干旱区生态环境知识资源中心

Background and aims: Plastic film mulching (PFM) is critical for agricultural production in arid and semi-arid areas in the world. There is an evidence that PFM alters soil microbial populations and soil nutrients. However, how PFM altering rhizosphere microorganisms and nutrients with plant growth remain unknown. We investigated the changes of rhizosphere soil microbial metabolic characteristics in response to PFM management, and its consequent effects on soil nutrients, plant growth and yield of wheat.

Methods: A field experiment of a local spring wheat cultivar Lunchun 8275 was carried out at a typical semi-arid area on the Loess Plateau. Wheat plants were treated with or without PFM, and measured for rhizosphere cultural microbial populations and microbial metabolic activities at jointing, flowering and maturity stages, respectively.

Results: Rhizosphere cultural microbial populations and nutrient contents were significantly altered possibly due to the improvement of soil thermal and water status under the PFM treatment. The results of cultural microbial populations were consistent with the principal components analysis of microbial metabolic activities. PFM changed the linear regression coefficients between cultural microbial populations and nutrients, microbial metabolic activities and nutrients with 0.67 and 0.20 respectively, but with -0.24 and -0.37 in CK. Meanwhile, wheat grain yield increased by 19.2% and water use efficiency enhanced by 40.7% under PFM.

Conclusions: This study demonstrated that PFM improved rhizosphere micro-environment, including soil thermal and water status, rhizosphere nutrients, cultural microbial populations and their metabolic activities, thereby increased crop yield. The present study might enhance our understanding the influence of PFM on the rhizosphere microbes and their roles in nutrient acquisition and plant growth improvement.