Comparison of Applicator Knives for Fall and Spring Strip-Till-Applied Anhydrous Ammonia

摘要

Anhydrous ammonia can cause damage to seedling corn when applied prior to corn planting. Deep placement with a modified injection knife used in conjunction with strip tillage could reduce the risk of plant toxicity following an anhydrous ammonia application, which could affect stand establishment and yield. This research evaluated the response of corn to fall and spring anhydrous ammonia applications at 0, 150, and 300 lb N acre-1 using a mole or C-Jet injection knife from 2011 to 2013 in Missouri. There was no difference in plant population or yield between the C-jet and mole knife when anhydrous ammonia was fall-applied. When N was applied in the spring and planted within 8 h, the C-jet increased plant population 2200 and 3600 plants acre-1 compared with the mole knife in 2011 and 2013, respectively. The C-jet increased plant height, vegetative stage of development, and yield 20 to 57 bu acre-1 compared with the mole knife in 2011. In a strip-till system with a silt loam soil, the C-jet could provide protection from the effects of anhydrous ammonia on stand establishment to farmers interested in planting immediately after application.