Maize yield response to a phosphorus-solubilizing microbial inoculant in field trials

Area of Science:

• Agricultural Science
• Soil Microbiology
• Agronomy

Background:

• Maize (Zea mays) yield is significantly influenced by phosphorus availability.
• The use of microbial inoculants, such as phosphorus-solubilizing fungi, offers a potential strategy to enhance nutrient uptake and crop productivity.
• Penicillium bilaiae is a known phosphorus-solubilizing fungus with potential agricultural applications.

Purpose of the Study:

• To evaluate the efficacy of Penicillium bilaiae inoculation on maize yield across varied environmental and management conditions in the United States.
• To analyze the variability in crop response to the inoculant and identify factors influencing its effectiveness.
• To determine the optimal application methods and conditions for P. bilaiae in maize production.

Main Methods:

• Multi-year, multi-site field trials were conducted across major US maize-producing regions from 2005 to 2011.
• A total of 92 small replicated plots and 369 large non-replicated trials were analyzed.
• Statistical analyses were employed to assess yield response, variability, and correlations with soil and environmental factors.

Main Results:

• Inoculation with P. bilaiae increased maize yield in a majority of trials (66/92 small plots, 295/369 large plots).
• Yield increases were statistically significant in small plots (1.8%) and higher and less variable in large plots (3.5%).
• Inoculation effectiveness was greatest in soils with low or very low phosphorus status, and formulation type (seed treatment vs. granular) did not significantly impact results.

Conclusions:

• Penicillium bilaiae inoculation is a viable strategy for enhancing maize yield, particularly in phosphorus-deficient soils.
• The effectiveness of inoculation can vary annually, but consistent benefits are observed across diverse agronomic and climatic conditions.
• Soil pH was not a significant factor influencing yield response, suggesting alternative mechanisms for phosphorus availability enhancement by P. bilaiae.