ripped plots in comparable slope positions. There have been no differences in wheat yield between treatments. Infiltration measurements show that soil ripping has potential to decrease water runoff, and if used in conjunction with stubble management to maximize snow trapping, may increase overwinter soil water storage.

Joseph L. Pikul Jr.
USDA-ARS
Northern Grain Insects Research Laboratory
2923 Medary Ave.
Brookings, SD 57006
Tel: 605-693-5258
Fax: 605-693-5240
email: JPIKUL@NGIRL.ARS.USDA.GOV