Nutrient and Weed Management in Organic Corn No-till Systems.

Organic corn growers typically rely on tillage as a primary weed control mechanism. The utilization of a roller-crimper to terminate cover crops and create weed-suppressive mulches in no-till system is gaining popularity among organic grain growers. This study was conducted to evaluate the use of cover crops in conjunction with animal manure on corn yield, plant nutrient content, and weed suppression in Kutztown, PA. A cereal rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth) cover crop mixture was grown in the fall of 2013 and rolled at corn planting in spring 2014. The treatments included rolled cover crop (CC) treatment, CC with subsurface banding of pelleted poultry litter (CC+PL) at 10 kg PAN per ha and compared to the grower’s standard treatment (tilled cover crop with dairy manure at 24.6 Mg/ha plus cultivation). Mean cover crop biomass was 13,272 kg/ha. Whole corn plant biomass at harvest was significantly (P=0.0253) greater in the grower’s treatment (94,805 kg/ha) than that of CC + PL (74,143 kg/ha). Corn grain yield in grower’s treatment was 11,171 kg/ha at 15.5% moisture and similar to that in the CC+PL treatment (10,204 kg/ha) but significantly greater than that in the CC (9,032 kg/ha) treatment. Similarly, nutrient contents of nitrogen and iron were not significantly different in either the grower’s or CC+PL treatments but were greater than those in CC treatment. Weed pressure in the CC+PL was 29% lower than that in the grower’s treatment and required no tillage during the growing season when compared to four cultivations in grower’s treatment. The integration of rolled cover crop and the addition of subsurface pelleted poultry litter would reduce weed pressure, reduce tillage, boost corn yield and plant tissue nutrient content effectively.