Addressing Soil Chloride Variability and Its Management

Addressing Soil Chloride Variability and Its Management, 1998 In the northern Great Plains, grid sampling is not used by many wheat producers because of its expense. To be profitable, responsive areas within fields (less than 30 lb Cl/A 2 ft) need to be characterized by a minimum number of soil samples. Five sites (Mandan, Valley City, Colfax, Gardner, and Hunter) in North Dakota were selected in order to study Cl variability. Each of these sites was sampled at small grid spacings.

IPNI-1996-USA-ND8

01 Mar 1998

1997 Annual Interpretive Summary

Addressing Soil Chloride Variability and Its Management, 1997

Four sites in North Dakota were selected in order to study chloride variability. This study has been conducted partially to investigate undocumented reports of chloride response in soils that test high in chloride, where no response was expected. The other purpose of this study was to determine the most appropriate soil sampling scheme for chloride. Grid sampling was employed at each site, with soil samples extending to a two foot depth for chloride determination. Currently, chloride levels are being analyzed from samples taken from a 110 foot grid at four North Dakota locations. Preliminary results suggest that field chloride level patterns might be represented by either a 220 foot grid or by topography sampling. Higher chloride levels appear to be located in depressional areas, while lowest chloride levels appear most frequently in upland positions which are lower in organic matter and coarser in texture. There appears to be a higher degree of variability for chloride than nitrate within a grid/management zone. ND-08F