Fertilization is an important agricultural practice for improving plant nutrition and achieving high yield, but it may also result in shifts in the microbial communities, which can, in turn, affect plant growth by changing nutrient turnover and increasing disease incidence or disease suppression. Long-term fertilization can influence soil biological properties and relevant soil ecological processes with implications for sustainable agriculture.
Researchers in Institute of Subtropical Agriculture, Chinese Academy of Science (ISA) collected soil samples from a long-term field site in Wangcheng County established in 1981 in subtropical China between mid summer and early autumn of 2009. The effects of long-term (>25 years) no fertilizer (CK), chemical fertilizers (NPK) and NPK combined with rice straw residues (NPKS) on soil bacterial and fungal community structures and corresponding changes in soil quality were determined by the methods of terminal restriction fragment length polymorphism (T-RFLP) and the real-time quantitative polymerase chain reaction (real-time qPCR). Redundancy analysis of the T-RFLP data indicated that fertilization management modified and selected microbial populations (Fig.1). Of the measured soil physiochemical properties, soil organic carbon was the most dominant factors influencing bacterial and fungal communities. In general, NPKS resulted in the greatest richness and biodiversity of the total microbial community, soil organic C, total N, MB-C, -N and -P compared to CK. The soil microbial biomass C: N: P ratio, an indicator of ecosystem nutrient limitation, also showed that the CK treatment may have a soil P limitation, which was not observed in the other treatments.
Their results suggest that different fertilization managements affected bacterial and fungal community size and composition structure, and the NPKS management induced the highest diversity and abundance of bacteria and fungi which enhanced the production of microbial compounds, and positively influenced C, N and P pools in the long-term system studied.
This study was jointly supported by the National Natural Science Foundation of China (41271279; 41090283), International S&T cooperation program of China (2011DFA30770) and .the CAS/SAFEA International Partnership Program for Creative Research Teams (KZCX2-YW-T07; 20100491005-8).
The study entitled “Soil microbial biomass and bacterial and fungal community structures responses to long-term fertilization in paddy soils” has been published in Journal of Soils and Sediments (DOI: 10.1007/s11368-013-0664-8), details could be found at:
http://link.springer.com/article/10.1007/s11368-013-0664-8/fulltext.html