Variable rate liquid nitrogen application for cotton and corn production

摘要

Variable rate technology was used in a cotton and corn rotation to apply a liquid nitrogen solution (30 percent N) based on yield and soil maps to evaluate precision agricultural, variable rate production versus conventional field averaged. A variable rate, liquid nitrogen applicator was designed and assembled to apply a 30 percent liquid nitrogen solution at lay by based on the soil and yield variability in a 30+-acre field. Both cotton nitrogen use efficiency for each soil series and maximum yield 25-foot grids, from either year 1998 or 2000 yields, were utilized to generate a nitrogen application map. Nitrogen application and yield data were used to compare the two production systems for three-tillage treatments typically used in eastern NorthCarolina. Initial results for cotton nitrogen application in years 2000 and 2001 showed that approximately the same rates were applied on the average for both production systems. For year 2000, the cotton yields for field averaged nitrogen application onthe clean till subsoil treatment were significantly higher than the variable rate application. There was no difference in nitrogen treatments with the chisel/disk and strip till treatment.