Soil Responses to Farming Management Practices in Western Kentucky.

Soil Responses to Farming Management Practices in Western Kentucky Katie M. LeBlanc & Iin. P. Handayani, Murray State University, Murray, Ky., USA Monitoring the changes of soil characteristics over time is important to better manage our farm, as well as to protect our natural resources. Modification of farming systems from conventional tillage to no till and organic based farming practices may change soil quality indicators. Evaluating soil physical characteristics could alleviate erosion, pollution and high costs of crop production. Soil physical characteristics such as soil organic matter (SOM), water holding capacity (WHC), bulk density (BD), total porosity, and aggregate stability (AS) are considered vital soil quality indicators. This study was designed to determine the effects of different farming practices in western Kentucky on selected soil physical characteristics. Soil samples were collected from the Murray State University farm in Calloway County, Kentucky. In August 2010, surface soil (0-7.5 cm and 7.5-15 cm) samples were collected from five fields: (1) sod as a control, (2) 3 years of organic farming (OF3), 5 years of organic farming (OF5), (4) 15 years of no-tillage systems (NT), and 15 years of conventional tillage (CT). The results show that the depths 0 to 15 cm, organic farming and no tillage practices resulted in improving soil organic matter (SOM), bulk density, porosity and aggregate stability with the highest values found in 5-yr organic farming and the lowest was in 15-yr conventional tillage systems. Soil compaction as indicated by bulk density reduced up to 15% and the ability of soil to hold water improved about 22% after 5 years of organic farming when comparing to 15-yr of conventional tillage farming practices. Improvement of soil physical properties under organic farming and no till practices indicates that continued organic matter supply into the soil can gradually improve soil quality and regenerate degraded lands.