Effect of Inoculant Products on Soybean (Glycine Max) Production in Western Kentucky

The symbiotic relationship between soybeans and Rhizobium bacteria is the foundation for nitrogen fixation and utilization during the growing season. Inoculants are products that are applied as a seed treatment that contain the live bacteria and introduce the bacteria to the field if a compatible legume has not been grown in several years. Inoculants have also been thought to boost already existing bacteria populations to increase the amount of nitrogen fixation. The goal of these products is to increase the amount of active nodules that are present on the roots. This study investigates the impact of different inoculants on soybean production. This study was conducted at the Murray State University’s Pullen Farm located in Murray, Kentucky. The primary soil complex is Grenada silt loam and has been under no-tillage system for several years. Seven total treatments were applied, a control, LAL Fix (a known inoculant), and five unknown inoculant treatments. Nodule counts and chlorophyll readings were taken. Soil samples were taken after harvest at two depths to determine soil nitrogen, soil organic matter, and soil pH. Grain grading was also done to examine seed quality. The findings of this study examine not only the effects of different inoculant products on nodulation, but also the end use of the nitrogen produced by these products.