[Characteristics of bacterial community in an arable mollisol under long-term phosphorus fertilization]

Soil samples were taken from the Gongzhuling national long-term experimental station in Jilin Province of Northeast China to study their basic physical and chemical properties and the characteristics of bacterial community under different fertilization systems, i.e., CK, P, N-P, N-P-K, manure-P, manure-N-P, and manure-N-P-K. The results showed that applying manure increased the contents of soil organic matter (OM), total nitrogen (TN), available phosphorus (AP), alkali-hydrolysable nitrogen (AN) and available potassium (AK) significantly, while applying chemical fertilizers had no significant effects on the contents of soil OM and AN. Comparing with CK, the total bacterial phospholipid fatty acids, G+ bacterial phospholipid fatty acids, and G- bacterial phospholipid fatty acids in treatments manure-N-P and manure-N-P-K increased by 34% and 62%, 58% and 74%, and 64% and 69%, respectively. Applying chemical fertilizers, especially P, decreased the bacterial phospholipid fatty acids. Except G bacterial phospholipid fatty acids whose content was significantly higher in treatment manure-P than in treatment N-P-K, the bacterial phospholipid fatty acids had no significant difference between treatments N-P, N-P-K and manure-P. There existed significant correlations between various groups of bacterial phospholipid fatty acids and soil OM, AN, AP, AK, and NO(3-)-N.