|Mcclenagan, J - WEST TEXAS A&M UNIVERSITY|
|Stewart, B - WEST TEXAS A&M UNIVERSITY|
Submitted to: Conservation Research Report
Publication Type: Other
Publication Acceptance Date: December 1, 1995
Publication Date: N/A
Technical Abstract: The semiarid Texas High Plains are a part of the U.S. Great Plains, one major grain producing region of the world. High Plains agriculture originally was dryland, but irrigation became common in the 1950s and over 50% of the cropland was irrigated by the early 1970s. Since then, irrigation has declined due to declining aquifer water levels, rising fuel costs, Texas water ownership laws, and tax allowances for groundwater depletion. As a result, dryland crop production has become increasingly important. In this study, we determined cropping system and tillage method effects on conditions of soil used for dryland crop production. Organic matter content (OMC) of the upper one inch of soil was greater with no- tillage (NT) than with stubble-mulch tillage (SMT), with continuous cropping than with fallow rotations, and with continuous wheat (CW) than with continuous sorghum. The greater OMC resulted in lower moduli of rupture values, which indicate a potential for less soil crusting and better seedling emergence. Dry soil aggregates were more stable with NT, which reduces the wind erosion potential. No-tillage also resulted in larger water-stable aggregates than SMT. Cropping systems did not affect aggregate size distributions or stability. Overall, NT and continuous cropping resulted in better quality of the upper soil layer than SMT and other cropping systems. This is highly important because continuous cropping, especially of grain sorghum, was the most productive and economically viable system. Use of such cropping practices should maintain soil quality and sustain dryland crop production in the region.