Rotational no-till and tillage-based organic corn produce management tradeoffs in the Northeast

Reducing the intensity and frequency of tillage in organic grain production systems is likely to produce several agronomic, economic, and environmental tradeoffs. We evaluated four organic corn (Zea mays L.) sequences in a 3-yr, full-entry organic cropping systems experiment. Two sequences included a hairy vetch (Vicia villosa Roth)/triticale (Triticale hexaploide Lart.) mixture sown after spelt harvest that differed in tillage practices (no-till [NT], conventional) before corn and corn harvest management (silage, grain). Two sequences included a red clover (Trifolium pretense L.)/timothy (Phleum pretense L.) mixture frost-seeded into spelt in late winter followed by conventional tillage preceding corn and either silage or grain harvest. Our results showed that late-season weed biomass did not differ across alternative sequences, although both tillage and NT corn production resulted in high in-row weed pressure in different years. Cover crop management prior to tillage-based corn production did not affect grain yields, but NT silage production resulted in lower yields compared with the tilled sequence. Corn silage yields were positively correlated with corn populations in both tilled and NT systems. The NT sequence lowered tillage frequency and intensity by 39 and 52%, respectively, compared with tillage-based corn production as measured using established metrics, including the soil disturbance rating, but did not significantly influence labile carbon pools. Sequences using underseeded red clover resulted in higher net returns compared with hairy vetch sequences due to additional income from fall forage harvests.