Developing Decision Criteria for Soil Salinity Management Options on Cropland: A Case Study in Southeast North Dakota

Soil salinization is an important research topic in North Dakota, and the issue may be growing in importance due to changing cropping patterns throughout the Northern Great Plains. Soil salinity is generally determined by measuring the electrical conductivity (EC) of soils. This study is based on EC measures recorded throughout 40 fields by a Veris® sensor, and were subsequently mapped. Simulated yields (based on EC), production costs, and expected profits were used to determine which of eight crop rotations maximize expected profit based on a given field’s average EC, as well as the variance of EC within the field. Principal components analysis was used to develop a single measure of EC that incorporates information about both the mean and variance of EC throughout a field. Results illustrate that for very low field-level EC (low salinity) the two most profitable rotations are corn-soy and continuous corn, while for field-level EC above 4.5 the most profitable rotation is wheat-barley. Preliminary results are also presented to indicate how precision agriculture technologies (mapping, row controlled planters, and swath controlled sprayers) could increase profit for each rotation by eliminating input expenditures in portions of a field where a loss is expected.