Influence of Bo, Cu and Mn on Soybean and Corn Grain Yields

Introduction

Soybean micro nutrient deficiency symptoms are rare to non-existent in eastern South Dakota. Zinc deficiency is more common in corn and frequently seen on poor, low organic matter and coarse texture soils. Field research investigating the other micro-nutrients (Boron, Copper and Manganese) has been limited. No visual boron, copper or manganese deficiencies have been recorded in South Dakota. However, much like zinc, soybean and corn can respond to boron, copper and manganese field applications without visual deficiency symptoms. For this reason, an on-farm research project was initiated to measure the influence of pre-emerge soil applications of boron, copper and manganese on soybean and corn yields in eastern South Dakota.

Summary

Boron, copper and manganese soil test levels at all sites were in the high category (EC-750) except for boron at the Garretson site which was in the medium category (Table 2). No micronutrients applications are recommended when soil levels are in the high category and 2 lbs/a boron are recommended for the medium category. Boron soil test levels ranged from 0.41 to 2.11 ppm. Copper soil test levels ranged from 0.76 to 2.44 ppm. Manganese soil test levels ranged from 5.9 to 40.0 ppm.

Grain yields at all sites were very good for soybeans, however August rains helped soybean yields remain near average (Table 3). The micro nutrient treatment applications at all remaining sites did not significantly influence soybean grain yields (table 3). Larger than normal numerical yield differences occurred at the Garretson and Arlington soybean sites, and the Crooks and Garretson corn sites. This may appear to indicate that micronutrient applications are needed. Statistical interpretation however could not determine a significant difference.

Modified from: http://igrow.org/up/resources/03-7010-2017.pdf

By:

Anthony Bly, SDSU Extension Soils Field Specialist

David Karki, SDSU Extension Agronomy Field Specialist

Sara Berg, SDSU Extension Agronomy Field Specialist

Acknowledgments

The soybean portion of this research work was partially funded by the South Dakota Soybean Research and Promotion Council. Other contributors were SDSU Extension, the South Dakota Agricultural Experiment Station, the Northeast Research Farm, and many farmer cooperators.