Long-term decomposed straw return positively affects the soil microbial community.

Area of Science:

• Soil Science
• Microbiology
• Agronomy

Background:

• Understanding the long-term effects of agricultural practices on soil ecosystems is crucial for sustainable farming.
• Straw return is a common practice, but the impact of decomposed versus fresh straw on soil microbial communities requires detailed investigation.

Purpose of the Study:

• To investigate the modifications in soil microbial community structure and composition induced by over 10 years of fresh and decomposed straw return.
• To identify key environmental factors influencing these microbial community variations.

Main Methods:

• Utilized phospholipid fatty acid analysis and high-throughput sequencing to analyze soil microbial community structure and composition.
• Compared microbial responses to different application rates of fresh and decomposed straw (~3750 and ~7500 kg ha⁻¹).

Main Results:

• Decomposed straw return significantly increased the relative abundance of bacteria and fungi compared to fresh straw, with effects varying by application rate.
• Observed an increase in bacteria related to nitrification and a decrease in those related to denitrification, leading to higher soil total nitrogen.
• Reduced pathogenic fungal populations (Alternaria) and showed a positive correlation between decomposed straw return, soil electric conductivity, and reduced soil-borne disease risk.

Conclusions:

• Long-term decomposed straw return promotes healthier soil microbial communities in terms of abundance and structure compared to fresh straw.
• Decomposed straw provides suitable nutrients and salinity, contributing to improved soil health and reduced risk of soil-borne diseases.
• Identifying key factors influencing microbial variation is vital for effective soil health management strategies involving straw return.