Soil microbial community shifts with long-term of different straw return in wheat-corn rotation system

Yao Su,Changlin Kou,Alin Shen,Man Yu,Jinling Lv,Zhenghua Ma,Hui Xi

doi:10.1038/s41598-020-63409-6

Yao Su, Changlin Kou + Show 5 more

Open Access

https://doi.org/10.1038/s41598-020-63409-6

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Abstract

Despite the integral role of the soil microbial community in straw decomposition, we still have a limited understanding of the complex response of microbial community to long-term of crop straw return in rotation system. Here we report on the structural and functional response of the soil bacterial and fungal community to more than 10 years of straw return in wheat-corn rotation system. Compared with single-season straw return, soil microbial phosphor lipid fatty acids (PLFAs) and catabolic activity were improved more greatly with double-season straw return. The relative abundance of bacteria and fungi decreased with double-season straw return, but increased with single-season straw return. The copiotrophic bacteria were more represented in the soils with corn straw return, while oligotrophic groups were more represented in soils with wheat straw return. Compared with wheat straw return, lower fungal community diversity and higher abundance of fungal pathogen (identified to be Leptosphaeria) were observed with corn straw return, especially at high return rates. Redundancy analysis showed that soil available potassium (P = 0.008) and ratio of C to N (P = 0.048) significantly affected the soil bacterial community, while soil electric conductivity (P = 0.04) was the significant factor impacting soil fungal community. It suggests that full corn straw return might have positive impact on soil mineral nutrient but negative impact on soil fungal community diversity and pathogenic risk, mainly due to the change in soil electric conductivity.

Highlights

Despite the integral role of the soil microbial community in straw decomposition, we still have a limited understanding of the complex response of microbial community to long-term of crop straw return in rotation system
Compared with CW-0, significantly higher soil organic carbon (SOC) was observed in CW-50%, CW-100% and C-50%, with increase of 25.2%, 14.2% and 13.0%, respectively, while with the decrease of 23.6%, 21.6% and 1.0% in C-100%, W-50% and W-100%, respectively
The relatively higher total N (TN) was observed in CW-50%, CW-100% and C-50%, with the increase of 10.6%, 13.8% and 10.9%, respectively

Summary

Introduction

Despite the integral role of the soil microbial community in straw decomposition, we still have a limited understanding of the complex response of microbial community to long-term of crop straw return in rotation system. Corn straw return increased the fungal biomass, but did not affect the bacterial in long-term (>30 years) in North-central China, especially at relatively high return rates (>4500 kg ha−1)[19,20]. The catabolic diversity and activity was improved by straw (rice, wheat and corn straw) return in short (three years) and long term (30 years)[19,20] Most of these studies applied phosphorlipid fatty acid (PLFA) analysis and Biolog plate method, which were limited in obtaining accurate information about the taxonomic composition and carbon metabolism of soil microbial community. It is hypothesized that (1) different rates of straw return might shift the soil microbial community structure and affect the activity differently; (2) high return rates might increase the pathogenic risk for crop, by increasing the abundance of pathogenic microbes in soils

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