For more than four decades, researchers from the University of Nebraska-Lincoln and other institutions have been studying the long-term effects of tillage on the soil at research plots at the High Plains Ag Lab near Sidney.

But now the plots are in a state of transition to an intermittent tillage study, which will study the effect of tillage every 6 years on soil quality change, says Drew Lyon, the university's dryland cropping system specialist at the Panhandle Research and Extension Center in Scottsbluff.

All treatments will be managed as no-till in the years between plowing. In the year of plowing, half of each previous tillage treatment plot will be plowed and the other half of each plot will remain no-till. 

Previously, the plots were cropped in alternate years to reflect the wheat-fallow rotation commonly used by farmers. The fallow plots received one of three treatments: plow, stubble-mulch, or no-till.

The new study will tell researchers about the long-term effects that occasional or intermittent tillage has on the soil, Lyon says. 

Soil scientists with the USDA-ARS at Akron, Colo., are sampling the soil prior to initiating these changes. This will allow a summary of the effects of the last 40 years on soil quality and serve to establish initial soil conditions at the start of the new study. 

The new study will likely need to run for 12 to 18 years before significant soil quality changes become evident, the university says.

The new long-term research project will be conducted on land that now-retired dryland crops specialist Charlie Fenster and Gary Peterson, a soil scientist at UNL in Lincoln at the time, used to study what happened when a native grass site was converted to cultivated land in a wheat-fallow system with conventional tillage. They were interested in following changes in soil total N content from the introduction of tillage.