Alterations in structural and functional responses of bacterial community in response to different levels of compost application in long term fertilized paddy ecosystems

In this study, we used pyro-sequencing tags between V1-V3 regions of the 16S rRNA gene to analyse and compare the effect of long term application of different compost levels on the composition of paddy soil bacterial communities. The treatments were (i) inorganic nitrogen (N), phosphorus (P) and potassium (K) fertilizers (NPK) (ii) NPK and organic compost (C) (NPKC750) (iii) NPKC1500 (iv) NPKC2250 (v) NPKC3000. Inorganic chemical fertilizer was applied as N–P2O5–K2O at a rate of 75-75-75 kg ha-1 from 1954-1970, 100-75-75 kg ha-1 from 1971-1978, 150-86-86 kg ha-1 from 1978-1985 and 110-70-80 kg ha-1 from 1986 onwards. Organic compost was prepared by fermenting rice straws for 5 months and then applied at 7.5, 15.0, 22.5 and 30.0 Mg ha-1 in the NPKC750, NPKC1500, NPKC2250 and NPKC3000 soils, respectively.本研究借助16S rRNA基因V1-V3区的焦磷酸测序标签（pyro-sequencing tags），分析并对比了长期施用不同梯度堆肥对稻田土壤细菌群落组成的影响。供试处理包括：(i) 无机氮（N）、磷（P）、钾（K）肥料（NPK）；(ii) 氮磷钾配施有机堆肥（C）的NPKC750处理；(iii) NPKC1500处理；(iv) NPKC2250处理；(v) NPKC3000处理。供试无机化肥以N-P₂O₅-K₂O形式施用：1954-1970年施用量为75-75-75 kg·ha⁻¹，1971-1978年为100-75-75 kg·ha⁻¹，1978-1985年为150-86-86 kg·ha⁻¹，1986年起调整为110-70-80 kg·ha⁻¹。有机堆肥通过发酵水稻秸秆5个月制备而成，分别在NPKC750、NPKC1500、NPKC2250及NPKC3000处理的土壤中以7.5、15.0、22.5和30.0 Mg·ha⁻¹的用量施用。