Long-Term Soil Test Monitoring in Minnesota Cropping Systems
Study Author(s): Dan Kaiser, University of Minnesota
Year(s) of study: 2012
Location(s): Jackson and Martin Counties, MN
Important: for the complete report, including all tables and figures, please download using the links to the right.
We were planning on starting about 10 field locations for 2012. However, due to the early spring we were not able to establish that many sites. Only three field locations were established over this time frame in Jackson and Martin Counties.
The data shows significant variability in the three sampling dates at two of the locations in all variables except for organic matter (OM) which should be stable. With the soils being hard and dry, some of the variability could have been due to inconsistencies with sampling depth. The greatest spike in soil test levels was seen at the July sampling for two of the locations. The Martin 2 location was only sampled twice and in both cases the soil test levels were similar.
More locations will be established for the 2013 growing season. In addition, we also are planning on including comparisons between the field moist/slurry soil test for K in order to better understand differences between this test and the air dried test and how it may vary depending on soil properties. Since the first year was as setup year we cannot draw any firm conclusions. With the additional sites we may expand upon the tests ran to better understand some of the variability being encountered out in the field.