Soil Amendment and Tillage Evaluations to Improve Germination with Subsurface Drip Irrigation

Achieving uniform cottonseed germination using subsurface drip irrigation (SDI) under low rainfall conditions or during hot, windy periods has been one of the biggest challenges facing SDI in the Texas High Plains.  A two-year field experiment evaluating four soil amendments placed from near drip laterals to the soil surface at 20 sites was established at the Texas AgriLife Research Station at Halfway, TX.  A separate experiment evaluating two tillage methods was also conducted.  Soil amendment treatments included two starch-based polymers (Polyacrylimide (Pam) Earth Chem, Inc., Scottsbluff, Nebraska and Zeba^TM, Absorbent Technologies, Inc., Beaverton, Oregon) both at 22kg/ha equivalent), composted cow manure (450 kg/ha), cow manure and gypsum (450 + 450 kg/ha), and an untreated check.  Tillage treatments included the use of a strip-tillage implement, the combination of subsoil plow (Paratill^® Bigham Brothers, Inc., Lubbock, TX) and strip-till, and a non-treated check.  Differences in measured, near-surface volumetric soil water content will be presented.  Finding methods to improve germination with SDI may help producers adopt more efficient irrigation systems and conserve water.