Seed Inoculation with Penicillum Bilaiae Improves Grain Production in the Pampas Region in Argentina.

Among the abundant microorganisms with potential contributions to crop production, the fungus Penicillum bilaiae participates in multiple processes enabling the release of nutrients and plant root formation. Although several studies showed the increase in grain yields in crops inoculated with this fungus, its use in farming crop production systems is limited. One of the reasons is the variable and unclear crop response to the inoculation depending on factors such as soil type and management practices. Twenty-six wheat (Triticum aestivum L.), 31 soybean [Glycine max (L.) Merrill] and 40 corn (Zea mays L.) field trials were conducted from 2008 to 2014 in the pampas region to quantify the grain yield response to seed inoculation with P.bilaiae under contrasting environmental and nutrient management conditions (P fertilization). The soils (Mollisols) tested between 8 and 25 mg Bray-1 extractable P kg^-1. Phosphorus fertilization increased corn, soybean and wheat grain yield by 490, 229, and 591 kg ha^-1 respectively. Seed inoculation with P.bilaiae increased corn, soybean and wheat yield by 501, 108, and 141 kg ha^-1 respectively. No interaction in grain yield responses was detected between P fertilization and seed inoculation. However, the frequency of sites with positive responses to seed inoculation increased from 81% to 91% for corn, 85% to 96% for soybean, and 69% to 96% for wheat in the P fertilized crops compared with the control without P fertilization. These results validated the contribution of seed inoculation with this beneficial soil microbe enhancing grain yields and P use efficiency for rainfed production systems.