Effects of furrow diking on corn response to limited and full sprinkler irrigation.

Corn (Zea mays L.) is a major irrigated crop in the Southern High Plains of the USA that is usually fully irrigated. The trend has been toward center pivot sprinklers equipped with low pressure, closely spaced spray heads that have a large instantaneous application rate that can cause surface water redistribution and/or runoff. This study was conducted to evaluate three surface tillage systems-furrow diking, clean furrows, and flat tillage-on corn yields and yield components during three different growing seasons under two irrigation regimes-full soil water replenishment (FI) and limited irrigation (LI), which was irrigated at the same time as FI but with one-half of the irrigation amount-in a semiarid environment at Bushland, TX. Irrigations were applied with a lateral-move sprinkler system equipped with low-drift spray nozzles. Yields were significantly (P < 0.05) affected by year and all treatments. The 1997 and 1999 yields were similar, but the 1998 yields were reduced by a combination of drought and disease. Furrow diking increased corn yields significantly across years and irrigation regimes in this semiarid environment. Irrigation regime almost doubled mean yield from 6.5 Mg ha -l to 12.6 Mg ha -l for the LI and FI regimes, respectively.