Wednesday, November 7, 2007
305-2

Soil Water Extraction Patterns in Skip Row Corn, Sorghum, and Sunflower.

David C. Nielsen1, Merle F. Vigil1, Francisco J. Calderon1, Joel Schneekloth2, David Poss1, W. Brien Henry1, and Joseph G. Benjamin1. (1) USDA-ARS, Central Great Plains Research Station, 40335 County Road GG, Akron, CO 80720, (2) Colorado State University, Central Great Plains Research Station, 40335 County Road GG, Akron, CO 80720

Growing crops in planting configurations that increase row spacing while maintaining field plant populations (skip row) has been proposed as a means to stabilize dryland crop yields under the erratic and sometimes very low precipitation conditions that frequently exit in the Great Plains. Doing so should force plants to undergo increased water stress (and restricted vegetative development) early in the season as higher in-row populations increase competition for soil water near the row. More soil water stored farther away from the row (in the skipped row area) should be available during the more critical reproductive stage compared with conventional 76 cm row spacing, leading to lower water stress during flowering and greater yield. This study compares the soil water extraction patterns in skip row corn, sorghum, and sunflower at Akron, CO. Results indicated that sorghum and sunflower were able to extract the stored soil water in the skip (76 and 114 cm from the planted row). Results for corn were inconsistent and appear to be variety dependent.