Maybe this link below has been posted before, it provided some interesting university insight into biological product performance. Click the link below for the document, but I pasted the summary below from the document. 61 site years and 59 had no yield response over N alone. 

https://www.ndsu.edu/fileadmin/snrs/Files/SF2080_Performance_of_Selected_N-fixing_Products.pdf

Sixty-one site years of N rate trials with and without the use of biological N fixing products were conducted in corn, spring wheat, sugar beet and canola in 10 states within the North Central Region of the U.S. Of the 61 site-years, 59 site-years had no yield increase with use of the product over N rate alone. Two site-years in corn had yield increases due to product use over the N rates alone. Given the low rate of positive benefits to the use of these products, growers should be skeptical of products that claim to provide asymbiotic/non symbiotic N-fixation for the purpose of allowing a farmer to decrease fertilizer N rate. It is good for farmers to be curious; however, the wise grower needs to test products of interest on their own farm in a replicated manner and search for un biased data on product performance before using them on whole fields. A recently published primer on how one might conduct on-farm research is provided in Thompson et al., 2022.