Journal Article

Nitrogen Fertilization Increases Soil Microbial Biomass and Alters Microbial Composition Especially Under Low Soil Water Availability

Zhao, Chunzhang, Xie, Lulu, Hu, Xuefeng, Yin, Chunying, Li, Wanting

2023

Overview

Soil microbial biomass and composition are affected by resource supply and water availability. However, the response of soil microbial communities to nitrogen fertilization under different water availability conditions is unclear. Therefore, this study conducted a 6-year pot experiment comprising five watering regimes (40%, 50%, 60%, 80%, and 100% of field capacity (FC)) and three nitrogen fertilization levels (NH 4 NO 3 solution; 0 [N0], 20 [N1], and 40 [N2] g N m −2  year −1 ) to investigate soil microbial biomass, composition, and properties. The results indicated that soil microbial biomass and composition were more strongly affected by nitrogen fertilization compared with water regime. Nitrogen fertilization increased soil microbial biomass and altered soil microbial community composition, especially under low soil water availability. Soil microbial biomass was positively linearly associated with soil water regimes under N0, whereas it responded polynomially to soil water regimes under N1 and N2. The maximal soil microbial biomass was observed at FC80 for N1 and FC60 for N2. Furthermore, the biomass of soil microbial groups with high nitrogen and carbon acquisition ability as well as the enzyme activities of carbon and nitrogen cycling (β-1,4-glucosidase and β-1,4-N-acetyl-glucosaminidase, respectively) were stimulated by nitrogen fertilization. Soil microbial biomass was affected directly by nitrogen fertilization and indirectly by nitrogen and water regimes, via altering soil pH, dissolved inorganic nitrogen (NH 4 + -N and NO 3 − -N) concentration, and soil organic carbon concentration. This study provides new insights into the effect of interaction between soil nitrogen and water availabilities on soil microbial biomass, composition, and its underlying mechanism. Graphical abstract

• Publisher: Springer US,Springer Nature B.V
• Subject: Ammonium nitrate / Availability / Biological fertilization / Biomass / Biomedical and Life Sciences / Carbon / Carbon - chemistry / Carbon cycle / Community composition / community structure / Ecology / Enzymatic activity / Enzyme activity / enzymes / Fertilization / Field capacity / Geoecology/Natural Processes / Glucosaminidase / Glucosidase / Life Sciences / Microbial activity / microbial biomass / Microbial Ecology / Microbiology / Microbiomes / Microorganisms / Moisture content / Nature Conservation / Nitrogen / Nitrogen - analysis / Nitrogen cycle / Organic carbon / plant available water / Soil / Soil - chemistry / Soil investigations / Soil Microbiology / Soil microorganisms / soil organic carbon / Soil pH / Soil water / Water / Water availability / Water Quality/Water Pollution / Water regimes