Azospirillum brasilense inoculation to enhance corn nitrogen uptake

Paulo Pagliari

Much work has been done to test Azospirillum brasilense as seed inoculation for corn and wheat in tropical countries for the last decade. The results have been very promising and either yield increases or a reduction in the amount of synthetic N fertilizer needed for maximum grain productivity has been observed. In 2021 the Minnesota Wheat Growers financed a research project to study this approach in wheat grown in MN. The results from the 2021 trial in MN showed very positive responses and an yield increase of 15% was observed 30% of the time when wheat was inoculated with Azospirillum brasilense. The main goal of this study is to generate initial data which will then be used to develop a larger proposal in partnership with the MN Wheat Growers. We intend in developing a biological product that can be used by MN grain growers to minimize the reliance on chemical fertilizer inputs, primarily nitrogen, as it is currently happening in tropical countries. Azospirillum is a free living bacteria which can fix atmospheric N and make it available for plants. Azospirillum is present in almost any soil, and off course are present in MN soils and we should be able to find a strain that has similar properties to those that we will test in this study. The strain used for the research in this trial and also in the wheat growers funded research will be from Brazil. EMBRAPA has this technology well developed and is currently being used at large scale across many countries in south America. We expect that corn will respond positively to Azospirillum inoculation, and similar to wheat, we expect that either an increase in grain yield or a decrease in the amount of N needed for maximum productivity will be observed.