Tillage and Soil Moisture Effects on Winter Pasture Production and Stocker Average Daily Gain.

Stocker cattle production on annual cool season winter pasture (CWP) is an important livestock enterprise in the southern Great Plains. CWP is established using no-tillage (NT) or conventional-tillage (CT) methods. In summer, CWP areas are usually fallowed chemically or with tillage depending upon establishment methods. Some producers have been slow to adopt NT due to the need for specialized planting equipment and perceptions of reduced forage mass (FM) and that rainfall capture and CWP establishment improves with tillage. To increase understanding of tillage effects on FM, stocker average daily gain (ADG) and soil moisture, we measured FM weekly, spring soil moisture, end of season water infiltration rate, and ADG on 10-NT 2.0 ha^-1 and 10-CT 2.0 ha^-1 CWP paddocks that have been in continuous NT or CT CWP-summer fallow production since the late 90’s. CT and NT paddocks were planted on September 24 and 25, 2015. Paddocks received 67 kg N ha^-1 and P and K were not limiting.  FM readings began November 11 (NT 485 ±22.4 kg ha^-1, CT 466 ±11 kg ha^-1).  Stocker steers (n=5/paddock, 243 ±1.8 kg) began grazing on December 16, 2015. On December 18, FM of NT paddocks (1658 ±63 kg ha^-1) had separated from CT (1431 ±93 kg ha^-1) and maintained this separation to cattle removal May 9, 2016 (NT 1886 ±246 kg ha^-1, CT 691 ±155 kg ha^-1). Mean grazing period ADG of NT steers (1.44 ±0.06 kg) was greater than CT steers (1.1 ±0.06 kg). Mean NT soil temperature from February 9 to May 9 at 7.6 cm depth was 1.4°C cooler than CT while soil moisture during this period was similar. Infiltration rates of CT paddocks (1.52 cm/hr) recorded on May 9 were higher (P < 0.01) than NT (0.66 cm/hr). FM and ADG of NT paddocks was higher than CT but differences cannot be explained by soil moisture within this year.