Effect of 25-year fertilization on soil microbial biomass and community structure in a continuous corn cropping system

Abstract

A split-plot trial with three replicas in Northeast China was carried out to investigate the effects of 25-year corn stalk (CS) and mineral fertilizer application on soil microbial biomass and the microbial community structure in a continuous corn cropping system. The main plots were treated with CS including 0 (CS₀), 2500 (CS₁), and 5000 (CS₂) kg ha⁻¹. Subplots were split into N (N), NP (NP), nitrogen, phosphorus, and potassium (NPK), and non-fertilizer control (O). The results showed that N application (CS₀N) decreased soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen, bacterial phospholipid-derived fatty acids (PLFAs), and fungal PLFAs compared with the treatments of O, NP, and NPK with CS₀. Compared with CS_0, CS application (CS₁ and CS₂) increased SMBC, total PLFAs, Gram⁺ PLFAs, and Gram⁻ PLFAs. CS of 5000 kg ha⁻¹ combined with NPK application (CS₂NPK) had the highest SMBC, soil microbial biomass nitrogen, total PLFAs, and bacterial PLFAs. Principal component analysis demonstrated that CS application had distinct effects on soil microbial community structure relative to the non-CS application. Our results provide a better understanding of the significance of corn stalk-balanced fertilization with NPK in promoting the soil microbial biomass and the microbial community structure in the continuous corn cropping system.

Keywords:

• continuous corn cropping system
• corn stalk
• mineral fertilizer
• PLFA
• soil microbial biomass

Additional information

Funding

This research was supported by the Key Program of National Natural Science Foundation of China [41230750]; the National High Technology Research and Development Program of China [2011AA050105]; the National Natural Science Foundation of China [40771215]; and the Knowledge Innovation Program of the Chinese Academy of Sciences [KZCX2-EW-QN606].