Managing Global Resources for a Secure Future

Soil health is a link between land management practices and their impact on water quality. Understanding soil health is important due to the significant resources used in the U.S. to incentivize conservation practices adoption to improve water quality. A field-scale paired watershed study was initiated in 2004 in northeast Indiana to measure the effect of tillage on soil health and the effect of tillage and grassed waterways on water quality. Over the course of the study, water quality and soil health were assessed in nearby conventionally tilled (fall chisel, spring disk) and continuous no-till fields in the Cedar Creek sub-watershed within the Western Lake Erie Basin. Grassed waterways were installed at each field during the course of the study. Each year from 2004 to 2010, water quality parameters (pesticides, nutrients, sediment and carbon) were measured and in 2004 and 2009, soil health parameters (physical, chemical, biological and nutrients) were measured. Both tillage practices and grassed waterways had an effect on water quality. However, the greatest impact on water quality was when no-till and grassed waterways were combined. Soil health indicators showed minimal effects to tillage. There was no marked difference in total soil carbon, bulk density, organic matter or β-glucosidase activity between years and tillage at any measured depth. Potentially mineralizable soil carbon and nitrogen, mean weight diameter and water stable aggregates (measures of soil aggregate stability) were less in 2009 than in 2004 for both tilled and no-till fields. Total nitrogen increased from 2004 to 2009 at all depths in the no-till field, but not in the tilled field. This research 1) reveals the complexity in quantifying SH owing to management practices, 2) emphasizes the beneficial effect of conservation practices for improving water quality in the WLEB and 3) decreases the expectation of no-till alone to reduce pesticide loading.