Strip-tilled soybeans yielded 2 bushels more per acre vs. no-tilled at the highest fertility rate and plant population in a Texas A&M University onfarm trial.

Strip-tilled soybeans yielded 23 bushels per acre at 70,000 seeds per acre; 24 bushels per acre at 125,000 seeds per acre; and 26 bushels per acre at 170,000 seeds per acre.

No-tilled soybeans yielded 24 bushels per acre at all three populations.

Delta Pine/Asgrow 5335 soybeans were planted April 1, 2009, at 80,000, 125,000 and 170,000 seeds per acre on 30-inch rows. They showed no or minimal difference in yield when planted in no-till or strip-till farming systems.

Additional fertility levels of nitrogen, phosphorus and/or sulfur in the strip-till plots probably allowed enhancement of the yield slightly with higher population levels.

Minimal yield differences may have been due to very dry growing conditions. There is also difficulty in establishing sound data from unreplicated trials.

Materials And Methods

The soybeans were planted on 30-inch rows with a White 6800 16-row planter. Each seeding rate of 32-row plots was planted twice — once on no-tilled and once on strip-tilled land.

The soybean seed was inoculated commercially with Helena Optimizer prior to planting. 

One quart per acre of Boundary herbicide was applied pre-emerge, and the crop was sprayed twice during the growing season with 24 ounces per acre of Roundup. Fertility applied was different on the two tests with the following nutrients applied:

  • No-till 5-23-53

  • Strip-till 22-45-53-6s

Results

Growth of the soybeans was good through June, but being dryland farmed and with minimal rainfall for the season, the yield was fair with the lack of rainfall the main limiting factor. Only about 7 inches of rain was received from October 2008 through May 2009, the end of the major growing season.

There was no difference in the yield of the various soybean plant populations on the no-till soybeans (at a lower fertility rate applied). 

There was minimal yield difference in the soybean plant populations on the strip-till (higher fertility rate) plots, which showed up as a 2 bushel-per-acre increase for the higher plant populations.

Although of minimal significance, the highest seed size was noted to be on the lowest plant population in either strip-till or no-till.