What is in this article?:
- Challenges and Benefits of Rolling Soybean Ground
- Degradation of soil and water quality
Land rolling use has steadily increased, especially on soybean fields in the Upper Midwest during the past few years. The practice began in Canada several years ago, gained steam in North Dakota and Northwest Minnesota where it has become routine, and now has spread into Southern Minnesota and some areas in Iowa.
The essential concern or need to use a land roller is to push down rocks, breakdown residue and level the ground for harvest and subsequently reduce grain and yield losses. The idea is that rolling makes combining beans faster and easier, and there is less chance of picking up rocks or corn root clumps which can damage guards, sickle sections or expensive internal combine parts.
Some of these problems or challenges are legitimate, but they are not dominant in every field or landscape, given other economic and environmental risks involved with using a land roller. The economic benefits of such practice have been difficult to document, especially in yield advantage, seed quality or seed loss. The cost of purchasing a land roller depends on its size. The approximate costs, as provided by some equipment dealers, can range in price from $17,000 for a 20-ft., $32,000 for a 45-ft. and $65,000 for the 85-ft. model. Custom land rolling rates can range from $3/acre to $10/acre, averaging $6.55/acre, according to Iowa State’s 2010 Iowa Farm Custom Rate Survey.
Research on using a land roller in Iowa and Minnesota showed no yield advantage in soybeans with rolling at different times and growth stages (see related gallery for table). Such data suggests costs are not covered by additional yield.
Impact on soil and water quality is a potential concern. Using a land roller during early spring and for multiple times (i.e., before and after planting) can create significant soil surface compaction, destroy soil surface aggregates and detach residue leading to a potential increase in soil erosion. Preliminary research from Iowa State University documents that land rolling a field reduced water infiltration. Reduced infiltration leads to increased surface runoff after rain events. The findings show a significant decrease in water infiltration by over three times the rate of control (non-rolled plots). This is a one-year evaluation and research will continue in 2011.