Tillage Requirements of Sweet Corn, Field Pea, and Watermelon Following Stocker Cattle Grazing

Winter annual grazing combined with vegetable production can potentially improve the sustainability of farming operations, particularly in the Southeast. However, winter grazing creates excessive soil compaction, which can adversely affect yields of subsequent summer crops. We initiated a study to determine the optimal tillage system following winter grazing for production of sweet corn (Zea mays, L.), Southern field pea (Vigna unguiculata L.), and watermelon (Citrullus lanatus L.) on a Wynnville fine sandy loam, in north-central Alabama of the southeastern U.S. from 2001 to 2003. Each fall, all plots were planted to ryegrass (Lolium multiflorum L.) and stocked with 6.7 cattle ha-1. In the spring, three surface tillage treatments (chisel/disk/level, disk/level, no surface tillage) and three deep tillage treatments (no deep tillage, in-row subsoiling, paratill) were arranged in a factorial randomized complete block design with four replications. Sweet corn ear weights responded to a combination of surface and deep tillage in 2002 and 2003. In 2001, the average response to surface tillage was 105% greater than no-surface tillage, compared with only a 14% increase with deep tillage over no-deep tillage in 2001. Southern field pea grown after winter annual grazing yielded 22% greater 2 of 3 years following surface tillage with disking; inclusion of chisel plowing with the disking showed no benefit. Watermelon yields following winter annual grazing were 39% and 58% greater in 2001 and 2002 with deep tillage alone, specifically in-row subsoiling, without any surface tillage. The tillage system for vegetable growers who choose to complement their operations with winter-annual grazing varies with the vegetable grown. In general, sweet corn responded best to a combination of surface and deep tillage, Southern field pea required only disking, and watermelon responded to in-row deep tillage with no additional surface tillage.