|Dusek, D - USDA-ARS - RETIRED|
Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Other
Publication Acceptance Date: July 10, 2000
Publication Date: N/A
Technical Abstract: Corn (Zea mays L.) is a major irrigated crop, in the Southern High Plains of the United States, 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 3-yr study (1997 through 1999) evaluated three surface tillage systems for corn under two irrigatio regimes in a semi-arid environment at Bushland, TX. The main treatments were furrow diking, clean furrows, and flat tillage. Imposed upon these tillage treatments were 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. Irrigations were applied using a lateral-move sprinkler system equipped with low-drift spray nozzles spaced 1.5-m apart with heads about 1.8 m above the ground and nozzled to simulate the flow rates at the outer end of a 400 m system with an irrigation capacity of 8 mm d-1. Each plot was 13.7 m wide (eighteen 0.75 m rows) with a water isolation border plot between the irrigation treatments. 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 did significantly increase corn yields across years and irrigation regimes in this semi-arid environment.