Feasibility of bioplastic mulch systems to stimulate early seed germination and plant growth for corn silage hybrids

A study was conducted at Vauxhall and Lethbridge, Alberta, Canada, in 2006 and 2007 to determine if covering corn (Zea mays L.) seed rows with bioplastic mulch accelerates growth and improves yield. Each site (location by year combination) included all factorial combinations of three seeding rates (64 000, 74 000, and 84 000 kernels ha-1), two Pioneer® corn hybrids [39J26 at 2350 corn heat units (CHU), high vigour; and Roundup Ready® 38K46 at 2775 CHU; low vigour], and seedbed preparation (1), bioplastic mulch covering each seed row, (2) same bioplastic system but removed 3 wk post-planting, or (3) no plastic covering. The use of a bioplastic mulch decreased days to anthesis and silking, and the removal of plastic often decreased days to anthesis a further day or two. Application and subsequent removal of plastic from corn rows always increased corn plant height relative to plots without plastic. However, the use of plastic without removal limited weed control, causing increased weed weight by 0.3-0.5 Mg ha-1 at the three sites. A yield reduction of 5-9Mg ha-1 occurred with plastic mulch vs. no plastic applied or plastic removed at Vauxhall in 2006 (High CHU hybrid) and at Lethbridge in 2007 (both hybrids). Otherwise, yield was not affected with plastic applied vs. no plastic. Removal of the plastic offers accelerated plant growth and proper timing of weed removal, but the feasibility in a corn silage system at recommended sowing dates is questionable due to logistics at planting and increased costs. The system would provide earlier harvest dates for silage or grain systems, which lessens the risk of frost effects in fall.