Planting Green Effects on Corn and Soybean Production

No‐till farmers who want more from their cover crops (CCs) are delaying CC termination until the main crop is planted. Delaying termination can help dry wet soils and reduce erosion. This process is referred to as planting green (PG). We hypothesized that PG would (i) dry soil at main crop planting, but conserve soil moisture later in the growing season; (ii) reduce soil temperature; (iii) reduce slug damage on main crops; and (iv) not reduce main crop yield. This experiment was conducted in Pennsylvania between 2015 and 2017 to compare two CC termination dates: preplant killed (PK) and planting green (PG) in corn (Zea mays L.) and soybean [Glycine max (L.) Merr.]. Planting green increased CC biomass an average of 94% and 94 to 181% compared to PK preceding corn and soybean, respectively. Soil was 7 to 24% drier and 0.9°C cooler at corn planting, and 8% drier and 0.7 to 2.4°C cooler at soybean planting in PG compared to PK. Slug damage was not different, lower, or higher in PG corn, and not different or lower in PG soybean compared to PK. Corn yield was reduced and not impacted by PG in higher and lower yielding environments, respectively. Soybean yield was stable across locations, and not affected by cover crop termination date. We concluded that corn was more vulnerable to yield losses from conditions created by PG than soybean; therefore, growers who desire potential benefits and lower risk from PG should first consider soybean. Core Ideas Planting green refers to planting the main crop into a living cover crop. Planting green increased cover crop biomass by 94% in corn and by 94 to 181% in soybean. Planting green dried the soil at main crop planting. Planting green cooled soil 0.7 to 2.4°C at planting. Soybean yield was not influenced by planting green; corn yield was reduced.