Transition from intensive tillage to no-tillage and organic diversified annual cropping systems
Transition to no-till (NT) and organic (ORG) farming systems may enhance sustainability. Our objectives were to compare transitional crop productivity and soil nutrient status among diversified NT and ORG cropping systems in Montana. Three NT systems were designed as 4-yr rotations, including a pulse (lentil [Lens culinaris Medik.] or pea [Pisum sativum L.]), an oilseed (canola [Brassica napus L.] or sunflower [Helianthus annuus L.]) and two cereal crops (corn [Zea mays L.], proso millet [Panicum miliaceum L.], or wheat [Triticum aestivum L.]). No-till continuous wheat was also included. The ORG system included a green manure (pea), wheat, lentil, and barley (Hordeum vulgare L.) and received no inputs. Winter wheat in the ORG system yielded equal or greater than in the NT systems, and had superior grain quality, even though 117 kg N ha–1 was applied to the NT winter wheat. After 4 yr, soil nitrate-N and Olsen-P were 41 and 14% lower in the ORG system, whereas potentially mineralizable N was 23% higher in the ORG system. After 4 yr, total economic net returns were equal between NT and ORG systems on a per-ha basis. Studying simultaneous transition to diversified NT and ORG cropping systems was instructive for increased sustainability.