Year Established: 2020 Start Date: 2020-02-28 End Date: 2021-02-26
Total Federal Funds: $9,964 Total Non-Federal Funds: $21,286
Principal Investigators: Anna Cates
Abstract: Farmers are increasingly interested in measuring the health of their soil with biological laboratory assays. The hope and promise of these tests is to inform fertility management by predicting mineralization of nutrients from the active, or rapidly cycling, organic matter pool. However, a pilot project in 2019 found preliminary evidence that active carbon, nitrogen, and aggregate stability vary with temperature and moisture. Misunderstanding the variability in soil testing can lead to higher soil sampling costs, unreliable results, and mistaken farm decisions. We propose to evaluate temperature and moisture effects on soil health tests on soil under varying management. In SW MN, varying tillage regimes varied moisture and temperature on a silty clay loam, and preliminary evidence showed that protein N is significantly correlated to both temperature and moisture. In addition, soil aggregation was reduced soil moisture varied more widely in preceding days. Soil health practices like increasing residue cover, reducing tillage, and growing cover crops are known to change the temperature and moisture regimes at the soil surface, so itâ€™s important to understand the relationship between these environmental variables and soil health tests. It may be that responses of soil microbes to environmental variables masks any differences due to changes in management. By monitoring temperature, moisture and soil health metrics on a small temporal scale, we can develop preliminary correction factors for growers sampling under various environmental conditions. These results will inform UMN Extension programing on how and when to use soil health tests in different operations.