SOIL-WATER STORAGE AND PRECIPITATION STORAGE EFFICIENCY OF CONSERVATION TILLAGE SYSTEMS

Surface residues associated with no-till and minimum-till fallow syste ms have an influence on soil water storage. Soil water storage, precip itation storage efficiency, and the relationship of soil water storage and precipitation for seasonal segments of fallow were determined for no-till (NT), minimum-till (MT), and stubble-mulch (SM) winter wheat- fallow methods The study was conducted an a Williams Loam (fine-loamy, mixed, Typic Argiborolls) near Sidney, Montana for 8 fallow seasons. Fallow method-did not significantly influence long-term soil water sto rage during the after-harvest (August-October 31) or over-winter (Nove mber 1-May 1) segments because after-harvest weed central was not need ed. Precipitation storage efficiencies were greatest for the over-wint er segment (59%) and least for the summer follow segment (13 to 20%). No-till and MT stored 12% (12-14 mm more) more soil water and increase d preciptation storage efficiency 16% when compared to SM for the 14-m onth fallow season. By using fallow segment relationships for precipit ation and soil water storage, producers may be able to go to more inte nsive cropping systems that take advantage of additional soil water.