Submitted to: Southern Conservation Agricultural Systems Conference
Publication Type: Proceedings
Publication Acceptance Date: 6/25/2007
Publication Date: 6/27/2007
Citation: Zhang, J.G., Raper, R.L., Balkcom, K.S., Arriaga, F.J., Kornecki, T.S., Schwab, E.B. 2007. Drawbar power requirements and soil disruption of in-row subsoiler points for conservation tillage. In: Wright, D.L., Marois, J.J., Scanlon, K., editors. Proceedings of the 29th Southern Conservation Agricultural Systems Conference, June 25-27, 2007, Quincy, Florida. Available at: http://www.ag.auburn.edu/auxiliary/nsdl/scasc/.
Interpretive Summary: In-row subsoiling is the most effect method to reduce the effects of soil compaction on crop production in the Southeastern U.S. Benefits of this practice include reduced erosion, increased rainfall infiltration, better plant growth and overall increased yields. Some producers in this region are using a new ‘splitter’ subsoiler point that claims to reduce soil disruption and take reduced energy for the in-row subsoiling operation. Experiments were conducted in the soil bins at the USDA-ARS National Soil Dynamics Laboratory to determine the effectiveness of this point as compared to a standard ripper point. Results showed that the ‘splitter’ point took increased energy to pull through the soil, but did cause reduced aboveground soil disturbance. Producers who are concerned about increased fuel costs may not want to adopt the ‘splitter’ point unless they are particularly focused on decreasing above-ground soil disruption.
Technical Abstract: Soil compaction can reduce crop yields by restricting root development. In-row subsoiling is a common tillage practice for disrupting the compacted soil profile, allowing roots to proliferate downward to obtain adequate soil moisture. The subsoiler system is composed of many important components, but the point assembly is the first element to contact the soil and can largely determine the draft requirement and soil disruption of the subsoiler. Two points were evaluated in a soil bin experiment at the USDA-ARS National Soil Dynamics Laboratory in Auburn, AL. A standard ripper point was compared with a ‘splitter point’ which is designed to fracture the soil and reduce above-ground soil disruption, especially in dry conditions. The subsoiler system was mounted on a three-dimensional dynamometer where measurements of draft force, vertical force, side force, speed, and depth of operation were determined and tillage power requirements were calculated. Measurements of soil disruption including spoil cross-sectional area, trench cross-sectional area and trench specific resistance were determined. Results showed that the splitter point required significantly greater drawbar power (28%) compared to standard ripper point the while disturbing similar amounts of below-ground soil. However, the splitter point did reduce the above-ground soil disruption by more than 10%. The splitter point was helpful in reducing above-ground disruption but the added energy cost could be prohibitive for many producers.