Jun 08, 2024

CAMPBELL: Performance of N-Fixing products in crop production conclusions

Posted Jun 08, 2024 9:15 AM

By STACY CAMPBELL
Cottonwood Extension District

Two weeks ago, my newspaper article was on performance of N-fixing products in crop production. N-Fixing organisms, usually species of bacteria, have the ability to ‘fix’ nitrogen (N) from the atmosphere where it is abundant as N2 gas, and convert it to plant available N. Legumes such as soybeans, and alfalfa are able to do this.

Lately, biological-based products have been marketed to enhance crop production. One class of products essentially consists of seed inoculants whose marketers claim they will either infect the seed, which enables them to perform N-Fixation functions similar to Rhizobia in legumes, or to inhabit the immediate soil outside the root (the rhizosphere) and use plant-root exudates as food-stuffs, enabling the N-fixing organisms to fix N from the air.

Trials to determine the yield benefit from one or more of these products added to different rates of N fertilizer were conducted by researchers from most of the land-grant universities in the North Central Region of the U.S. through the 2022 growing season to determine their possible value to farmers. If you missed that article go to Hays or Great Bend Post and type my name into search posts.

One of the results of publishing the compilation of research trials has been an opening of communication by the lead author with other startups of N-fixing organisms in the US and in Europe. The author has visited with representatives and scientists from these industries, and has discussed with them what might be done to improve their chances in the marketplace when they decide the product is ready to sell. The discussions always settled on four points. The N-fixing bacteria are living organisms:

The organisms need to be kept alive through transportation and storage intervals between manufacturer, shipper, warehouses, distributor, dealer, and finally on farm storage before use. There should be a method of analysis developed to determine whether the organism is alive and functioning in the soil/plant after application. The organism should be able to ‘win a war’ with other native microorganisms in order to survive and perform its function. The organism should be adapted to variable moisture, variable soil pH and variable soil salts in order to perform its function.

Although the firms that manufacture these products were convinced that when the product left the point of manufacture, that the organisms are alive, they all are concerned of the viability by the time they reached the point of field application.

Presently, according to industry people that the author of the research compilation has visited with, there are no quick assays or analyses available to determine whether the organisms in the container, in the soil or plant are alive and functioning in the manner they need to function to benefit the end- user. These tests need to be developed to support the product and provide confidence to the farmer that the product is performing.

To date, land-grant researchers associated with the Committee of Specialized Soil Amendments and Products, Growth Stimulants, and Soil Fertility Management Programs have found a low frequency of N fertilizer rate replacement from the application of commercial N-Fixing bacterial products to corn. It is possible that future related products might be beneficial if manufacturers consider ways to maintain viability of the organisms from point of production to point of field application, are able to assay organism activity in the field, and screen organisms for their ability to compete with other soil organisms and remain active in a wide range of possible soil environments.

Farmers should strive to be curious regarding new products, but also to be skeptical; testing products of interest in replicated trials on their farms.

If you would like to discuss or have questions on how to conduct replicated trials on your farms, feel free to give me a call 785-628-9430.

Stacy Campbell is a Crop Production Extension agent in the Cottonwood District (which includes Barton and Ellis counties) for K-State Research and Extension. You can contact him by e-mail at [email protected] or by calling 785-628-9430.