Stover harvest and tillage effects on corn seedling emergence

Corn (Zea mays L.) stover is an increasingly important feedstock for biofuel and bioproduct production; however, excessive harvest of corn stover from agricultural fields may affect corn seedling emergence and subsequent plant population which may reduce corn growth and yield. Field experiments were conducted over four consecutive growing seasons in southwestern Ontario to determine under continuous corn cropping system the effects of no-tillage (NT), conventional tillage (CT), and five rates of stover harvest (0, 25, 50, 75, and 100 wt. %) on corn seedling emergence in a Harrow sandy loam and in a Brookston clay loam. Time to achieve 50% seedling emergence (t(0.5)), emergence rate constant (k(G)), and final seedling population (M-G) were adequately simulated using the Gompertz function. Irrespective of stover removal rate and soil type, t(0.5) was 2 d longer, and k(G) was 32% lower, under NT compared to CT. In Harrow sandy loam, stover removal from NT reduced t(0.5) in 1 out of 4 yr. The 100% removal reduced t(0.5) relative to 0, 25, 50, and 75% removal by 1.1-2.2 d in 2015. Averaged across both tillages and all removal rates, k(G) was greater in Harrow sandy loam than in Brookston clay loam. Stover removal rates had no effect on M-G but averaged over all removal rates and soil types, M-G was 9% lower for NT compared to CT in 2016. No-tillage practice under corn production can impede seedlings emergence early in the growing season and stover removal from the field can help mitigate against this effect.