TILLAGE TOOLS FOR MANURE INCORPORATION AND N CONSERVATION

Abstract

Full incorporation of manure directly after application can reduce odor and ammonia emissions but requires plowing that is incompatible with reduced-tillage systems. Our objectives were to determine the impact of partial incorporation using an Aerway soil aerator set at 15 degrees (maximum angle) within 1 h of manure application on N availability and corresponding corn (Zea mays L.) grain yield. Aerway incorporation was compared with chisel plow incorporation, surface application without incorporation, and an inorganic N control (134 kg N ha -1 1 applied at side-dress time) in a randomized complete block design (six replicates). The trial was conducted (2005-2007) at the Musgrave Research Farm (Central NY). All treatments received a starter N application of 34 kg N ha -1 . Manure was applied approximately 2 weeks before corn planting (70,025, 84,030, and 88,700 L ha -1 in 2005, 2006, and 2007, respectively). Soil samples (0-20 cm and 0-30 cm depth) were taken before manure application, at planting, side-dressing, and harvest. In all 3 years, trends suggested higher soil nitrate levels (0-30 cm) at planting and side-dressing for chisel and Aerway incorporation compared with surface application, although means were not significantly different from the surface application treatment in the exceptionally wet spring of 2006 and the drought of 2007. Grain yields for the Aerway treatment were equivalent to the chisel plow treatment in Years 1 and 2 and greater in Year 3. We conclude that Aerway incorporation can be an effective alternative to chisel plow incorporation.