Soil scientists with the USDA's Natural Resources Conservation Service are currently working on a project that will help farmers know how tillage methods impact soil quality. According to NRCS Soil Scientist Dave Kohake, the Dynamic Soils Properties study, based out of Lincoln, Neb., is the first of its kind for NRCS.
“In the past, studies have dealt more with the soil’s intrinsic properties. This project will focus more on the dynamic soil properties affected by management,” Kohake says.
The Dynamic Soil Properties study is focusing on two tillage methods — conventional tillage and no-till. For this study’s purposes, a field is considered to have been conventionally tilled any time the soil has been disturbed with full-width tillage implements, such as discs, chisel plows, field cultivators. A field is considered to have been no-tilled if it has not had any manipulation to the soil’s surface within the past 15 years. A couple organically farmed sites will also be evaluated.
The Dynamic Soil Properties study team identified five sites for each tillage method across southeast Nebraska with similar soil types. The team has been traveling around to these selected sites throughout the fall to collect soil samples.
Once at the site, the soil scientists prepare the test location by setting up a grid. Within the grid, five sampling pits are dug. The pits are all 16 inches deep. This is the depth where the impact of different farming techniques can be detected.
The soil scientists then begin identifying the different layers of soil. A sample of each layer is taken to the USDA’s National Soil Survey Center’s laboratory in Lincoln for analysis.
The NSSC lab will check each site’s soil samples for several properties, including bulk density and organic carbon content.
“The amount of organic carbon content found within soil is the best indicator we have for soil quality. The higher the carbon content, the higher the soil quality or health,” Kohake says.
This study will compare the lab results to show how conventional tillage, no-till and organic farming methods impact soil properties. The results from this fall’s study should be available by next planting season.
“This study should provide some useful information on how different management systems are affecting various dynamic soil properties," Kohake says. "Hopefully, the information can be used to make better management decisions in the future for improving soil quality.”